Aerocaribbean ATR crash in Cuba
Yes, it certainly looks feathered, however that is meaningless. The blades are designed to go to the feather position in any shutdown event, normal or abnormal.
Failure of the propellor to feather after any shutdown event would be a big concern.
Failure of the propellor to feather after any shutdown event would be a big concern.
Last edited by twochai; 8th Nov 2010 at 00:00.
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Hi,
Well .. it's not meaningless at all !!
This plane crashed .... and one propeller at least show a feathered position.
So we can already (under some reserves) know that one engine was shutdown BEFORE the plane crashed.
Why ? .. this will be one duty of the investigation.
Yes, it certainly looks feathered, however that is meaningless. The blades are designed to go to the feather position in any shutdown event, normal or abnormal.
Failure of the propellor to feather after any shutdown event would be a big concern.
Failure of the propellor to feather after any shutdown event would be a big concern.
This plane crashed .... and one propeller at least show a feathered position.
So we can already (under some reserves) know that one engine was shutdown BEFORE the plane crashed.
Why ? .. this will be one duty of the investigation.
All we know is that the engine was not operating when the wreckage photo was taken and the propellor blades appeared to be in the fully feathered position, as they should be.
We do not know whether the feathering occurred pre-crash, or post crash!
We do not know whether the feathering occurred pre-crash, or post crash!
It would be highly irregular for a propeller to go into feather during or after the accident. They tend to stay in the pitch they were at just prior to impact.
Besides feathering, there is also swirled tip damage to look for at the instant of crash. Then of course a good look at the gearbox, engine blading, and instrument panel is helpful.
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According to the ICAC the primary cause was Severe Icing
Nota Informativa del Instituto de Aeronáutica Civil de Cuba
After the State Commission has made the analysis of data collected in the data recorder (black box) and evaluated them, as set out in the Convention of Civil Aviation for air accident investigation, in conjunction with the Bureau Survey and Analysis for the Safety of Civil Aviation of France (BEA) and representatives of the aircraft manufacturer ATR, reports that this flight was developing normally until they had extreme weather conditions on the route, following which the aircraft entered a severe icing condition (high concentration of ice) up to 20 000 feet (6 thousand 36 meters), which together with crew error in handling the situation, caused the accident itself.
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This is what Reuters has.
The piece mentions pilot error but doesn't specifically say what the error was (unless I've read it wrong). Perhaps the error was in taking the plane up to 20,000 feet?
HAVANA, Dec 16 (Reuters) - Icing and pilot error caused the Nov. 4 crash of a Cuban Aero Caribbean passenger plane in which the 68 people on board were killed, the Cuban government said on Thursday.
Investigators found that "extreme weather conditions" led to a "severe" build up of ice on the plane that, "combined with errors by the crew in the handling of the situation, caused the accident," the Civil Aeronautics Institute said in a statement.
It said the plane, an ATR 72-212 twin turboprop, built by ATR, a joint venture of Europe's EADS <EAD.PA> and Italian group Finmeccanica <SIFI.MI>, had been in good condition and functioned properly before plummeting to the ground in central Cuba.
On that day, Cuba had the unusual condition of a cold front sweeping down from the north while a small hurricane brushed along the island's eastern tip.
The combination of cold air and very high humidity from the storm created conditions conducive for icing unusual on the tropical island, airplane experts told Reuters.
Most planes flying that day remained at lower altitudes to avoid icing, they said.
The institute said the Aero Caribbean plane flew at 20,000 feet (6,036 metres) after taking off from the eastern city of Santiago en route to Havana on the northwest coast.
The victims included 28 foreigners from 10 countries.
ATR said the plane was 15 years old, had flown almost 25,000 hours and had been operated by state-owned Aero Caribbean since 2006.
The accident was the worst in Cuba since Sept. 3, 1989 when a Soviet-made Ilyushin-62M jet airliner crashed after takeoff from the Havana airport, killing all 126 people on board. (Reporting by Nelson Acosta; Editing by Jeff Franks and Vicki Allen)
The piece mentions pilot error but doesn't specifically say what the error was (unless I've read it wrong). Perhaps the error was in taking the plane up to 20,000 feet?
