Mcdonnell Douglas 500-E accident near Oklahoma City, Oklahoma, July 1, 1999
On July 1, 1999 at about 4:30 am local time, a Mcdonnell Douglas 500-E (helicopter), registered N686F, was substantially damaged in an accident near Oklahoma City, Oklahoma (Downtown Airpark airport). It was a public-use flight under general aviation rules (Part 91). 1 person had minor injuries; 2 others were unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
During a practice autorotation, the pilot flared the helicopter too low, which resulted in the tailboom contacting the ground. A factor was the dark night light conditions.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 1, 1999 · about 4:30 am local time
- Place
- Oklahoma City, Oklahoma · Downtown Airpark · map
- Type
- Accident
- Injuries
- 1 person had minor injuries; 2 others were unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Mcdonnell Douglas 500-E
- Registration
- N686F · no longer on the register · serial E-524
- Damage
- Substantial damage
- Flight
- Public-use flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
During a night practice autorotation, after reapplying power, the pilot flared the helicopter too low, and the tailboom contacted the ground. Tail rotor control was lost, 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, private
- Ratings: single-engine land; rotorcraft: helicopter
- Flight time: 400 hours in all; 130 in this make and model; 105 in the last 90 days; 36 in the last 30 days
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 3,676 hours
- Last inspection: 100-hour inspection, June 17, 1999; 81 hours since
- Maximum gross weight: 3,000 lb
- Seats: 4
- Landing gear: fixed
- Engine: Allison 250C-20B (turboshaft); 0 hours total
The flight
- Departed from: 2DT at 3:50 am
- Flight plan: none
- Runway 0
Weather at the time
- Light: night, dark
- Wind: from 120° at 9 knots
- Visibility: 10 statute miles
- Sky: scat at 2,500 ft
- Temperature: 79°F (26°C), dew point 73°F (23°C)
- Altimeter: 29.00 inHg
- Observation at 3:56 am from OKC, 5 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.
Other NTSB records under N686F 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.