Hiller UH-12E accident near Cedar Hill, Texas, May 11, 1984
On May 11, 1984 at about 2:15 am local time, a Hiller UH-12E (helicopter), registered N46RJ, was destroyed in an accident near Cedar Hill, Texas (Cow Patch airport). It was a personal flight under general aviation rules (Part 91). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 11, 1984 · about 2:15 am local time
- Place
- Cedar Hill, Texas · Cow Patch · 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
- N46RJ · registry record · serial 1528
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
DURING THE INITIAL NIGHT FLIGHT AFTER AN OIL CHANGE & ANNUAL INSPECTION, THE HELICOPTER EXPERIENCED A TOTAL POWER PLANT FAILURE. AN AUTOROTATION WAS PERFORMED & THE HELICOPTER STRUCK A BUILDING PRIOR TO COMING TO REST. INSPECTION OF THE WRECKAGE REVEALED ENGINE FAILURE WAS A RESULT OF OIL STARVATION. INVESTIGATION REVEALED THE OIL SYSTEM HAD BEEN ADEQUATELY SERVICED, HOWEVER, THE DRAIN VALVE HAD NOT BEEN CLOSED & UPON ENGINE START AND TAKEOFF THE OIL WAS PUMPED OVERBOARD.
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: private
- Ratings: single-engine land; rotorcraft: helicopter
- Flight time: 1,384 hours in all; 23 in this make and model; 37 in the last 90 days; 9 in the last 30 days; 1,194 as pilot in command
- Medical certificate: Class 3 (valid medical--no waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 2,848 hours
- Last inspection: 100-hour inspection, May 10, 1984; 0 hours since
- Maximum gross weight: 2,800 lb
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming VO-540-9A (piston); 0 hours total
The flight
- Departed from: TA04 Cedar Hill TX at 2:15 am
- Destination: Mansfield TX
- Flight plan: none
- Runway 0
Weather at the time
- Light: night, bright
- Wind: from 180° at 15 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 70°F (21°C), dew point 0°F (-18°C)
- Altimeter: 29.00 inHg
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.
Other NTSB records under N46RJ the same tail number, which may have belonged to a different aircraft at the time
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.