Introduction

This Pilot’s Operating Handbook contains the information necessary for the safe and efficient operation of the RV-10 aircraft N720AK.

This handbook is divided into sections for quick reference:

1. General - Aircraft specifications and descriptive data
2. Limitations - Operating limitations, placards, and markings
3. Engine Information - Engine specifications and operating parameters
4. Emergency Procedures - Procedures for handling emergencies
5. Abnormal Procedures - Procedures for abnormal situations
6. Normal Procedures - Normal operating procedures and checklists
7. Performance - Performance charts and data
8. Weight and Balance - Weight and balance data and calculations
9. System Descriptions - Description of aircraft systems
10. Handling, Servicing, and Maintenance - Ground handling, servicing, and maintenance information

General

Introduction

The RV-10 is a four-place, single-engine experimental aircraft powered by a Lycoming YIO-540-D4A5 six-cylinder reciprocating engine driving a Whirlwind constant-speed propeller. The aircraft is primarily constructed of alclad aluminum using flush rivets to the maximum extent possible. N720AK is operated under FAA Experimental Amateur-Built rules.

For aircraft systems descriptions see Section 8. For systems-reference detail beyond what is needed for normal operation, see the sys-*.md pages.

Exterior Dimensions

General Specifications

Performance Specifications

Van’s published numbers for the RV-10 with a 260 HP engine. Cruise figures at 8,000 ft. Speeds are KTAS unless noted.

N720AK-specific test stalls: V~S0~ 48 / V~S~ 56 / V~S1~ 61 KIAS at ~2,190 lb test weight (see Section 2).

Engine

Fuel injection and ignition are managed by the EFII System32 electronic engine management system (dual ECU); see sys-73-efii.md. The mechanical engine reference is in sys-71-engine.md.

Propeller

Fuel

Oil

Maximum Weights

Specific Loadings

Symbols, Abbreviations and Terminology

Airspeed Terminology

Engine Terminology

Navigation and Avionics

Electrical

Weight and Balance

General

Operating Limitations

General

This section provides the operating limitations, instrument markings, color coding and basic placards necessary for the safe operation of the airplane and its systems.

Airspeed Limitations

V~NE~ is true airspeed, not indicated. At altitude, indicated airspeed at V~NE~ is lower than 200 KIAS. The Dynon SkyView shows TAS in the wind bug area; verify TAS rather than IAS when operating near V~NE~.

Stall speeds are at ~2,190 lb test weight. At max gross (2,700 lb) add approximately 10%.

Power Plant Limitations

Power Plant EFIS Markings

Tachometer

Oil Temperature

Oil Pressure

Cylinder Head Temperature

Target CHT at all power settings is < 400 °F. Do not exceed 420 °F. If CHT approaches 400 °F in climb, enrich Fuel Trim (+10 % CW on the System32 controller) or reduce climb angle.

Weight Limits

Center of Gravity Limits

CG envelope per Van’s RV-10 documentation. See Section 7 (Weight & Balance) for the loading worksheet.

Flight Maneuver Limitations

Slips in clean configuration require care. The RV-10 rudder can aerodynamically stall during slips with flaps up, resulting in a sudden and uncommanded snap roll. Slips are most predictable with flaps extended, which reduces the angle of attack required for a given airspeed and prevents rudder stall.

Spins are prohibited. The RV-10 is not approved for intentional spins, and Van’s has not demonstrated spin recovery for the type. PARE is the universal procedure if a spin is entered inadvertently — see Section 4.

Types of Operations

The airplane is approved for the following operations when equipped in accordance with FAR 91:

• Day VFR
• Night VFR
• Day IFR
• Night IFR
• Non-Icing

Fuel Limitations

Mogas Limitations (EFII System32)

When using premium unleaded mogas (91 octane minimum):

• Altitude limit: Stay below 8,000 ft density altitude (higher vapor pressure than avgas)
• Temperature limit: Do not use mogas in OAT above 100 °F
• High terrain: Use 100LL when flying over high terrain with limited landing options
• Mogas reaches its vapor point more easily than avgas at altitude and in heat

Placards

Additional Engine Information

Key Engine Data

Engine Management System

The engine is managed by the EFII System32, which replaces the stock Bendix fuel servo, magnetos, mixture cable, and engine-driven fuel pump with:

• Dual ECUs — independent fuel and ignition control. Either ECU can run the engine.
• Port fuel injection — six EFII PMI injectors (one per cylinder).
• Electronic ignition — coil packs, automotive NGK plugs in EFII SPA-6 18 → 14 mm adapters.
• Dual electric fuel pumps — Walbro GSL391 ×2, Bus Manager auto-cutover at 22 PSI Borla output absolute.
• Borla 203133 MAP-referenced fuel pressure regulator — 45 PSI injector differential setpoint (DIFF mode on Dynon).

Pilot controls reduce to: throttle, propeller, Fuel Trim knob (±50% authority on the System32 controller — replaces the mixture lever). Fuel mixture, ignition timing, accelerator-pump enrichment, and warm-up enrichment are all handled automatically by the ECU based on MAP, RPM, and temperature inputs.

For complete System32 reference see sys-73-efii.md. For the mechanical engine reference see sys-71-engine.md. For the fuel system see sys-28-fuel-system.md.

Operating Limits Reference

See Section 2 for the authoritative table. Quick reference:

Power Settings (Reference)

Cooling

CHT management on this airframe (Lycoming IO-540 with EFII System32 in an RV-10 cowl) is the primary high-power-climb concern. Per Section 2, target CHT is < 400 °F at all power settings. Do not exceed 420 °F. If CHT approaches 400 in climb:

1. Enrich Fuel Trim (+10% CW on the System32 controller).
2. Reduce climb angle (lower the nose, accept a higher airspeed and a lower vertical rate).

CHT alarms are configured in the Dynon EMS sensor config (.dfg). See sys-71-engine.md — Cooling and the EMS sensor config in Public/Configs/Dynon/.

Emergency Procedures

These procedures are derived from the efis-editor checklist file. Update the source JSON and regenerate to modify.

Engine Failures

System32 Restore Function

Run any time the engine is rough, faltering, or has quit.

• ECU Select … OPPOSITE ECU

  shifts fuel control to the other ECU; sensors are independent

• Fuel Selector … OTHER TANK / VERIFY ON

• Fuel Pump Breakers … BOTH IN

• Fuel Pump Mode … 2

• Fuel Trim … ADJUST

  if engine firing but rough — try richer (CW) then leaner

• Emergency Power Switch … ON

  bypasses Bus Manager

Engine Failure During Takeoff Run

• Throttle … IDLE
• Brakes … APPLY
• Stop … STRAIGHT AHEAD
• Wing Flaps … RETRACT
• Fuel Selector … OFF
• Key Switch … OFF
• Master Switch … OFF

Engine Failure Immediately After Takeoff

Pitch … ONSPEED

Landing Spot … WITHIN ±30º

above turnback altitude / per TLAR — see Turnback Procedure

• ECU Select … OPPOSITE ECU

  one shot — if no restart, commit to landing

• Fuel Selector … OFF

• Key Switch … OFF

• Master Switch … OFF

• Wing Flaps … AS REQUIRED

  33º on short final

• Doors … UNLATCH PRIOR TO TOUCHDOWN

Engine Failure In Flight

Airspeed … BEST GLIDE 95 KIAS

NRST Button … HOLD / AP ENGAGE

AP flies to nearest field at best glide; tunes comms

Best Field … DECIDE

is the nearest field actually best? terrain, wind, surface

• System32 Restore Function … EXECUTE

  ECU Sel / Fuel Sel / Pump Brkrs / Pump Mode / Fuel Trim / Emerg Pwr

If engine restored:

• Continue to Nearest Suitable … MONITOR

  do not switch back to test — leave the bad ECU off

If engine not restored:

• Forced Landing … EXECUTE

  as described in Emergency Landing Without Engine Power

Engine Failure On Approach

Airspeed … ONSPEED

best glide gives more distance, but already configured for landing

Best Surface … LAND

may not be the runway — pick what works

• ECU Select … OPPOSITE ECU

  if time / altitude permits — one shot

• Fuel Selector … OFF

• Key Switch … OFF

• Doors … UNLATCH PRIOR TO TOUCHDOWN

Forced Landings

Emergency Landing Without Engine Power

• Squawk … 7700

• Airspeed … BEST GLIDE / ONSPEED

  95 KIAS clean / ONSPEED with flaps

• Fuel Selector … OFF

• Key Switch … OFF

  kills ECUs; engine dies clean

• Wing Flaps … AS REQUIRED — 40º RECOMMENDED

• Master Switch … OFF

• Radio Call … MAYDAY 121.5

  time permitting

• Doors … UNLATCH PRIOR TO TOUCHDOWN

• Touchdown … SLIGHTLY TAIL LOW

• Brakes … APPLY HEAVILY

Turnback Procedure

Decided on the ground per pre-takeoff brief.

⚠️ WARNING: Below 200 ft AGL, turnback is non-recoverable. Land ahead.

• Pitch … ONSPEED IMMEDIATELY

  single AOA reference — best blend of turn rate and stall margin

• Turn Direction … INTO CROSSWIND

  wind drifts you toward centerline during reversal

• Bank … 45º

  any less wastes altitude; any more loses stall margin

• Coordinate … BALL CENTERED

  uncoordinated stall is non-recoverable at low altitude

• On Speed … MAINTAIN TO TOUCHDOWN

Note: If turn not working: WINGS LEVEL, LAND AHEAD AS SLOW AS POSSIBLE.

Don’t stall. Everything else is secondary.

Precautionary Landing With Engine Power

Lowest sustainable energy at touchdown — drag it in with power.

• Airspeed … ONSPEED
• Wing Flaps … 16º
• Selected Field … FLY OVER
• Terrain And Obstructions … NOTE
• Wing Flaps (On Final) … 33º
• Airspeed … SLOW TONE
• Power … CONTROL DESCENT RATE
• Avionics Master … OFF
• Doors … UNLATCH PRIOR TO TOUCHDOWN
• Touchdown … SLIGHTLY TAIL LOW
• Key Switch … OFF
• Brakes … APPLY HEAVILY

Ditching

Goal is lowest sustainable energy at touchdown — fly the slow tone.

• Transmit Mayday … 121.5 MHZ, GIVING LOCATION
• Squawk … 7700
• Heavy Objects … SECURE OR JETTISON
• Flaps … 16º - 33º
• Power … ESTABLISH 300 FT/MIN DESCENT, SLOW TONE

Approach:

High Winds, Heavy Seas — INTO THE WIND

Light Winds, Heavy Swells — PARALLEL TO SWELLS

• Cabin Doors … UNLATCH
• Touchdown … LEVEL ATTITUDE AT ESTABLISHED DESCENT
• Airplane … EVACUATE
• Life Vests and Raft … INFLATE

Landing With A Flat Main Tire

• Approach … NORMAL

• Wing Flaps … FULL DOWN

• Touchdown … GOOD TIRE FIRST

  hold airplane off flat tire as long as possible with aileron

Landing Without Elevator Control

• Airspeed … 80 KIAS

• Elevator Trim … LEVEL FLIGHT

• Glide Angle … CONTROL WITH POWER

• Elevator Trim … FULL NOSE UP

  in flare — rotates to horizontal for touchdown

• Throttle … CLOSE AT TOUCHDOWN

Fires

Engine Fire During Start On Ground

If engine starts:

• Throttle … FULL OPEN

  max airflow first; engine still on full fuel

• Fuel Pump Breakers … PULL BOTH

  engine consumes residual fuel + sucks fire in for 3-5s, then dies

• Key Switch … OFF

• Fuel Selector … OFF

• Doors … UNLATCH

• Evacuate / Extinguisher … AS REQUIRED

If engine fails to start:

• Throttle … FULL OPEN

• Starter … CONTINUE CRANKING

  attempt to clear fuel from intake

• Fuel Pump Breakers … PULL BOTH

• Key Switch … OFF

• Emergency Power Switch … OFF

  Emergency Power independently powers ECUs — both must be off

• Fuel Selector … OFF

• Doors … UNLATCH

• Fire Extinguisher … AS REQUIRED

• Evacuate … IMMEDIATELY

Engine Fire In Flight

Fuel Selector … OFF

Key Switch … OFF

• Emergency Power Switch … OFF

• Master Switch … OFF

  kills any wire-arc source that may be feeding the fire

• Cabin Heat / Air … OFF

  close firewall vents

• Airspeed … INCREASE

  slip or dive to blow out fire

• Forced Landing … EXECUTE IMMEDIATELY

If fire not extinguished:

• Sideslip … INTO FIRE SIDE

  keep flames away from cabin

• Land … IMMEDIATELY

Electrical Fire / Smoke In Cockpit

Key Switch … OFF

kills ECUs / fuel pumps / most electrical load

Master Switch … OFF

• Emergency Power Switch … OFF

Vents / Cabin Air … OPEN

clear smoke

• Fire Extinguisher … AS REQUIRED
• Land … AS SOON AS PRACTICABLE

If engine required to reach landing site:

• Emergency Power Switch … ON

  restores engine power only — non-essential systems stay dead

• Monitor … FOR RECURRENCE

Note: If smoke returns, Emergency Power → OFF and re-isolate.

