Mcdonnell Douglas 369E accident near Moreno Valley, California, October 8, 1999
On October 8, 1999 at about 3:05 am local time, a Mcdonnell Douglas 369E (helicopter), registered N991SD, was substantially damaged in an accident near Moreno Valley, California. It was a public-use 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
The failure of the pilot to maintain sufficient forward airspeed to preclude an inadvertent encounter with loss of tail rotor effectiveness, which resulted in a loss of yaw control. The pilot's failure to initiate timely remedial action is a factor.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 8, 1999 · about 3:05 am local time
- Place
- Moreno Valley, California
- Type
- Accident
- Injuries
- No one was hurt; 3 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Mcdonnell Douglas 369E
- Registration
- N991SD · no longer on the register · serial 500E
- Damage
- Substantial damage
- Flight
- Public-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The Sheriff's Department helicopter was orbiting over ground based law enforcement activity. It was a dark night and the winds aloft were 20 to 25 knots at 500 feet agl. The pilot said he was attempting to shine the helicopter's spotlight on a vehicle; however, the wind kept blowing the helicopter past the location on each of the first two orbits. On the third orbit, the pilot inadvertently allowed the helicopter to slow below translational lift speed and the helicopter yawed 180 degrees to the right uncontrollably. The pilot momentarily recovered directional control of the helicopter but then the right yaw resumed. He made several more attempts to recover directional control of the helicopter but when he saw the altitude becoming low, he flew to a pre-selected landing zone where the helicopter landed hard while in a right yawing spin. During the landing the main rotor blades severed the tail boom and the helicopter came to rest on its right side.
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: multi-engine land; single-engine land; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 2,737 hours in all; 94 in this make and model; 174 in the last 90 days; 51 in the last 30 days; 2,153 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 5,474 hours
- Last inspection: 100-hour inspection, September 1, 1999; 30 hours since
- Maximum gross weight: 3,000 lb
- Seats: 4
- Landing gear: fixed
- Engine: Allison 250C20B (turboshaft); 0 hours total
The flight
- Departed from: HMT Hemet CA at 2:50 am
- Flight plan: none
- Runway 0
Weather at the time
- Light: night, dark
- Wind: from 340° at 9 knots
- Visibility: 35 statute miles
- Sky: clear
- Temperature: 77°F (25°C), dew point 28°F (-2°C)
- Altimeter: 29.00 inHg
- Observation at 2:55 am from RIV, 1 miles away
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.
Other NTSB records under N991SD 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.