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A320 crash in the Hudson River - history of stalls? 3
- Thread starter plasgears
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i agree, but there is probably a small fire under all the smoke ...
if there was this sort of "serious" event in the past, don't you think the engines would have been changed out ?
if the cause of the Hudson River ditching was bird strike, how would the previous event have affected this one ?
of course what they're chasing is the chance that the earlier event was "waved off" by Airbus, EASA, and the FAA (even though there was and AD issued for some underlying problem) and that the plane was affected in some way and this exasperated the recent bird strike.
of course too, there is the possibility that if this did happen then the earlier event allowed the plane to survive the bird strike (creating a "leak-before-burst" situation) but nobody would claim credit for that lucky chance.
if there was this sort of "serious" event in the past, don't you think the engines would have been changed out ?
if the cause of the Hudson River ditching was bird strike, how would the previous event have affected this one ?
of course what they're chasing is the chance that the earlier event was "waved off" by Airbus, EASA, and the FAA (even though there was and AD issued for some underlying problem) and that the plane was affected in some way and this exasperated the recent bird strike.
of course too, there is the possibility that if this did happen then the earlier event allowed the plane to survive the bird strike (creating a "leak-before-burst" situation) but nobody would claim credit for that lucky chance.
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The engines on this aircraft are result of the engineering and manufacturing expertise of P&W and Rolls Royce. Both of these companies have a reputation for building robust engines that take “Compressor Stalls” in stride. By the way a Compressor stall is generally associated with inlet airflow anomalies and nacelle inlet design, not the engine hardware, and except for the washingmachine-toothbrush-womens- hairdryer engine company compressor stalls are well tolorated and a common occurrence while taxing in hot weather.
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AD2009-01-01 effective Dec 31 08. On 15Dec08 an A321 powered by a CFM56-5B1/P experienced HPC stalls on both engines during climb out. The AD is concerned about EGT margin greater than 80degC. Greater than 80DegC requires a borescope insp. Failed borescope engine to be replaced and no aircraft to have two 80degC margin engines.
There is a lot of chatter about the A321 that crashed into the Hudson had a stall history, but nothing from an official source (doing a quick search)
There is a lot of chatter about the A321 that crashed into the Hudson had a stall history, but nothing from an official source (doing a quick search)
80 deg C Margin??? Is there any info related to hours in service? Is this only happening on climb-out under certain ambient conditions below ten thousand (250 Knot Restriction)? I’m a little curious about how an AD gets issued on this problem without these particular engines being removed, torn down, and subjected to intense scrutiny. The thing that jumps out at me is the fact that both these engines apparently experienced the same event at the same power setting at the same time under the same flight conditions. If there is some type of temp anomaly deriving a pressure differential that is initiating the HPC event I would seriously wonder why this would not have come up during the initial testing of the engine for Cert. plus the testing done on the A/C with Nacelle in place.
For the non engine guys: The Stall event is characterized by an instantaneous and severe reduction air flow while the compressor is still running at speed – at a certain pressure ratio. The pressure recovery is sudden (read loud bang) as the flow is restored.
Note to Plasgears… Sorry, just having a bit of fun at GE’s expense. GE engines tend to have better fuel efficiencies than PW and RR.
For the non engine guys: The Stall event is characterized by an instantaneous and severe reduction air flow while the compressor is still running at speed – at a certain pressure ratio. The pressure recovery is sudden (read loud bang) as the flow is restored.
Note to Plasgears… Sorry, just having a bit of fun at GE’s expense. GE engines tend to have better fuel efficiencies than PW and RR.
Not braggin', but large northern Can geese can easily exceed 10 pounds... I don't know about the area of the crash, but many cities in Manitoba and Ontario (and likely others) are having an increase in the resident goose population. Our office is located in a developed suburban area and we often have flocks of 50 to 100 birds.
Dik
Dik
In my opinion as a 35 year veteran of aviation but admittedly NOT an engine guru, I am just delighted that when both engines experienced their goose-induced shutdowns that the engines simply failed without catastrophically damaging the aircraft and compromising the ability to effect a survivable landing. To all the engineers who have labored over the years to make the engines more resistant to failure AND especially more resistant to catastrophic failure, if I was wearing a hat I would doff it in your honor. To think of the forces that must have been contained in those damaged engines and what would have happened to those engines (and the airframe) if they were, for example, 1950's vintage makes me very glad for the advance of technology.
Engines are certified to resist selected component egression through the engine cases. Kevlar banding around the Fan section has been very successful in coping with catastrophic fan blade failure. The engine cores are a different story however, although compressor blade failures do not normally breach the casings (they usually chew stuff up), the same can’t be said for compressor or turbine disk failure, the loads are just way too high.
Took a big goose-like bird thru a J-75 (F-105D) on a morning low-level. Approx 350 KIAS at around 500 ft somewhere over Georgia, 1965. During lunch Republic borescoped the engine and I flew the PM sortie. Big hats off to P&W. As stated above, GE engines efficient but not too robust.
Engines are certified to tolerate birdstrikes to 2 different criteria. For what are considered flocking birds, then the engine has to tolerate multiple strikes to all engines related to frontal area, and still maintain thrust proportionate to losing one engine (i.e. twins can loose 50% power, 4 engined aircraft can lose 25% of power).
