Aerospatiale AS-355-F accident near Bear Valley, California, March 26, 1989
On March 26, 1989 at about 8:33 pm local time, a Aerospatiale AS-355-F (helicopter), registered N84MH, was substantially damaged in an accident near Bear Valley, California (Bear Valley Stolport airport). It was a positioning flight under general aviation rules (Part 91). No one was hurt; 3 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
IMPROPER IN-FLIGHT PLANNING/DECISION BY THE PILOT, WHICH RESULTED IN A LOSS OF AIRCRAFT CONTROL DURING A SLOW SPEED, DOWNWIND APPROACH TO A HIGH ALTITUDE STOLPORT. CONTRIBUTING FACTORS WERE: HIGH DENSITY ALTITUDE, TAILWIND, IMPROPER WEATHER EVALUATION BY THE PILOT, SNOW COVERED TERRAIN, WHITEOUT CONDITIONS BEFORE TOUCHDOWN, AND THE SNOWBANK.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 26, 1989 · about 8:33 pm local time
- Place
- Bear Valley, California · Bear Valley Stolport · map
- Type
- Accident
- Injuries
- No one was hurt; 3 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Aerospatiale AS-355-F · all AS-355-Fs on the register
- Registration
- N84MH · registry record · serial 5173
- Damage
- Substantial damage
- Flight
- Positioning flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE EMERG MED SVC (EMS/MEDIVAC) FLT DEPARTED MODESTO HOSPITAL TO TRANSPORT A PATIENT FROM BEAR VALLEY, CA. THE PILOT MADE AN APCH TO THE BEAR VALLEY STOLPORT FROM THE SOUTH-SOUTHWEST. ELEV OF THE STOLPORT WAS 7073'. DRG THE APCH AT SLOW SPEED, THE HELICOPTER BEGAN TO YAW TO THE LEFT. THE PLT APPLIED RGT PEDAL, BUT TO NO AVAIL. HE LOWERED THE NOSE TO BEGIN A GO-AROUND, BUT THE YAW BEGAN TO ACCELERATE. THE PLT THEN SHUT DOWN BOTH ENGS & MADE AN AUTOROTATION. JUST BEFORELANDING, LOOSE SNOW WAS BLOWN UP & WHITEOUT CONDITIONS OCCURRED. DRG TOUCHDOWN, THE HELICOPTER PITCHED FORWARD INTO A SNOWBANK & WAS DAMAGED. THE PLT RPRTD THE WIND WAS LIGHT & VARIABLE. A SHERIFF'S DEPUTY RPRTD THE WIND WAS FROM THE SOUTH/SOUTHWEST AT 5 TO 10 KTS. THE INVESTGATION REVEALED NO EVIDENCE OF A TAIL ROTOR DRIVE MALFUNCTION OR FAILURE.
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: airline transport pilot, flight instructor, commercial pilot, flight engineer
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: helicopter; instructor: instrument airplane; instructor: instrument helicopter; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 4,700 hours in all; 120 in this make and model; 60 in the last 90 days; 20 in the last 30 days; 400 on instruments
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 2,385 hours
- Last inspection: continuous airworthiness programme, February 22, 1989; 37 hours since
- Maximum gross weight: 5,300 lb
- Seats: 4
- Landing gear: fixed
- Engine: Allison 250-C20F (turboshaft); 0 hours total
- Operator: Care, INC
The flight
- Departed from: Modesto CA at 7:56 pm
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 15 statute miles
- Sky: scat at 4,000 ft
- Temperature: 36°F (2°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 3 |
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.