Cabin Fire

• Master Switch … OFF
• Vents / Cabin Air / Heat … CLOSED
• Fire Extinguisher … ACTIVATE

⚠️ WARNING: After discharging an extinguisher in a closed cabin, ventilate the cabin.

• Land … AS SOON AS POSSIBLE
• Airplane … INSPECT FOR DAMAGE

Wing Fire

• Navigation Light … OFF
• Strobe Light … OFF
• Pitot Heat … OFF

Note: Sideslip to keep flames away from fuel tank and cabin. Land as soon as possible. Flaps only as required for final approach and touchdown.

Electrical / Engine Malfunctions

Primary Alternator (Hartzell) Failure

Symptoms: Bat 1 voltage dropping, alternator amps zero, low-voltage indication.

• Bat 1 Voltage … CHECK

• Alternator Field Switch … CYCLE OFF / ON

  one attempt only

If still failed:

• Non-Essential Loads … REDUCE

  VPX may auto-shed; help it

• MZ-30 … VERIFY OPERATING

  Bat 2 voltage holding, generator amps positive

• Plan Diversion … NEAREST SUITABLE

  Bat 1 will eventually drain even with reduced load

If Bat 1 voltage critical:

• Emergency Power Switch … ON

  moves essential bus to Bat 2 / MZ-30

MZ-30 Generator Failure

Symptoms: Bat 2 voltage dropping, generator amps zero or low.

• MZ-30 Enable Switch … VERIFY ON

• Generator Amps … CHECK

  expect 5-30A in normal operation

• Bat 2 Voltage … MONITOR

If still failed:

• MZ-30 Enable Switch … OFF

  regulator may have OVP-locked; disable to prevent damage

• Continue on Hartzell / Bat 1 … FLIGHT NOT AT RISK

  Plan return when convenient — primary system intact

Bus Manager Failure / Switch to Endurance Bus

Symptoms: multiple essential systems unresponsive; primary bus dead.

Emergency Power Switch … ON

bypasses Bus Manager — connects Bat 2 / MZ-30 directly to essential bus

• Non-Essential Loads … OFF
• Squawk … 7700
• Mayday Call … 121.5
• Land … AS SOON AS PRACTICABLE

⚠️ WARNING: If Emergency Power does not restore essential bus, both systems have failed. No further reversion available — land immediately.

Loss of Oil Pressure

• Confirm with Secondary Indication … OIL TEMP / NOISE

  if oil temp also rising — engine is losing oil. Likely seizure imminent.

• Power … REDUCE

  minimize damage; lowest power that maintains flight

• Best Field … LOCATE

  treat as if engine will seize

• NRST Button … HOLD

• Mayday … 121.5 / 7700

Note: Be prepared to execute Forced Landing — engine may quit at any time.

High Oil Temperature

• If Climbing … STOP CLIMB

• RPM … DECREASE

• Airspeed … INCREASE

• Fuel Trim … +10%

  richer mixture cools the cylinders

• Plan Diversion if Sustained … NEAREST SUITABLE

Runaway Trim

Avionics Master … OFF

kills power to SV-AP-PANEL — stops all trim servo commands

• Airspeed … REDUCE

  unload trim forces

• Trim … MANUALLY OVERRIDE

  with stick pressure

• Land … AS SOON AS PRACTICABLE

Note: There is no dedicated trim circuit breaker. The avionics master is the only kill switch for the trim servos.

Icing / Static

Inadvertent Icing Encounter

• Pitot Heat … ON

• Icing Conditions … EXIT

  turn back or change altitude for warmer/colder OAT

• Cabin Heat … ON

• Defroster … MAX AIRFLOW

• Engine Speed … INCREASE

  minimize prop blade ice buildup

• Land … NEAREST AIRPORT

⚠️ WARNING: With ¼ inch ice on leading edges, expect significantly higher stall speed.

• Wing Flaps … LEAVE RETRACTED
• Approach … 80-90 KIAS
• Land … LEVEL ATTITUDE

Static Source Blockage

Erroneous instrument readings suspected.

• Alternate Static Source … TOGGLE ON

  panel toggle, top left

• Airspeed … REFERENCE TABLE

  Cruise — 50 ft higher than normal

  Approach — 30 ft higher than normal

Inadvertent IMC / Upset

180º Turn In Clouds

• Wings … LEVEL ON AUTOPILOT

• Compass Heading … NOTE

• Time … NOTE

• Standard Rate Turn … INITIATE

  60 seconds for 180º

• Level Flight … MAINTAIN

• Heading … RECIPROCAL CONFIRMED

Emergency Descent Through Clouds

• Heading … EAST OR WEST

  minimizes compass swings during bank changes

• Power … REDUCE

  for 500-800 FPM descent

• Trim … STABILIZED 80 KIAS

• Turn Coordinator … MONITOR

  corrections by rudder alone; hands off the wheel

Upon breaking out:

• Normal Cruising Flight … RESUME

Upset Recovery — Power / Push / Roll

Power … ADJUST

nose-low: throttle back. nose-high: throttle forward.

Push … UNLOAD

Roll … WINGS LEVEL

shortest direction; coordinated rudder

• Recover … PITCH TO LEVEL

  after wings level, smoothly pitch to level flight

Spin Recovery — PARE

⚠️ WARNING: RV-10 is not approved for intentional spins, and Van’s has not demonstrated spin recovery for the type. PARE is the universal procedure if a spin is entered inadvertently.

• P - Power … IDLE

• A - Ailerons … NEUTRAL

• R - Rudder … FULL OPPOSITE ROTATION

• E - Elevator … FORWARD BRISKLY

  to break stall

Note: Hold inputs until rotation stops, then neutralize rudder and recover from dive.

Abnormal Procedures

These procedures are derived from the efis-editor checklist file.

Abnormal

Loss of Fuel Pressure

• Fuel Pressure … CHECK GREEN

  should be 45 PSI DIFF; auto-cutover trips when Borla output drops to 22 PSI absolute (Dynon DIFF varies with MAP)

• Pump 2 Annunciator … VERIFY ENGAGED

  amber on EFII controller — Bus Manager auto-cutover

If Pump 2 not engaged:

• Fuel Pump Mode … 2

  manual override

• Fuel Selector … OTHER TANK

  rules out tank issue

If pressure restored:

• Fuel Pump Mode … TRY 1/AUTO

  if Pump 1 actually failed, Bus Manager auto-cuts back to Pump 2 when Borla output drops to 22 PSI absolute

• Plan Diversion … NEAREST SUITABLE

Single ECU Failure

Symptoms: rough running, EGT spread, ECU GRAY/RED on controller.

• ECU Select … OPPOSITE ECU

• Fuel Trim … ADJUST

  if sensor failure caused rich/lean condition

• Power … REDUCE TO SMOOTH

• Plan Diversion … NEAREST SUITABLE

Note: Once you’ve identified the bad ECU, do NOT switch back to test.

Door Open In Flight

⚠️ WARNING: FLY THE AIRPLANE FIRST.

• Airspeed … SLOW TO ~100 KIAS

  reduces airflow load on door

• Door … DO NOT ATTEMPT TO CLOSE

  cannot be re-latched against airflow

• Occupant … BRACE / HOLD

• Land … NEAREST SUITABLE

Smoke / Smell Investigation

Use this when something smells off but no fire is visible.

• Source … ATTEMPT TO IDENTIFY

  electrical / oil / fuel / hot dust / exhaust

• Recent Switch Activations … NOTE

  anything just turned on?

• Vents … OPEN

• Plan Diversion … NEAREST SUITABLE

  do not wait for it to escalate

Note: If smoke or visible fire develops → Electrical Fire / Smoke In Cockpit.

CO Alarm In Flight

CO Guardian audible alarm above 50 PPM. Most likely source: heat muff exhaust crack.

• Cabin Heat … OFF

• Vents … OPEN

• Oxygen Mask … DON / CONSTANT FLOW

  especially at altitude — CO displaces O2 in blood

• Land … AS SOON AS PRACTICABLE

Note: Have the heat muff and exhaust inspected before next flight.

Oxygen System Failure / Hypoxia

Symptoms: lightheadedness, tunnel vision, fingernails turning blue, fatigue. EDS-4iP not pulsing.

• O2 Mode Switch … EMERGENCY (CONSTANT FLOW, ALL PORTS)

  panel toggle bypasses pulse-on-demand and supplies all ports continuously

• Cannulas / Masks … VERIFY SEATED

• Bottle Pressure … CHECK

• Descend … BELOW 10,000 FT MSL

  if symptoms persist, declare and divert

Normal Procedures

These procedures are derived from the efis-editor checklist file. Update the source JSON and regenerate to modify.

Memory Items

Memory Items — N720AK

These items must be performed from memory before reaching for the checklist. Practice them so they are automatic.

ENGINE FAILURE — A B C

Airspeed … BEST GLIDE / ONSPEED

Best field … LOCATE / NRST

Checklist … SYSTEM32 RESTORE

ENGINE FIRE

Fuel Pump Breakers … PULL BOTH

Key Switch … OFF

Fuel Selector … OFF

LOSS OF FUEL PRESSURE

Fuel Pump Mode … 2

Fuel Selector … OTHER TANK

ELECTRICAL FIRE / SMOKE

Key Switch … OFF

Master Switch … OFF

Vents … OPEN

LOSS OF POWER TO ELECTRONICS

Emergency Power Switch … ON

RUNAWAY TRIM

Avionics Master … OFF

UPSET RECOVERY — POWER PUSH ROLL

Power … ADJUST

Push … UNLOAD

Roll … WINGS LEVEL

INADVERTENT IMC

Wings … LEVEL ON AUTOPILOT

180º Turn … STANDARD RATE

Preflight

Preflight Inspection

Approach:

• Gust Lock … REMOVE
• Inlet Covers … REMOVE
• Pitot / AoA Cover … REMOVE
• AR(R)OW Documents … AVAILABLE

Left Wing:

• Fuel Tank Vent Opening … CHECK
• Fuel Tank Sump … DRAIN / CHECK
• Fuel Quantity … CHECK VISUALLY
• Fuel Filler Cap … SECURE
• Wing Tie-Down … DISCONNECT
• Wingtip Lights / Antennas … CHECK
• Aileron / Flap … CHECK
• Main Wheel Tire / Brake … CHECK

Empennage:

• Baggage Door … CHECK / SECURE
• Static Source Openings … CHECK
• Tail Tie-Down … DISCONNECT
• Control Surfaces … FREE / CHECK
• Lead Weights … CHECK
• ELT Antenna … CHECK

Right Wing:

• Main Wheel Tire / Brake … CHECK
• Aileron / Flap … CHECK
• Wingtip Lights / Antennas … CHECK
• Wing Tie-Down … DISCONNECT
• Fuel Quantity … CHECK VISUALLY
• Fuel Filler Cap … SECURE
• Fuel Tank Sump … DRAIN / CHECK
• Fuel Tank Vent Opening … CHECK

Nose:

• Propeller and Spinner … CHECK

  nicks, security, oil leaks

• Nose Wheel + Tire … CHECK

• Engine Inlets / Air Intake … CLEAR

  look in for nests, debris, blockage

• Engine Oil Level … CHECK

  Do not operate with less than 8 quarts.

  Fill to 9 quarts for extended flight.

