Sunday, August 30, 2020

Loss of Engine Power (Total): Piper PA-18-135, N1124; accident occurred August 30, 2019 in Fairbanks, Alaska

Forward facing view of accident airplane at accident site.

Rear facing view of accident airplane at accident site.

Accident airplane’s engine and separated number 3 cylinder at accident site.

Remnants of black paint visible in one of the bottom number 3 cylinder stud holes.

Black paint visible in a cylinder stud hole on the number 3 cylinder.

Number 3 cylinder bottom two cylinder studs with fretting visible on engine’s case.

Back side of number 3 cylinder flange.

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

Additional Participating Entity:

Federal Aviation Administration / Flight Standards District Office; Fairbanks, Alaska

Aviation Accident Factual Report - National Transportation Safety Board:

Investigation Docket - National Transportation Safety Board:

Location: Fairbanks, AK
Accident Number: ANC19LA048
Date & Time: 08/30/2019, 1310 AKD
Registration: N1124
Aircraft: Piper PA-18
Aircraft Damage: Substantial
Defining Event: Loss of engine power (total)
Injuries: 1 None
Flight Conducted Under: Part 91: General Aviation - Personal

On August 30, 2019, at about 1310 Alaska daylight time, a float-equipped Piper PA-18 airplane, N1124, sustained substantial damage during a forced landing following a total loss of engine power while in cruise flight near Fairbanks, Alaska. The commercial pilot was not injured. The airplane was privately owned and operated by the pilot, under the provisions of Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed and a flight plan had been filed. The flight departed Chena Marina Airport (AK28), Fairbanks, Alaska.

According to the pilot, she had been airborne for about 2 1/2 hrs when the engine began to sound "funny", and she decided to return to AK28. About 16 minutes later and 13 miles west of AK28 the engine lost all power, and she conducted an emergency landing to a heavily forested area. The airplane sustained substantial damage to the wings. An initial examination of the engine revealed that the No. 3 cylinder had separated from the engine's case.

The airplane was equipped with a narrow deck Lycoming O-320-A1H engine. A detailed engine examination revealed that the bottom two cylinder hold down studs for the No. 3 cylinder were intact, and the stud's threads were in relatively good condition. The remaining cylinder hold down studs were fractured, with fretting present on the engine's case. In addition, black paint was chipped and broken around the cylinder's hold down nuts, and paint was present inside the cylinder hold down stud holes located on the cylinder's flange. Paint was not present on the backside of the cylinder's flange.

Maintenance records revealed that the airplane engine's cylinders had been replaced on July 24, 2003, about 815.7 hours before the accident with overhauled cylinder assemblies. The most recent annual inspection of the airframe and engine was completed on September 11, 2018.

Lycoming's Overhaul Manual – Lycoming Direct Drive Aircraft Engines, Section 3, General Overhaul Procedures stated in part:


All machined bosses should be masked before painting. Do not paint areas under hold down nuts where torque is required.

The closest weather reporting facility is Fairbanks International Airport, (PAFA), Fairbanks, Alaska. At 1353, a METAR from PAFA was reporting in part: wind, 020 at 4 knots; visibility, 10 statute miles; sky condition, few clouds 6,000 ft, few clouds 10,000 ft; temperature, 63° F; dew point 43° F; and an altimeter setting of 30.04 inches of mercury.

In the recommendation section of the National Transportation Safety Board Accident/Incident Reporting Form 6120.1, the pilot stated that when she made the decision to return to AK28 no suitable landing areas were close by; however, if she would have proceeded directly to a suitable lake for landing rather than attempting to return to her departure airport, the accident may have been avoided.

Pilot Information

Certificate: Commercial
Age: 65, Female
Airplane Rating(s): Single-engine Land; Single-engine Sea
Seat Occupied: Front
Other Aircraft Rating(s): None
Restraint Used:
Instrument Rating(s): Airplane
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: Class 2 With Waivers/Limitations
Last FAA Medical Exam: 01/28/2019
Occupational Pilot:No
Last Flight Review or Equivalent: 10/06/2018
Flight Time: 4858 hours (Total, all aircraft), 586 hours (Total, this make and model), 4717 hours (Pilot In Command, all aircraft), 73 hours (Last 90 days, all aircraft), 58 hours (Last 30 days, all aircraft), 3 hours (Last 24 hours, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Make: Piper
Registration: N1124
Model/Series: PA-18
Aircraft Category: Airplane
Year of Manufacture: 1955
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 18-3985
Landing Gear Type: Tailwheel
Seats: 2
Date/Type of Last Inspection: 09/11/2018, Annual
Certified Max Gross Wt.: 1760 lbs
Time Since Last Inspection:
Engines: Reciprocating
Airframe Total Time: 3984.4 Hours at time of accident
Engine Manufacturer: Lycoming
ELT: C91A installed, activated, did not aid in locating accident
Engine Model/Series: O-320 A1H
Registered Owner: On file
Rated Power:150 hp
Operator:On file
Operating Certificate(s) Held: None

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: PAFA
Distance from Accident Site:
Observation Time: 2153 UTC
Direction from Accident Site:
Lowest Cloud Condition: Few / 6000 ft agl
Visibility: 10 Miles
Lowest Ceiling:
Visibility (RVR):
Wind Speed/Gusts: 4 knots /
Turbulence Type Forecast/Actual:
Wind Direction: 20°
Turbulence Severity Forecast/Actual:
Altimeter Setting: 30.04 inches Hg
Temperature/Dew Point: 17°C / 6°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point:Fairbanks, AK
Type of Flight Plan Filed: VFR
Destination: Fairbanks, AK
Type of Clearance:None
Departure Time: AKD
Type of Airspace: Class G

Wreckage and Impact Information

Crew Injuries: 1 None
Aircraft Damage: Substantial
Passenger Injuries:N/A
Aircraft Fire: None
Ground Injuries:N/A
Aircraft Explosion: None
Total Injuries: 1 None
Latitude, Longitude: 64.892500, -148.368889

1 comment:

  1. She's lucky very make it out alive in Alaska having to put down in a heavily wooded tall conifer forest.