Amateur-built DHC-2 accident near Port Alsworth, Alaska, September 9, 1998
On September 9, 1998 at about 6:45 pm local time, a amateur-built DHC-2, registered N1433Z, was substantially damaged in an accident near Port Alsworth, Alaska. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). 5 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to maintain adequate airspeed which resulted in an inadvertent stall. Factors associated with this accident were the pilot's unfamiliarity with the geographic area, the low clouds, his becoming disoriented, and the blind canyon into which he flew. An additional factor was the intentionally disabled stall warning system.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 9, 1998 · about 6:45 pm local time
- Place
- Port Alsworth, Alaska · map
- Type
- Accident
- Injuries
- 5 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built DHC-2
- Registration
- N1433Z · registry record · serial 595
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
The float equipped airplane was attempting to cross a mountain pass, following two other company airplanes. The first two pilots, and passengers, described five to seven miles visibility, 700 feet ceilings, clouds hanging on the mountainsides, and misty rain. The route of flight required several turns in the pass. The pilot had not flown through the pass in marginal Visual Flight Rules (VFR) weather before this flight. After the first two airplanes went through the pass, they lost radio contact with the accident pilot, and did not see or hear from him again. The wreckage was later located at the head of an intersecting canyon, two miles before the correct pass. The airplane had been modified with a Short Take Off and Landing (STOL) kit. Canadian certification flight tests had determined that this modification eliminated aerodynamic warning of impending stalls, and therefore required an audible stall warning. Company pilots indicated it was common for the stall warning system to activate at an airspeed 10-15 miles per hour above the actual stall. At the time of the accident, the airplane did not have the ventral fin installed, and a takeoff flaps setting was selected. The audible stall warning circuit breaker was found in the pulled (disabled) position.
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
Pilot
- Certificate: flight instructor, commercial pilot, private
- Ratings: single-engine land; single-engine sea; instructor: airplane single-engine; instrument: airplane
- Flight time: 1,720 hours in all; 150 in this make and model; 338 in the last 90 days; 118 in the last 30 days; 1,670 as pilot in command; 25 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 12,948 hours
- Last inspection: 100-hour inspection, August 19, 1998; 65 hours since
- Maximum gross weight: 5,370 lb
- Seats: 5
- Landing gear: fixed
- Engine: P&W R-985-AN14B (piston); 0 hours total
- Operator: Rust'S Flying Service, INC.
The flight
- Departed from: LHD Anchorage AK at 12:30 pm
- Destination: Hoholitna River AK
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 090° at 10 knots
- Visibility: 5 statute miles
- Sky: overcast at 4,500 ft; not recorded
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.
Other NTSB records under N1433Z the same tail number, which may have belonged to a different aircraft at the time
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number ANC98FA145.