Hiller UH-12E accident near Tolleson, Arizona, August 16, 1989
On August 16, 1989 at about 11:30 am local time, a Hiller UH-12E (helicopter), registered N7086, was substantially damaged in an accident near Tolleson, Arizona (Cnty Boy Crop Dusting Arp airport). It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
AN ENGINE FAILURE DUE TO WATER CONTAMINATION IN THE FUEL SUPPLY WHICH PRECEDED AN AUTOROTATION AND COLLISION WITH THE GROUND DURING NIGHT TIME CONDITIONS.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 16, 1989 · about 11:30 am local time
- Place
- Tolleson, Arizona · Cnty Boy Crop Dusting Arp · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Hiller UH-12E · all UH-12Es on the register
- Registration
- N7086 · no longer on the register · serial 1699
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT OF THE SPRAY HELICOPTER EXPERIENCED AN ENGINE FAILURE AFTER A TAKEOFF FROM A REFUELING STOP. THE AIRCRAFT AUTOROTATED INTO AN OPEN FIELD, BOUNCED AND ROLLED OVER INTO ITS SIDE. A FUEL SAMPLE TAKEN ON THE SAME DAY REVEALED THAT APPROXIMATELY 15% OF THE FUEL WAS WATER. A LATER TEST OF THE FUEL BY THE COMPANY REVEALED THAT CONTAMINATION WAS TWO QUARTS TO FIVE GALLONS OF FUEL. THE PILOT REPORTED NO MECHANICAL PROBLEMS WITH THE AIRCRAFT PRIOR TO THE ACCIDENT.
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: helicopter; rotorcraft: helicopter
- Flight time: 20,000 hours in all; 4,000 in this make and model; 300 in the last 90 days; 100 in the last 30 days; 18,000 as pilot in command; 1,000 on instruments
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 3,292 hours
- Last inspection: annual inspection, March 20, 1989; 120 hours since
- Maximum gross weight: 2,800 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming VO-540-C2A (piston); 0 hours total
- Operator: Moseley Aviation, INC.
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: night, dark
- Wind: from 210° at 5 knots
- Visibility: 35 statute miles
- Sky: clear
- Temperature: 79°F (26°C), dew point 68°F (20°C)
- Observation at 11:50 am from PHX, 14 miles away
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.
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.