Accident and Serious Incident Reports: Helicopters

On 15 July 2002, a Sikorsky S-61 helicopter operated by Bristow suffered a catastrophic engine failure and fire. After an emergency landing and evacuation, the aircraft was destroyed by an intense fire.

On 24 February 2008, a Sikorsky S-61N being operated by British International Helicopters on a passenger flight from Værøy to Bødo attempted a visual approach at destination in day IMC and came close to unseen terrain before accepting an offer of assistance from ATC to achieve an ILS approach to runway 07 without further event. None of the 18 occupants were injured.

On 12 March 2009, a Sikorsky S-92A crew heading offshore from St. John's, Newfoundland declared an emergency and began a return after total loss of main gear box oil pressure but lost control during an attempted ditching. The Investigation found that all oil had been lost after two main gear box securing bolts had sheared. It was noted that ambiguity had contributed to crew misdiagnosis the cause and that the ditching had been mishandled. Sea States beyond the capability of Emergency Flotation Systems and the limited usefulness of personal Supplemental Breathing Systems in cold water were identified as Safety Issues.

On 28 December 2016, yaw control was lost during touchdown of a Sikorsky S92A landing on a North Sea offshore platform and it almost fell into the sea. The Investigation found that the loss of control was attributable to the failure of the Tail Rotor Pitch Change Shaft bearing which precipitated damage to the associated control servo. It was also found that despite HUMS monitoring being in place, it had been ineffective in proactively alerting the operator to the earlier stages of progressive bearing deterioration which could have ensured the helicopter was grounded for rectification before the accident occurred.

On 23 August 2018, a low experience Sikorsky S92 First Officer undergoing line training made a visual transit between two North Sea offshore platforms but completed an approach to the wrong one. The platform radio operator alerted the crew to their error and the helicopter then flew to the correct platform. The Investigation attributed the error primarily to the inadequate performance of both pilots on what should have been a straightforward short visual flight but particularly highlighted the apparent failure of the Training Captain to fully recognise the challenges of the flight involved when training and acting as Pilot Monitoring.

On 24 July 2019, whilst a Sikorsky S92A was commencing a second missed approach at the intended destination platform, visual contact was acquired and it was decided that an immediate visual approach could be made. However control was then temporarily lost and the aircraft almost hit the sea surface before recovery involving engine overtorque and diversion back to Halifax. The Investigation concluded that the crew had failed to safely control the aircraft energy state in a degraded visual environment allowing it to enter a vortex ring condition. As context, operator procedures, Flight Manual content and regulatory requirements were all faulted. 

On 14 October 2019, a Sikorsky S92A manoeuvring below low cloud in poor daylight visibility in an unsuccessful attempt to locate the intended private landing site flew north towards rising ground approximately ¾ mile east of it, coming within a recorded 28 feet above terrain near to occupied houses before making an emergency climb and over-torqing the engines followed by an unstable but successful second approach. The Investigation found relevant operator procedures absent or ineffective, an intention by the management pilot in command to reach the landing site despite conditions and uncertainty about the applicable regulatory context for the flight. 

On 14 March 2017, control of a Sikorsky S92A positioning in very poor visibility at 200 feet over the sea in accordance with an obstacle-marked FMS ground track in order to refuel at a coastally-located helipad was lost after it collided with late-sighted terrain ahead before crashing into the sea killing all on board. The Investigation attributed the accident to the lack of crew terrain awareness but found a context of inadequate safety management and issues with the operational control and oversight of the operations by the operator, and confusion regarding responsibility for, and the discharge of, aviation oversight of SAR operations in the state.

On 2 June 2012, a Dornier 328 and a commercially-operated Robinson R44 helicopter came into close proximity within the airport perimeter whilst both were departing from Bern in VMC as cleared. The Investigation attributed the conflict to inappropriate issue of clearances by the controller in a context of an absence of both a defined final approach and take off area and fixed departure routes to the three designated departure points.

On 26 September 2009, a Piper PA28-140 flown by an experienced pilot was about to touch down after a day VMC approach about a mile behind an S76 helicopter which was also categorised as 'Light' for Wake Vortex purposes rolled uncontrollably to the right in the flare and struck the ground inverted seriously injuring the pilot. The Investigation noted existing informal National Regulatory Authority guidance material already suggested that light aircraft pilots might treat 'Light' helicopters as one category higher when on approach and recommended that this advice be more widely promulgated.

Category: 

SKYbrary Partners:

Safety knowledge contributed by: