Kaman Aerospace CORP K-1200 accident near Donnelly, Idaho, June 16, 2010
On June 16, 2010 at about 8:40 pm local time, a Kaman Aerospace CORP K-1200 (helicopter), registered N134WC, was substantially damaged in an accident during maneuvering (hover) near Donnelly, Idaho. It was an external-load 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 collision of two counter-rotating main rotor blades for undetermined reasons, which resulted in a loss of control.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 16, 2010 · about 8:40 pm local time
- Place
- Donnelly, Idaho · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Kaman Aerospace CORP K-1200 · all K-1200s on the register
- Registration
- N134WC · no longer on the register · serial A94-0006
- Damage
- Substantial damage
- Flight
- External-load flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
While lifting a heavy external load off the ground, the leading edges of two of the logging helicopter's counter-rotating main rotor blades collided with each other. The collision resulted in the destruction of a significant portion of both of those blades and the separation of one of the two main rotor pylons. Control of the helicopter was no longer possible, and it impacted the terrain in the inverted position. Detailed postaccident examinations of the helicopter’s components, tests, and witness interviews did not reveal evidence of any pre-existing anomalies or malfunctions or of any pilot action that would have led to the blades colliding. Although the helicopter was operating at an estimated 288 pounds above its maximum certified gross weight of 12,000 pounds, there is no evidence that this played a role in causing or contributing to the blade-to-blade contact. The event that initiated the accident sequence was not determined.
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
What happened, in order
- Unknown or undetermined during maneuvering (hover) defining event
- Loss of control in flight during maneuvering (hover)
The NTSB's findings
- cause Not determined › Not determined › (general) › (general) › Unknown/Not determined
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Directional control › Attain/maintain not possible
- Aircraft › Aircraft oper/perf/capability › Aircraft capability › Maximum weight › Incorrect use/operation
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; rotorcraft: helicopter
- Flight time: 27,600 hours in all; 12,760 in this make and model; 292 in the last 90 days; 130 in the last 30 days
- Last flight review: December 8, 2008
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: sngl
- Injury: fatal
The aircraft
- Airframe total time: 24,053 hours
- Last inspection: approved inspection programme, June 15, 2010
- Maximum gross weight: 12,000 lb
- Seats: 1
- Landing gear: fixed
- Engine: Lycoming T-53 (turboshaft); 0 hours total
- Operator: Woody Contracting INC
The flight
- Departed from: Donnelly ID at 7:00 pm
- Destination: Donnelly ID
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: overcast at 1,200 ft
- Temperature: 45°F (7°C), dew point 0°F (-18°C)
- Altimeter: 29.87 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight 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.
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 WPR10FA295.