• Oil Door / Preheat Plug … STOWED / SECURE

Before Starting Engine

• Preflight Inspection … COMPLETE

• Seats, Belts, Shoulder Harnesses … ADJUST AND LOCK

• Doors … LOCKED

• Circuit Breakers … ALL IN

• Left Panel Switches … UP / NORM

• Start Battery Select … BOTH

• Avionics Master … OFF

• Autopilot Switch … OFF

• Key … ON

• OnSpeed … BLINKING

• Fuel Pump Mode … 2, THEN 1/AUTO

  verify Pump 1 GREEN

• ECU Select … ECU1

• Fuel Quantity Indicators … CHECK

• Fuel Selector … FULLEST TANK

• Fuel Pressure … 45 PSI / GREEN

• Brakes … TEST AND SET

Starting Engine

• Propeller … HIGH RPM

• Throttle (Prime) … 2 PUMPS COLD / 1 PUMP WARM

  watch for AP indicator on EFII controller per pump

• Throttle … OPEN 1/4 INCH

  If cold, wait 10s for primer fuel to evaporate

• Propeller Area … CLEAR

• Starter … PRESS

  release after engine starts

If engine doesn’t start within 5 revolutions:

- disengage starter,

- wait ~10s for primer fuel to evaporate,

- retry start.

After Engine Starts:

• RPM … ADJUST TO 700

  reset to 700 as engine warms up

• Oil Pressure … GREEN

  if not in green within 30 seconds — shut down

• Avionics Master … ON

• Autopilot Switch … ON

• Strobes … ON

• Alternator Current … VERIFY POSITIVE

• Radios … SET / AWOS / ATIS

• Altimeter … SET

• Heading Indicator … SET

Before Taxi

• Wing Flaps … RETRACT, VERIFY UP
• Fuel Trim … LEAN -10% FOR TAXI
• Lights … AS REQUIRED
• Brakes … TEST ON ROLL

Runup

Note: ECU controller colors: BLUE = active fuel control. GREEN = standby. RED = p-lead grounded (ignition off). GRAY = not communicating.

• Fuel Trim … 0%
• Doors … CLOSED AND LOCKED
• Elevator and Rudder Trim … TAKEOFF
• Flight Controls … FREE AND CORRECT
• Flight Instruments … SET

Governor Cycle:

• Brakes … HOLD

• Throttle … 2000 RPM

• Propeller Control … 1800 RPM

• Throttle … +2“ MP

  let RPM stabilize

• Propeller Control … HIGH RPM

ECU + Fuel System Check (1600 RPM):

• Throttle … 1600 RPM

• Ignition (ECU p-leads) … CHECK

  1 OFF, Both, 2 OFF, Both

  expect ~100 RPM drop / smooth running per side

  verify active BLUE / disabled RED on EFII controller

  at Both, verify ECU1 BLUE / ECU2 GREEN

• ECU FUEL SEL … PRI / SEC / PRI

  verify active GREEN, backup BLUE through transitions

• Fuel Pump Mode … 1 / 2 / 1/AUTO

  fuel pressure should not budge through cutover

  verify pump annunciators follow selection (active green)

• Engine Instruments (Oil Px, Temp) … CHECK

• MZ-30 Generator … VERIFY OUTPUT

  Bat 2 voltage charging; gen amps positive (won’t show at idle)

• Throttle … IDLE

Before Takeoff

• Fuel Gauge … CHECK QUANTITY

• Fuel Pressure … 45 PSI / GREEN

• Fuel Trim … 0%

• ECU Select … ECU1

• Radios, Flight Plan … SET

• Transponder … ALT, 1200

• Strobes … AS REQUIRED

• Nav Lights … AS REQUIRED

• Pitot Heat … AS REQUIRED

• iPad / ForeFlight … CONNECTED

  Dynon WiFi — AHRS, traffic, GPS

• Flaps / Trim … SET FOR TAKEOFF

Takeoff Briefing — REACT:

• R - RPM … 2700, FULL POWER
• E - Engine gauges … GREEN
• A - Airspeed … ALIVE
• C - Centerline … TRACKING
• T - Takeoff abort point … IDENTIFIED
• Turn Direction (Engine-Out) … TOWARD CROSSWIND
• Radio Call … MAKE

Normal Takeoff

• Wing Flaps … 0º / 16º

• Centerline … ALIGN

• Power … FULL THROTTLE / 2700 RPM

  advance over ~5 seconds

• Elevator … BACK TO LIFT NOSE

  hover nose wheel; let plane fly itself off

• Pitch … ONSPEED

• Wing Flaps … UP

At 300 AGL:

• Propeller … 2500 RPM
• Climb Speed … START OF TONE / VY 95 KIAS

In Flight

Climb

• Climb Speed … VY 95 KIAS to 1000 AGL

• CHTs … MONITOR < 400ºF

  if approaching 400: Fuel Trim +10% or reduce climb angle

At 1000 AGL — Cruise Climb:

• Airspeed … 120 KIAS
• Power … FULL THROTTLE / 2500 RPM
• Engine Gauges … CHECK

Cruise

• Power … AS DESIRED

  default: full throttle / 2400 RPM

• Fuel Trim … 0%

• Elevator + Aileron Trim … ADJUST

• Engine Gauges … CHECK

• Lights … AS REQUIRED

Pre-Maneuver

• Fuel Selector … MORE FULL

• Lights … AS REQUIRED

• Clearing Turns … PERFORM

  90º L - 90º R / 180º turn

• Maneuvering Speed … 125 AT GROSS

Descent

• Fuel Selector … MORE FULL
• Power … AS DESIRED
• Lights … AS REQUIRED

Before Landing — GUMPS

G - Gas:

• Fuel Selector … FULLEST TANK
• Fuel Pump Mode … 1/AUTO
• Fuel Pressure … 45 PSI / GREEN
• Fuel Trim … 0%

U - Undercarriage:

• Gear … FIXED — VERIFIED

M - Mixture:

• Fuel Trim … 0% (replaces mixture)

P - Prop:

• Propeller … FULL FORWARD

  say it now; do it with first flap deployment

S - Switches / Seatbelts:

• Seats, Belts, Harnesses … ADJUST AND LOCK
• Lights … LANDING / TAXI
• Transponder … ALT
• Doors … LATCHED
• Brakes … TEST

Normal Landing

• Throttle … IDLE
• Flaps … 33º @ 87 KIAS
• Propeller … FULL FORWARD
• Pitch … ONSPEED
• Trim … ADJUST
• Throttle … MAINTAIN ALTITUDE / GLIDEPATH

On short final:

• Throttle … IDLE
• Touchdown … MAINS FIRST
• Landing Roll … HOLD NOSE WHEEL OFF
• Braking … MINIMUM REQUIRED

Postflight

After Landing

• Flaps … UP
• Elevator and Rudder Trim … TAKEOFF
• Lights … AS REQUIRED
• Pitot Heat … OFF
• Transponder … ALT, 1200

Securing Airplane

• Throttle … IDLE

• Hobbs + Tach Time … RECORD

• Avionics Master … OFF

• Autopilot Switch … OFF

• Lights … OFF

• Key Switch … OFF

  kills ECUs / fuel pumps — engine stops

• Gust Lock … INSTALL

Non-Standard Takeoff and Landing

Short Field Takeoff

• Flaps … 16º

• Power … FULL THROTTLE / 2700 RPM

• Elevator … BACK TO LIFT NOSE

  fly off; let plane accelerate in ground effect

• Climb Speed … ONSPEED / VX 80 KIAS

  until obstacles cleared

• Flaps … RETRACT

Maximum Performance Climb

• Power … FULL THROTTLE / 2700 RPM
• Airspeed … ONSPEED / VX 80 KIAS
• Fuel Selector … MORE FULL
• CHTs … MONITOR < 400ºF

Short Field Landing

Drag-it-in: behind the power curve, power for descent rate, AOA for airspeed.

• Flaps … 33º BELOW 87 KIAS

• Airspeed … SLOW TONE

  high AOA, slower than ONSPEED — touchdown speed minimized

• Power … MAINTAIN DESCENT GRADIENT

  throttle controls rate of descent at this AOA

• Trim … ADJUST

• Power … REDUCE TO IDLE

  as obstacle is cleared

• Touchdown … MAIN WHEELS FIRST

• Brakes … APPLY HEAVILY

• Flaps … RETRACT

Go Around

Note: Pressing “Nose Up” on the autopilot during a coupled approach engages go-around mode automatically.

• Power … FULL THROTTLE / 2700 RPM
• Pitch … ONSPEED
• Flaps … RETRACT
• Trim … SET FOR TAKEOFF
• Climb Speed … VY 95 KIAS

Performance

Performance figures below are Van’s published numbers for the RV-10 with a 260 HP engine, augmented with N720AK-specific test data where available. Treat the published figures as a planning reference; verify against actual aircraft performance over the course of Phase I and ongoing operation.

V-Speeds (Reference)

See Section 2 for authoritative values. Quick reference:

Stall and Approach Speeds

Stall speeds at ~2,190 lb test weight, level flight, idle power. At max gross (2,700 lb), add approximately 10%.

Operationally we fly OnSpeed AOA (solid tone) for normal approach and slow tone (drag-it-in) for short field; see OnSpeed.

Takeoff Performance

Van’s published ground-roll figures, sea level, ISA, no wind, paved runway. Van’s does not publish a 50 ft obstacle distance for the RV-10.

Apply standard corrections for density altitude, wind, runway slope, and surface (grass adds ~15%). For obstacle clearance, plan generously — the 50 ft figure is generally 1.5–2× ground roll for piston singles.

Climb Performance

Van’s published rate of climb at sea level, ISA, full power:

In practice, climb at V~Y~ (95 KIAS) until 1,000 AGL, then transition to cruise climb at 120 KIAS, full throttle, 2,500 RPM. Reduce climb angle or richen Fuel Trim if CHT approaches 400 °F.

Cruise Performance

Van’s published cruise (260 HP, 8,000 ft, ISA):

Operationally we cruise at full throttle / 2,400 RPM with Fuel Trim 0% at altitudes from 6,000 to 12,000 ft. Verify actual TAS, fuel flow, and CHT against the EFIS as the airframe accumulates hours.

Landing Performance

Van’s published ground-roll figures, sea level, ISA, no wind, paved runway, max braking. Van’s does not publish a 50 ft obstacle distance for the RV-10.

For short-field landing, fly the slow tone with power for descent control (drag-it-in technique); see Section 5 → Short Field Landing.

Range and Endurance

Van’s published range at 8,000 ft, no reserves, full 60 gal fuel, gross weight:

Plan a 45-minute reserve at cruise burn for night/IFR (FAR 91.167), 30-minute reserve for day VFR (FAR 91.151), or longer per personal minimums.

Glide Performance

Best glide is 95 KIAS with the propeller pulled to full coarse (low RPM). Pulling the prop coarse reduces drag substantially compared to leaving it at high RPM — this is the difference between a usable glide and falling out of the sky.

Confirm actual glide ratio and altitude loss with at-altitude glide tests during Phase I and ongoing operation. Record altitude lost per 360° turn at 20°, 30°, 45° bank for use in pre-takeoff turnback briefing planning per the EAA Power-Loss-on-Takeoff Working Group methodology.

Add 250–500 ft pad to measured 360° altitude loss to define “high key” altitude for turnback feasibility — see Vac’s working-group writeup.

Weight and Balance

Aircraft Identification

Datum & Reference Arms

The datum is 99.44 inches forward of the wing leading edge. All arms below are aft of datum.

Allowable CG Range

CG must remain within 107.84“ – 116.24“ aft of datum at all loadings.

Empty Weight & Balance

Aircraft was weighed empty in level flight attitude. Includes 12 quarts of oil; no fuel. Weighing date: 2025-11-18.

Empty CG = 175,730 / 1,643 = 106.96 in aft of datum.

The empty weight reflects N720AK’s actual configuration as of 2025-11-18. The Monkworkz MZ-30 generator and BOSCH relay (~2.6 lb total) were installed 2026-03-09, and the Borla regulator replaced the Aeromotive 2026-03-17. These changes are minor (~3 lb net) but the airplane has not been re-weighed since. Re-weigh at the next condition inspection or major mod.

Weights and Capacities

Sample Loadings

All four scenarios use the empty weight (1,643 lb @ 106.96“) and assume 12 qts oil.

Most Forward CG

Most Aft CG

Max Gross — Typical 4-Up Loading

First Flight / Single Pilot Light Loading

Sample Calculation Worksheet

Use this template for actual flights. CG = Total Moment ÷ Total Weight.

CG must be between 107.84 and 116.24 inches aft of datum.

Total weight must not exceed 2,700 lbs.

Source Documents

• Authoritative W&B sheet: Public/Weight-Balance/N720AK_WB_11_18_2025.pdf on Google Drive (2025-11-18 weighing).
• A ForeFlight-compatible aircraft profile export is planned so that guest pilots can compute W&B for N720AK in ForeFlight.

