Mcdonnell Douglas 369E accident near Big Timber, Montana, June 25, 2003
On June 25, 2003 at about 3:00 pm local time, a Mcdonnell Douglas 369E (helicopter), registered N1502, was substantially damaged in an accident near Big Timber, Montana. It was a public-use flight under public-use (government) rules. 2 people had minor injuries. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
Fretting on the outside diameter of the compressor coupling adapter which resulted in fatigue and subsequent fracture of the adapter, and ultimately the disconnection of the compressor from the turbine assembly. Contributing factors were low rotor RPM, uneven terrain and collapse of the right skid on landing.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 25, 2003 · about 3:00 pm local time
- Place
- Big Timber, Montana · map
- Type
- Accident
- Injuries
- 2 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Mcdonnell Douglas 369E
- Registration
- N1502 · registry record · serial 0324E
- Damage
- Substantial damage
- Flight
- Public-use flight · public-use (government) rules
The NTSB's narrative final · quoted from the NTSB record
While operating at an altitude of about 40 feet and 40 knots airspeed on a low level coyote predation flight the pilot of the (Hughes) McDonnell Douglas 369E helicopter heard a loud bang and observed both the "Engine Out" and "Auto Relight" warning lights illuminate. The pilot reduced collective and immediately transitioned to a forced landing onto uneven terrain during which the helicopter touched down hard and the right skid separated. Post-crash examination of the Rolls Royce (Allison) 250-C20B turboshaft engine revealed that the compressor coupling adapter had fractured circumferentially resulting in the disconnection of the compressor from the turbine assembly. Further examination revealed that the Rolls Royce (Allison) manufactured compressor adapter coupling had been installed approximately 1,005 hours earlier and that the separation had been the result of multiple fatigue fractures in the coupling associated with severe fretting on the adapter's outer diameter where it inserts into the spur adapter gearshaft.
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: instructor: helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 9,450 hours in all; 6,100 in this make and model; 150 in the last 90 days; 35 in the last 30 days; 9,200 as pilot in command; 2,500 on instruments
- Last flight review: April 4, 2003
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
- Injury: minor injuries
The aircraft
- Airframe total time: 7,866 hours
- Last inspection: annual inspection, February 20, 2003; 19 hours since
- Maximum gross weight: 3,000 lb
- Seats: 4
- Landing gear: fixed
- Engine: Allison 250-C20B (turboshaft); 0 hours total
- Fire on the ground
- Operator: Usda Aphis Wildlife Services
The flight
- Departed from: 6S0 Big Timber MT at 2:40 pm
- Destination: HLN Helena MT
Weather at the time
- Light: daylight
- Wind: from 300° at 9 knots
- Visibility: 10 statute miles
- Sky: a few clouds at 10,000 ft
- Temperature: 48°F (9°C), dew point 39°F (4°C)
- Altimeter: 30.21 inHg
- Observation at 2:53 pm from LVM, 27 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| 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.
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number SEA03TA116.