Piper PA-18-150 accident near Mcgrath, Alaska, September 4, 2011
On September 4, 2011 at about 11:00 pm local time, a Piper PA-18-150, registered N13973, was substantially damaged in an accident during approach (VFR pattern final) near Mcgrath, Alaska (Mcgrath airport). It was a personal flight under general aviation rules (Part 91). 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot inadvertently switched off the engine magnetos during short final approach, which resulted in a loss of engine power. Contributing to the accident was the manufacturer's placement of the magneto switches in the cabin.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 4, 2011 · about 11:00 pm local time
- Place
- Mcgrath, Alaska · Mcgrath · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-18-150 · all PA-18-150s on the register
- Registration
- N13973 · registry record · serial 18-8985
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The airplane was on short final approach to the airport when its engine would not respond to throttle input. The airplane descended into trees and impacted terrain. The pilot reported that immediately prior to the loss of engine power, he had made an elevator trim control adjustment and was in the process of making a throttle adjustment when he heard a snap and the engine quit operating, "as if the magnetos had been shut off." Examination of the airplane established that the throttle cable was intact. The engine was run, and no anomalies were noted. During the engine run, the magneto switches were turned off while the engine was at cruise rpm. The switches made an audible click/snap when turned off. Following a similar August 29, 2011, accident also involving a Piper PA-18 airplane, the pilot reported that, during the initial climb, he inadvertently switched off the engine magnetos with his coat sleeve while using the trim handle, causing the airplane’s engine to shut down. As with this accident airplane, the magneto switches were located on the left side of the cabin, just above the trim handle. As a result of incidents involving the inadvertent shutting off of the magneto switches, the Federal Aviation Administration published a notice of proposed rulemaking announcing its intent to issue an airworthiness directive requiring the reconfiguration of the magneto switches on Piper PA-18 airplanes. Given the absence of any mechanical issues with the airplane, as well as the location of the magneto switches and the trim handle, it is likely the pilot inadvertently shut off the magnetos switches while trimming the airplane on short final approach.
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
- Engine shutdown during approach (VFR pattern final)
- Loss of engine power (total) during approach (VFR pattern final) defining event
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Personnel issues › Task performance › Use of equip/info › (general) › Pilot
- factor Aircraft › Aircraft power plant › Ignition system › Switching › Unintentional use/operation
- factor Environmental issues › Task environment › Physical workspace › Positioning/available space › Contributed to outcome
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 23,000 hours in all; 6,000 in this make and model
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: frt
- Injury: serious injuries
The aircraft
- Airframe total time: 1,364 hours
- Last inspection: annual inspection
- Maximum gross weight: 1,750 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-360 SERIES (piston); 0 hours total
The flight
- Departed from: Kingston Creek AK at 5:00 pm
- Destination: PAMC Mcgrath AK
- Flight plan: not recorded
- Runway 05, 2,000 ft by 60 ft
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: broken clouds at 20,000 ft; scat at 2,900 ft
- Temperature: 61°F (16°C), dew point 48°F (9°C)
- Altimeter: 29.26 inHg
- Observation at 5:53 pm from PAMG, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 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.