Unlikely. You can be sure that the FAA/NTSB pulled all relevant engine maintainance logs already.

The way I read it, they have the capability to comply with the AD without any additional maintenance staff or equipment.

thank you that would make more sense. still the wording is unfortunate.

many many years ago, during the first flight of the 767 one leading edge slat jammed and curled back over the leading edge- due to a poorly designed actuation linkage. The other side was as I recall could only be partially extended for the same linkage problem. The resultant landing was very fast so as to maintain control and had some very hot brakes as a result So the first 5 or 6 airplanes had to have major rework in that area before delivery. How do I know this? Was involved in the tooling side of the rework.

Slfool, Excellent find:ok:

ManaAdaSystem. Your post 340. Agree totally

350 Million Flight Hours with minimal problems on the CFM56 Family.
Sounds like a pretty good track record.
Risk is never ZERO.

Southwest gives US$5000 plus a US$1000 travel voucher to each passenger. This article also has a nice summary of other rapid decompression events in airline history. There have been many others in business jets and military aircraft.

https://www.bloomberg.com/news/artic...n-fatal-flight

This!

It seems strange to me that so many people here seem focused on generating magic bullet theories about how the departed fan blade struck a cabin window well aft of the event when most of the damage to the cowling was due to engine imbalance.

Is it so hard to believe that the massive forces shaking the cowling apart could to throw debris into the air-stream with sufficient force to dislodge a cabin window?

Given the delay between the initial blade failure and the window failure, I think the evidence available supports the hypothesis that pieces of the cowl, or other secondary debris struck the window as the unbalanced engine wound down.

I've seen enough footage of imbalanced rotating objects destroying things to know you should never underestimate the devastating effects such phenomena can have on their surroundings.

Note that in the first two videos below, the engines are mounted in test stands which are far more rigid than an airplane's engine pylon. In flight, I would expect a lot more movement of the engine during wind-down:


These videos are of helicopters, but illustrate how quickly things can go wrong when rotating parts are no longer balanced:

800 million, in fact, as of a couple of years ago.

Up In The Air: The World’s Hardest-Working Jet Engine Has Logged 91,000 Years in Flight

I don't see many posters maintaining that the departing blade struck the window, particularly in view of the NTSB's early finding that no window fragments were found inside the cabin.

As for the damage to the nose cowl being largely due to out-of-balance forces rather than to the blade scything through it, I think your earlier advice applies:

Anybody seen pictures yet of the remains of the failed fan blade?

It seems strange to me that so many people here seem focused on generating magic bullet theories about how the departed fan blade struck a cabin window well aft of the event when most of the damage to the cowling was due to engine imbalance.

The NTSB experts speculated it would be 12-15 months for their report to be concluded. it seems some patience is required by the amateurs. :bored:

In 355 replies there is very little comment about the 'piloting input' and about what was done and what you might have done; except for some total rubbish about RT. I'm glad there was this level of expertise up front. Given the severely reduced command time in some carriers worldwide this could have been a very different outcome.

Agree on the 7700, but do we have any indication that this was not done as part of the checklist or even memorized items?

Workload on the ground: I could not care less about that. The ground has infinite resources compared to the flight deck. The moment that an emergency becomes apparent, whether explicitly declared or not, that controller will already have help from either his supe or colleagues.

Moving workload from the controller to the flight deck, even if it is reduced by a factor 10, is a big no-no imho.

In the end, it boils down to this: the flight crew made it clear that they had a problem and needed to land immediately. From that point on, it is up to the controller to ensure that they get priority handling and as much air space as they need. And if you listen closely, the controller did warn them about traffic below them which was a factor during the initial descent. There was absolutely nothing unprofessional about either the flight crew or the controller.

And on a side note: ICAO standard phraseology exists for one purpose only: to ensure that flight crews and ATC have an unambiguous understanding of each other's intentions and communications. In many cases, that results in longer than strictly necessary speech to accommodate non-native English speakers. Being a non-native English speaker myself, I do appreciate that. At the same time, I cannot critique a native English speaking crew talking to a native English speaking controller diverting from standard ICAO phraseology in an emergency situation where communications and intent are clear on both ends.

In short: there was no need to explicitly yell "Mayday-Mayday-Mayday" or "we are declaring an emergency". It would only consume much needed brain cycles.

PineappleFrenzy

yes it's hard to believe

The blade loss video show large motions at the inlet, but motion alone is not enough. You have to couple it with mass and rate of change.

The even more challenging forces are gust loads in extreme turbulence or aircraft upsets and these don't end up like what you see in the pictures. As long as the inlet remains a box structure designed to aircraft principals it will hold up through all types of loadings.

my life just passed in front of me :)

PineappleFrenzy.

“Given the delay between the initial blade failure and the window failure, I think the evidence available supports the hypothesis that pieces of the cowl, or other secondary debris struck the window as the unbalanced engine wound down...”

Wound down sure. Absent a shaft brake or lock, what does windmilling do in such a circumstance?

Just about all aero structures have critical vibration frequency and amplitude limits. Engine cowling is no different.

It is primarily designed for noise suppression, with strength considerations for ramp rash (nose cowl) and anti-flutter properties (clamshell & nose cowling). Modern engine cowlings are not considered primary protective structures from high energy engine parts. That's the purpose of the engine and fan cases.

While obvious, it is useful to recall that blade out test rigs are designed primarily to evaluate the disk, fan, and fan case strength and performance. The inlet bell is a multi-purpose structure that has no bearing on the blade test data, by design, outside of the purpose of containing the high energy fragments.

The windmilling vibration loads are still tremendous - the FAA has made Boeing show that the rest of the aircraft can readily handle the blade out vibrations for an extended ETOPS diversion - it wasn't trivial.
One story was that after a blade out event on a 747, the aircraft vibrations were so severe the crew had difficulty reading the flight deck gauges (one variation of the story - perhaps antidotal - was that there was a Boeing exec on the flight - after the flight he promptly asked engineering to go make sure the aircraft could handle that level of vibration..)