System Descriptions

The Airplane

The RV-10 is a four-place, single-engine, low-wing aircraft with tricycle landing gear. The airframe is primarily aluminum alloy construction with flush rivets, except for some steel components including the engine mount, landing gear legs, control surface bellcranks, and miscellaneous hardware. Wing tips, tail fairings, cowling, and wheel fairings are fiberglass.

Engine and Components

The aircraft is powered by a Lycoming YIO-540-D4A5 (S/N EL-36315-48E), 260 HP at 2,700 RPM, six-cylinder horizontally opposed, fuel injected, normally aspirated, air cooled. Compression ratio 9:1 as configured for the EFII System32. Installed new on 2025-11-18.

Electronic Engine Management

The EFII System32 provides:

• Full Electronic Ignition: Dual redundant ignition with individual coil packs for each cylinder
• Electronic Fuel Injection: Precise fuel metering with automatic mixture optimization
• Redundant ECUs: Two independent Engine Control Units; panel switch allows manual ECU selection if needed

The System32 controller on the panel provides mixture control through the electronic fuel injection system.

Detailed reference: EFII System32 (ATA 73)

Fuel Pumps

Two electric fuel pumps (primary and backup) pressurize the fuel line to the engine. The system includes:

• Automatic Switchover: If fuel pressure drops below threshold, the System32 automatically activates the backup pump
• Manual Selection: Panel switch (PMP 2) allows manual pump selection
• Fuel Return: Excess fuel returns to the originating tank

Detailed reference: Fuel System (ATA 28)

Propeller

Detailed reference: Propeller (ATA 84)

Landing Gear

The landing gear is a fixed tricycle configuration with:

• Steerable nose wheel (Beringer AV-VANS-102-01)
• Main gear with Matco WHLWI600XLT-2 wheels and brakes
• Wheel fairings on all three wheels
• Main tires: Desser retreads (no inner tubes)

Tire size and pressure values: see sys-61-brakes.md. Verify and update at next servicing — pressures are not currently logged in the maintenance data.

Brake System

Hydraulic disc brakes are operated by toe pedals on both pilot and copilot rudder pedals.

Detailed reference: Brakes & Wheels (ATA 61)

Flight Control System

Dual controls are fitted. Primary flight controls:

• Ailerons: Operated through push-pull tubes
• Elevator: Operated through push-pull tubes
• Rudder: Cable operated, connected to rudder pedals

Trim Systems

• Pitch Trim: Electric servo-actuated trim tab on elevator, controlled by hat switch on stick grip
• Roll Trim: Electric servo in wing, controlled by hat switch on stick grip
• Yaw Trim: None installed

Co-Pilot Trim Enable

A panel switch enables or disables trim authority from the co-pilot stick grip. This allows the pilot to disable co-pilot trim inputs when desired.

Flaps

Electric flap motor with position indicator on EFIS. Controlled by:

• Panel-mounted flap switch
• Stick grip switch (both sticks)

Flap positions range from reflex (−3°) to full (33°). Operational notches: 0°, 16°, 33°.

Detailed reference: Flight Controls (ATA 27)

Fuel System

Fuel is stored in two wing tanks with a selector valve on the center tunnel.

Fuel System Components

• Wing Tanks: Integral tanks in wing leading edges
• Fuel Selector: Three-position valve (LEFT / RIGHT / OFF) on center tunnel
• Fuel Pumps: Primary and backup electric pumps (see Engine section)
• Fuel Return: Returns to selected tank
• Fuel Strainer: Drain before first flight of day

Note: The fuel system does not support inverted flight.

Detailed reference: Fuel System (ATA 28)

Electrical System

Power Sources

The two charging systems are fully isolated. The primary alternator charges Battery 1 only, and the Monkworkz generator charges Battery 2 only.

A Generator Enable switch on the panel (next to the alternator field switch) controls the generator. A normally-open relay disconnects the generator from Battery 2 whenever the ignition key is off, preventing parasitic battery drain.

Bus Architecture

The electrical system uses a dual-bus architecture managed by the flyEFII System32 Bus Manager:

• Essential Bus: Powers critical engine systems (ignition, fuel injection, fuel pumps)
• Main Bus: Powers avionics and other aircraft systems via VPX Sport

Emergency Endurance Bus

If a battery fails or bus voltage drops critically, the System32 Bus Manager automatically:

1. Disconnects non-essential loads from the main bus
2. Preserves all available power for the essential bus
3. Maintains engine ignition and fuel injection

The EMERGENCY POWER switch on the panel manually activates this mode.

VPX Sport Power Distribution

The Vertical Power VPX Sport provides:

• Electronic circuit breaker protection
• Load monitoring and display on EFIS
• Automatic load shedding if needed
• No physical circuit breakers to reset

Detailed reference: Electrical Power (ATA 24)

Pitot-Static System

Pitot

The pitot tube incorporates a second orifice angled to measure differential pressure for Angle of Attack (AoA) display on the EFIS.

Static

The static system feeds:

• Dynon Skyview HDX AHRS
• Backup instruments (if installed)

Instrument Panel

Primary Flight Display

Dynon Skyview HDX provides:

• Primary Flight Display (PFD)
• Multi-Function Display (MFD)
• Engine monitoring
• Moving map with terrain
• Traffic display (ADS-B In)
• Autopilot interface

Navigation and Communication

Detailed reference: Navigation & Instruments (ATA 34) | Communications (ATA 23)

Autopilot

Dynon 3-Axis Autopilot with:

• Roll servo (aileron)
• Pitch servo (elevator)
• Yaw damper

Controlled via:

• Dynon autopilot panel
• Stick grip disconnect button

Detailed reference: Autopilot (ATA 22)

Transponder and ELT

Panel Switches

Left Panel:

• Pitot Heat
• Landing Light
• Taxi Light
• Nav Lights
• Strobe Lights

Center Panel:

• Flap switch
• Alternator field
• Generator enable
• Avionics power
• Emergency power

EFII System32 Switches:

• Ignition Select
• ECU Select
• Fuel Pump Mode
• Start Battery Select

Other:

• Master switch (keyed)
• O2 mode switch (pulse/constant)
• Co-pilot trim enable

Control Sticks

Both pilot and co-pilot have Tosten CS Military stick grips with identical button functions:

The flap switch is panel-mounted (one tap down: 0° → 16°; second tap: 16° → 33°; one tap up retracts fully). Flaps will not deploy above 90 KIAS (speed inhibit).

Detailed reference: Flight Controls (ATA 27) | Avionics & Wiring (ATA 42)

Oxygen System

Mountain High EDS-4iP pulse-demand oxygen system:

Operating Modes

A panel toggle selects between:

• Pulse Mode: Oxygen delivered in pulses synchronized with inhalation (normal operation, conserves oxygen).
• Emergency / Constant Flow: Continuous oxygen flow to all ports simultaneously. Use for hypoxia, mask seal issues, or if pulse mode fails. The toggle is the system on/off — there is no separate emergency switch.

See the Oxygen System Failure / Hypoxia checklist in Section 4b.

Detailed reference: Oxygen (ATA 35)

Heating, Ventilation and Defrosting

Cabin Heat

Heat is provided from a heat muff on the exhaust system. Controlled by push-pull knob on panel.

Ventilation

Fresh air is supplied through:

• Eyeball vents under instrument panel (pilot and copilot)
• NACA ducts on fuselage sides

Defrost

Windshield defrost air from the heating system.

Cabin Features

Seating

Four-place seating:

• Front: Pilot and copilot, side-by-side
• Rear: Two passengers

Restraints

Crow Kam Lock harnesses at all four seats — see sys-52-doors-airframe.md.

Baggage Area

Access through rear baggage door on the right side of the fuselage.

Exterior Lighting

Wing Tip Lights

Each wing tip contains:

• AeroLEDs Pulsar (NSP/660): 3-in-1 LED combining position light (red/green), strobe, and rear-facing white position light
• AeroLEDs AeroSun VX: Landing and taxi light with built-in wig-wag mode

Tail Light

• AeroLEDs SunTail: LED position light (white) and strobe

Lighting Controls

Detailed reference: Lighting (ATA 33)

Handling, Servicing and Maintenance

General

The airplane should be moved using a tow bar which connects to the nose wheel. The airplane may be pushed or pulled from the inboard portions of the prop blades. Do not push on the spinner!

Ground Handling

The airplane has three tie-down rings:

• One on each wing (near outboard bellcrank access panel)
• One on the tail

The tie-down rings are removable and may be kept inside the baggage compartment.

Jacking

The airplane can be jacked from:

• Tie-down ring locations
• Main spar just outboard of fuselage (protect with padded boards)

Engine Air Filter

Detailed reference: sys-71-engine.md — Alt Air Door

Brake Service

Warning: Use only MIL-PRF-83282 specification hydraulic fluid (Royco 782). Do not substitute automotive brake fluid — it will damage the seals.

Brake lining part numbers and replacement procedure: see Matco WI600 Series manual referenced in sys-61-brakes.md.

Landing Gear Service

Wheels: Matco WHLWI600XLT-2 main, Beringer AV-VANS-102-01 nose.

Tires: Desser retreads on the mains (no inner tubes). Tire size and operating pressure are not currently logged — record at next servicing in sys-61-brakes.md.

Wheel Bearings

Repack main wheel bearings with Aeroshell #5 grease at annual condition inspection.

Propeller Service

The Whirlwind WWA-RV10 is a sealed propeller — no field lubrication required. Inspect leading edges for nicks/erosion, hub for oil weeps, and spinner attachment at each preflight and condition inspection.

A 5-year manufacturer maintenance clock started at first engine run on 2025-11-18; next major prop maintenance event due 2030-11-18.

Detailed reference: sys-84-propeller.md

Oil System Service

Oil Change Procedure

1. Change oil and filter every 50 hours / 4 months (whichever first).
2. Remove and inspect oil suction screen for metal.
3. Cut filter and inspect for metal.
4. Replace crush washers as required.
5. Refill with 9 quarts (8 minimum for operation; do not exceed 12).
6. Run engine briefly and check for leaks.

50-Hour Companion Tasks

Perform these at every oil change:

Spark plugs: Remove, clean, inspect electrodes, re-gap, rotate top↔bottom.

Oil analysis: Take sample for Blackstone Labs before draining old oil.

Anti-Splat oil separator evacuation tube: Inspect where the evacuation tube enters the exhaust pipe. Remove any carbon coking or buildup that could block crankcase blowby flow. The evacuation tube is saddle-mounted to the exhaust pipe with two stainless steel clamps — look up into the tube entry point and scrape/clean any deposits. If excessive buildup is found, shorten the inspection interval. The safety bypass (0.5 PSI pop-off valve) provides a backup path if the tube blocks, but does not eliminate the need for inspection. See Anti-Splat installation guide.

PLX O2 sensor health: Check sensor health percentage on the DM-6 gauge (requires firmware V2.0+). Replace the wideband sensor if health drops below 50%. Also check reaction time — below 150ms is excellent, above 251ms indicates a degraded sensor. 100LL avgas poisons the sensor faster than mogas; expect 300-500 hours of life on avgas. See PLX Gen4 sensor diagnostics.

Fuel System Service

Fuel Strainer

Drain fuel strainer:

• Before first flight of day
• After each refueling
• Check for water and sediment

Fuel Tank Sumps

Drain each tank sump and check for water/contamination:

• Before first flight of day
• After refueling

Generator Service

Monkworkz MZ-30

The MZ-30 requires no brushes or field winding — maintenance is minimal.

Condition inspection items:

• Inspect generator mount bolts and silicon/fiberglass gasket
• Check 12 AWG phase wires from generator to regulator for chafe, routing clear of exhaust, and no tension from engine movement
• Check regulator mounting on engine mount
• Inspect Pico-Lock connectors (input and output) for security — add maintenance loops if missing
• Verify cooling ducts (3/4“ corrugated nylon) are intact and connected to both generator and regulator
• Check regulator blink code LED (4 flashes/sec = enabled and normal)
• Verify shear coupling is intact: generator should NOT rotate freely. If it does, the shear coupling has split — contact Monkworkz for replacement.
• Keep ferrous metal shavings away from generator exterior (permanent magnets)

Operational check:

With engine running and enable switch on, Battery 2 voltage should show a charging indication. The BOSCH relay (0332019155) should be energized (audible click when enable switch is toggled with ignition on).

Do not open the regulator box — adhesive inside dampens vibration, and opening risks tearing components off the circuit board.

