- Date
- July 12, 2023, 16:20 local (Jul 13, 2023, 00:20 UTC)
- Place
- Ninilchik, AK · Highway
- Injuries
- 2 uninjured
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N83391Aeronca 7DC
- Defining event
- Enroute: Loss of engine power (total)
- Weather
- Visual (VMC) · Day
- Status
- Completed
- Report
- Approved by Office Director
- Investigation class
- Class 3
- NTSB office
- Alaska Regional Office
- Parties
- FAA
- FAA report
- 20230712014669A
- Case key
- 192670
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
A total loss of engine power due to a shift of a crankshaft main bearing, which resulted in a lack of lubrication and subsequent overheating and failure of the engine crankshaft.
Findings · 2
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.
Analysis
While en route during a scenic flight, the pilot noticed the engine was not making enough power for the set power setting and the oil pressure and oil temperature gauges both indicated zero. He started a climb to clear rising terrain when the engine started to vibrate violently and then the engine lost all power. The pilot made a forced landing on to a road and, after touching down, veered to avoid traffic. The airplane impacted a guardrail and nosed over, sustaining substantial damage to the fuselage and wings. A postaccident examination of the engine revealed that the crankshaft’s No. 1 main bearing had spun, smearing metal into the crankcase and blocking the oil port. Numerous fragments of bearing material were found inside the engine. Based on the available information, it is likely that the shift of the No. 1 main bearing resulted in a lack of lubrication and subsequent failure of the engine. The reason for the bearing shift was not determined; the owner was not able to provide maintenance records for the engine.
Factual narrative
On July 12, 2023, about 1620 Alaska daylight time, a Aeronca 7DC airplane, N83391 sustained substantial damage when it was involved in an accident near Ninilchik, Alaska. The pilot and passenger were not injured. The airplane was operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. Pilot reported that he and a friend were on a scenic flight from the Homer Airport (HOM), Homer, Alaska, to the Soldotna Airport (SXQ), Soldotna, Alaska. En route he noticed the engine was not making enough power for the set power setting. At full throttle the engine was only producing about 2,400 rpm. He ran through checklist memory items for loss of engine power, which included applying carburetor heat; however, there was no change in the engine power. The pilot also opened both wing tanks to increase fuel in the header tank, which also resulted in no change. He then noticed the oil pressure gauge and oil temperature gauge both indicated zero. The pilot initiated a climb to clear rising terrain when the engine started to vibrate violently and then lost all power. He initiated a forced landing on to a road and, after touching down, he veered left to avoid cars. The airplane impacted a guardrail and then nosed over. The airplane sustained substantial damage to the fuselage and wings. A postaccident examination of the engine revealed that the crankshaft’s No. 1 main bearing had spun, smearing metal into the crankcase and blocking the oil port. Numerous fragments of bearing material were found inside the case. The owner was not able to provide maintenance records for the engine.
Aircraft
- Registration
- N83391
- Reported as
- Aeronca 7DC
- Category
- Airplane
- Serial number
- 7AC2058
- Built
- 1946
- Airframe hours
- 4,542.6
- Engine
- Continental C-85-12, 96 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · March 3, 2023 · 55 hours before
- Departed
- PAHO · Homer, AK
- Destination
- PASX · Soldotna, AK
- Airport
- PASX · Soldotna
- Equipment
- Electronic flight bag or handheld device
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 26
- Injuries
- None
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Medical
- Class 1, With waivers/limitations
- Seat
- Front
- Restraint
- 3-point
- Flight hours
- 79.9 total · 17.9 in this make and model · 23.5 as pilot in command · 50.7 in the last 90 days · 21.9 in the last 30 days · 0 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 250° at 9 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- 5,000 ft broken
- Temperature
- 57 °F, dew point 54 °F
- Altimeter
- 30.16 inHg
- Observed at
- PAHO
Docket · 4
The files NTSB released with the investigation on May 16, 2024, on NTSB’s docket system: statements, records, photos and specialists’ reports. 6.8 MB in all.
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.
Other investigations on N83391 · 1
Matched to the same aircraft by N-number and date.