Incident at Dogskin Lake, Manitoba

1997-03-21: The pilot of a Bell 206B helicopter was picking up a sling load when the long line accidentally snagged on the left skid. Upon pickup the pilot felt some instability in the load and set the load back down on the ground. A ground worker observed the helicopter's left skid dangling from the helicopter and informed the pilot. The pilot hovered the aircraft while the ground worker removed the dangling skid. The pilot then flew the helicopter back to the operator's base in Lac Du Bonnet where ground crew were able to support the helicopter to enable its shutdown. The initiating failure to the Bell high skid gear was traced to the crack in the aft cross tube at the fuselage fitting location. The crack had initiated at the top rivet holes under the P/N 206-050-110 strap on the crosstube and had progressed approximately two-thirds of the way around the circumference of the tube prior to its failure. It is believed that when the long line caught the skid during the lift attempt, the weight of the sling load snapped the remaining portion of the tube, causing the skid to separate. The crack location has been identified by the manufacturer as an ongoing problem with a history of past service fatigue. In April of 1994 the manufacturer issued several alert service bulletins covering the full range of 206 helicopter landing gear. The service bulletins (206-94-78 for the 206A/B models) call for the replacement of all subject crosstubes with an improved crosstube, no later than 30 September 1994. Presently there is no Airworthiness directive mandating the replacement of the Bell crosstubes. The failed crosstube was an original model with approximately 14,000 hours time in service at the time of the occurrence.