What aircraft was involved and where did it happen?

The accident on 2004-10-11 involved a KAMAN AEROSPACE CORPORATION K-1200, registration HB-XQA, at Grandvillard, FR, CH.

Kaman K-1200 K-MAX Accident near Grandvillard, Switzerland (HB-XQA)

On October 11, 2004, a KAMAN AEROSPACE CORPORATION K-1200 (registration HB-XQA) was involved in an aviation accident near Grandvillard, FR, CH. Investigators recorded the probable cause as: The accident was due to a failure of the clutch assembly. The failure of the clutch assembly was caused by excessive stresses and fatigue of the bearing surfaces of the coupling shaft of the freewheel unit. This summary draws on records from the Swiss Transportation Safety Investigation Board (STSB / SUST).

Sourcesthe Swiss Transportation Safety Investigation Board (STSB / SUST)Primary reportUpdated 1785034239Data API Editorial standards

On 11 October 2004, a Kaman K-1200 K-MAX helicopter (HB-XQA) operated by Rotex Helicopter AG crashed near Grandvillard, Switzerland, due to a failure of the clutch assembly caused by excessive stresses and fatigue of the freewheel coupling shaft. Delayed load release was a contributing factor.

Event

On 11 October 2004 at approximately 16:52 local time, a Kaman K-1200 K-MAX helicopter, registration HB-XQA, crashed at a location known as 'Petit Truyo' in the municipality of Grandvillard, Canton Fribourg, Switzerland. The accident site was about 30 km south of Fribourg at an elevation of 1040 m (3412 ft AMSL).

Aircraft Information

The helicopter was a Kaman K-1200 K-MAX, a single-engine medium-lift helicopter designed for external load operations. The aircraft was owned and operated by Rotex Helicopter AG, based in Balzers, Liechtenstein.

Investigation

The Swiss Aircraft Accident Investigation Bureau (BFU) conducted the investigation. The investigation included metallurgical examination of the clutch assembly components and analysis of the freewheel unit.

Cause

The BFU determined that the accident was due to a failure of the clutch assembly. The failure was caused by excessive stresses and fatigue of the bearing surfaces of the coupling shaft of the freewheel unit. Additionally, the delayed separation of the load from the cargo hook very likely contributed to the accident.

Probable cause

The accident was due to a failure of the clutch assembly. The failure of the clutch assembly was caused by excessive stresses and fatigue of the bearing surfaces of the coupling shaft of the freewheel unit. The delayed separation of the load from the cargo hook very likely contributed to the accident.

2004-10-11: KAMAN AEROSPACE CORPORATION K-1200 (HB-XQA) — Grandvillard, FR, CH