Live Updates: United plane’s engine explodes after takeoff from DIA; debris falls from sky
The broken blade(s) caused damage to the fuselage.
Photos taken Saturday after the plane returned to the Denver airport show a gaping hole under the right wing, suggesting some of the engine debris struck the plane itself. Sumwalt acknowledged the aircraft's underbody was damaged but said the damage wasn't structural. The damaged part is a composite fairing that smooths out the plane to make it more aerodynamic.
The purpose of the Kevlar fan barrier is to contain the blades when they break. In this case, 1 of the 22 blades first broke at the base, struck the blade next to it and broke that roughly halfway up. Then a blade was kicked out the front, lodged in the ring and broke the ring off - starting the disintegration if the entire cowling. Think of a plastic bag held in front of a strong fan and blowing up then breaking - that is apparently what happened when the cowl ring separated.
This is all from the preliminary NTSB report calling out metal fatigue on the PW engine series used here. As for the damage to aerodynamic fairing - waiting to see if that was from the cowling coming off and striking or if the blade hit the fairing. They recovered one blade in embedded in the cowling ring and another from a field apparently so no blades were found embedded in the plane. To me - this is looking like a contained fan blade breakage but ... the cowling essentially being blown off was not anticipated in testing and led to the damage you are seeing.
Either way - awesome job by the crew to get this plane down, and smart call not doing a ground evac. Juan Brown/BlancoLirio channel on YouTube has a good overview just prior to the NTSB Preliminary report.
“Forigive your enemy, but remember the bastard’s name.”
-Scottish proverb
February 23, 2021, 11:21 AM
sns3guppy
About seventeen years ago I watched a 777 shed a lot of material from an engine, during a catastrophic failure, in Saudi Arabia. At about 1,000' on takeoff at Riyadh, a bang occurred, with smoke, and I watched a large volume of parts exit the rear of the engine and fall. The airplane made a left turn on a crosswind, downwind, and returned to land uneventfully. Much like the airplane in Denver.
Despite the very significant amount of damage, no rotating parts exited the engine, into the fuselage.
There's no evidence yet that a fan blade did the fuselage damage to the UAL 777 at denver; the fact that the entire nacelle and afterbody separated, however, provided ample material departing the engine pod to cause damage; it's very possible that the nacelle did that. That's significant because the nature of the damage from rotating parts ejected from the engine, vs. items blowing aft, is radically different.
I arrived in UAE on a flight from Kandahar, Afghanistan, some years ago, to find a large amount of damage to one engine. It looked like a grenade went off in there, with numerous missing part of blades and other damage. The flight from Afghanistan, and the approach and landing, was uneventful. It was one of 61 engine failures I'd had up to that time, some more eventful. One of those events became a forced landing, during a firefighting flight on an active forest fire, and resulted in putting the airplane on the mountainside.
The drama that's been whipped up in the media with the UAL 777 event makes it seem like quite an event; from a crew perspective, it was notable, but handled exactly as expected, with full controllability and a safe outcome. There were clearly several elements of the event noteworthy and of concern, from damage to the fuselage to parts falling in populated areas, to external combustion (fire) which remained until landing. Never the less, even with the damage that's been so well documented, the event could have had a much worse outcome; the fact that it appears as contained as it was, is a significant testament to the engine and modern turbojet engines in general.
Despite dramatic public events like the one in discussion, these events are rare. Browne stated he'd had one failure in 14 years. Many pilots have never had an engine failure. While mine have been light piston, large radial, turboprop and turbojet, most were on large radials, which have a much higher incidence of failures. The rarity of these events today is quite remarkable; again, quite a testament to modern equipment, maintenance, and technology. Given the number of operating hours and the demands placed on this equipment, it's all the more remarkable.
February 23, 2021, 12:45 PM
corsair
February 23, 2021, 11:08 PM
V-Tail
United Airlines Unveils New Environmentally Friendly Single-Engine Boeing 777
February 23rd, 2021
DENVER, CO—United Airlines announced the arrival of their new, environmentally friendly single-engine Boeing 777 at a press conference Tuesday. This comes after a successful test flight on Saturday at Denver International.
United said the new airliner, dubbed the "777 Eco," will be twice as energy efficient, due to having 50% fewer engines. In addition to lower carbon emissions, the plane will also provide a much quieter ride for passengers seated on the right side of the cabin.
“Turns out you really only need one engine to fly these puppies,” said a United spokesperson. “After a short test flight around Denver and an exciting fireworks show, we are proud to announce the brand-new Boeing 777 Eco!"
The spokesperson claimed previous reports that a normal airliner had suffered engine damage were false. “There was no emergency-- this was all planned in advance,” she noted. “We wanted to illustrate that the 777 Eco is symbolically blowing up the concept of twin-engine airliners and that we’re sprinkling the city with the symbolic shrapnel of lower emissions!”
Officials said safety was a top priority when designing their new plane, and that the single-engine design shouldn’t be of concern to passengers. “These jet engines are pretty safe,” the spokesperson noted. "And with one less engine, that's one less thing that can blow up! Win-win!"
הרחפת שלי מלאה בצלופחים
February 24, 2021, 08:22 AM
Ozarkwoods
quote:
Originally posted by r0gue: Finders keepers! That would make an AMAZING fire ring.
Juan Brown has an interview with captain of a UAL 777, Capt. Behnam that went through similar 200 miles outside of Honolulu. Pretty cool and obviously damn fine job by that pilot and crew.
“Forigive your enemy, but remember the bastard’s name.”
-Scottish proverb
March 03, 2021, 01:07 PM
corsair
^^^^Keep in mind, this pilot's incident was in 2018 and not the recent DEN-HNL incident.
Juan Brown has an interview with captain of a UAL 777, Capt. Behnam that went through similar 200 miles outside of Honolulu. Pretty cool and obviously damn fine job by that pilot and crew.
Fantastic, edge-of-your-seat interview with Captain Behnam. I'm going to have my wife watch it.
_________________________ “ What all the wise men promised has not happened, and what all the damned fools said would happen has come to pass.”— Lord Melbourne
