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TransAsia plane crash


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This is now the third aviation accident where the aircraft is clearly fully stalled, as if the pilots we're training have no concepts or practice at the very basics of flight. Tragic.

Reports indicate the crew made a Mayday call and that they'd lost an engine. From the photo below, it certainly looks like the port prop is not rotating as rapidly as the starboard.

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Given that there's not much space to put an aircraft down around Songshan - and you can see from the video he's got a lot of high-rise real estate limiting his options - he may have been trying to get it to the river and just ran out of airspeed keeping it clear of the buildings.

Edit: This video does seem to show the port prop windmilling.

Vince

Edited by vince14
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Reports indicate the crew made a Mayday call and that they'd lost an engine. From the photo below, it certainly looks like the port prop is not rotating as rapidly as the starboard.

0.jpg

Given that there's not much space to put an aircraft down around Songshan - and you can see from the video he's got a lot of high-rise real estate limiting his options - he may have been trying to get it to the river and just ran out of airspeed keeping it clear of the buildings.

Edit: This video does seem to show the port prop windmilling.

Vince

Fuel??? Clearly the #1 engine isn't making power and when they hit...no explosion?

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Well, if he lost #1, he most likely VMCd the plane. I have a buddy that used to fly ATRs. Heck, if I had signed with Eagle, I would have flown them as they were my first choice out of Miami.

Anyway, I will ask him what the deal is. The plane should have been controllable single engine with a properly trained and proficient crew.

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I think the port stab damage comes from clipping the last building before the bridge, and in the still you can see the port prop in full feather. Tragic

It looked like the port prop was still rotating, although much slower. If it was in full feather, would it not be stationary? The aircraft should be capable to climbing away with an engine out, as long as the prop feathers. Not too many twin engine planes can maintain level flight with a failed engine and a prop that doesn't properly feather.

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It'll be interesting to see the outcome of the investigation. Losing an engine shouldn't cause the plane to crash automatically. The piece of stab is missing because it hit one of the buildings across the road as it went by (visible in the video). Poor slobs in the van couldn't have known what hit them.

All multi-engine pilots are taught what to do if the worst case scenario happens: losing an engine on takeoff. The ATR has 2x ~2000 shp engines, so losing one even on a fully loaded airplane wouldn't make it unflyable (and if it did, the airplane wouldn't have been certificated).

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All multi-engine pilots are taught what to do if the worst case scenario happens: losing an engine on takeoff. The ATR has 2x ~2000 shp engines, so losing one even on a fully loaded airplane wouldn't make it unflyable (and if it did, the airplane wouldn't have been certificated).

Yeah, but getting past certification and what happens in a real in-flight emergency are two different things. Look at the Lauda Air crash - Boeing said the 767 could fly with one thrust reverser deployed, no problems and the FAA certified it. Sadly for the 223 people on Lauda Air 004, the thrust reverser certification flight took place at 10,000 ft and Mach 0.3, where it was easy for the pilots to regain control. When it happened to the Lauda crew at 24,000 ft and Mach 0.78, they had less than six seconds to identify the problem and apply all corrective actions.

Vince

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All multi-engine pilots are taught what to do if the worst case scenario happens: losing an engine on takeoff. The ATR has 2x ~2000 shp engines, so losing one even on a fully loaded airplane wouldn't make it unflyable (and if it did, the airplane wouldn't have been certificated).

True. But they are in the most critical phase of flight, takeoff. No "do overs". They're heavy with fuel plus passengers and baggage (all of which should be already factored in anyway...) but also field elevation and air density play into it, again all should have been factored into take off performance. Now toss in a loss of an engine. Losing power, losing altitude, instinct is to pull up and add power on the good engine which is likely part of their emergency procedure but if you add too much power...puts you into VMCair, minimum control speed (Duty Cat mentioned that earlier...believe he was an S-2 guy so I bet he knows all about that) because you're asymmetric. Almost lost a couple of P-3 friends off the coast of WA state a few years back; had #1 & #2 shutdown for training, they got slow and pushed up power on #3 and #4 and all of a sudden they're in a spin down to 500 feet before they got engines back on line and recovered. Bent the wing spar, tore the wing skin open and bent the fuselage.