HAVANA, Dec 16 (Reuters) - Icing and pilot error caused the Nov. 4 crash of a Cuban Aero Caribbean passenger plane in which the 68 people on board were killed, the Cuban government said on Thursday.
Investigators found that "extreme weather conditions" led to a "severe" build up of ice on the plane that, "combined with errors by the crew in the handling of the situation, caused the accident," the Civil Aeronautics Institute said in a statement.
It said the plane, an ATR 72-212 twin turboprop, built by ATR, a joint venture of Europe's EADS <EAD.PA> and Italian group Finmeccanica <SIFI.MI>, had been in good condition and functioned properly before plummeting to the ground in central Cuba.
On that day, Cuba had the unusual condition of a cold front sweeping down from the north while a small hurricane brushed along the island's eastern tip.
The combination of cold air and very high humidity from the storm created conditions conducive for icing unusual on the tropical island, airplane experts told Reuters.
Most planes flying that day remained at lower altitudes to avoid icing, they said.
The institute said the Aero Caribbean plane flew at 20,000 feet (6,036 metres) after taking off from the eastern city of Santiago en route to Havana on the northwest coast.
The victims included 28 foreigners from 10 countries.
ATR said the plane was 15 years old, had flown almost 25,000 hours and had been operated by state-owned Aero Caribbean since 2006.
The accident was the worst in Cuba since Sept. 3, 1989 when a Soviet-made Ilyushin-62M jet airliner crashed after takeoff from the Havana airport, killing all 126 people on board. (Reporting by Nelson Acosta; Editing by Jeff Franks and Vicki Allen)
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Icing again...
Seems ATR and Icing still do not really like each other, do they?
All icing accidents seem to add 'pilot error'. But what does that really mean: maybe it just means: do not fly into severe icing conditions. No one does this intentionally (except maybe for some test pilots). Might it be that the ATR is still more prone to icing handling problems than the manufacturer wants to admit?
Let us hope we get some better insight after the final report. Seems worth investigating further.
MD
Seems ATR and Icing still do not really like each other, do they?
All icing accidents seem to add 'pilot error'. But what does that really mean: maybe it just means: do not fly into severe icing conditions. No one does this intentionally (except maybe for some test pilots). Might it be that the ATR is still more prone to icing handling problems than the manufacturer wants to admit?
Let us hope we get some better insight after the final report. Seems worth investigating further.
MD
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Investigators found that "extreme weather conditions" led to a "severe" build up of ice on the plane that, "combined with errors by the crew in the handling of the situation, caused the accident," the Civil Aeronautics Institute said in a statement.
It said the plane, an ATR 72-212 twin turboprop, built by ATR, a joint venture of Europe's EADS <EAD.PA> and Italian group Finmeccanica <SIFI.MI>, had been in good condition and functioned properly before plummeting to the ground in central Cuba.
On that day, Cuba had the unusual condition of a cold front sweeping down from the north while a small hurricane brushed along the island's eastern tip.
The combination of cold air and very high humidity from the storm created conditions conducive for icing unusual on the tropical island, airplane experts told Reuters.
The combination of cold air and very high humidity from the storm created conditions conducive for icing unusual on the tropical island, airplane experts told Reuters.
Most planes flying that day remained at lower altitudes to avoid icing, they said.
The institute said the Aero Caribbean plane flew at 20,000 feet (6,036 metres) after taking off from the eastern city of Santiago en route to Havana on the northwest coast.
The engine looks feathered to me. Severe icing blocking the air intake necessitating/forcing a shutdown? I'd find it highly unlikely the prop feathered after the crash. Also it isn't bent, suggesting it wasn't powered at impact (you'd expect to see bent blades if it was).
I don't think they stood a chance, regardless of pilot actions. Do Cuba have a history of always finding fault with the pilot?
ECAM Actions.
Can anyone give a technical justification for why the ATR seems to get into difficulties with icing at altitude, whereas other current types do not have a history of losses due to this. There seem to have been at least three other losses of the type (American at Roselawn, FedEx in Texas, ATI at Milan) due to icing.
Seems ATR and Icing still do not really like each other, do they?
1) low speed - no significant ram rise to make living easier in icing
2) (relatively) low performance - once iced, its difficult to climb above the icing layer.
