Sikorsky issues ASB for mandatory S-92 checks

Lockheed Martin’s Sikorsky has issued a mandatory Alert Service Bulletin (ASB) affecting all S-92 helicopters.

The ASB is in response to a December 2016 incident involving a CHC S-92 that was attempting to land on a north sea oil and gas platform.

According to a preliminary report by the UKs Air Accidents Investigation Branch (AAIB) the S-92 got into difficulties whilst trying to land on the West Franklin platform, and left ‘minor damage’ to the helipad.

Following the report Sikorksy issued the ASB, saying that checks are required on the S-92s tail rotor pitch change shaft.

In a statement issued to Helicopter Investor, Sikorsky said “Safety is our top priority, and Sikorsky is working closely with our customer and investigative authorities to determine the root cause of the loss of tail rotor authority in the Dec. 28 installation landing. Although the investigation into the Dec. 28 incident has not been completed, Sikorsky released an Alert Service Bulletin on Jan. 10 to define additional interim inspection requirements for the S-92 Tail Rotor Pitch Change Shaft. Those procedures include an off-aircraft check of the PCS bearing and that check must be done before next flight with some leeway for getting back to base.”

“We are committed to keeping our customers informed. We will further communicate findings if the investigation reveals any safety or airworthiness issues that affect the S-92 helicopter fleet.”