Cessna 170 accident near Big Lake, Alaska, April 9, 2018
On April 9, 2018 at about 3:30 am local time, a 1948 Cessna 170, registered N4133V, was destroyed in an accident during approach near Big Lake, Alaska. It was an instructional flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot’s exceedance of the airplane’s critical angle of attack, which resulted in an aerodynamic stall.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 9, 2018 · about 3:30 am local time
- Place
- Big Lake, Alaska · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 170 UNDESIGNAT, built 1948 · all 170s on the register
- Registration
- N4133V · no longer on the register · serial 18465
- Damage
- Destroyed
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that, during the approach to land on a gravel airstrip, he increased engine power to "extend the approach," the airplane pitched up in a nose-high attitude, aerodynamically stalled, and yawed to the right. Subsequently, the airplane impacted a snowbank to the right side of the airstrip. A postcrash fire destroyed the airplane. The pilot reported that there were no preaccident 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
- Loss of control in flight during approach defining event
- Aerodynamic stall/spin during approach
- Runway excursion during landing (flare/touchdown)
- Collision with terrain or object (not controlled flight into terrain) during landing
- Fire/smoke (post-impact) during post (impact)
The NTSB's findings
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Angle of attack › Capability exceeded
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- Environmental issues › Physical environment › Object/animal/substance › Snow/ice › Contributed to outcome
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 9,000 hours in all; 3 in this make and model; 6 in the last 90 days; 6 in the last 30 days; 9,000 as pilot in command; 500 on instruments
- Medical certificate: Class 3 (without waivers/limitations)
- Seat: left
- Injury: no injuries
Passenger
- Certificate: private
- Ratings: single-engine land; single-engine sea
- Medical certificate: Class 3
- Seat: unk
- Injury: no injuries
The aircraft
- Airframe total time: 3,483.5 hours
- Last inspection: annual inspection, July 26, 2017
- Maximum gross weight: 2,200 lb
- Seats: 4
- Landing gear: fixed
- Engine: Cont Motor C145 SERIES (piston); 3,310 hours total
- Fire on the ground
The flight
- Departed from: BGQ Big Lake AK
- Destination: Big Lake AK
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 060° at 7 knots
- Visibility: 10 statute miles
- Sky: scat at 10,000 ft
- Temperature: 48°F (9°C), dew point 19°F (-7°C)
- Altimeter: 29.70 inHg
- Observation at 2:56 am from PAWS, 9 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
2 documents, released by the NTSB on June 12, 2018. 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 | Accident Picture | PDF, 1 page | 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.