3) low weight - heavier aeroplanes pick up less ice than light ones. I'll be damned if I know how it works, yet it's reason behind C-5 having no wing ice protection whatsoever and A-320 having only outboard wing leading edges de-iced.
4) laminar wing - an ice magnet if there was ever one
5) unpowered controls relying on horn balances to reduce hinge moment
All of these is not enough to make the aeroplane truly dangerous. The missing ingredient is ignorant pilot to make the combination deadly. The last crew of the N401AM being exception, they were the test pilots, flying in icing conditions that were rare and previously undiscovered (they were light to moderate) without ever realizing that.
How do you handle severe icing except to turn tail and run/descend into warmer air?
Severe icing is defined as one that overwhelms the aeroplane's deicing system. Obviously, whether the icing is considered severe is not just dependent on the state of the atmosphere but also on the aeroplane's equipment. Areas of severe icing at altitude are quite limited, in horizontal, vertical and temporal sense and are impossible to predict. Metman might warn that conditions are conductive to severe icing, but forecasting where and when it will strike is beyond the ability of current meteorology. Therefore the only procedure when one stumbles on severe icing is to run away.
Severe icing blocking the air intake necessitating/forcing a shutdown?
Originally Posted by WHBM
Can anyone give a technical justification for why the ATR seems to get into difficulties with icing at altitude, whereas other current types do not have a history of losses due to this. There seem to have been at least three other losses of the type (American at Roselawn, FedEx in Texas, ATI at Milan) due to icing.
Mt. st Pietro crash was attempt to force the aeroplane somewhere where it just wasn't able to go, icing was only accessory. Both pilots came from DC-9 and were unaccustomed to ATR's low performance.
Regarding the Lubbock, methinks NTSB video makes great CRM teaching tool. Watch it an be shocked.
I have earned my keep through five European winters and six summers in the front right seat of ATR 42-300. Fact that I'm able to write this post says something about soundness of the design.
Excellent observations, Clandestino.
Very true.
Also a fact of life.
In fact, I think it has more to do with the size of the exposed surfaces, than the aircraft's weight. A wing with a large leading edge radius is much less susceptible to performance loss in icing conditions than a wing with a small radius leading edge (all else being equal, which of course it never is).
Some airfoil profiles are certainly more susceptible to performance degradation in ice than others, as has been well established through the years.
It is also instructive to review the Roselawn accident report, particularly its conclusions:
ASN Aircraft accident Aérospatiale/Aeritalia ATR-72-212 N401AM Roselawn, IN
1) low speed - no significant ram rise to make living easier in icing
(relatively) low performance - once iced, its difficult to climb above the icing layer.
low weight - heavier aeroplanes pick up less ice than light ones. I'll be damned if I know how it works, yet it's reason behind C-5 having no wing ice protection whatsoever and A-320 having only outboard wing leading edges de-iced.
laminar wing - an ice magnet if there was ever one
It is also instructive to review the Roselawn accident report, particularly its conclusions:
ASN Aircraft accident Aérospatiale/Aeritalia ATR-72-212 N401AM Roselawn, IN
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Seems ATR and Icing still do not really like each other, do they?
All icing accidents seem to add 'pilot error'. But what does that really mean: maybe it just means: do not fly into severe icing conditions. No one does this intentionally (except maybe for some test pilots). Might it be that the ATR is still more prone to icing handling problems than the manufacturer wants to admit?
All icing accidents seem to add 'pilot error'. But what does that really mean: maybe it just means: do not fly into severe icing conditions. No one does this intentionally (except maybe for some test pilots). Might it be that the ATR is still more prone to icing handling problems than the manufacturer wants to admit?
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low weight - heavier aeroplanes pick up less ice than light ones. I'll be damned if I know how it works, yet it's reason behind C-5 having no wing ice protection whatsoever and A-320 having only outboard wing leading edges de-iced.
In fact, I think it has more to do with the size of the exposed surfaces, than the aircraft's weight. A wing with a large leading edge radius is much less susceptible to performance loss in icing conditions than a wing with a small radius leading edge (all else being equal, which of course it never is).
Weight has nothing to do with ICE but the size does.
Bigger size =longer wing span= thicker leading edge= MORE ICE = less ICE on wings !!!
Why ?
