Friday, December 31, 2021

Loss of Engine Power (Partial): Van's RV-10, N878TD; accident occurred June 16, 2021 near Hicks Airfield (T67), Fort Worth, Tarrant County, Texas

Aviation Accident Factual Report - National Transportation Safety Board

Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Dallas, Texas

Investigation Docket - National Transportation Safety Board:
Location: Fort Worth, Texas
Accident Number: CEN21LA273
Date and Time: June 16, 2021, 07:30 Local
Registration: N878TD
Aircraft Damage: Substantial
Defining Event: Loss of engine power (partial) 
Injuries: 1 None
Flight Conducted Under: Part 91: General aviation - Personal

Factual Information

On June 16, 2021, about 0730 central daylight time, an experimental, amateur-built RV-10 airplane, N878TD, was substantially damaged when it was involved in an accident near Fort Worth, Texas. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot departed Hicks Airfield (T67), Fort Worth, Texas, about 0700 and headed northwest before returning to T67. The pilot reported that, during the initial climb following a touch-and-go landing, the engine backfired and lost power about 200 ft above ground level (agl). As the airplane descended, it collided with a power line before impact with terrain and a tree. The pilot added that the engine continued to run before the impact but did not develop enough power to maintain altitude. The airplane sustained damage to the landing gear, engine, and substantial damage to the fuselage during the accident.

Examination of the airplane revealed that the engine was equipped with an electronic ignition system, (labeled as #1 and #2) and automotive-style sparkplugs. The sparkplugs and valve covers were removed from each cylinder and the engine rotated by hand. Continuity through the valve train to the accessory section was noted. The bottom set of sparkplugs appeared wet and black in color. 

The ignition system was field tested by passing a magnet over the flywheel ignition sensor; spark was only observed on one bank of the ignition system. The ignition leads and coil labels did not necessarily correspond to the associated cylinder. The ignition firing order was not confirmed.

The ignition control boxes were located behind the firewall, and the fuselage was cut open to allow access to the boxes. The output cable on ignition box #1 was found disconnected.

The pin connectors were fully secured. Additionally, as mounted, access to the boxes were limited and could only be done from under the instrument panel and by reaching above the rudder pedals.

Pilot Information

Certificate: Private 
Age: 67
Airplane Rating(s): Single-engine land 
Seat Occupied: Left
Other Aircraft Rating(s): None
Restraint Used:
Instrument Rating(s): None
Second Pilot Present:
Instructor Rating(s): None 
Toxicology Performed:
Medical Certification: Class 3 With waivers/limitations 
Last FAA Medical Exam: January 13, 2021
Occupational Pilot: No 
Last Flight Review or Equivalent: September 15, 2020
Flight Time: 465 hours (Total, all aircraft), 23 hours (Total, this make and model), 454 hours (Pilot In Command, all aircraft), 9 hours (Last 30 days, all aircraft), 1 hours (Last 24 hours, all aircraft)

Aircraft and Owner/Operator Information

Registration: N878TD
Model/Series: RV10 
Aircraft Category: Airplane
Year of Manufacture: 
Amateur Built: Yes
Airworthiness Certificate: Experimental (Special) 
Serial Number: 40669
Landing Gear Type: Tricycle
Seats: 4
Date/Type of Last Inspection: January 12, 2021 Condition 
Certified Max Gross Wt.:
Time Since Last Inspection: 
Engines: 1 Reciprocating
Airframe Total Time: 23 Hrs at time of accident
Engine Manufacturer: Lycoming
ELT: C126 installed, not activated 
Engine Model/Series: O-540-A1D5
Registered Owner: 
Rated Power:
Operator: On file
Operating Certificate(s) Held: None

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual (VMC) 
Condition of Light: Day
Observation Facility, Elevation: KAFW
Distance from Accident Site: 5 Nautical Miles
Observation Time: 07:53 Local 
Direction from Accident Site: 30°
Lowest Cloud Condition: Few / 25000 ft AGL 
Visibility: 10 miles
Lowest Ceiling: 
Visibility (RVR):
Wind Speed/Gusts: / 
Turbulence Type Forecast/Actual:  /
Wind Direction: 
Turbulence Severity Forecast/Actual:  /
Altimeter Setting: 30.05 inches Hg
Temperature/Dew Point: 25°C / 21°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Fort Worth, TX
Type of Flight Plan Filed: None
Destination: Fort Worth, TX 
Type of Clearance: None
Departure Time:
Type of Airspace:

Airport Information

Airport: Hicks Airfield T67 
Runway Surface Type: Asphalt
Airport Elevation: 855 ft msl
Runway Surface Condition: Dry
Runway Used: 14
IFR Approach: None
Runway Length/Width: 3760 ft / 60 ft
VFR Approach/Landing: Forced landing; Touch and go

Wreckage and Impact Information

Crew Injuries: 1 None
Aircraft Damage: Substantial
Passenger Injuries:
Aircraft Fire: None
Ground Injuries: 
Aircraft Explosion: None
Total Injuries: 1 None
Latitude, Longitude: 32.93023,-97.411447 (est)


  1. Auto spark plugs? Crazy ignition system? Shoddy maintenance. $$$ aircraft. Go figure.

    1. Of course auto spark plugs, they're standard for electronic ignition systems.

  2. The Sub-D connectors on the LSE Plasma ignition modules are •input• power and •input• signal from the crank position sensors; the outputs are the RG-400 coax cables going from the LSE box to the ignition coils. No difference in outcome, but wanted to ensure the minor error was corrected. These are VERY reliable if installed correctly and maintained.

  3. those that do no have any real knowledge should refrain from commenting. the light speed ignition system has been installed on thousands of experimental aircraft for well over 20 years. its very well engineered and a know product. it has used auto plugs since it was designed. shoddy maintenance? i would say a costly over sight not tightening the sub d hold down screws. nothing more.

    1. Some real knowledge about that disconnected DB-15 connection:

      It is true that the disconnected DB-15 connection (labeled "output" on the boxes in the docket photo and described in the instruction book) is separate from the DB-15 input connector and from the BNC-connected output cables that go from the LSE box to the ignition coils.

      What's interesting about the disconnected DB-15 output connector is it's usage. Photos in the docket show that plug having a single cable recognizable as twisted pair, consistent with the Interconnect Feature used when two boxes are installed.

      The instruction manual describes the “Interconnect” feature:
      "If used, this interconnection advances the timing of the operating system when one of the systems is turned off or is otherwise disabled. The interconnection has no effect on either ignition when both systems are on."

      For the disconnected interconnect between box 1 & 2:
      1. There would be no effect if both boxes were on & functioning.
      2. Without the interconnect, when one of the boxes quit functioning, the other would not advance the timing, but would mimic performance of installations experiencing magneto failure while having one original magneto retained and one electronic ignition box installed.

      Other pins available on the DB-15 output port include a P-lead pin to retain a mag switch function, a timing control and some display functions, but nothing that would disable the box when disconnected.

      The aircraft would have been able to operate indefinitely with that DB-15 output connector disconnected and likely had been doing so.

      Saying not tightening the sub d hold down screws was a costly over sight is inconsistent with with the knowledge available from the manufacturer's instruction. There was more to the power loss than the inconsequential disconnected interconnect between the two boxes.

  4. Corrosion inside valve covers?

    Rust in oil breather?

    This accident found its place to happen.