The CH-53K transport helicopter program has found a mechanical problem in the main gearbox and is in the process of designing a fix, according to a Navy official.

Quill rods that hold the gearbox together near the main rotor cracked due to vibration experienced during ground testing in Stratford, Conn., and West Palm Beach, Fla., said Rear Adm. C.J. Jaynes, the Navy’s program executive officer for air anti-submarine warfare, assault and special mission programs. Engineers plan to make the rods thicker or introduce some other technology to dampen the vibration.

The prototype CH-53K. Photo: Sikorsky
The prototype CH-53K. Photo: Sikorsky

Jaynes, who spoke April 14 at the Navy League’s Sea-Air-Space Exposition, said “this is not an unusual failure for a new gearbox” and that “we’re looking to have a solution in place around the July timeframe.” She said the problem is not expected to cause a significant delay in the program, which is slated to have its first flight by year’s end.

The CH-53K, whose prime contractor is Sikorsky Aircraft, a division of United Technologies [UTX], is being developed to replace the Marine Corps’ aging CH-53E Super Stallion heavy-lift helicopter. The Marines plan to begin fielding the new helicopter in 2019 to transport troops, equipment and supplies from ships to land.

The Navy continues to address problems found in the CH-53E after a Navy MH-53E Sea Dragon caught fire and crashed in January 2014, killing three sailors aboard, Jaynes said. Fuel lines, wiring harnesses and hydraulic lines are being inspected in the CH-53E fleet of about 150 aircraft.

“It’s a very intense inspection and it’s taken several of the aircraft out of service until we get the inspections done,” she said.