Sunday, July 11, 2021

Flight Control System Malfunction/Failure: Fisher Flying Products - Super Koala, N220FF; accident occurred July 06, 2019 at Mercer County Regional Airport (KHZE), Hazen, North Dakota

Aviation Accident Final Report - National Transportation Safety Board

The National Transportation Safety Board did not travel to the scene of this accident.

Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Fargo, North Dakota

Investigation Docket - National Transportation Safety Board:

Location: Hazen, North Dakota 
Accident Number: CEN19LA219
Date & Time: July 6, 2019, 10:45 Local
Registration: N220FF
Aircraft Damage: Substantial
Defining Event: Flight control sys malf/fail
Injuries: 1 None
Flight Conducted Under: Part 91: General aviation - Flight test


The airplane owner and a mechanic had reassembled the airplane's wings and re-rigged the flight controls; the pilot had subsequently been having trouble with aileron control during test flights. The accident flight was the fourth test flight of the day to diagnose and fix the issue. During takeoff, the airplane "quickly" became airborne and began to roll to the left about 15 ft above the ground. The pilot applied full right aileron; however, the airplane continued to roll left and descend, and the airplane impacted the ground in a left-wing-low attitude, resulting in substantial damage to the left wing spar, bottom fuselage, cowling, engine, landing gear, and firewall.

Postaccident examination of the airplane revealed improper rigging of the ailerons. The improper rigging and improper aileron cable tensions most likely resulted in a loss of aileron control during takeoff.

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The airplane owner's and mechanic's improper rigging and cable tension of the aileron control system, which resulted in a loss of control during takeoff.


Aircraft Aileron control system - Incorrect service/maintenance
Aircraft Lateral/bank control - Attain/maintain not possible
Personnel issues Repair - Maintenance personnel
Personnel issues Repair - Owner/builder

Factual Information

On July 6, 2019, at 1045 central daylight time, an experimental amateur-built Freeman Super Koala, N220FF, experienced a hard landing during a return to Mercer County Regional Airport (HZE), Hazen, North Dakota, following a loss of aileron control. The commercial pilot was uninjured and the airplane was substantially damaged. The airplane was registered to and operated by the airplane owner under Title 14 Code of Federal Regulations Part 91 as a maintenance test flight that was not operating on a flight plan. Day visual meteorological conditions prevailed at the time of the accident. The local flight originated from HZE.

The pilot reported that the airplane had undergone reassembly of its wings and flight control rigging prior to the flight. On the day of the accident, he performed the fourth test flight of the airplane. He reported the airplane was having issues with the ailerons being fully functional once in flight. The pilot and the airplane owner were attempting to diagnose and fix the issue. The pilot preflighted the airplane, taxied out, performed a run-up, and confirmed the controls were free and correct. During the takeoff form runway 14, the airplane "quickly" became airborne and about 15 ft above the ground began to roll to the left. After applying full right aileron, the airplane continued to roll left and descend, which led to a left wing-low impact with the ground roughly 10-20 ft from the runway. The airplane's left wing spar, bottom fuselage, cowling, engine, landing gear, and firewall were substantially damaged.

The Federal Aviation Administration (FAA) inspector from the Fargo, North Dakota, Flight Standards District Office reported the airplane was purchased by the current owner from an estate. The airplane was disassembled and transported via trailer to Hazen, North Dakota. The airplane owner along with a FAA certificated mechanic assembled the airplane and they told the inspector they had issues with the aileron cable tensions. The airplane owner reported that he called the kit manufacturer but was unable to get the information he needed. After several attempts to properly adjust the aileron cable tensions, they determined that test flights would be needed. Post-accident inspection of the airplane revealed improper rigging of the ailerons and improper cable tensions. Inspection of the airplane maintenance logbook revealed the airplane was not properly signed off for return to service after maintenance.

History of Flight

Prior to flight Aircraft maintenance event
Takeoff Flight control sys malf/fail (Defining event)
Uncontrolled descent Collision with terr/obj (non-CFIT)

Pilot Information

Certificate: Commercial; Flight instructor 
Age: 30, Male
Airplane Rating(s): Single-engine land; Multi-engine land
Seat Occupied: Unknown
Other Aircraft Rating(s): None 
Restraint Used: 4-point
Instrument Rating(s): Airplane 
Second Pilot Present: No
Instructor Rating(s): Airplane single-engine; Instrument airplane
Toxicology Performed: No
Medical Certification: Class 2
Last FAA Medical Exam:
Occupational Pilot: Yes
Last Flight Review or Equivalent:
Flight Time:

Aircraft and Owner/Operator Information

Registration: N220FF
Model/Series: Super Koala 
Aircraft Category: Airplane
Year of Manufacture: 2008 
Amateur Built: Yes
Airworthiness Certificate: Experimental (Special)
Serial Number: 020
Landing Gear Type: 
Tricycle Seats: 2
Date/Type of Last Inspection: Condition
Certified Max Gross Wt.: 830 lbs
Time Since Last Inspection: 
Engines: 1 Reciprocating
Airframe Total Time: 
Engine Manufacturer: Rotax
Engine Model/Series: 503DCSI
Registered Owner: 
Rated Power: 50 Horsepower
Operating Certificate(s) Held: None

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual (VMC)
Condition of Light: Day
Observation Facility, Elevation: BIS,1661 ft msl 
Distance from Accident Site: 46 Nautical Miles
Observation Time: 10:52 Local
Direction from Accident Site: 145°
Lowest Cloud Condition: Few / 4300 ft AGL
Visibility 10 miles
Lowest Ceiling: None 
Visibility (RVR):
Wind Speed/Gusts: 8 knots / 
Turbulence Type Forecast/Actual: None / None
Wind Direction: 140°
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting: 30.29 inches Hg
Temperature/Dew Point: 22°C / 14°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Hazen, ND (HZE)
Type of Flight Plan Filed: None
Destination: Hazen, ND (HZE)
Type of Clearance: None
Departure Time: 
Type of Airspace:

Airport Information

Airport: Mercer County Regional Airport HZE
Runway Surface Type: Asphalt
Airport Elevation: 1814 ft msl
Runway Surface Condition:
Runway Used: 14 
IFR Approach: None
Runway Length/Width: 4999 ft / 75 ft
VFR Approach/Landing: Full stop

Wreckage and Impact Information

Crew Injuries: 1 None
Aircraft Damage: Substantial
Passenger Injuries:
Aircraft Fire: None
Ground Injuries: N/A 
Aircraft Explosion: None
Total Injuries: 1 None 
Latitude, Longitude:  47.29,-101.580833(est)

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