Fuses: Input and output fuses are internal to the regulator. If either blows, the regulator likely needs service. Fuses can be tested with an ohmmeter (should show near-zero resistance). Contact Monkworkz for replacement.

Battery Service

The two charging systems are fully isolated. Do not charge with non-LiFePO4 chargers — EarthX batteries have an internal BMS and require lithium-specific charging.

Approved chargers (filed in shop):

• OptiMate Lithium 4s 5A (TM-291) — 5A maintainer
• OptiMate TM-275 v2 — 9.5A charger / maintainer / 13.6V power supply (TUNE mode for avionics work without battery drain)

Charger sleep behavior: OptiMate units enter sleep once fully charged and check voltage hourly. If a continuous parasitic load is present (panel powered for configuration), the maintainer may not detect drain and the battery can deplete. Use TM-275 TUNE mode (continuous 13.6 V) for any avionics work session that requires panel power.

Detailed reference: sys-24-electrical.md — EarthX Battery & Chargers

Lubrication Schedule

Oxygen System Service

Mountain High EDS-4iP system:

• Refill oxygen per Mountain High procedures
• Inspect cannulas and tubing
• Verify pulse delivery operation

Dynon Maintenance Log — Scheduled Items

The following items are configured in the Dynon SkyView maintenance log (SETUP MENU > SYSTEM SETUP > AIRCRAFT INFORMATION > MAINTENANCE LOG). The MAINT LOG page is accessible via MENU > MAINT LOG. Past-due items show in red at startup.

Tach-Based Items

Date-Based Items

Not in Dynon — Track Separately

Pitot Heat Check

Verify pitot heat operation before flight into potential icing conditions:

1. Turn on PITOT HEAT switch
2. Verify pitot tube warms (carefully touch)
3. Monitor current draw on VPX display

Workshop, Tools & Supplies

N720AK Build & Maintenance Reference

Overview

This page documents the tools, supplies, and workshop equipment used to build and maintain N720AK. It also collects condition inspection tips and lessons learned — access tricks, fastener notes, and reassembly gotchas that aren’t in any manual.

Specialty Aircraft Tools

Cleaveland Aircraft Tool

Industrial Services of WNY (iflyrv10.com)

Billet brackets and custom RV-10 parts:

Electronics & Sensors

PLX Devices

Mouser Electronics

Digi-Key

Hardware & General Supplies

Aircraft Spruce

Harbor Freight

Maintenance Supplies

Consumables to Keep on Hand

Wheels & Brakes

MATCO Manufacturing

Modifications & Accessories

AirWard

MotoPOD

Hardpoint kit for belly cargo pod. Correspondence with David Shelton (2015-2016). Hardpoints installed during build; pod itself was never produced for RV-10.

Gallagher Aviation

Mountain High

Savvy Aviation

Condition Inspection

Tips & Lessons Learned

Hard-won notes on access, fasteners, and reassembly — things that aren’t in any manual.

Interior Panels

• Front seat pan panels — outboard bottom screw (pilot & copilot): The outboard bottom screw on each front panel is partially blocked by the gear leg tube and the AeroSport plastic side panel. To install this screw without stripping it, pull back the plastic side panel first, then use a long screwdriver laid against the gear leg tube. Do NOT attempt to drive this screw with the plastic panel in place — you will strip the screw head.

AN/MS/NAS Fastener Cross-Reference

Van’s RV-10 plans use AN (Air Force-Navy) part numbers, but most retailers now sell under MS (Military Standard) or NAS (National Aerospace Standard) designations. The fasteners are identical — only the numbering system changed. This table maps between systems.

How to Read AN Part Numbers

Bolts (AN3-AN20): AN4-7A = AN standard, 4 = 4/16“ (1/4“) diameter, 7 = 7/8“ grip length (in 1/8“ increments), A = no drilled shank (cotter pin hole Absent). Without the “A” suffix, the shank is drilled for a cotter pin. For longer bolts: -12 = 1-1/4“ (first digit = whole inches, second = 1/8“ increments, so 1“ + 2/8“).

Hex head bolts (AN3-AN20) use the bolt number to encode diameter:

Rivets (AN426, AN470): AN426AD4-5 = AN standard, 426 = 100-degree countersunk head, AD = 2117-T4 aluminum alloy, 4 = 4/32“ (1/8“) diameter, 5 = 5/16“ length (in 1/16“ increments).

Screws (AN507, AN509, AN515, AN525, AN526): AN509-10R8 = AN standard, 509 = 100-degree flush structural, 10 = 10-32 thread, R = Phillips recess, 8 = 8/16“ (1/2“) total length.

Nuts: AN365-1032A = AN standard, 365 = elastic stop nut, 1032 = 10-32 thread, A = cadmium-plated steel. Suffix “C” = stainless steel.

Screws

Aircraft Spruce lists AN509 screws under MS24694, AN507 under MS24693, and AN515/AN526 under MS35206. AN525 washer head screws are still sold under the AN525 designation.

Solid Rivets

Aircraft Spruce lists these under the MS20426 / MS20470 numbers but cross-references the AN numbers on each product page.

Rivet sizing examples:

Bolts

AN3-AN20 bolt part numbers remain identical under the NASM designation. Aircraft Spruce and other retailers sell them under both AN and NASM numbers interchangeably. AN4-7A = NASM4-7A = 1/4“ bolt, 7/8“ grip, no cotter pin hole.

NAS6603-NAS6610 are NOT direct substitutes for AN bolts — they are close-tolerance bolts for shear applications with different specifications (160 KSI vs ~125 KSI for AN bolts).

Nuts

Aircraft Spruce sells AN365 nuts under the MS21044 number (e.g., MS21044N3 = AN365-1032A). The AN310 castle nut is sold as NASM310 with identical part numbering.

Washers

MS20002 / NAS1439 washers are for internal-wrenching (socket head) bolts only — they are NOT equivalents for AN960 or AN970.

Blind Rivets

Blind rivet dash numbers: First number = diameter in 32nds (4 = 1/8“), second number = max grip in 16ths (3 = 3/16“, 4 = 1/4“, 5 = 5/16“).

CherryMAX (CR32xx) rivets are a significant upgrade over CS4-4 and LP4-3: they have a locked spindle that creates a bulbed blind-side head similar to a solid rivet, providing higher shear and tension strength. Many builders substitute them throughout the build.

Nutplates (Anchor Nuts)

Nutplates are riveted to structure with AN426AD3 rivets (typically -3.5 length). The K1000 series is by far the most common in RV-10 construction.

Cotter Pins & Clevis Pins

Aircraft Spruce lists cotter pins under MS24665. Example: AN380-4-5 = MS24665-355 (1/8“ dia, 1-1/4“ long).

Quick-Reference Summary

For the most common RV-10 fasteners, here is what to search for at Aircraft Spruce:

Sources

• Aircraft Spruce MS24694 (AN509)
• Aircraft Spruce MS24693 (AN507)
• Aircraft Spruce MS35206 (AN515)
• Aircraft Spruce AN525
• Aircraft Spruce AN426 Solid Rivets
• Aircraft Spruce AN365 Elastic Stop Nuts
• Aircraft Spruce AN310 Castle Nuts
• Aircraft Spruce AN960 Flat Washers
• Aircraft Spruce AN970 Large Washers
• Aircraft Spruce K1000 Nutplates
• Aircraft Spruce Cherry Rivets
• Aircraft Spruce MS24665 Cotter Pins
• Aircraft Spruce CherryMAX CR3213
• Monroe Aerospace AN960/NAS1149 Cross-Reference Chart
• Skybolt AN-MS-NAS Hardware Reference (PDF)
• Pegasus Auto Racing AN Bolt Identification
• FAA AC 43.13-1B Chapter 7 - Bolts
• Spencer Aircraft Fastener Cross-References

Hangar Facility — KBDU

Flooring

Swisstrax Ribtrax Pro interlocking tiles, Slate Grey. Wall-to-wall coverage of KBDU hangar. Custom L-shaped layout: ~41’ x 15’6“ main area with 18’6“ x 7’6“ extension.

Ordered 2026-01-26 from Swisstrax (Order #60309, rep Jacob Crawford). Total $4,337.01. Invoice filed at Private/Invoices/swisstrax-hangar-flooring-order-60309-2026-01-26.pdf.

References

All order confirmations and invoices archived to Google Drive Private/Invoices/ organized by vendor.

Autopilot

ATA Chapter 22 — N720AK Systems Reference

Overview

N720AK uses the Dynon 3-axis autopilot integrated with the Skyview HDX EFIS. The system provides roll (aileron), pitch (elevator), and yaw damper servo control. The autopilot is controlled via the Dynon autopilot panel on the instrument panel and can be disconnected instantly via the red button on the Tosten CS Military stick grip.

Components

How It Works

Control Wheel Steering (CWS)

The Dynon autopilot supports Control Wheel Steering mode. Press and hold the autopilot disconnect button on the stick grip to temporarily override the autopilot, manually fly the aircraft to a new attitude/heading, then release the button. The autopilot will hold the new state. This allows quick course corrections without fully disconnecting and re-engaging the autopilot.

Disconnect Logic

The autopilot disconnects when:

• The red disconnect button on either stick grip is pressed
• Manual force is applied to the controls (servo clutch slip)

Servo Installation

Inspection & Maintenance

References

• Dynon SkyView Autopilot In-Flight Tuning Guide (Rev F)
• Dynon SkyView System Installation Guide (Rev AV)
• Dynon AP Roll Servo for RV-10 Right Wing (Doc 101046-003, Rev H) — Kit P/Ns: 100870-001 Right Roll Bracket, 100872-001 Right Support Bracket, 100966-008 Aluminum Pushrod 3.0“, 100836-000 Large Male Rod End. Hardware: AN3H-3A, AN3H-10A, AN3H-17A, AN970-3, AN365-1032A.
• Dynon AP Pitch Servo for RV-10 Linear Actuator (Doc 101046-007, Rev E) — Kit P/Ns: 100973-002, 100836-000, 100982-001.
• Dynon AP Yaw Tiller Arm/Bow Kit for RV-10/14 (Doc 102710-000, Rev A) — Kit P/Ns: 102701-000, 102702-000, 100904-001, 100905-000, 101877-000.

Communications

ATA Chapter 23 — N720AK Systems Reference

Overview

N720AK’s communications stack includes the Garmin GMA 245 audio panel, Dynon Com Panel, and intercom system. The audio panel provides Bluetooth connectivity for phone calls and music.

Components

How It Works

Antennas

COM Antennas

The CI-121 is a straight vertical whip (standard Cessna-style). The CI-122 is a bent configuration designed for underside mounting.

All antenna coax is RG-400. See wing root connectors for the right wing COM antenna coax routing through the wing root CPC.

NAV Antenna

• Bob Archer — single nav antenna for GTN 650

Transponder & ADS-B Antennas

See also Navigation & Instruments.

Both are non-TSO monopole antennas fed by 50 Ω RG-400 coax, with omnidirectional vertically-polarized radiation patterns.

GPS Antennas

Dynon SV-GPS-250/A

Garmin GA 35

• Installation Instructions (Rev F)

ELT Antenna

Antenna Summary

Wiring

Inspection & Maintenance

References

• Garmin GMA 245 Pilot’s Guide
• Garmin GTN 650 Pilot’s Guide
• Artex ELT 345 Manual
• Comant CI-121 Datasheet
• Comant CI-122 Datasheet
• Dynon SV-COM-425 Customer Drawing
• Bob Archer — Antennas for Aircraft
• Bob Archer Antenna Installation Instructions
• Garmin GA 35 Installation Instructions (Rev F)
• Garmin GA 35 Product Page
• Dynon SV-GPS-250/A Product Page
• Dynon SkyView System Installation Guide
• ACR Artex 110-773 Whip Antenna
• Artex ELT 345 Manual

Electrical Power

ATA Chapter 24 — N720AK Systems Reference

Overview

N720AK’s electrical system uses a dual-bus architecture managed by the flyEFII System32 Bus Manager. Power distribution and electronic circuit breaker protection are provided by the Vertical Power VPX Sport. Two EarthX ETX900 lithium batteries provide redundant power with fully isolated charging systems: a 60-amp primary alternator charges Battery 1, and a Monkworkz MZ-30 generator charges Battery 2.

Components

How It Works

Bus Architecture

• Essential Bus: Powers critical engine systems — ignition, fuel injection, fuel pumps. Managed by System32 Bus Manager.
• Main Bus: Powers avionics and other aircraft systems via VPX Sport electronic breakers.

