Piper PA18 accident near Delta Junction, Alaska, September 30, 2018
On September 30, 2018 at about 9:30 pm local time, a 1966 Piper PA18, registered N5907Y, was substantially damaged in an accident during maneuvering (low-alt flying) near Delta Junction, Alaska. It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The total loss of engine power due to carburetor icing, which resulted from the pilot's failure to use carburetor heat while operating at low power settings in conditions conducive to the formation of carburetor ice.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 30, 2018 · about 9:30 pm local time
- Place
- Delta Junction, Alaska · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA18 150, built 1966 · all PA18s on the register
- Registration
- N5907Y · registry record · serial 18-8414
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
According to the pilot, while maneuvering the airplane in mountainous terrain, he reduced engine power and initiated a descent; the engine then began to cough and run roughly. He applied full throttle, and the engine subsequently lost total power. In an attempt to restore power, he applied carburetor heat and switched fuel tanks while initiating an emergency descent. The engine restarted; however, it continued to run roughly and would not develop full power. He continued the emergency descent and landed the airplane on a mountain ridge. Upon touchdown, the left main landing gear separated from the fuselage and the left wing struck the ground, which resulted in substantial damage to the left wing. A postaccident examination of the engine, which included an engine test run, revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. According to a carburetor icing probability chart, an airplane operating in the ambient conditions at the accident site could expect carburetor icing while at cruise power and at glide power. It is likely that, when the pilot reduced engine power for the descent, carburetor ice formed and resulted in the loss of engine power.
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
- Loss of engine power (partial) during maneuvering (low-alt flying) defining event
- Loss of engine power (total) during maneuvering (low-alt flying)
The NTSB's findings
- cause Environmental issues › Conditions/weather/phenomena › Temp/humidity/pressure › Conducive to carburetor icing › Effect on equipment
- cause Aircraft › Aircraft systems › Ice/rain protection system › Intake anti › ice, deice › Not used/operated
- cause Personnel issues › Action/decision › Action › Delayed action › Pilot
- cause Personnel issues › Action/decision › Info processing/decision › Identification/recognition › Pilot
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 475 hours in all; 475 in this make and model; 20 in the last 90 days; 15 in the last 30 days; 440 as pilot in command
- Last flight review: August 24, 2018
- Medical certificate: Class 3 (without waivers/limitations)
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 4,782.8 hours
- Last inspection: annual inspection, June 8, 2018
- Maximum gross weight: 1,750 lb
- Landing gear: fixed
- Engine: Lycoming O-360 (piston); 4,030 hours total
The flight
- Departed from: Delta Junction AK
- Destination: Delta Junction AK
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 110° at 10 knots
- Visibility: 10 statute miles
- Sky: a few clouds at 13,000 ft
- Temperature: 52°F (11°C), dew point 27°F (-3°C)
- Altimeter: 30.15 inHg
- Observation at 9:53 pm from D66
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on March 18, 2020. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Carburetor Icing Chart | PDF, 1 page | View Download |
| 3 | Photos | PDF, 2 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Other NTSB records under N5907Y the same tail number, which may have belonged to a different aircraft at the time
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.