Plane Down in Hudson River - NYC

[lomapaseo]

So the engines (as I see it) WERE NOT at a governed, stabilized idle, even though the gages might have suggested that. They were trapped by their degraded steady-state line intersecting the accel schedule

So equal damage then? Wow and little fan damage evident.

So where's the damage? Low compressor or high compressor? and what is the EGT?

If the EGT is high than I agree it's damage, but if the EGT is low than it probably is a governed limit.

[dvv]

Dream Buster, have a look: Tupolev 124 ditching in Neva River - Wikipedia, the free encyclopedia

[barit1]

So where's the damage? Low compressor or high compressor? and what is the EGT?

There are a few sturdy low compressor stages bolted to the fan rotor, and they may be in fairly good shape - so I'm betting on:

1) primarily high compressor damage; and as a result,

2) high EGT - significantly higher than idle, anyway.

[billy34-kit]

rumour around Airbus, the front crew ''MAY'' haved **** up with one engine identification... time to put the hole hero thing on the hold!!

[barit1]

I'll believe it when I see the FDR traces.

[VFD]

So the engines (as I see it) WERE NOT at a governed, stabilized idle, even though the gages might have suggested that. They were trapped by their degraded steady-state line intersecting the accel schedule.

Sounds good to me. Let me point out the turbines involved were not out of the can engines. FAA has been pretty much accepting engine manufacturers recommendations on leaving high time engines on frame.

I do not think the NTSB is going to let this accident slide through the cracks without testing injestion abilities on turbines that are long in the tooth compared to a fresh engine. Especially in light of a "pressure sensor" failure on one of the turbines just days before causing a surge.

VFD

[lomapaseo]

I do not think the NTSB is going to let this accident slide through the cracks without testing injestion abilities on turbines that are long in the tooth compared to a fresh engine

Well this can open up a can of worms. It is a known fact that the engines are at least as good as the test engine when they come out of the shop. After that it's a case of how much wear. Nobody can dial in all the variables involved with an ingestion so the idea is to make the single demonstration test strong enough to get you through what mother nature deals up most of the time.

You can draw lines in the sand all you want but in the end they will be blown away by the next day when you leave them out in the open.

About all the NTSB can do as an investigating agency (not a regulator) is ask questions about the specific engines installed vs their maintenance history and manufacturers recommendations. They can have an analysis performed to show just how much operating margin was available at the time of the incident and then review this against published standards, AD's etc.

It there is a question about ingestion adequacy it needs to be asked against the acceptable regulatory standard at the time or against service history over time.

[lomapaseo]

barit1

There are a few sturdy low compressor stages bolted to the fan rotor, and they may be in fairly good shape - so I'm betting on:

1) primarily high compressor damage; and as a result,

2) high EGT - significantly higher than idle, anyway.

agree in principal

but I heard from day one that as both engines came out of the water there was notable damage to the front vanes on the LPC. I haven't seen any pics of this yet and it may be unique. I'm sure the investigators have already scoured the total fleet wide service history for any similarities

[barit1]

Allow me to point out that ingestion testing is usually NOT carried out using brand new, "out of the can engines". That's a needless expense; generally an engine to be used in a destructive test has as much tired, disposable hardware as can be scraped up. It's less expensive, and probably meets VFD's objective better too.

[News Shooter]

Sully answers the ditch switch question

Sully?s Tale | Flight Today | Air & Space Magazine

[Southernboy]

Recurrent training.

I notice he twice refers to "Annual recurrent training," is that only one sim ride a year & if so is that the norm in the US?

[DC-ATE]

Don't know what it is these days, but when I was flying we had two sim sessions six months apart. One was a PT (Proficiency training) and the other, a PC (Proficiency Check).

[MES Drvr]

Do not forget about the B-727 that landed in the water on approach to Ft. Walton Beach -I think- near Pensacola, FL. I cannot remember the details or if any body was killed. The flight was operated by National Airlines. The year was either 1976 or 78.

[Um... lifting...]

National Airlines Flight 193 - Wikipedia, the free encyclopedia

Fort Walton didn't make sense to me, as that airport is co-located with Eglin AFB, has precision radar and isn't particularly close to the water... about a mile from the water to the threshold IIRC.
Pensacola was where it occurred... which is also about a mile from the water to the threshold of Rwy 25... they were 1,000' lower than they thought they were, evidently. Three drownings... airplane sunk in 12 feet of water. The field is about 100' MSL and there are bluffs of about that height coming out of the bay... they're lucky the aircraft wasn't a little higher or the airport a bit farther inland or they would have been a smoking hole.

[mickjoebill]

It may be 70%, it may be 35% - the fuel control still is programmed to avoid compressor stall, and that's the limiting speed for the engine in that degraded state.
So the engines (as I see it) WERE NOT at a governed, stabilized idle, even though the gages might have suggested that. They were trapped by their degraded steady-state line intersecting the accel schedule.

As a layman when it comes to turbines, is this aspect of the event a control system design failure (under extreme circumstances) to command delivery of fuel?
If so, would a "bird strike" button that is programmed to deliver appropriate amount of fuel regardless of any other sensor inputs be a good idea?



mickjoebill

[barit1]

No - I wrote this paragraph to specifically address that:

He then creates an acceleration fuel schedule that is close to, BUT NOT ABOVE, the stall line. That way, when the pilot calls for acceleration, the control can predictably deliver that acceleration without stalling. Whether a mechanical or electronic control, it makes no difference; the principles are the same.

The acceleration fuel schedule is there for a very good reason, and trying to override this (i.e. pump more fuel) will do you NO GOOD WHATSOEVER.

[HotDog]

Recurrent training.

--------------------------------------------------------------------------------

I notice he twice refers to "Annual recurrent training," is that only one sim ride a year & if so is that the norm in the US?

I think the reference is to the annual emergency procedures training that may include ditching and live raft drills in a pool.

[forget]

Testimony
February 24, 2009

Statement of Peggy Gilligan, Deputy Associate Administrator for Aviation Safety Before the U.S. House of Representatives, Committee on Transportation and Infrastructure, Subcommittee on Aviation on US Airways Flight 1549


Testimony

[ATCNetwork]

Controller Patrick Harten talks about flight 1549

Controller Patrick Harten talks about flight 1549 - ATC Network - News Item

[kwh]

One thing that strikes me, as mere SLF...

...and with reference to Capt. Sullenberger's lament about the state of the piloting profession in the US, is that the two pilots at the sharp end of Flight 1549 were both hugely experienced people possibly at the chronological tail end of their careers. Ditto the cabin crew, I notice, probably (I speculate) for very similar reasons. Most people seem to regard this as a good thing, and for everybody else on board 1549 it obviously had no downside at all, but more holistically I wonder....

Clearly it was a bit of a result that Capt. Sullenberger was there to do the driving, but in ten years time he won't be. The co-pilot was another hugely experienced bloke, in fact more experienced than Capt. Sullenberger, with plenty of command experience of his own. Surely in a perfect world, you'd have a Captain Sullenberger on the flight deck, with somebody along side him of more tender years and with less experience learning his trade from one of the best. If this incident had happened in ten or fifteen years time, that's the guy who you'd (well, I'd) want to be taking over the driving when the excrement hit the air-conditioner. One wonders who, in fifteen years time, will be flying US domestic planes. Presumably not people who have had fifteen years and thousands of hours flying alongside people like Capt. Sullenberger or his co-pilot...