Emergency Endurance Bus

If a battery fails or bus voltage drops critically, the System32 Bus Manager automatically:

1. Disconnects non-essential loads from the main bus
2. Preserves all available power for the essential bus
3. Maintains engine ignition and fuel injection

The EMERGENCY POWER switch on the panel manually activates this mode.

Endurance bus radio behavior: The GTN 650 is COM1. If power goes out on the GMA 245, it hard-connects COM1 from the GTN 650 directly to the headphones. This ensures radio communication is maintained even if the audio panel loses power on the endurance bus.

VPX Sport

The VPX Sport provides:

• Electronic circuit breaker protection (no physical breakers to reset)
• Load monitoring and display on EFIS
• Automatic load shedding if needed
• Programmable power channels

Fuses (Non-VPX)

Discrete fuses outside the VPX electronic breaker system, located above the essential bus bar behind the pilot PFD:

Monkworkz MZ-30 Generator

Installed 2026-03-09. The MZ-30 is a permanent-magnet generator driven off the engine’s vacuum pump pad, providing independent charging for Battery 2. Manual version 4, dated 2024-10-22.

Specifications

Voltage selection: Ships configured for 14.6 VDC. For lithium batteries (EarthX), the lower 14.2 VDC setting is recommended per Monkworkz Feb 2026 guidance. To select 14.2V, disconnect pin 1 (VSEL) on the input side Pico-Lock connector. Voltage is set at startup and cannot be changed while running.

Architecture

The two battery charging systems are fully isolated:

The bus manager’s internal screw that previously allowed the primary alternator to cross-charge Battery 2 has been removed. Each battery has a dedicated charging source.

Generator → Battery 2 Wiring

The generator output connects to the Battery 2 stud inside the bus manager (Drawing 5A, bus manager installation guide page 13). A BOSCH 0332019155 normally-open relay (30A, 12V, internal diode) sits between the generator output and Battery 2 to prevent parasitic draw when the engine is off.

Relay coil power: Essential bus + generator enable switch. This design means:

• Turning off the ignition key de-energizes the essential bus, opening the relay and disconnecting the generator from Battery 2 — regardless of enable switch position
• The enable switch provides pilot control to disable the generator in flight
• The generator cannot turn itself on (unlike the Monkworkz reference diagram which powers the relay from the generator output)

Note: The manual recommends connecting to the switched side of the master contactor to avoid parasitic draw from the regulator’s ~30mA diagnostic blink code circuit. The BOSCH relay achieves the same purpose.

MZ Regulator Connections

The MZ regulator is mounted on the engine mount with the following connections:

Generator side (3-phase, #6 screw terminals, 12 AWG):

• Terminal 7 (~1), Terminal 8 (~2), Terminal 9 (~3) → MZ Generator (phases can be connected in any order)

Input Molex Pico-Lock (pre-wired, 22-24 AWG):

• Pin 1: Voltage_Select (connected = 14.6V, disconnected = 14.2V)
• Pin 5: GEN_Thermistor → Generator thermistor (required — system will not produce output without it)
• Pin 6: GND

Output Molex Pico-Lock (22-24 AWG):

• Pin 1: Enable → Pilot enable switch (pin 1 to switch center, pin 6 to switch N.O.)
• Pin 2: Output_Active — pulls to ground when regulator is active and maintaining ≥14V (works with Dynon/Garmin EFIS contact inputs). Orange/brown wire, currently coiled up and unused near the Monkworkz enable switch.
• Pin 3: +i_Shunt (internal fuse used as shunt, 1.1 mΩ nominal)
• Pin 4: −i_Shunt
• Pin 5: Proportional_Current → Dynon EMS pin 31 (0–~2.7V = 0–30A, brown/blue wire)
• Pin 6: GND

Power output (#6 screw terminals, 10 AWG Tefzel):

• Terminal 17: Output_Power_Positive → BOSCH relay → Battery 2 stud (bus manager)
• Terminal 18: Output_Power_Ground (to clean metal airframe ground, no paint/corrosion)

Caution: The Pico-Lock connectors are delicate — add ~0.5“ maintenance loops in the connector wires, secured to nearby 12/10 AWG wires with a small pre-load toward the connector to prevent unseating.

Cooling

Both generator and regulator require cooling via 3/4“ holes in the engine baffling with corrugated nylon tubing routed from the baffling. The duct material is a force fit into the generator, regulator, and baffling holes. RTV can improve the seal.

Generator Enable Switch

Panel-mounted next to the primary alternator field switch. Controls the relay coil circuit (essential bus → enable switch → relay coil → ground).

The enable switch wiring connects pin 1 (Enable) to the switch center post and pin 6 (GND) to the switch’s normally-open terminal, grounded at the regulator end (not at the panel — grounding at the panel can cause ground loops and erratic behavior per manual section 2.1).

Startup Behavior

After engine start, when RPM exceeds ~1200, the MZ-30 performs an internal self-test (2–4 seconds). If all checks pass, it begins providing output voltage. The enable switch can be set ON as part of the pre-start checklist or activated at idle.

Protection Features

• Overvoltage Protection (OVP): Shuts down output in <1 second if overvoltage detected. If OVP triggers 3 times in one flight, system shuts down for the remainder of that flight. If this occurs across 3 separate flights (9 total OVP events), the regulator requires service/replacement from Monkworkz.
• Thermal protection: Two-stage — first reduces to half current limit, then full shutdown if temperature continues rising. Recovers automatically when temperature drops below recovery threshold.
• Current limiting: Electronic current limiting at 30A. Output fuse is internally replaceable by a repair shop only.
• Shear coupling: Located between input spline and motor shaft. Breaks if vacuum drive torque is exceeded — contact Monkworkz for replacement if generator rotates freely.

Regulator Blink Codes

The regulator has a diagnostic LED on the output side:

The Output Active pin (pin 2) also provides status: it “flashes” on an 8-second cycle (4s ground, 4s open) if the generator is overheating, providing an in-cockpit indication.

Dynon EMS Monitoring

The MZ-30’s proportional current output (pin 5, 0–~2.7V = 0–30A) is wired to Dynon EMS pin 31. This pin previously carried the CO Guardian PPM signal to the Dynon EMS — only the EMS display was removed when the wire was repurposed. The CO Guardian unit remains installed in the cabin and still provides an audible alarm above 50 PPM. The alarm is not currently wired into the GMA 245 audio panel, so it sounds in the cabin but is not heard through the headsets.

References

• Monkworkz MZ-30 product page
• MZ-30 Installation and Operation Manual V4 (2024-10-22)
• VAF: Monkworkz Wiring for Amps Readout
• Bus Manager Installation Guide, Drawing 5A (page 13)

Wiring

KiCad migration: All connector pinouts and wiring data below should eventually be ported to proper KiCad schematics. The text tables here are transcribed from build notes and serve as the interim reference.

Wiring Stations (Station-by-Station Topology)

Complete wiring map of the aircraft, from tail to firewall.

Rear Tailcone

• ELT
• SunTail (rear position/strobe)
• Elevator trim servo

Tailcone / Baggage Area Junction (RIGHT)

• Elevator autopilot servo
• ADSB
• Net hub
• Battery 1 positive (large gauge)
• Battery 2 positive (large gauge)
• Main battery negative (large gauge)

Tailcone / Baggage Area Junction (LEFT)

• Alt static line from panel
• EFIS hub connection
• Starter solenoid 1 drive
• Starter solenoid 2 drive
• Starter annunciator wire
• Emergency air override (yellow and red lines)
• O₂ supply and pressure lines (blue and red)
• Oxygen wiring harness
• Pitot air hose (blue)
• AoA hose (green)

Passenger Area (LEFT)

• O₂ lines (blue and red)
• Left passenger O₂ harness
• Left door ajar sensor
• Power wire for left door ajar servos

Passenger Area (RIGHT)

• O₂ lines (blue and red)
• Right passenger O₂ harness
• Right door ajar sensor
• Power wire for right door ajar servos

Left → Center Tunnel

• Flap position sensor harness
• Flap motor wires

Wing Connection Area (LEFT)

• Pitot heat power and ground (14 AWG)
• Heated pitot status wire
• Fuel level sensor left
• AoA air hose (green)
• Pitot air hose (blue)
• 2× shielded 3-wire bundles for left lights
• Green sync wire for left lights
• 5-wire trim bundle for left roll trim

Wing Connection Area (RIGHT)

• AP splice for red, black, yellow — 3-way (rear, connector, front)
• AP bundle extension from connector
• 2× shielded 3-wire bundles for right lights
• Green sync wire for right lights
• Right wing COM antenna coax from panel (inline connector)
• Right wing NAV antenna coax from panel (inline connector)

Gear Support Mount (LEFT) — Under-Seat Terminal Blocks

• EMS ground for trim servo sensors
• Pitch trim motor power and ground
• Roll trim motor power and ground
• Roll trim position sensor
• Pitch trim position sensor
• Trim bundle from left wing
• 5V (red/white) EMS power for trim servo sensors

Gear Support Mount (RIGHT) — Under-Seat Terminal Blocks

• Green sync wire for lights
• Wig-wag power
• Nav power
• Strobe power
• Taxi power
• Landing power
• Tail light bundle from rear
• 16 AWG ground wire for lights
• AP servo black, red, yellow spliced together
• 2× 3-wire light bundles + green sync crossing to left wing root
• 2× 3-wire light bundles + green sync from right wing root

Forward Center Tunnel

• 2× red power wires for fuel pumps
• Ground wire for fuel pumps (1 wire spliced to 2)

Control Sticks (LEFT and RIGHT)

• Main bundle from SteinAir panel harness
• COM flip sensor wire

Pilot Knee Side (LEFT)

• O₂ pilot wiring harness
• O₂ lines (blue and red)

Copilot Knee Side (RIGHT)

• O₂ copilot wiring harness
• O₂ lines (blue and red)

Left Firewall Penetration — Engine Sensors

• CHT wires × 6
• EGT wires × 6
• Fuel pressure ground and data
• Oil pressure ground and data
• Oil temp ground and data
• Spliced 5V wire (red/white) for fuel pressure, oil pressure, oil temp sensors

Right Firewall Penetration — EFII / Power

• 60A fuse → bus manager
• Ammeter shunt wires
• Spark plug wires for EFII
• Ignition coil wires (71 and 88)
• Pressure sensor wires
• All remaining EFII outputs

Terminal Blocks Under Seats

Two terminal blocks located under the front seats distribute wiring between the wing roots, center tunnel, and panel.

Left Terminal Block

Right Terminal Block

Wing Root Connectors (CPC)

CPC barrel connectors (series 1, 17–18 pin) at each wing root carry all wing wiring.

Right Wing Root Exit

Left Wing Root Exit

Autopilot Servo Wiring (Wing)

Wire color mapping between the wing harness and the Dynon roll/pitch servo connector.

Dynon EMS-220 Connector (37-Pin)

Complete pinout for the SV-EMS-220 engine monitoring module. Updated 2026-03-04.

Through Firewall

Across Panel

Down Left (Under Panel)

Shared Power

Unused Pins

Panel Mounting Fasteners

Screw/bolt specs for every panel-mounted component. Useful reference for panel removal and reinstallation.

Connector Inventory

Summary of all connector types used in N720AK wiring (all installed).

Inspection & Maintenance

EarthX Battery & Chargers

Chargers

Charger Behavior Notes

The OptiMate chargers enter sleep/maintenance mode once the battery is fully charged, checking voltage roughly once per hour. Important: If a continuous parasitic load is present (e.g. panel powered on for configuration), the charger may not detect the drain during its sleep intervals and the battery can discharge. This caused a drain-to-zero event during initial setup. The TM-275’s TUNE mode (continuous 13.6V power supply) avoids this problem. (Per EarthX Engineering, Dillon Hinners, 2026-01-13.)

Hartzell Alternator Maintenance

Per the AL 12-E160/V installation manual: battery terminal torque 50 in-lb, safety wire .032. Annual: check bearings. 5yr/1000hr: inspect brushes (replace if <0.250“ from holder case edge). 5A enable CB, 60A main breaker.

References

• VPX Sport Installation & Operating Manual (Rev G4)
• VPX Sport Installation & Operating Manual (Rev G3) — previous revision
• VPX Getting Started Guide (Rev A)
• EFII Bus Manager Installation Instructions
• EarthX ETX900 Installation & Maintenance Manual
• Hartzell AL 12-E160/V Alternator Installation Manual (P/N 99-9900)
• Power & Lighting Schematic
• VPX Pro/Sport Load Planning Worksheet

Flight Controls

ATA Chapter 27 — N720AK Systems Reference

Overview

N720AK has dual controls (pilot and co-pilot) with push-pull tube actuation for ailerons and elevator, cable actuation for rudder. The stick grips are Tosten CS Military with multiple programmable buttons. Electric trim is provided for pitch and roll axes.

