The US aviation regulator on Tuesday ordered a more thorough inspection of engines similar to those of a Boeing 777 which suffered a dramatic failure over Denver a few days earlier.
The incident, in which a Pratt & Whitney engine caught fire and scattered debris over a Denver suburb shortly after takeoff for Honolulu, led to dozens of Boeing 777s stranded in the world for security reasons.
“US operators of aircraft equipped with certain Pratt & Whitney PW4000 engines (must) inspect these engines before continuing with flight,” said the Federal Aviation Administration (FAA).
The regulator said he was issuing the order “following a fan blade failure on Saturday on a Boeing 777-200 that had just left Denver International Airport.”
Before they can return to the sky, “operators must perform a thermo-acoustic imaging (TAI) inspection of the large titanium fan blades on the front of each engine. TAI technology can detect cracks on interior surfaces. hollow fan blades, or in areas that cannot be seen on visual inspection, ”he said in a statement.
Metal fatigue emerged as the prime suspect in the engine failure, which left no injuries.
Steve Dickson, the FAA chief, said at a town hall on aviation safety earlier on Tuesday that “we want to understand what happened and take the necessary steps to prevent such a situation from happening again. “.
“We are fortunate that there were no deaths or injuries,” Dickson added.
The near-crash over Denver was another setback for Boeing, which only recently resumed deliveries of the 737 MAX on the ground following two fatal crashes.
It also raises new questions about the FAA, which has come under heavy attack for its oversight of Boeing in certifying the 737 MAX, and whether maintenance was adequate on the plane, aviation experts have said.
Even before the Denver incident, U.S. aviation safety regulators had weighed more stringent inspections on the jets and their Pratt & Whitney engines, U.S. officials said Tuesday.
The FAA reviewed inspection records and maintenance history after a Japan Airlines fan blade incident on December 4 last year “to determine the cause of the fracture and assess whether to adjust inspections blades, ”an FAA spokesperson said Tuesday. The flight landed in Japan without injuries.
Following an incident in February 2018 with another United aircraft, the FAA reviewed 9,000 fan blade inspection reports and issued an airworthiness directive setting out new rules for inspections.
– Metal fatigue –
In a briefing Monday, the National Transportation Safety Board said it was too early to know if the problem in Denver was similar to the Japan Airlines flight, or the February 2018 incident, which involved another Boeing 777. and Pratt & Whitney.
“A preliminary on-site examination indicates damage consistent with metal fatigue,” said NTSB Chairman Robert Sumwalt.
He said two fan blades fractured on the number two engine of the Boeing 777-200 on Saturday. One of them was later found on a football field, while the other remained lodged in the engine.
The NTSB also plans to look at the United plane’s inspection record to see “who knew what, when, what could have been done and what should have been done,” Sumwalt said.
“Fatigue means you can have a crack in the material and when you load it over and over again, the crack slowly grows,” said Robert Kielb, professor in the School of Engineering at Duke University.
“This is an example of an event where we learn something about the design 20 years after it goes into service, then immediately put the fleet on the ground, find out what’s going on and fix it.”
– Headache for Boeing –
Following the Denver incident, Boeing said all 128 of the 777s fitted with Pratt & Whitney engines were grounded.
Of the 128 planes, only 69 were in service while 59 were in stock.
In addition to United, which withdrew 24 planes from service, the airlines affected included Japanese carriers Japan Airlines and All Nippon, as well as South Korean companies Asiana and Korean Air.
On Monday evening, a Delta Air Lines flight on a Boeing 757 en route to Seattle from Atlanta was diverted to Salt Lake City “as a precaution following an indicator warning of a possible problem with one of its engines” , a Delta spokesperson mentioned.
“The flight landed safely without incident and taxied to the boarding gate unassisted.”
Boeing only recently resumed deliveries of the 737 MAX after a 20-month global grounding after two crashes killed 346 people.
The MAX began returning to commercial service at the end of 2020, with air travel still depressed due to the coronavirus pandemic.
Boeing executives said last month they expected it would take about three years for activity to return to pre-pandemic levels.
Michel Merluzeau, expert at the consulting firm AIR, admitted that the last problem did not seem to be the result of poor design of the aircraft.
“It’s not really a problem for Boeing,” he said. “It’s more about maintenance – how United or Pratt & Whitney maintain engines that have been in service for a while.”
The episode “is an embarrassing headline, but as a practical matter it will have no impact on Boeing,” said Scott Hamilton of Leeham News, an aviation news site.
(Except for the title, this story was not edited by The Bharat Express News staff and is posted Platforms.)