Someone mentioned the port prop still turning. The port prop is feathered but still is "windmilling", I don't know if ATR engines have a prop brake, I'm guessing not but as long as it feathers it no longer becomes a danger to you. I'm also going to assume that these props (like a lot of modern turbo props) are spring loaded to feather...i.e. when you shut down they go to feather as the forces acting on the prop (ATM, CTM) go away. Take a look out on the line next time you go to the airport at the turbos or at an airshow, the C-130Js, T-6A/Bs.

Edited by 82Whitey51
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The plane should have been controllable single engine with a properly trained and proficient crew.

Depending on circumstances of course...

When did everyone decide that a twin airplane could lose an engine in any situation and it would always work out?

Edited by TaiidanTomcat
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True. But they are in the most critical phase of flight, takeoff. No "do overs". They're heavy with fuel plus passengers and baggage (all of which should be already factored in anyway...) but also field elevation and air density play into it, again all should have been factored into take off performance. Now toss in a loss of an engine. Losing power, losing altitude, instinct is to pull up and add power on the good engine which is likely part of their emergency procedure but if you add too much power...puts you into VMCair, minimum control speed (Duty Cat mentioned that earlier...believe he was an S-2 guy so I bet he knows all about that) because you're asymmetric. Almost lost a couple of P-3 friends off the coast of WA state a few years back; had #1 & #2 shutdown for training, they got slow and pushed up power on #3 and #4 and all of a sudden they're in a spin down to 500 feet before they got engines back on line and recovered. Bent the wing spar, tore the wing skin open and bent the fuselage.

Someone mentioned the port prop still turning. The port prop is feathered but still is "windmilling", I don't know if ATR engines have a prop brake, I'm guessing not but as long as it feathers it no longer becomes a danger to you. I'm also going to assume that these props (like a lot of modern turbo props) are spring loaded to feather...i.e. when you shut down they go to feather as the forces acting on the prop (ATM, CTM) go away. Take a look out on the line next time you go to the airport at the turbos or at an airshow, the C-130Js, T-6A/Bs.

I thought the ATR had auto-feather, but I might be wrong. If the prop didn't feather in time it'd be a huge problem for the crew. The ATR is underpowered at the best of times, so to lose an engine whilst heavy is not a fun place to be - add in a windmilling prop and a built-up environment and you're looking at a worst-case scenario.

I used to fly the Caravan, and with the prop feathered it'd glide for what felt like days, but with a windmilling prop it felt like it had all the glide performance of a Shipping Container.

Vince

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It's been way too many years to recall for sure, but on the King Airs and Dash-8s I flew, the autofeather system was armed and would activate only under certain conditions, like both throttles above a certain limit and loss of torque by a certain amount. Basically takeoff conditions. I think if there was a loss of power under other conditions, like cruise, the prop would just windmill until the crew feathered it, but my memory is a bit foggy on that one. I may have to dig up my manuals, now. You'd think that the ATR was still in conditions that would've armed the autofeather since he had just taken off and would have been at takeoff or climb power. The one time I had an engine just quit on me, as opposed to shutting it down myself, the autofeather did its thing and it was surprisingly anticlimactic, and the full Dash-8 still climbed pretty well. I'm surprised an engine failure would've been a problem on the ATR, which has the same basic engines as the Dash-8 and probably similar performance.

Looking at the video, when the plane first appears in the frame, it looked to me like he's already descending at a pretty steep angle, almost like he's gliding. Then the nose comes up because he's trying to stretch his glide to clear the bridge and it stalls and rolls.

Ben

EDIT: My next Internet stop was my local news station's web site: http://www.wral.com/taiwan-plane-crash-toll-rises-to-35-vp-visits-funeral-home/14427067/ Looks like the crew may have shut down the wrong engine? Wow. :blink:/>

Edited by Ben Brown
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I agree with Duty Cat. The key words "properly trained" and "proficient" come to mind. Crews that are proficient and alert should not end up crashing an aircraft in this kind of situation. Unfortunately, reality of life is that nobody tells you that this take-off is going to include a low-speed and low altitude engine problem.

These pilots were probably taken completely by surprise. How long had it been since they did a recurrent sim? When I taught Recurrents on business jets in simulators, the pilots were usually told they would have an engine failure (not which one, though), very soon after V1, meaning they would be taking off single engine. About 20% of the time, the first attempt led to digging in a wing on the runway and crashing on rotation. This, with experienced pilots who KNEW they were going to have a failed engine. The second attempt was always successful for those who crashed.

