Piper PA-31-350 accident near Aniak, Alaska, August 4, 2008
On August 4, 2008 at about 11:50 pm local time, a Piper PA-31-350, registered N40YR, was substantially damaged in an accident during initial climb near Aniak, Alaska (Aniak airport). It was flown under charter and air-taxi rules (Part 135). 1 person was seriously injured and 2 people had minor injuries; 5 others were unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A partial loss of engine power during takeoff due to a failure of the left engine's turbocharger as a result of the failure of a turbine shaft bearing. Contributing to the accident was unsuitable terrain for a forced landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 4, 2008 · about 11:50 pm local time
- Place
- Aniak, Alaska · Aniak · map
- Type
- Accident
- Injuries
- 1 person was seriously injured and 2 people had minor injuries; 5 others were unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-31-350 · all PA-31-350s on the register
- Registration
- N40YR · registry record · serial 31-7952008
- Damage
- Substantial damage
- Flight
- Flight · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
The airline-transport-certificated pilot was departing in a twin-engine airplane that was about 130 pounds below its maximum gross weight. About 200 feet above the ground, the pilot reported a loss of engine power in the left engine and smoke was seen coming from the left engine by ground witnesses. The pilot indicated that he feathered the left engine, but that the airplane was descending and he elected to make an emergency landing on a gravel bar about .5 mile from the airport. Following the accident, the operator's maintenance personnel removed the left engine from the airframe and shipped it to an engine repair facility for examination. The airplane's left engine, which was equipped with a turbocharger, was placed on a test stand where it was started and ran, but it would not produce power (measured in manifold pressure) above ambient pressure. The engine's turbocharger was removed and replaced. A second engine run, with the new turbocharger installed, resulted in the engine developing full power. The original turbocharger was disassembled and inspected. The inspection revealed that one of the turbine shaft bearings had failed and that the turbine shaft and blades were damaged. One thrust bearing had fractured, with half of the bearing missing.
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
What happened, in order
- Powerplant sys/comp malf/fail during initial climb defining event
- Loss of engine power (total) during initial climb
- Off-field or emergency landing during emergency descent
The NTSB's findings
- cause Aircraft › Aircraft power plant › Turbocharging (recip only) › Turbocharger › Failure
- factor Environmental issues › Physical environment › Terrain › Rough terrain › Contributed to outcome
Pilot
- Certificate: airline transport pilot, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: glider; instrument: airplane; rotorcraft: glider
- Flight time: 3,941 hours in all; 98 in this make and model; 293 in the last 90 days; 92 in the last 30 days; 2,846 as pilot in command
- Last flight review: July 10, 2008
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 10,047 hours
- Last inspection: approved inspection programme, July 25, 2008; 14 hours since
- Maximum gross weight: 7,368 lb
- Seats: 8
- Landing gear: retractable
- Engine 1: Lycoming TIO-54D (piston); 0 hours total
- Engine 2: Lycoming LTIO-54D (piston); 0 hours total
- Operator: Frontier Flying Service Inc.
The flight
- Departed from: PANI Aniak AK at 6:50 pm
- Destination: PAHX Shageluk AK
- Runway 28, 6,000 ft by 150 ft
Weather at the time
- Light: daylight
- Wind: from 300° at 6 knots
- Visibility: 10 statute miles
- Sky: overcast at 3,000 ft
- Temperature: 55°F (13°C), dew point 45°F (7°C)
- Altimeter: 30.11 inHg
- Observation at 6:56 pm from PANI, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 | 2 | 4 |
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.