Piper PA-18-150 accident near Wasilla, Alaska, August 20, 2021
On August 20, 2021 at about 2:55 am local time, a 1975 Piper PA-18-150, registered N89ZW, was substantially damaged in an accident during taxi (from runway) near Wasilla, Alaska (Wolf Lake airport). 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 pilot’s inability to maintain control of the airplane during taxi after it encountered the prop wash from a larger airplane that was conducting a high-power engine run on the same taxiway.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 20, 2021 · about 2:55 am local time
- Place
- Wasilla, Alaska · Wolf Lake · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-18-150, built 1975 · all PA-18-150s on the register
- Registration
- N89ZW · registry record · serial 18-7509114
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that, after landing he taxied back up the runway to the north. As he reached the end of the runway, and approached the most northerly taxiway, he had to maneuver around another airplane that was parked partially in the taxiway easement and on the runway. As he began to make a right turn onto the taxiway, the airplane was blown sideways about 15-20 ft as a result of the wind from the operating propellers (prop-wash) from a turbo-prop airplane performing a full engine run at a maintenance hangar. The pilot stated that his airplane was dropped onto its left wing and subsequently was spun to the south. Despite the pilot’s attempt of using full brakes to keep the airplane in place, the airplane slid backward and was temporary lifted airborne before it collided with the ground. As a result of the impact, the airplane sustained substantial damage to the left rear spar and aileron. The pilot reported that there were no preimpact mechanical failures or malfunctions with the airplane that would have precluded normal operation.
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
- Prop/jet/rotor blast/suction during taxi (from runway) defining event
The NTSB's findings
- Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Directional control › Capability exceeded
- Environmental issues › Physical environment › Object/animal/substance › Aircraft › Ability to respond/compensate
Pilot
- Certificate: private
- Ratings: single-engine land; single-engine sea
- Flight time: 879 hours in all; 879 in this make and model; 33 in the last 90 days; 10 in the last 30 days; 855 as pilot in command
- Last flight review: October 7, 2020
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 3,147 hours
- Last inspection: annual inspection, June 2, 2021; 50 hours since
- Maximum gross weight: 2,000 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming O-320-A2B (piston); 702 hours total
The flight
- Departed from: 88AK Sterling AK at 2:00 am
- Flight plan: none
- Runway 18/3, 2,600 ft by 100 ft
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: a few clouds at 10,000 ft
- Temperature: 60°F (16°C), dew point 47°F (8°C)
- Altimeter: 29.98 inHg
- Observation at 5:53 pm from PAAQ, 6 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
2 documents, released by the NTSB on December 9, 2021. 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, 10 pages | View Download |
| 2 | Photographs (Provided by the Pilot) | PDF, 4 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
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.