Navy’s P-8As Unaffected by FAA’s Boeing 737 Engine Inspection Requirement After Fatal Southwest Incident

April 23, 2018 5:58 PM
Aviation Machinist Mate 1st Class Joseph Ihrig, left, and Aviation Machinist Mate 2nd Class Miko Brandon, right, both assigned to Patrol Squadron (VP) 4, perform a fan blade loop inspection on a P-8A Poseidon aircraft onboard Naval Air Station Whidbey Island’s Ault Field on Dec. 6, 2017. VP-4 is currently conducting its Fleet Readiness Training Plan in preparation for their upcoming deployment. US Navy photo.

The Navy’s fleet of P-8A Poseidon aircraft are not in any immediate risk of facing the same engine failure that caused the April 17 emergency landing of a Boeing 737 – which the P-8 design is derived from – a Navy spokeswoman told USNI News.

The Federal Aviation Administration on Friday issued an emergency airworthiness directive mandating that any plane whose CFM56-7B engine had conducted more than 30,000 takeoff-and-landing cycles must be inspected within 20 days. This would affect 352 engines in the U.S. and 681 engines worldwide, according to the FAA statement.

However, the Navy’s P-8s are not among them. Though the P-8 – which is built on the same 737 production line as the commercial planes but then pulled aside for the addition of military-specific gear – uses the same CFM56-7B engine, “there is no immediate risk to or action to be taken by the P-8A community. The Navy’s P-8A engines remain well below the cycle limit for required inspections of fan blades,” P-8 program office spokeswoman Denver Beaulieu-Hains told USNI News today.
“The FAA mandates inspection [for commercial aircraft] to start at 20,000 cycles, while the current high-time P-8A has accrued 5,175 cycles (as of 13 Apr 18) since it entered service in 2012. At the current cycle rate, the first engine in the P-8A fleet will hit the 20,000 cycle point in about 10 to 15 years.”

Lt j.g. True Jones, a pilot assigned to the “Skinny Dragons” of Patrol Squadron (VP) 4, climbs aboard a P-8A Poseidon aircraft at Naval Air Station Whidbey Island’s Ault Field during a routine maintenance check on Jan. 22, 2018. US Navy photo.

Beaulieu-Hains said that Naval Air Systems Command had previously determined that the P-8 engines’ fan blades – the component that failed in the Southwest Airlines Flight 1380 incident at more than 30,000 feet altitude that killed one passenger and forced an emergency landing – would be inspected when the planes are brought in for their first scheduled depot maintenance visit, which would occur “no later than the 6,000-cycle threshold, with a recurring 6,000-cycle inspection interval through 20,000 cycles. After 20,000 cycles have accumulated, the engine will be inspected at a 3,000-cycle interval,” she said.

Boeing has sold its P-8A to the U.S. Navy, the Royal Australian Air Force and the United Kingdom Royal Air Force, and its P-8I variant to the Indian Navy. The Navy has 64 planes in its inventory as of January and is slated to buy 111 total, according to NAVAIR.

Megan Eckstein

Megan Eckstein

Megan Eckstein is the former deputy editor for USNI News.

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