Robinson R22 accident near Alpine, Texas, September 5, 1992
On September 5, 1992 at about 9:30 pm local time, a 1991 Robinson R22 (helicopter), registered N4073S, was destroyed in an accident during enroute (cruise) near Alpine, Texas. It was a personal flight under general aviation rules (Part 91). 1 person was killed and 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
Failure by the pilot-in-command, for unknown reasons, to maintain sufficient altitude to clear surrounding terrain. Factors were mountainous terrain and high density altitude.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 5, 1992 · about 9:30 pm local time
- Place
- Alpine, Texas · map
- Type
- Accident
- Injuries
- 1 person was killed and 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Robinson R22 BETA, built 1991 · all R22s on the register
- Registration
- N4073S · no longer on the register · serial 1889
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
While on a cross-country flight over mountainous terrain, the helicopter impacted the side of a mountain at 6,800 feet, about 90 feet below the crest. The investigation revealed that the tail rotor hit the side of the mountain first. Wreckage was distributed down the side of the mountain to about the 6,500-foot level. Density altitude, calculated using a pressure altitude of 6,800 feet and an estimated temperature of 85 degrees, was 9,900 feet. The helicopter's gross weight was calculated to be 1,229 pounds. Maximum gross weight for out-of-ground effect hover performance at 9,900 density altitude was 1,210 pounds. Examination of the wreckage revealed no evidence of pre-impact flight control malfunction or airframe or system failure. The engine performed within manufacturer specifications and certification standards during a postaccident test run. The pilot had no memory of the accident, there were no witnesses, and the phase of operation was unknown.
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
- Unknown or undetermined during unknown
- Controlled flight into terrain or object (CFIT) during enroute (cruise) defining event
The NTSB's findings
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Altitude › Not attained/maintained
- cause Personnel issues › Task performance › Use of equip/info › (general) › Pilot
- factor Environmental issues › Physical environment › Terrain › Mountainous/hilly terrain › Not specified
- factor Environmental issues › Conditions/weather/phenomena › Temp/humidity/pressure › High density altitude › Not specified
Pilot
- Certificate: commercial pilot, private
- Ratings: multi-engine land; single-engine land; rotorcraft: helicopter
- Flight time: 608 hours in all; 36 in this make and model; 137 in the last 90 days; 110 in the last 30 days; 360 as pilot in command
- Last flight review: May 1, 1992
- Medical certificate: Unknown
- Seat: rgt
- Injury: serious injuries
Pilot-Rated Passenger
- Certificate: commercial pilot, private
- Ratings: rotorcraft: helicopter
- Flight time: 624 hours in all; 0 in this make and model
- Seat: left
- Injury: fatal
The aircraft
- Airframe total time: 1,094 hours
- Last inspection: 100-hour inspection, September 4, 1992; 9 hours since
- Maximum gross weight: 1,370 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-320-B2C (piston); 0 hours total
- Operator: Helicopters International
The flight
- Departed from: E29 Sonora TX at 6:45 pm
- Destination: MRF Marfa TX
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: at 7 knots
- Visibility: 10 statute miles
- Sky: overcast at 12,000 ft; clear
- Temperature: 90°F (32°C), dew point 46°F (8°C)
- Altimeter: 29.87 inHg
- Observation at 9:35 pm from MRF, 11 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.