Pratt & Whitney’s jet engines in spotlight
DENVER: Showers of jet engine parts over residential areas on both sides of the Atlantic have caught regulators’ attention and prompted the suspension of some older Boeing planes from service.
Sunday’s incidents involving a United Airlines 777 in Denver and a Longtail Aviation 747 freighter in the Netherlands put enginemaker Pratt & Whitney in the spotlight, though there is no evidence they are related.
Pratt & Whitney said it was coordinating with regulators to review inspection protocols. It is expected to increase inspections ordered after previous incidents.
After the Colorado engine failure, when United Flight 328 dropped debris on a northern Denver suburb before landing safely, Boeing recommended the suspension of 777s with the same variant of PW4000 turbine. Japan, meanwhile, imposed a mandatory suspension.
Damage to a fan blade on the engine that failed on United Flight 328 was consistent with metal fatigue, based on a preliminary assessment, the chairman of the US air accident investigator said yesterday.
The Pratt & Whitney PW4000 engine failed with a ‘‘loud bang’’ four minutes after takeoff from Denver, National Transportation Safety Board chairman Robert Sumwalt told reporters after an initial analysis of the flight data recorder and cockpit voice recorder.
He said it remained unclear whether the incident was consistent with an engine failure on a different Hawaiibound United flight in February 2018 that was attributed to a fatigue fracture in a fan blade.
‘‘What is important that we really truly understand the facts, circumstances and conditions around this particular event before we can compare it to any other event,’’ he said.
The European Union Aviation Safety Agency (EASA) weighed in yesterday, requesting more information on the Pratt engines in light of the weekend’s events. A woman sustained minor injuries in the Dutch incident, which scattered turbine blades on the town of Meerssen. One was found embedded in a car roof.
After receiving more information, EASA said the incidents were unrelated
The US Federal Aviation Administration (FAA) said it would soon issue an emergency airworthiness directive based on the United event.
Both incidents involve the same type of PW4000 engine that equips a relatively small number of older planes, some grounded by the Covid19 pandemic, limiting the likely repercussions.
They bring a new headache for Boeing as it recovers from the much more serious 737MAX crisis, which resulted in the grounding of its flagship narrowbody jet after two deadly crashes.
‘‘This is certainly an unwelcome situation for both Boeing and Pratt, but from time to time issues will pop up with aircraft and engines,’’ Flight Global managing editor Greg Waldron said.
‘‘The PW4000powered 777200 is slowly fading from service,’’ adding that the pandemicdriven slump meant airlines forced to suspend it ‘‘should be able to fill any network gaps’’ with 787s or other 777s equipped with General Electric engines.