MD Helicopter 369D accident near Trona, California, March 7, 2009
On March 7, 2009 at about 6:00 pm local time, a MD Helicopter 369D, registered N501EF, was substantially damaged in an accident during approach (VFR pattern final) near Trona, California. It was flown under charter and air-taxi rules (Part 135). 3 people had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to maintain control while landing in a high density altitude environment due to a loss of tail rotor effectiveness.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 7, 2009 · about 6:00 pm local time
- Place
- Trona, California · map
- Type
- Accident
- Injuries
- 3 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- MD Helicopter 369D
- Registration
- N501EF · registry record · serial 270091D
- Damage
- Substantial damage
- Flight
- Flight · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
The helicopter pilot was flying passengers and equipment to a landing zone on a peak with an elevation of 9,993 feet. He made one high pass around the summit and assessed the wind as light and variable. He made a right circling approach and slowed from 60 knots to 40 knots. The airspeed suddenly decreased to 20 knots and the helicopter yawed 90 degrees to the right. He temporarily stabilized the situation, but then the helicopter went into a violent and uncontrollable right spin. It spun down vertically until it collided with terrain, rolled onto its right side, and slid about 75 yards before coming to a stop facing uphill. One of the passengers held a rotorcraft/helicopter pilot certificate. He indicated that on the first landing attempt the pilot appeared to be running out of left pedal. The second attempt was at a different angle to the landing zone, but once again the pilot seemed to run out of left pedal and the helicopter began to spin. The pilot could not recover during the attempt and the helicopter made three turns before colliding with the terrain. The Rotorcraft Flying Handbook refers to unanticipated yaw that does not subside on its own as a loss of tail rotor effectiveness. It notes that, if not corrected, this can lead to a loss of control. It may occur in all single-rotor helicopters at airspeeds less than 30 knots. A common cause is insufficient tail rotor thrust for a given power setting at higher altitudes, where tail rotor thrust and efficiency are reduced. Another potential cause is encountering a quartering tailwind from certain directions.
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
- Loss of tail rotor effectiveness during approach (VFR pattern final) defining event
- Loss of control in flight during approach (VFR pattern final)
- Collision with terrain or object (not controlled flight into terrain) during landing
- Fire/smoke (post-impact) during post (impact)
The NTSB's findings
- Environmental issues › Conditions/weather/phenomena › Temp/humidity/pressure › High density altitude › Contributed to outcome
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Prop/rotor parameters › Capability exceeded
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Directional control › Not attained/maintained
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
Pilot
- Certificate: airline transport pilot, commercial pilot, private
- Ratings: multi-engine land; single-engine land; instrument: airplane; rotorcraft: glider; rotorcraft: helicopter
- Flight time: 7,868 hours in all; 1,300 in this make and model; 7 in the last 90 days; 6 in the last 30 days; 6,881 as pilot in command
- Last flight review: December 26, 2008
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: rgt
- Injury: minor injuries
The aircraft
- Airframe total time: 6,897 hours
- Last inspection: 100-hour inspection, October 11, 2008
- Maximum gross weight: 3,000 lb
- Seats: 4
- Landing gear: fixed
- Engine: Rolls Royce 250 C20 (turboshaft); 0 hours total
- Fire on the ground
- Operator: Airwest Helicopters, Inc.
The flight
- Departed from: Inyokern CA at 5:40 pm
- Destination: Rogers Peak CA
Weather at the time
- Light: daylight
- Wind: at 3 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 54°F (12°C), dew point 21°F (-6°C)
- Altimeter: 30.11 inHg
- Observation at 6:56 pm from KIND, 205 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 2 |
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.