Plane down in Hudson River

[gtalum]

A compressor stall is not caused by fuel contamination. It's caused by a disruption of the airflow over the blades of the compressor fans. Like any airfoil, these blades can stall, and that causes the engine to lose power and then backfire when it reignites. This can result in the engine shutting down completely, or it can return to normal operation. Sometimes if the engine shuts down, it cannot be restarted easily, which is what happened with the double compressor stall last Thursday.

Compressor stalls can be the result of physical damage to the blades (most frequently from birdstrikes, very occasionally from pre-existing defects in the blades) or from operating the engine beyond it's service capabilities.

[Nimbus]

One news story I read said that they would still be able to recover bird strike DNA from the compressor blades even though the engines received a high pressure wash upon impact.

The compressor stall several days ago occurred 20 minutes into the flight perhaps after the engines had been throttled back. Compressor stalls usually occur when the engines are not spinning fast enough relative to altitude. An engine back firing could have caused the turbines to slow down enough that the turbine driven compressor stalled as well. The investigators will be meticulous, if there is even a slight chance that the engine outages were caused by factors other than simultaneous bird strikes they will find the cause.

[MGC]

I was on a Delta flight years ago in Atlanta that suffered compressor stall as we started our takeoff roll. About midway down the runway the pilot aborted the takeoff. The engine was making a loud popping noise under full thrust. My next most scary flight was a possible engine fire on a Northwest flight out of New Orleans. Pilot returned to MSY and we had to catch a different plane. I imagine the people on that US Air flight were scared bigtime....MGC

[Dionne]

Newsday.com is now reporting that last month the FAA made a statement regarding the CFM56-5B engine. The words used were to "closely monitor" this type of engine as compressor stalls, which are considered unusual events, have been happening. Suspect cause is "deterioration". There is a method of testing the engine....it has to do with the exhaust temperature.

At about the same time the French issued an air worthiness directive on the same engines.

While this has nothing to do with the bird strikes on Flight 1549 and subsequent stalls.....it certainly gets me to thinking.

Airbus is not alone with this engine. The CFM56 is also mounted on 737's.

[cycloneye]

Divers find engine

[HURAKAN]

Feather found on Hudson crash jet

US investigators examining the jet that ditched into New York's Hudson River last week say they have found a feather and evidence of "soft body impact".

Police divers have also found the jet's second engine at the river's bottom.

Investigators have already confirmed that a collision with a flock of birds caused the US Airways Airbus A320 to lose power and ditch in the river.

All 155 passengers and crew of Flight Flight 1549 survived the landing on the Hudson, which made headlines worldwide.

DNA analysis

"What appears to be organic material was found in the right engine and on the wings and fuselage," the National Transportation Safety Board (NTSB) said in its latest statement.

The right engine has been externally examined and "numerous internal components of the engine were significantly damaged".

Samples of the "organic material" are being sent to the Department of Agriculture for DNA analysis and the single feather "found attached to a flap track on the wing" is being sent to bird identification experts at the Smithsonian Institution.

The right engine remained attached to the airliner when it hit the water on 15 January.

The left engine separated and has now been located in mud on the bottom of the river near where the jet ditched.

It is expected to be lifted to the surface on Thursday, the NTSB said.

Evidence from the plane's flight data recorders confirmed the testimony of pilot Capt Chesley B "Sully" Sullenberger that the plane had collided with a flock of birds.

The recorders show both engines cut out simultaneously and the sound of thumps can be heard after Capt Sullenberger remarks about approaching birds.

The plane had only managed to reach a top altitude of 3,200ft (975m).

The 155 passengers and crew were rescued from the sinking aircraft by boats - Capt Sullenberger was the last to leave after checking the plane for any remaining passengers or crew.

Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/1/hi/w ... 843798.stm

[somethingfunny]

A singular feather? O_o

Is it known if Captain Sullenberger (a native of my adopted hometown of Denison, TX!) was also on the flight two days prior that had the suspected compressor failure?