Recurrent training on business jets under FAR 91 was every 6 months for most operators. Between Recurrents, they rarely (if ever) practised such emergencies.

Military pilots practise these kinds of problems in-flight as well, and fairly frequently, but as Whitey described, even those guys can sometimes get themselves into trouble.

Aviation is unforgiving. To be able to react properly to such an emergency with no notice, and perform flawlessly, is not an easy task. That's why pilots get the big bucks, because their job is to keep passengers alive and not crash. It's sad when this happens, but I am definitely not surprised, given human nature and variation in proficiency and even day-to-day factors like fatigue and other external problems.

ALF

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Wow flashback to my twin training. I got my ticket in a twin Comanche the only airplane to have it's VMC arbitrarily raised by 10 MPH to cut down on the single engine accidents it was having.

One training departure over the open flat lands of Oklahoma my instructor cut fuel to an engine and the airplane yawed. So as trained I pulled the throttle back on the side that was yawing. Got real quite in the plane, he'd killed the right engine but he stomped on the left rudder. He looked at me with a grin and said; "Quiet isn't it?" Teaching me to verify which engine actually died before I removed what power I actually had.

So sad that we still make these stupid fundamental errors in our aircrew training.

Edited by majortomski
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First clue: Dead Foot, Dead Engine.

Just like yaw...

Except that it is always necessary to confirm with engine indications on instruments which one is in fact failed or losing thrust.

Your instructor taught you an important lesson.

ALF

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It's been way too many years to recall for sure, but on the King Airs and Dash-8s I flew, the autofeather system was armed and would activate only under certain conditions, like both throttles above a certain limit and loss of torque by a certain amount. Basically takeoff conditions. I think if there was a loss of power under other conditions, like cruise, the prop would just windmill until the crew feathered it, but my memory is a bit foggy on that one. I may have to dig up my manuals, now. You'd think that the ATR was still in conditions that would've armed the autofeather since he had just taken off and would have been at takeoff or climb power. The one time I had an engine just quit on me, as opposed to shutting it down myself, the autofeather did its thing and it was surprisingly anticlimactic, and the full Dash-8 still climbed pretty well. I'm surprised an engine failure would've been a problem on the ATR, which has the same basic engines as the Dash-8 and probably similar performance.

Looking at the video, when the plane first appears in the frame, it looked to me like he's already descending at a pretty steep angle, almost like he's gliding. Then the nose comes up because he's trying to stretch his glide to clear the bridge and it stalls and rolls.

Ben

EDIT: My next Internet stop was my local news station's web site: http://www.wral.com/taiwan-plane-crash-toll-rises-to-35-vp-visits-funeral-home/14427067/ Looks like the crew may have shut down the wrong engine? Wow. :blink:/>/>

The Dash 8 would windmill with no issues at all as the engine isn't mechanically linked to the prop. Feathering would stop it but it could still windmill especially if the aircraft isn't flying straight and level.

At least I think the Dash 8 is the same as the Twin Otter, the prop on that is linked by magnetism. For engine washes we could hold the prop by hand and run the engine up to dry out the engine.

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The Dash 8 would windmill with no issues at all as the engine isn't mechanically linked to the prop. Feathering would stop it but it could still windmill especially if the aircraft isn't flying straight and level.

At least I think the Dash 8 is the same as the Twin Otter, the prop on that is linked by magnetism. For engine washes we could hold the prop by hand and run the engine up to dry out the engine.

Hi Scooby,

The PW-120 on the Dash-8 is a free turbine engine, so exhaust blew across the power turbine, which was connected to the gearbox. The PT-6 on the Twotter was the same setup, except the engine is turned around backwards, so yes, you could run the engine with the prop held in place. Some of our line guys used to hold the prop on our King Airs when we'd start up, just to annoy us. It's been a while, but I'm pretty sure the ATR has a variant of the PW-1XX engine as the Dash-8 and EMB-120. It's all still the same basic engine, though. IIRC, the ATR had a prop brake so they could run the #2 engine like an APU. The Dash-8 and Brasilia had real APUs and didn't need the prop brake. In flight, regardless of engine type, if the prop was just windmilling, aerodynamically it was like you had a 13 ft diameter speed brake out there until you feathered it.

Ben

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