Doran Jaffas
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Didn't hear about this on the news. This airport's about 15 minutes air time from my home base.
Crashes in the News - Thread
- Thread starter choppergirl
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Turd Ferguson
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It's one of Great Lakes Air Venture's Twin Commanches. One person on board, a renter age 60-ish was uninjured.
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Turd Ferguson
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"Well folks, looks like we still have 90,000 lbs of thrust remaining so other than a sight decrease in performance, there is no cause for alarm....."
Doran Jaffas
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It just makes for an uncomfortable day for that pilot. Sorry to hear that. Thanks for replying.
Richard6
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Well they missed the "big one" as they say in NASCAR. It appears that a part of the engine struck the fuselage of the aircraft under the wing. It that part would have hit the cablin of the aircraft about 4 feet higher, there would/could be serious consequences.
It is not clear at this time what the altitude that aircraft was at when the engine blew. If the cabin was under pressure, the resulting hole in the cabin would have cause considerable decompression.
Reports said that he had just taken off.
Turd Ferguson
Well-Known Member
Engine blew at 13k airport elevation is 5000 so delta p on the fuse ~2.0 psi?
That makes sense... Broomfield (where the engine parts landed) is not very far from DEN.
David L. Downey
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All true ..but what if the fan blade that departed and possibly sliced through the inlet lip had continued through the cabin side and passenger(s)?
Worried about that kind of failure consequence every time I got aboard. Those huge fan blades scare me!
Worried about that kind of failure consequence every time I got aboard. Those huge fan blades scare me!
The containment ring on that PW4000 engine appears to be intact, so the majority of the highest energy blade debris was prevented from exiting the engine/nacelle. But, as frequently happens, parts can escape forward, and they still have enough energy to do damage.
Modern turbofans are tremendously reliable, and safe. Still, I'll admit to a little uneasiness when seated near the back of a DC-9 and its descendants, looking out the window and seeing that engine about 18” from my head. "Great. Get decapitated at worst. At best, I get to listen to this thing for the entire trip while basking in the aroma of the lavatory right behind me."
Modern turbofans are tremendously reliable, and safe. Still, I'll admit to a little uneasiness when seated near the back of a DC-9 and its descendants, looking out the window and seeing that engine about 18” from my head. "Great. Get decapitated at worst. At best, I get to listen to this thing for the entire trip while basking in the aroma of the lavatory right behind me."
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wktaylor
Well-Known Member
Looks like ONE, possibly TWO, of the hollow fan blades failed simultaneously... or in rapid sequence... due to fatigue cracking. Blades are hollow for weight and cooling. Damage to United Boeing 777 engine consistent with metal fatigue, NTSB says
When a rotating blade [engine fan, compressor, turbine... or propeller] is suddenly 'liberated' it 'follows the combined forces' already on-it... thrust, pitching, rotation, twisting, etc... combined with any secondary impacts or structural damage [ricochet, blunting, splitting, etc].
The path/motion that happens to the blade segment after sudden liberation can appear to be 'PFM'... but it actually is the resultant of the combined raw massive-forces and 'other damage' acting simultaneously... pure physics... especially at takeoff thrust for a heavy weight jet. AND this is a huge engine!
When a rotating blade [engine fan, compressor, turbine... or propeller] is suddenly 'liberated' it 'follows the combined forces' already on-it... thrust, pitching, rotation, twisting, etc... combined with any secondary impacts or structural damage [ricochet, blunting, splitting, etc].
The path/motion that happens to the blade segment after sudden liberation can appear to be 'PFM'... but it actually is the resultant of the combined raw massive-forces and 'other damage' acting simultaneously... pure physics... especially at takeoff thrust for a heavy weight jet. AND this is a huge engine!
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And, it is "extra fun" on a long Herc flight if the prop sync is turned off or just slightly "off"
BUZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ...
Still, I suppose things are much worse in a big 4 engine recip.
Richard6
Well-Known Member
Another question.
I've often read or heard the sometimes when a passenger jet has to make a landing short of the destination, they have to dump fuel because they can not land when weighed down with all that unused fuel. I did not hear that this flight dumped fuel. So why was it OK to land with a heavy fuel load? Yes I understand the urgency of the situation, but either it is OK to land heavy or not?
OK more than one question,
How is it possible for a commercial jet to take off with a large fuel load but not land with the same load?
Richard
I've often read or heard the sometimes when a passenger jet has to make a landing short of the destination, they have to dump fuel because they can not land when weighed down with all that unused fuel. I did not hear that this flight dumped fuel. So why was it OK to land with a heavy fuel load? Yes I understand the urgency of the situation, but either it is OK to land heavy or not?
OK more than one question,
How is it possible for a commercial jet to take off with a large fuel load but not land with the same load?
Richard
Landing forces are higher than take-off forces. Overweight landings can be done (as in this case), and an inspection is required. But with a smooth landing like this, there will be no issue.
Jetliners frequently take off with more fuel than is permitted for their normal landing weight. As part of the preflight briefing, the crew computes and briefs the amount of fuel the can safely land with (which depends on runway length and conditions, and can exceed their normally allowed landing weight by a lot). If they need to dump fuel, they can do it, but if they land above the normally allowed weight it just prompts some special analysis after landing (esp a look at vertical speed at touchdown) and some inspections.
Also, on the case of the 777, dumping fuel is not recommended if there is an engine fire.
Dumping fuel makes the folks below unhappy and requires some extra paperwork. Still, I'd hope every crew would do it in a particular case if it enhanced the safety of passengers.
Folks who know more will chime in, hopefully.
davidb
Well-Known Member
I’ve heard this particular 777 was at or near max landing weight at takeoff so no need to dump fuel.
Turd Ferguson
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Fuel dumping is kinda thing of the past. If you have to land you just land overweight and maintenance takes over after that. They may have to do an inspection on the plane. Scope and detail of the inspection depends on how the landing is recorded by the boxes.
YouTube analysis here
David L. Downey
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I Grew up in Brazil.
The pilots of the twin and 4 engine airliners of the day loved to abuse the pax seated over the wing by intentionally not synchronizing the engines...especially DC-4s! The grind would perceptibly drive back and forth across the cabin from side to side. Meanwhile they could be seen with hands-on the throttles looking back at us and grinning. Loved those planes though...
