Breaking News: Plane lands safely in CO after dropping parts

According to “Ask a Pilot”, it refers to the size (weight) of the aircraft and wake turbulence, meaning ATC needs to know so they can keep the following airplanes separated the correct distance.

The actual pilots here can probably explain it better, but all planes above a certain maximum takeoff weight (regardless of how heavy they actually are at that moment) are referred to as “heavy” by ATC. It serves as a warning to other planes in the area to maintain greater separation, because big planes generate more wake turbulence that small ones. IICR the “heavy” label applies to all widebody aircraft, as well as some versions of the 757. And I think there’s a special designation for the A380, since it generates even more wake turbulence than a typical widebody.

Anyone in the area with an unusual surname, like “Darko” perhaps?


The corresponding term for A380 & larger airplanes (assuming any other such behemoths are ever built) is “super” as in “Denver Approach, Lufthansa 328 super at one two thousand feet.”

And in an oddly timed coincidence, in the Netherlands a 747 cargoliner landed safely after pieces fell off during an engine fire, slightly injuring two people on the ground.

Powered by a Pratt & Whitney PW-4000 series engine. Well, four of them. Kissing cousin to the PW-4000 series in the UA Flight 328 777. So, the FAA is a little displeased. FAA President just issued an Emergency Airworthiness Directive for the PW-4000 series engines in certain 777s. Statement viewable here.

“Immediate or stepped-up inspections” of those engines, “likely mean[ing] that some airplanes will be removed from service.”

Not a good day. I hope they find whatever is wrong. If there’s anything at all.

Great play-by-play commentary from takeoff to touchdown by Captain Joe here:

Maybe it is time to get rid of your Boeing stock, as yet another of their planes (this time a 747) started losing parts midflight, dropping wreckage that injured two unlucky devils on the ground (as well as some houses and cars) in the Netherlands, although thankfully like the 777, the plane managed to safely make an emergency landing, this time apparently somewhere in Belgium.

Perhaps the jetpack guy in LA has the right idea.

Maybe you should read reports more carefully - apparently this is an issue with a particular engine that is mounted in some Boeing airplanes and not the Boeing airframe design.

But do go ahead and unload your stock so others who are more informed can purchase shares cheaply and reap the benefits when this is sorted out and Boeing is on an upswing again.

Or maybe, not being an expert in any of this, I’m wrong.

Just sayin’ stock tips off an internet forum should be taken with a very large lump of salt.

Indeed, and and for that matter the PW4000 is also one of the engine options on the Airbus A330 (and A300 and A310, but I don’t think there are many of those in service anymore, except maybe hauling cargo).

Also, I think the PW4000 was actually a relatively unpopular engine option on the 777, although I’d have to look up the relative numbers. I’m pretty sure the majority of 777s use either GE or Rolls Royce engines, and are thus unaffected by the Emergency Airworthiness Directive. IIRC United is one of the few major users of P&W engines on the 777.

I missed the edit window, but I found a cite for the quote above.

Boeing said there were 69 777s with the Pratt & Whitney 4000-112 engines in service and another 59 in storage.

So yeah, relatively few 777s use that type of engine.


PW4xxx engines were not a huge commercial success. But they’re used on some small fraction of B757s, B767s, B777s, A300s, A310s, and A330s. Plus a bunch of USAF airplanes.

Agree with @Broomstick that this is a P&W issue, not a Boeing issue. Boeing will catch some heat, but P&W is the one on the hook for all the remediation costs.

I read this as “dropping pants”.

How long could the plane stayed in the air after the engine
exploded? In the video it looks like the engine was vibrating badly
after the explosion. Could metal fatigue cause the damaged
engine to break off of the wing?

Glad that no one was killed or injured. It seems fortunate
that this occurred over land and not over the middle of the

How long? In general for hours. The flight was scheduled for about 7 hours in the air, so they had that much fuel. Burn rate is higher at low altitude, but one engine can be more efficient than two. So maybe only 5 hours circling around Denver at relatively low altitude.

Whether vibrations would eventually rip the engine off is strictly unanswerable but is very unlikely. This is very far from the first such failure on long haul jets in general.

The engine wasn’t doing much good where it was, and in fact things might have gotten better, not worse, had it off broken off cleanly. Which they are designed to do if the loads get excessive, rather than wrenching out a big hunk of wing along the way.

In general, engine failures in flight are not high hazard events. Even those where parts get shed. Certianly much riskier than a flight where nothing goes wrong, but having an engine come apart mid-ocean is a major annoyance, but no reason for people to think death is certain and survival a miracle. More the opposite.

Interestingly, per NTSB today, they are considering this a contained engine failure, at least for now. The engine parts all stayed inside the engine case and were ejected out the back as designed. It was the comparatively flimsy cowling parts that came apart and punched some minor holes in the unpressurized part of the fuselage.

There definitely is concern about cowlings coming apart too readily. There’s a wildcard there that we don’t have good engineering on.

That’s a lot of weight to lose off one side of a plane. Why wouldn’t it just roll like this one

No, not like that. Decent thinking on your part, but not correct.

The thrust of the good engine makes the airplane want to turn towards the bad engine. If the bad engine fell off cleanly the lack of weight of the bad engine is a counterbalancing force that makes the overall situation more balanced, not less.

AA191 you linked to was a much different situation. They were just after liftoff and very slow. They had the wing flaps deployed to the takeoff setting which includes having leading edge flaps/slats deployed along the full span of the wing.

When AA 191’s left engine broke off it pivoted up and over the front of the wing, passing over the wing before falling to Earth. In the course of that it tore a massive hole in the deployed leading edge flaps/slats and ripped out a bunch of hydraulics. Which lack of hydraulic pressure then caused all the leading edge flaps on that wing to retract. That massively increased the stall speed of that one wing, but not the other one that was unaffected. The left wing promptly stalled and the airplane rolled over and died.

Had they been 50 knots faster they could have recovered from the lift asymmetry of two differently flying wings; but as slow as they were they had one completely unflyable wing and the ground only seconds away. That combo was not recoverable.

Thanks for that explanation. As always you can be counted on to make it understandable for us land lubbers.
Personal anecdote about AA191:
I grew up in Des Plaines and was attending a high school less than a mile from the crash site. I did not see the crash but several of my friends, who were outside for gym class and had an unobstructed view. As you can imagine, even in the time before cell phones, that news spread through the entire school within about 5 mins.

Thank you LSLGuy for your
excellent answer to my question.

LSLGuy has provided an excellent explanation. The visual confirmation is in the pre-crash photo, seen here: note that the heavy wing, the one still holding an engine, has rolled up rather than down.