Enstrom F-28C accident near Pendleton, Oregon, April 7, 1999
On April 7, 1999, a Enstrom F-28C (helicopter), registered N51770, was substantially damaged in an accident near Pendleton, Oregon. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 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
A loss of power due to water contamination of the fuel. Factors include the inability of the helicopter to perform a successful autorotation immediately after takeoff.
Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 7, 1999 · cases in 1999
- Place
- Pendleton, Oregon · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Enstrom F-28C · all F-28Cs on the register
- Registration
- N51770 · registry record · serial 445
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
During takeoff from the refueling pad, the helicopter's engine lost power and the pilot attempted an autorotation. Because the aircraft did not yet have sufficient airspeed or altitude to complete a successful autorotation, it landed hard and the main rotor blades flexed downward and impacted the tail boom. It was later determined that water contamination had accidentally been transferred from a portable refueling barrel to the aircraft's fuel system during hot refueling (with engine still running). It could not be determined how water was introduced into the refueling barrel.
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: commercial pilot
- Ratings: single-engine land; instructor: airplane single-engine; instructor: helicopter; instructor: instrument airplane; instrument: airplane; rotorcraft: helicopter
- Flight time: 20,000 hours in all; 20,000 in this make and model
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Last inspection: annual inspection
- Maximum gross weight: 2,600 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming HIO-360-F1AD (piston); 0 hours total
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 20 statute miles
- Sky: scat
- Temperature: 61°F (16°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| 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.
Connections how this case links to the rest of the register
- N51770 on the register today · the tail number may have moved to another aircraft since
- Enstrom F-28 147 registered today · the model family and its accident history
- Enstrom 216 aircraft on the register
- Engine: Lycoming HIO-360-F1AD 34 aircraft carry this series today · as the NTSB recorded it
- Accidents and incidents in Oregon 1,864 since 1982 · 279 in the last ten years
- Oregon 7,001 aircraft registered
The whole map of how records connect · these connections as data: /graph/accident/SEA99LA048.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
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 does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.