Components

How It Works

Stick Grip Button Layout

Trim Systems

• Pitch Trim: Electric servo-actuated trim tab on elevator, controlled by hat switch on stick grip
• Roll Trim: Electric servo in wing, controlled by hat switch on stick grip
• Yaw Trim: None installed

Elevator Trim Tab Setting

N720AK’s elevator trim tabs were set using Bill DeRouchey’s method (via myrv10.com trimming tips) instead of the stock Van’s procedure. The stock instructions to set both trim tabs at 35° down creates an asymmetry problem where one tab fails to rise to trail position while the other overshoots, causing tail twisting forces.

The corrected method:

1. Move the trim servo to full nose-up position
2. Set the starboard (right) trim tab trailing edge to 3“ below the elevator trailing edge
3. Run the starboard trim tab to trail position
4. Set the port (left) trim tab to trail position

The key requirement is that both trim tabs reach the neutral/trailing position at the same time, and that neither tab goes up while the other goes down.

Co-Pilot Trim Enable

A panel switch enables or disables trim authority from the co-pilot stick grip. When disabled, the co-pilot’s trim hat has no effect. This prevents inadvertent trim inputs from passengers.

Flaps

Electric flap motor with position indicator on EFIS. Controlled by:

• Panel-mounted flap switch
• Stick grip switch (both sticks)

Flap positions range from reflex (-3°) to full (33°).

Flap operation:

• Flaps will not deploy above 90 KIAS (speed inhibit)
• One tap down: 0° → 16°
• Second tap down: 16° → 33° (full)
• One tap up: returns to 0° (full retract)
• Momentary click — no need to hold the switch

Inspection & Maintenance

Control Stick Slop Fix

The RV-10 control stick bases can develop play between the brass bushing and the welded cylinder of the stick base. On N720AK, the pilot side only had noticeable slop (co-pilot was fine). The fix was a single AN960-6 washer (sized for AN6 bolt) placed around the brass bushing so it sits against the welded cylinder. No delrin bushing replacement was needed — the original brass bushings were retained, and the single washer was sufficient to eliminate the play.

Quadrant Cable Boots

Replacement cable boots for the throttle/mixture/prop quadrant: see VAF thread on Q-43 boots.

Photos

References

• Ray Allen trim system installation instructions
• Tosten CS Military Wiring Diagram
• Tosten CS Military Stick Assembly Drawing (Rev A, P/N 3-12-02) — Drill 3/16 dia hole, use 10-32 socket head cap and lock nut.
• PH Aviation PHA-09P Flap Actuator Installation — 12 VDC, 4A full load, 150 lb capacity, 5“ stroke, 0.4 in/sec, internal limit switches, built-in potentiometer. Mount: AN5-23 bolt. Compatible with Garmin GAD 27 positioning.
• Aerosport Throttle Quadrant Installation
• Aerosport RV-10 Cable Lengths for Quad Arm Rest
• Tosten Military Style Grip (MS) product page
• Throttle/prop cables: California Push-Pull — PN 176-VTT-2.25-89.5 (throttle), PN 176-VTT-2.25-64.5 (prop)

Fuel System

ATA Chapter 28 — N720AK Systems Reference

System Overview

N720AK uses the EFII System32 electronic fuel injection system with a Borla 203133 inline MAP-referenced fuel pressure regulator (installed 2026-03-17, replacing the original Aeromotive Compact EFI regulator). This is a modern port EFI system — no venturi, no mechanical fuel injection servo. The fuel system is a pressurized loop: fuel flows from the tanks, through filters and pumps, around a fuel rail past six port injectors, through the regulator, and back to the selected tank via a return line.

The injector differential pressure setpoint is 45 PSI, displayed directly on the Dynon EMS in DIFF mode.

The entire fuel tune — injector pulse widths, fuel maps, mixture scheduling — depends on the regulator maintaining a constant pressure differential across the injectors. If this differential changes (due to regulator wear, filter clogging, pump degradation, or plumbing restrictions), the ECU’s fuel calculations become wrong and the tune must be re-evaluated. Every component in this system exists to ensure that differential stays rock-steady.

Physical Plumbing — Tank to Injector and Back

Flow Path (supply side)

LEFT TANK (30 gal)  ──┐                                    ┌── RIGHT TANK (30 gal)
                       │                                    │
              Safety-wired                         Safety-wired
              shutoff valve                        shutoff valve
                       │                                    │
              40μ pre-filter                        40μ pre-filter
              (TS Flight Lines)                    (TS Flight Lines)
                       │                                    │
                       └──── Under seats ────┬──── Under seats ────┘
                                             │
                                     Andair duplex valve
                                     (tank selection)
                                             │
                                ┌────────────┴────────────┐
                                │                         │
                          Walbro 391 pump           Walbro 391 pump
                          (primary)                 (backup)
                                │                         │
                                └────────────┬────────────┘
                                             │
                                    10μ Aeromotive post-filter
                                    (mounted with 8L clamp to
                                     engine mount diagonal)
                                             │
                                        FUEL RAIL
                                    ┌──┬──┬──┬──┬──┬──┐
                                    │  │  │  │  │  │  │
                                   Cyl injectors (×6)
                                    │
                              End of rail
                                    │
                            ┌───────┴───────┐
                            │               │
                     Fuel pressure    MAP reference line
                      regulator ◄──── (from throttle body
                     (Aeromotive)      orifice port)
                            │
                        RETURN LINE

Flow Path (return side)

                        RETURN LINE
                            │
                    Through firewall
                            │
                    Andair duplex valve
                    (routes return to
                     selected tank)
                            │
                  ┌─────────┴─────────┐
                  │                   │
             LEFT TANK           RIGHT TANK

Key Design Points

• Pressurized loop: The pumps pressurize fuel continuously. The regulator bypasses excess fuel back to the tank. The injectors pull from a fuel rail that’s always at pressure.
• Dual pumps: Primary and backup Walbro 391 pumps on a rack. Only one runs at a time. A bus manager switch selects 1/AUTO or 2. In 1/AUTO mode, the bus manager automatically cuts over from pump 1 to pump 2 if Borla output (absolute) drops to 22 PSI or below. The cutover is controlled by the bus manager and performed by a relay mounted under the panel. Note: the Dynon shows the injector differential (Borla output minus MAP), so the displayed value when cutover trips depends on current MAP — at 10 inHg MAP the Dynon would read ~12 PSI DIFF when the trip fires.
• Two-stage filtration: 40μ pre-filter before the pumps (protects pumps), 10μ post-filter after the pumps (protects injectors and regulator).
• MAP reference: The regulator’s vacuum reference comes from an orifice port on the throttle body that provides a stable, damped manifold pressure signal. This is a small restrictive fitting — not a wide-open port — to prevent fuel pressure from chasing rapid MAP transients.
• Return routing: The return line goes back through the firewall to the Andair duplex valve, which routes it to whichever tank is currently selected. This is a direct run — no additional valving on the return side.

Components

Fuel Tanks

Shutoff Valves

Pre-Filters (40 micron)

Andair Duplex Valve

• Spec sheet (GDrive)
• Data sheet (GDrive)

Fuel Pumps — Walbro 391

Pump replacement notes:

Viton crush washers for pump fittings: One Hydraulics SS9500-02V (primary source, where N720AK’s were purchased). Alternate source: Titan Fittings SS-9500V series.

Post-Filter (10 micron) — Aeromotive

Fuel Rail

• Configuration: Common rail feeding all 6 cylinders
• Injectors: 6 port fuel injectors, one per cylinder

Fuel Pressure Regulator — Borla 203133

Why Borla replaces the Aeromotive: The Aeromotive Compact EFI regulator (with 0.020“ bypass orifice drilled by ProTek Performance) exhibited significant injector differential droop under load with the Walbro 391 pumps — MAP slope of −0.295 PSI/inHg in ground runs. The Borla holds much better: ground run with the same pumps showed −0.089 PSI/inHg, a 3× improvement, and the Borla brings the airplane closer to the reference N88810 baseline (−0.014 PSI/inHg, essentially flat).

The Borla is set to 45 PSI injector differential as displayed on the Dynon (in DIFF mode, engine off). Fuel pressure should not budge meaningfully from 45 PSI through any flight regime — that is the new health criterion.

See The MAP-Referenced Regulator for full theory.

MAP Reference Line

The vacuum reference line connects from an orifice port on the throttle body to the regulator. The orifice provides a stable, damped manifold pressure signal — it’s a small restrictive fitting, not a wide-open port. This prevents the regulator from chasing rapid MAP transients during throttle changes.

The MAP reference orifice is integral to the EFII-supplied throttle body (stock configuration — no aftermarket modification needed).

Fuel Pressure Sensor — Dynon Kavlico

See Dynon Service Bulletin 120414 regarding blocked baro compensation ports on sensors manufactured July 2013 – June 2014.

Fuel Lines

How It Works: The MAP-Referenced Regulator

How It Maintains Constant Differential

The Borla regulator is a mechanical diaphragm device (the same theory applied to the prior Aeromotive — only the calibration and quality differ):

• One side of the diaphragm sees fuel pressure from the fuel rail
• Other side sees manifold pressure (via a vacuum reference line from the throttle body) plus a calibrated spring

The diaphragm balances these forces:

Fuel_absolute = MAP_absolute + Spring_force

When MAP rises (throttle opened), the diaphragm sees more pressure on the reference side, so it allows fuel pressure to rise by the same amount. When MAP drops (throttle closed), fuel pressure drops to match. This is called 1:1 tracking — every PSI change in MAP produces a matching PSI change in fuel pressure.

The result: The spring force sets the differential, and it stays constant:

$$ P_{\text{fuel}} - P_{\text{MAP}} = F_{\text{spring}} \approx 45 \text{ PSI (constant, post-Borla install)} $$

What Goes Wrong

The Critical Quantity: Injector Differential Pressure

The pressure drop across each fuel injector determines how much fuel flows during the injector’s open time:

True_differential = Fuel_absolute − MAP_absolute

For N720AK, this should be constant at 45 PSI regardless of throttle position, altitude, or flight phase. Post-Borla install (2026-03-17), the regulation is essentially flat — anything more than ~1 PSI of variation under load warrants investigation.

Why It Matters

The EFII ECU calculates injector pulse width assuming a known, constant pressure differential. If the differential changes:

• Higher differential → more fuel per pulse → richer mixture → wasted fuel, fouled plugs, potentially hydraulic lock
• Lower differential → less fuel per pulse → leaner mixture → hot cylinders, detonation risk, rough running

All fuel tuning depends on this value being stable. If the differential changes — due to regulator wear, filter clogging, pump degradation, or plumbing restrictions — the fuel maps become wrong and must be re-evaluated.

What Changes the Differential

Monitoring the Differential Over Time

Track these metrics at each annual or whenever the fuel system is serviced:

1. Startup fuel pressure (gauge, engine off, pump on) — this is the spring setpoint
2. Run the regulator_diagnostic.py script on a representative flight log
3. Compare against the baseline in the flight log history table below

If any of these metrics change significantly, investigate before flying further. A change in the differential means the fuel tune is no longer valid.

Sensor Reference Frames

This is the most important subtlety in interpreting fuel system data. The two sensors measure in different reference frames:

• MAP sensor measures absolute pressure (relative to vacuum). 29.92 inHg at sea level on a standard day.
• Fuel pressure sensor (Dynon Kavlico) measures gauge pressure (relative to local atmosphere). Reads 0 PSI with no fuel pressure at any altitude.

The Gauge-vs-Absolute Problem

When we naively compute Fuel_gauge − MAP_psi, we get:

Delta_gauge = Fuel_gauge − MAP_psi
            = (Fuel_absolute − Atmosphere) − MAP_absolute
            = (Fuel_absolute − MAP_absolute) − Atmosphere
            = True_differential − Atmosphere

This is not the true injector differential. It’s offset by atmospheric pressure (~14.7 PSI at sea level, ~10.5 PSI at 9,000 ft).

