Piper PA-28-161 accident near Skwentna, Alaska, September 1, 1996
On September 1, 1996 at about 11:05 pm local time, a Piper PA-28-161, registered N4366Y, was substantially damaged in an accident near Skwentna, Alaska. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). 1 person had minor injuries; 2 others were unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
corrosion and subsequent fatigue failure of the crankshaft, which resulted in engine failure and a forced landing. Factors related to the accident were: the lack of suitable terrain for a forced landing, and the operator's non-compliance with a service bulletin.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 1, 1996 · about 11:05 pm local time
- Place
- Skwentna, Alaska · map
- Type
- Accident
- Injuries
- 1 person had minor injuries; 2 others were unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-28-161 · all PA-28-161s on the register
- Registration
- N4366Y · no longer on the register · serial 28-8416053
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
The pilot & 2 passengers departed on a local area sightseeing flight. While in cruise flight at about 4,000 ft, the engine developed a vibration, then lost power. Oil spray was deposited on the windshield. The pilot performed an emergency landing on a sand bar. After landing, he noticed that the entire propeller, propeller flange, & the outboard end of the engine crankshaft were missing from the engine. Examination of the engine revealed evidence of fatigue cracking, emanating from a corrosion pit on the inner diameter surface of the crankshaft bore. Numerous other corrosion pits were found adjacent to the fracture origin. The engine manufacturer reported the engine was built & shipped from the factory on 4/13/81. The engine was the subject of a mandatory service bulletin (S/B), dated 1018/94, that addressed the inspection of the inside bore of the crankshaft for the presence of corrosion. The S/B required that an initial inspection be conducted within the next 200 hrs of operation or 1 year from the date of the S/B. The operator's company manual stated the Director of Maintenance shall ensure that current manufacturer's mandatory S/B's were complied with. No record of compliance with the S/B was noted in the engine maintenance records.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instrument: airplane
- Flight time: 3,100 hours in all; 1,586 in this make and model; 70 in the last 90 days; 20 in the last 30 days; 3,069 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 8,453 hours
- Last inspection: annual inspection, April 12, 1996; 63 hours since
- Maximum gross weight: 2,440 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming O-320-D3G (piston); 0 hours total
The flight
- Departed from: MRI Anchorage AK at 5:40 pm
- Flight plan: VFR
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 100 statute miles
- Sky: clear
- Temperature: 45°F (7°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 1 | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.