Air traffic safety officers focus on engine fan blades in their investigation into the causes of a massive fan blade Engine failure aboard a Boeing 777-222 airliner on Saturday that scatters huge pieces of aircraft over the suburbs of Denver.
This engine failure can be related to several others that stretch for years. But first, let’s review the details of the recent event.
United Airlines Flight 328 towards Honolulu reported a right engine failure shortly after leaving Denver International Airport at 12:49 p.m. The engine caught fire and began to disintegrate as the passengers recorded and photographed the failing engine in flight.
Chad Schnell was among the passengers in the front row, looking at the damaged and burning engine. He saw that in front of the window:
Some of the missing engine parts ended up on someone else’s lawn in Broomfield, Colorado.
Debris is strewn in the front yard of a home near 13th and Elmwood, Saturday, February 20, 2021, in Broomfield, Colorado in this photo shared on Twitter by the Broomfield Police Department.Broomfield Police Department via AP
Here’s a scale comparison to put that in perspective:
The aircraft with 231 passengers and 10 crew members returned to Denver and landed safely shortly after takeoff. Fortunatly nobody was hurt.
Who makes the engines for the Boeing 777?
For United Airlines Flight 328, it was Pratt & Whitney, a subsidiary of defense company Raytheon. After you Parent company“Pratt & Whitney designs, manufactures and services the world’s most advanced aircraft engines and auxiliary propulsion systems for commercial, military and corporate aircraft.”
The Federal Aviation Administration has mandated enhanced fan blade tests for Pratt & Whitney PW4077 engines such as those used by the United 777. Commercial airlines around the world have suspended their 777s pending investigation. Boeing has recommended the cessation of operations of the 69 in service and 59 in stock 777 Pratt and Whitney 4000-112 engines until further notice.
United has 44 other Boeing 777s, all with GE engines that are not affected by United’s 777 grounding or FAA policy. For example, the airline will use one of these planes to fly between San Francisco and Taipei, Taiwan in March instead of one of its grounded 777s, according to United spokesman Charlie Hobart.
American Airlines has 67 Boeing 777s in its fleet. They are powered by Rolls-Royce and GE engines, which are also not affected by the FAA directive. The planes were used for international flights before the pandemic and are now widely used for flights within the United States, spokeswoman Sarah Jantz said.
Has that happened before?
Another incident involving a Boeing aircraft powered by Pratt & Whitney engines dropped engine parts after a separate explosion in the air over the Netherlands that same day.
The Dutch incident involved a Boeing 747 cargo aircraft powered by Pratt & Whitney PW4000 engines, a smaller version of the United Airlines Boeing 777 that was involved in the Denver incident. according to Reuters. Longtail Aviation Flight 5504, a cargo plane, scattered small pieces of metal over Meerssen, causing damage and injuring a woman shortly after take-off on Saturday.
The troubled United flight is reminiscent of one from February 2018, in which a United Boeing 777 from San Francisco lost its engine cover and started shaking about an hour before Honolulu. But the plane could land safely The passengers were afraid. Investigators said a broken fan blade caused the failure.
This 777 also had Pratt & Whitney 4000 series engines, similar to those that failed on Saturday’s flights.
The NTSB report The 2018 failure was caused by a fan blade that broke off and damaged the engine. The board cited inadequate inspections of the fan blades and said the inspectors were not adequately trained.
Inspections of the failed fan blade in 2010 and 2015 had shown evidence of weakening the titanium, but an inspector traced them back to the way they were painted, according to the NTSB. Bloomberg reported that the engine was a Pratt & Whitney PW4077. The NTSB concluded that the Pratt & Whitney division of Raytheon Technologies Corp. has not created adequate testing standards.
In December, two fan blades broke off on a Japan Airlines 777-200 with a Pratt & Whitney 4000-112 engine on a flight from Naha to Tokyo. as reported by the Seattle Times.
The Associated Press reported The FAA wants more frequent inspections of the hollow fan blades used in Pratt & Whitney 4077 engines on United aircraft.
The National Road Safety Committee Two of the 777’s fan blades were broken, other blades were damaged, and part of it was embedded in the engine’s safety ring – metal or composite to hold broken blades in the engine Aerospace America.
The first examination of the NTSB showed:
- The inlet and hood were separate from the engine.
- Two fan blades were broken.
- A fan blade was broken near the root.
- An adjacent fan blade broke in the middle of the span.
- Part of a blade was embedded in the security ring.
- The rest of the fan blades showed damage to the tips and leading edges.
The NTSB said it was too early to draw any conclusions about what caused the engine failure. Most of the damage was confined to the engine and the aircraft suffered minor damage.
The investigation is still ongoing. The cockpit voice recorder and the flight data recorder are located in Washington, where the NTSB analyzes the data.
The 777 series is a twin-engine American wide-body aircraft manufactured by Boeing Commercial Airplanes. It is the largest double jet in the world and started flying in 1994. It was officially introduced in 1995.
United is the only US airline to have the Pratt & Whitney PW4000 in its fleet, the FAA said. United says they have 24 of the 777s in use.
The United 777 aircraft will be 26 years old on Saturday.
SOURCE USA TODAY Network Coverage and Research; National Road Safety Committee; Federal Aviation Administration; Associated Press; Aviation Week; Aerospace America; flightglobal.com; skybrary.com
Dawn Gilbertson, Javier Zarracina, Karina Zaiets, Jon Briggs, Steve Kiggins, and Shawn Sullivan contributed to this report.
Released 4:54 UTC February 23, 2021
Updated February 23, 2021 at 05:39 UTC