Altitude Effect

Atmospheric pressure decreases with altitude:

$$ P_{\text{atm}} = 14.696 \times \left(1 - 6.8756 \times 10^{-6} \times h\right)^{5.2559} \quad [h \text{ in feet}, P \text{ in PSI}] $$

As you climb, the gauge delta changes even if the regulator is perfect — because Atmosphere in the equation above is changing.

The Correction

To recover the true injector differential:

$$ \Delta_{\text{true}} = \Delta_{\text{gauge}} + P_{\text{atm}}(h) = P_{\text{fuel,gauge}} - P_{\text{MAP(psi)}} + P_{\text{atm}}(h) $$

Dynon Baro Compensation

Dynon’s Kavlico fuel pressure sensor has baro compensation — an atmospheric vent port that keeps the gauge reading accurate as altitude changes. This does NOT convert the reading to absolute; it just ensures the gauge reading is a faithful measurement of Fuel_absolute − Atmosphere at any altitude.

The baro compensation means the sensor is a good gauge sensor, but it doesn’t eliminate the need for the altitude correction when computing the true injector differential. The correction is required because of the reference frame mismatch between the gauge fuel pressure sensor and the absolute MAP sensor.

Caveat — Dynon Service Bulletin 120414: Some Kavlico sensors manufactured July 2013 – June 2014 had a blocked baro compensation port (environmental seal covering the vent). This causes the sensor reading to drift ~0.5 PSI per 1,000 ft of altitude change. Test by removing the silicone gasket from the connector and checking if altitude-dependent drift decreases. See: https://dynonavionics.com/bulletins/support_bulletin_120414.php

When to Apply Altitude Correction

How to Test Whether Your Sensor Needs Correction

Use the --alt-scan flag on the diagnostic script. It applies a range of correction fractions (0.0 to 1.0) to the altitude term and finds the fraction that minimizes residual sigma:

uv run --with numpy --with matplotlib python3 scripts/regulator_diagnostic.py /path/to/log.csv --alt-scan

• Fraction $\approx 1.0$ → Sensor is gauge, correction needed (e.g., Garmin Kavlico)
• Fraction $\approx 0.0$ → Sensor already behaves as absolute, no correction needed

For Garmin GDU 460 fuel pressure, we confirmed fraction = 1.0 (standard gauge sensor). For Dynon SkyView fuel pressure on N720AK, we found fraction $\approx 0.0$ — this is still under investigation. The regulator noise ($\sigma = 1.4$ PSI) may be swamping the altitude signal (~0.4 PSI/1,000 ft). Fix the regulator first, then re-test.

Diagnostics

Running the Script

cd ~/code/rv10

# Dynon SkyView log
uv run --with numpy --with matplotlib python3 scripts/regulator_diagnostic.py /path/to/dynon_log.csv

# Garmin log (needs altitude correction)
uv run --with numpy --with matplotlib python3 scripts/regulator_diagnostic.py /path/to/garmin_log.csv --alt-correct

# Multiple flights
uv run --with numpy --with matplotlib python3 scripts/regulator_diagnostic.py flight1.csv flight2.csv

# Altitude correction scan
uv run --with numpy --with matplotlib python3 scripts/regulator_diagnostic.py /path/to/log.csv --alt-scan

# Skip plot (console output only)
uv run --with numpy --with matplotlib python3 scripts/regulator_diagnostic.py /path/to/log.csv --no-plot

Step 1: Load and Filter Data

The script auto-detects Dynon vs Garmin format. It extracts:

• Session time, MAP (inHg), fuel pressure (PSI gauge), fuel flow (gal/hr), pressure altitude (ft)
• Engine-on filter: MAP > 15 inHg, fuel pressure > 5 PSI, session time > 5 minutes
• Steady-state filter: |dMAP/dt| < 0.05 inHg/sec (throttle not moving)

Step 2: Compute Delta

$$ P_{\text{MAP(psi)}} = P_{\text{MAP(inHg)}} \times 0.49115 $$

$$ \Delta_{\text{gauge}} = P_{\text{fuel}} - P_{\text{MAP(psi)}} $$

Apply altitude correction if using --alt-correct.

Step 3: Key Metrics

Step 4: Bin Analysis

The script divides steady-state data into MAP bins (15–19, 19–22, 22–26 inHg) and computes $\sigma$ within each bin. High within-bin scatter indicates sticking/hunting independent of the MAP slope.

Step 5: Diagnostic Plot

The 4-panel plot shows:

1. Delta vs MAP — reveals MAP slope and scatter pattern
2. Delta vs Fuel Flow — reveals flow-dependent droop
3. Delta vs Time (colored by |dMAP/dt|) — reveals sticking events and altitude correlation
4. Delta histogram — reveals distribution shape (unimodal = good, bimodal = sticking)

Flight Log Analysis History

Reference Baseline: N88810 (Healthy Regulator)

Same Aeromotive regulator, EFII System32, Garmin GDU 460 (gauge fuel pressure sensor). Flight: X05 → KGAD, 2026-02-09. Altitude range: sea level to 6,161 ft.

After altitude correction (confirmed fraction = 1.0 for Garmin sensor):

• True differential: $35.03 \pm 0.08$ PSI — essentially perfect
• MAP slope: $-0.011$ PSI/inHg — essentially zero
• Fuel flow slope: $+0.046$ PSI/(gal/hr) — flat
• Residual $\sigma$: 0.07 PSI

This proves the Aeromotive regulator CAN perform essentially perfectly with the EFII System32.

N720AK Flight History

Key findings:

• MAP slope is consistent at $-0.30$ PSI/inHg across all flights — this is a structural characteristic of the regulator, not flight-dependent
• Sticking/hunting varies dramatically (residual $\sigma$: 0.18 to 1.25) — worse on longer flights with more throttle changes, possibly temperature-dependent
• Startup fuel pressure varies (32.0 to 35.8) — may indicate the regulator settles at different stick points on startup

Diagnosis: N720AK Regulator

Problem 1: MAP Under-Tracking (Slope = −0.30 PSI/inHg)

The regulator does not follow MAP changes on a 1:1 basis. For every 1 inHg increase in MAP, the injector differential drops by 0.30 PSI. Over the 10 inHg operating range, that’s ~3 PSI of sag — about 9% of the 33 PSI setpoint.

Likely causes:

• Vacuum reference line partially restricted or leaking
• Diaphragm stiffness or age
• Spring rate mismatch

Effect: At high power, injectors see less differential than intended → leaner than the ECU expects. At idle, richer than expected. The ECU’s fuel map is calibrated assuming constant differential — this slope means the actual air-fuel ratio shifts with power setting.

Problem 2: Mechanical Sticking / Hunting (Variable, up to σ = 1.25 PSI)

Random, non-repeatable variation in the differential, worst at mid and high power settings, worse on longer flights.

Likely causes:

• Diaphragm friction or contamination
• Valve seat wear or debris
• Spring fatigue causing hysteresis

Effect: Random variation in fuel delivery per injector pulse → uneven cylinder mixture, potentially rough running.

Recommendations

1. Inspect vacuum reference line — check for kinks, cracks, loose fittings, contamination
2. Replace or rebuild the regulator — the sticking won’t be fixed by a vacuum line repair
3. After replacement, re-fly and re-analyze — target σ < 0.2 PSI and MAP slope near zero
4. After regulator fix, re-test the baro port question — with low regulator noise, the altitude signal will be detectable

Open Questions

• Dynon baro compensation behavior: Our analysis showed the altitude correction fraction = 0.0 for N720AK, suggesting the Dynon is removing altitude effects internally. But the physics says a baro-compensated gauge sensor should still need the correction. The regulator noise (σ = 1.4 PSI) likely swamps the altitude signal (~0.4 PSI/1,000 ft). Fix the regulator first, re-test with clean data.
• Startup fuel pressure variation: 32.0 to 35.8 PSI across flights. Is this temperature-dependent? Different regulator stick points? Pump output variation?
• Baro port status: Cannot conclusively test from current flight data. Fix regulator first.
• Dynon differential display: Dynon offers a built-in Fuel_gauge − MAP differential display, but this shows True_differential − Atmosphere, not the true injector differential. It shifts with altitude. Not sufficient for regulator health monitoring without manual altitude correction.

References

• EFII System32 Installation Manual (Rev 9-13)
• EFII System32 Installation Manual (Rev 6-19)
• EFII System32 Operating Procedures (12-20)
• EFII System32 Fuel Flow & RPM Config (Rev 10-19)
• EFII System32 Initial Tuning — CSP (Rev 6-20)
• EFII System32 Upgrade Installation Manual
• Regulator Diagnostic Script — auto-detects Dynon/Garmin CSV, computes diagnostic metrics, generates 4-panel plot
• Regulator Diagnostic Plan — workflow for analyzing regulator health
• Andair FS2020-D2 Duplex Valve Spec Sheet
• Andair FS20 Fuel Selector Data Sheet
• Aeromotive 13129 EFI Bypass Regulator Manual
• Dynon Service Bulletin 120414 — blocked baro compensation ports on Kavlico sensors
• JDAir Fuel Drain & Vent Fairings Combo — silver drain fairing, blue vent fairing
• Flight log data: maintenance/fuel-system/flight-logs/

TODO: Information Needed

Component Data Sheets and Part Numbers

• Aeromotive regulator — Aeromotive Compact EFI Regulator with 0.020“ bypass orifice (ProTek Performance / Robert Paisley)
• Walbro 391 pumps — pump curves filed: GDrive, also images/walbro-gsl391-pump-curves.png
• ProTek Performance pump rack — dual electric fuel pump, supplied by EFII
• Aeromotive post-filter — Aeromotive 12347, 10-micron, serviceable
• TS Flight Lines pre-filter — private label, no part number available; 40 micron, serviceable
• Andair duplex valve — FS20-20-D2-6M, with 5x EF20 elbow fittings
• EFII fuel injectors — part number, flow rating
• Fuel rail — manufacturer, part number
• Kavlico fuel pressure sensor — exact Dynon part number, data sheet
• Shutoff valves — Peterson Fluid Systems 09-0910, -6 AN panel mount ball valve

Fuel Lines

• Supplier name and contact info
• Line type (AN size, material — stainless braided PTFE?)
• Lengths for each run (tank to valve, valve to filter, filter to duplex, duplex to pump rack, pump to post-filter, post-filter to rail, regulator return through firewall, firewall to duplex return, duplex to tank return)
• AN fitting sizes at each connection
• Any adapters or reducers in the system
• Torque specs for AN fittings
• Photos of routing under seats and through firewall

Pump Replacement

• Viton crush washers — Titan Fittings SS-9500V
• Step-by-step replacement procedure
• What does it take? Time, tools, access?
• Photos of pump internals (healthy pump)
• How to tell when pumps need replacement

Filter Servicing

• Pre-filter cleaning procedure (solvent? compressed air?)
• Post-filter cleaning procedure
• Photos of clean filter element vs contaminated
• What does contamination look like? What does it mean?
• Replacement schedule or inspection criteria

Photos Needed

• Overall fuel system routing (overview)
• Pre-filter location and mounting
• Post-filter mounted on engine mount diagonal
• Pump rack
• Fuel rail and injectors
• Regulator and MAP reference line connection
• Throttle body orifice fitting
• Andair duplex valve
• Firewall passthrough
• Clean vs dirty filter elements

System Questions

• Fuel type — 100LL or premium unleaded 91 octane mogas minimum
• Total usable fuel per tank — 29.5 gallons per tank
• Pump selection — bus manager switch (1/AUTO or 2), auto cutover at 22 PSI Borla output absolute via relay under panel
• MAP reference orifice — integral to EFII throttle body, stock configuration
• Fuel pressure sensor tap location on the rail

Doors & Airframe

ATA Chapter 52/53 — N720AK Systems Reference

Overview

N720AK has two forward-opening gull-wing doors (pilot and co-pilot) and a rear baggage door. The doors use aftermarket latches and hardware from Planearound, with Aerosport low-profile exterior handles. The windshield and windows are Cee Bailey replacements.

Doors

Components

Door Operation

Windshield & Windows

• Material: Aircraft-grade acrylic (ASTM 4082), 0.250“ thickness for side glass
• Tint: Available in light gray, light green, or clear (all FAA-approved for night flight)
• Status: Cee Bailey’s was acquired by LP Aero Plastics in June 2025. Replacement parts available from LP Aero (sales@lpaero.com, 724-744-4448).
• VAF thread: Cee Bailey’s RV-10 Products

Interior

Aerosport Products

N720AK uses a comprehensive set of Aerosport Products interior components:

Interior Paint

Sherwin Williams Jetflex.

Seats & Restraints