FAA requires operators inspect PW210s powering some Sikorsky and Leonardo helicopters

The US order comes after Transport Canada issued an emergency airworthiness directive.

The Federal Aviation Administration is requiring helicopter operators to promptly complete inspections of some Pratt & Whitney Canada (P&WC) PW210 turbines due to a problem involving exhaust frame cracks.

The agency mandated visual inspections in an airworthiness directive (AD) released on 26 June, a move coming after Transport Canada issued a related emergency AD in May addressing the issue, which affects PW210As, PW210A1s and PW210Ss.

Leonardo Helicopters AW169s have PW210As and Sikorsky S-76Ds are powered by the PW210S. The FAA’s order applies to 48 turbines on US-registered helicopters.

“This AD was prompted by reports of circumferential cracks found at the turbine exhaust frame external surface, caused by thermal stress from engine starts,” says the FAA’s order, which takes effect on 14 July.

“A manufacturer investigation revealed that the cracks originated from a turbine exhaust frame wall found below the minimum required thickness,” it adds.

The FAA is unclear how quickly the cracks might spread but says the problem could cause turbine exhaust frames to fail.

The AD requires visual inspections as specified in Transport Canada’s order. Operators will need to complete those inspections on engines that have logged more than 7,000 cycles within 5h of flight time or 20 engine starts, whichever comes first.

Engines with 2,000-7,000h must be inspected within 50h or 200 starts, and inspections must be repeated at intervals of less than 200 starts.

Also, operators who find cracks exceeding 9.5in (24.1cm) must ground the aircraft until they replace the component.

The US regulator did not follow its typical process of accepting comments before finalising the rule.

“The risk to the flying public justifies forgoing notice and comment prior to adoption of this rule because multiple circumferential cracks at the turbine exhaust frame external surface have been reported,” the AD says.