For single birds, the engine just has to tolerate the impact without endangering the aircraft, but can fail completely.
The critical bit is what the certifying authorities dictate a flocking bird weighs. 20 years ago, the limit was 1.5lb, with the single bird tested at 4lb. Later, the goal was shifted to a 2.5lb flocking bird and an 8lb singleton. I beleive that there is at least talk, if it hasn't made it into the certification requirements already, of the flocking bird test going at 4lb and the singleton up round 12lb somewhere.
Now some will comment that canda geese flock, but the engine manufacturers will design and test to what the FAA and JAA say are the limits, so if you want to blame anyone, blame them.
For single birds, the engine just has to tolerate the impact without endangering the aircraft, but can fail completely.
The critical bit is what the certifying authorities dictate a flocking bird weighs. 20 years ago, the limit was 1.5lb, with the single bird tested at 4lb. Later, the goal was shifted to a 2.5lb flocking bird and an 8lb singleton. I beleive that there is at least talk, if it hasn't made it into the certification requirements already, of the flocking bird test going at 4lb and the singleton up round 12lb somewhere.
Now some will comment that canda geese flock, but the engine manufacturers will design and test to what the FAA and JAA say are the limits, so if you want to blame anyone, blame them.
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lwi101
Specifier/Regulator
- Mar 17, 2009
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The question was covered in the NTSB investigation and is included in the prelim report. The A/C was involved in a compressor stall some days before the ditching. The CP incident did not result in complete loss of power. The A/C continued to its scheduled destination, and received a maintenance write up. Some parts were changed, and no further incidents occurred. The word "Stall" seems to confuse a lot of reporters. I don't have the NTSB link handy, but it should be easy to find.
January 21, 2009
NTSB Update On Hudson River Ditching: Feather Found
From : AVWEB
The NTSB on Wednesday afternoon released new factual information in connection with its continuing investigation of US Airways Flight 1549, the Airbus 320 that ditched into the Hudson River in New York on Jan. 15. Factual updates from the board are generally considered preliminary information and no conclusions are drawn from the findings. The right engine has been externally examined and documented, the safety board said. An examination of the first-stage fan blades revealed evidence of soft body impact damage. Three of the variable guide vanes are fractured and two are missing. The engine's electronic control unit is missing and numerous internal components of the engine were significantly damaged. What appears to be organic material was found in the right engine and on the wings and fuselage. Samples of the material have been provided to the U.S. Department of Agriculture for a complete DNA analysis. A single feather was found attached to a flap track on the wing. It is being sent to bird identification experts at the Smithsonian. The left engine has been located in about 50 feet of water near the area of the Hudson River where the aircraft ditched. The NTSB is working with federal, state and local agencies to recover the engine, which is expected to occur sometime on Thursday.
The NTSB also learned that the right engine experienced a surge during a flight on Jan. 13, and a temperature probe was subsequently replaced. The NTSB's Survival Factors group is interviewing passengers to learn more about the events surrounding the ditching and the emergency evacuation and rescue, and the Operations and Human Performance group is interviewing US Airways flight operations training personnel. The on-scene documentation of the airplane is expected to be completed by the end of the week. The aircraft will then be moved to a more permanent storage site where more detailed documentation of the damage can be performed at a later date.
Now, somebody know what happened with the LEFT engine ? any
NTSB preliminary report about it ?
NTSB Update On Hudson River Ditching: Feather Found
From : AVWEB
The NTSB on Wednesday afternoon released new factual information in connection with its continuing investigation of US Airways Flight 1549, the Airbus 320 that ditched into the Hudson River in New York on Jan. 15. Factual updates from the board are generally considered preliminary information and no conclusions are drawn from the findings. The right engine has been externally examined and documented, the safety board said. An examination of the first-stage fan blades revealed evidence of soft body impact damage. Three of the variable guide vanes are fractured and two are missing. The engine's electronic control unit is missing and numerous internal components of the engine were significantly damaged. What appears to be organic material was found in the right engine and on the wings and fuselage. Samples of the material have been provided to the U.S. Department of Agriculture for a complete DNA analysis. A single feather was found attached to a flap track on the wing. It is being sent to bird identification experts at the Smithsonian. The left engine has been located in about 50 feet of water near the area of the Hudson River where the aircraft ditched. The NTSB is working with federal, state and local agencies to recover the engine, which is expected to occur sometime on Thursday.
The NTSB also learned that the right engine experienced a surge during a flight on Jan. 13, and a temperature probe was subsequently replaced. The NTSB's Survival Factors group is interviewing passengers to learn more about the events surrounding the ditching and the emergency evacuation and rescue, and the Operations and Human Performance group is interviewing US Airways flight operations training personnel. The on-scene documentation of the airplane is expected to be completed by the end of the week. The aircraft will then be moved to a more permanent storage site where more detailed documentation of the damage can be performed at a later date.
Now, somebody know what happened with the LEFT engine ? any
NTSB preliminary report about it ?
"It is being sent to bird identification experts at the Smithsonian." ...
this is an ex-parrot; vis-a-vis his metabolic processes, he's had his lot; all statements to the effect that this parrot is a going concern are henceforth inoperative ...
this is an ex-parrot; vis-a-vis his metabolic processes, he's had his lot; all statements to the effect that this parrot is a going concern are henceforth inoperative ...
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