Because shorter span allowes much less bending of the wing.
More bending on the wing will shed all the ice in pieces downstream...
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Can anyone give a technical justification for why the ATR seems to get into difficulties with icing at altitude, whereas other current types do not have a history of losses due to this
ATR-42s have been operated non-stop in Canada since around 1990. Thats 20 years and no crashes.
VFD
About the only areas in Canada that generally can form Rime Ice is just along the coastlines. Profound difference between cold, snow vs -1c rime conditions
Let's face it. Icing over a tropical island (except in CBs, which are avoided for other reasons) is probably one of those once-in-a-career events. Just as flying into volcanic ash over Europe was a never-in-a-career event (until - oops! - it happened).
It just rose up to bite this crew, whereas a crew recently transferred from, say, Ontario, might have been more alert to the possibility and more familiar with appropriate responses.
It just rose up to bite this crew, whereas a crew recently transferred from, say, Ontario, might have been more alert to the possibility and more familiar with appropriate responses.
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A lot of good posts so fare.Except the one with the bending wings-sorry.From the maintenance side i want to add some of my experience what can go wrong with the systems.The worst failures and bad condition of the equipment i found in areas where
icing conditions are very rare with very little need to use anti/de icing.Even procedures
to switch on these systems ones a day or week wont garanty they will work properly
when it counts.
De-icing boots don't like to be exposed to the sun all day.Found them working on ground at 30° C satis,next flight (thunderstorms all around with heavy hale) a total of
8 meters leading edge failed and had to be replaced due to weak rubber.
Some of the valves supplying pressure and suction to the boots (dual distributor valves) are heated with 115 V ACW- but no indication if there is problem with the heating.
You will find out in icing conditions when the valve gets stuck...
Electrical heated prop blades don't like moisture when their surface is very little damaged only.Have seen the local guys doing a test in the hangar.All good of course.When they asked me to sign for the job i did the test again and put water on the blades-nice blue sparks were coming out of the heating element.2 of 8 blades had to be replaced...
Another issue are "frozen" powerlever on the ATR.Happens often - a special grease
needs to be applied on the linkage in the aft upper nacelle.I know 3 companys who don't know the partnumber of the grease and never ordered or used it.
But even with the correct grease applied the lever can freeze due to the critical design of the cooling duct on top of the nacelle.If this panel is not correct sealed,or
the internal duct is leaking you get a lot water direct on the quadrant and the power lever will freeze.
Hope this was not too boring.
Due to the picture showing one prop in feather there are two options in my mind:
1: they had a problem with at least one prop blade leading to heavy vibration-
engine shut down.
2: they tried to leave FL 200 but couldn't retard the frozen powerlever-
Fire handle pulled,engine shut down.
icing conditions are very rare with very little need to use anti/de icing.Even procedures
to switch on these systems ones a day or week wont garanty they will work properly
when it counts.
De-icing boots don't like to be exposed to the sun all day.Found them working on ground at 30° C satis,next flight (thunderstorms all around with heavy hale) a total of
8 meters leading edge failed and had to be replaced due to weak rubber.
Some of the valves supplying pressure and suction to the boots (dual distributor valves) are heated with 115 V ACW- but no indication if there is problem with the heating.
You will find out in icing conditions when the valve gets stuck...
Electrical heated prop blades don't like moisture when their surface is very little damaged only.Have seen the local guys doing a test in the hangar.All good of course.When they asked me to sign for the job i did the test again and put water on the blades-nice blue sparks were coming out of the heating element.2 of 8 blades had to be replaced...
Another issue are "frozen" powerlever on the ATR.Happens often - a special grease
needs to be applied on the linkage in the aft upper nacelle.I know 3 companys who don't know the partnumber of the grease and never ordered or used it.
But even with the correct grease applied the lever can freeze due to the critical design of the cooling duct on top of the nacelle.If this panel is not correct sealed,or
the internal duct is leaking you get a lot water direct on the quadrant and the power lever will freeze.
Hope this was not too boring.
Due to the picture showing one prop in feather there are two options in my mind:
1: they had a problem with at least one prop blade leading to heavy vibration-
engine shut down.
2: they tried to leave FL 200 but couldn't retard the frozen powerlever-
Fire handle pulled,engine shut down.