Kaman K-600 accident near Nordman, Idaho, November 20, 2003
On November 20, 2003 at about 11:45 pm local time, a Kaman K-600 (helicopter), registered N286M, was substantially damaged in an accident near Nordman, Idaho. It was an other work-use flight under external-load helicopter rules (Part 133). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The total failure of the helicopter's right main rotor shaft while in an ascending hover due to the propagation of a fatigue crack that initiated in a corrosion pit on the surface of a slot in the wall of the subject shaft. Factors include accumulation of corrosion on the surface of the shaft.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- November 20, 2003 · about 11:45 pm local time
- Place
- Nordman, Idaho · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Kaman K-600
- Registration
- N286M · registry record · serial 60-286
- Damage
- Substantial damage
- Flight
- Other work-use flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
While ascending in a hover to take the slack out of a long-line, the Part 137 logging helicopter experienced the complete failure of its right main rotor mast (shaft). An NTSB metallurgical inspection determined that the mast had failed due to the propagation of a fatigue crack that originated on the inside surface of an opening in the shaft wall (L-crank slot). The fatigue crack originated in two shallow corrosion pits (0.0033 and 0.0029 of an inch wide) on the inner surface of the L-crank slot. Although the shaft had been overhauled/inspected approximately 1,000 hours prior to the accident (1,200 hour interval), the Military Technical Order that regulates the overhaul of this mast does not address a specific inspection for corrosion, nor how to address any corrosion that is detected.
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: single-engine land; instrument: helicopter; rotorcraft: helicopter
- Flight time: 15,000 hours in all; 500 in this make and model
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
- Injury: fatal
The aircraft
- Airframe total time: 6,435 hours
- Last inspection: continuous airworthiness programme, November 14, 2003; 4 hours since
- Maximum gross weight: 9,150 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming T-53-L-13 (turboshaft); 0 hours total
The flight
- Departed from: Priest Lake ID at 10:30 pm
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 39°F (4°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 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 N286M 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.