Mcdonnell Douglas 600N accident near Rialto, California, March 10, 1999
On March 10, 1999 at about 1:55 am local time, a Mcdonnell Douglas 600N (helicopter), registered N626SB, was substantially damaged in an accident near Rialto, California. It was a public-use flight under general aviation rules (Part 91). 3 people had minor injuries. The weather was instrument conditions (cloud, fog or low visibility).
The NTSB's probable cause their words, unchanged
The pilot's improper in-flight decision to maneuver in the area while observed inclement weather approached, which led to a loss of control. Contributing factors were the low ceilings, mountainous terrain and spatial disorientation.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 10, 1999 · about 1:55 am local time
- Place
- Rialto, California · map
- Type
- Accident
- Injuries
- 3 people had minor injuries.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft
- Mcdonnell Douglas 600N
- Registration
- N626SB · no longer on the register · serial RN024
- Damage
- Substantial damage
- Flight
- Public-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
During a routine law enforcement patrol flight, the pilot responded to the 4,700-foot mean sea level mountainside to investigate circumstances related to an apparent abandoned vehicle. Upon arriving at the site, the pilot performed a toe-in landing to discharge his crewmember. The crewmember proceeded to evaluate the vehicle while the pilot orbited the area. While orbiting, the pilot observed that low elevation clouds were approaching. However, the visibility initially was about 10 miles, and the cloud height appeared between 500 and 600 feet above the ground. After a few minutes, the crewmember returned to the helicopter, and they departed. Seconds after taking off the pilot lost visual reference with the ground. The pilot further indicated that he continued flying by reference to his flight instruments and the helicopter began spinning. Between 1 and 1.5 minutes later the spinning stopped, and the helicopter lost altitude until impacting the mountainside.
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, military
- Ratings: single-engine land; instrument: helicopter; rotorcraft: helicopter
- Flight time: 1,654 hours in all; 35 in this make and model; 104 in the last 90 days; 72 in the last 30 days; 1,612 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 266 hours
- Last inspection: approved inspection programme, February 18, 1999; 66 hours since
- Maximum gross weight: 3,850 lb
- Seats: 8
- Landing gear: fixed
- Engine: Allison 250-C47M (turboshaft); 0 hours total
The flight
- Departed from: L67 Rialto CA at 1:08 am
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 240° at 11 knots
- Visibility: 10 statute miles
- Sky: scat at 5,000 ft
- Temperature: 52°F (11°C), dew point 43°F (6°C)
- Altimeter: 30.00 inHg
- Observation at 1:53 am from ONT, 17 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 | |||
| 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.