A Fokker 27 loses it's propeller at take-off in Paris (CDG)
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I recall, if gear box low pressure red light illuminates, feather and shut down that engine asap to preserve the gear box. Not saying this has anything to do with this incident, .........but?
As for this incident, absolute respect and total applause to the crew who must have had a brown trouser moment few of us are ever likely to experience and to have got the machine and themselves safely back down when their minds ( and imagination ! ) must have been somewhere, anywhere, else when they heard the noise of the fuselage ripping and could only hope the flight controls were not damaged....And, for you non-freightdogs, at 01.10 when your levels of alertness and concentration are not at their best no matter for how long you've been regular night flying....
DaveReid .093 that's it. I knew there was a 8 something in there somewhere, but I couldn't remember what mark it was.
Chris what does that give as prop RPM at a climb of 14,200 engine RPM? I'm no wizard at math.
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Fokker 27 crashed
Could happen to everybody .. but for sure this Fokker is too much OLD and we hope that they decide to STOP definitely the FOKKER 27.
I was a good aircraft 50 years old ago but not in 2013.
It is correct..one blade hit the fuselage and due to vibrations all propeller falled down with the first part of the engine .. COULD BE A DISASTER !
About the crew .. Good job but not very good, some mistake about the coordination and sop.
I was a good aircraft 50 years old ago but not in 2013.
It is correct..one blade hit the fuselage and due to vibrations all propeller falled down with the first part of the engine .. COULD BE A DISASTER !
About the crew .. Good job but not very good, some mistake about the coordination and sop.
pigboat,
If Dave and I are right about the particular gearbox ratio here, your answer is:
Prop speed = 0.093 * 14200rpm = 1320 rpm
pailot77,
Can't comment on the F27, but the issue here seems to have been the maintenance of the Dart powerplant - specifically the gearbox or the airscrew. My guess is that the sequence started with a propellor blade failure.
Can someone confirm if the blade anti-ice is electrical? In any case, the rubber layer on its leading edge can conceal cracks, as in the case of that DC6 accident quoted earlier on this thread.
If Dave and I are right about the particular gearbox ratio here, your answer is:
Prop speed = 0.093 * 14200rpm = 1320 rpm
pailot77,
Can't comment on the F27, but the issue here seems to have been the maintenance of the Dart powerplant - specifically the gearbox or the airscrew. My guess is that the sequence started with a propellor blade failure.
Can someone confirm if the blade anti-ice is electrical? In any case, the rubber layer on its leading edge can conceal cracks, as in the case of that DC6 accident quoted earlier on this thread.
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I recall, if gear box low pressure red light illuminates, feather and shut down that engine asap to preserve the gear box. Not saying this has anything to do with this incident, .........but?
The reason for the procedure was that accessory gearbox was not covered by the fire extinguishers and low px would sometimes end in a fire. They did provide it with a fire detection system though!
The reason for the procedure was that accessory gearbox was not covered by the fire extinguishers and low px would sometimes end in a fire. They did provide it with a fire detection system though!
Pailot77 I think I would say the actions of the crew were all good. They got the airplane back on the ground in spite of major structural failure. That to me says they acted in a very highly professional manner given the situation in which they found themselves. Two things, did the engine autofeather during the loss of the prop and has the engine been torn down yet? On teardown verify the HP and IP turbine blades for signs of liquid aluminum spatter.
did the engine autofeather
Stick and rudder skills. No magenta line in the F27.
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Trim they usually sense the drop in oil pressure or negative torque then something triggers and the blades go to feather.
It can be called NTS or auto feather depending on the installation.
And as for the glass its not really the glass more of the fact you have a 3rd generation yaw damper fitted.
I don't know but I suspect that the F27 has a 1st generation yaw dampener which does a double integral off a heading source. So its not possible to depart with it in.
Also as well modern glass TP are fitted with low drag props. The older aircraft are fitted with prop profiles that thrash the air into submission but the newer Knife props tend to have a bit more science about them. It can come as a bit of surprise when you fly a newer type that they just won't disk and dump the energy like the old ones do.
Conversely when a donk goes everything is so much easier and slower.
Also as well if the F27 AP has as many spare parts available as the ones fitted to my old heap, the ones that even have them, they will be lucky to use it for anything other than wing leveller in cruise. And like or not your much more in the loop to small changes in the aircraft prior to anything going wrong when flying manually regularly. But conversely your workload is so much higher all the time. But to be honest once your up to it you develop so much extra capacity and the flying becomes like changing gear in your car.
The panels you can see which the prop went through a Kevlar screens to stop ice penetrating the cabin but obviously not up to stopping a prop blade.
The forces involved with a blade going are are utterly incredible. And once the blade had gone I don't think there would be any time for any auto feather feature to kick in, if it even would as they still had fuel going to the engine and a such it wasn't spooling down, before the hub departed. Which to be honest is just as well as the hub must have been pulled forward away from the aircraft.
Thumbs up to the crew from another pilot that fly's an old heap.
It can be called NTS or auto feather depending on the installation.
And as for the glass its not really the glass more of the fact you have a 3rd generation yaw damper fitted.
I don't know but I suspect that the F27 has a 1st generation yaw dampener which does a double integral off a heading source. So its not possible to depart with it in.
Also as well modern glass TP are fitted with low drag props. The older aircraft are fitted with prop profiles that thrash the air into submission but the newer Knife props tend to have a bit more science about them. It can come as a bit of surprise when you fly a newer type that they just won't disk and dump the energy like the old ones do.
Conversely when a donk goes everything is so much easier and slower.
Also as well if the F27 AP has as many spare parts available as the ones fitted to my old heap, the ones that even have them, they will be lucky to use it for anything other than wing leveller in cruise. And like or not your much more in the loop to small changes in the aircraft prior to anything going wrong when flying manually regularly. But conversely your workload is so much higher all the time. But to be honest once your up to it you develop so much extra capacity and the flying becomes like changing gear in your car.
The panels you can see which the prop went through a Kevlar screens to stop ice penetrating the cabin but obviously not up to stopping a prop blade.
The forces involved with a blade going are are utterly incredible. And once the blade had gone I don't think there would be any time for any auto feather feature to kick in, if it even would as they still had fuel going to the engine and a such it wasn't spooling down, before the hub departed. Which to be honest is just as well as the hub must have been pulled forward away from the aircraft.
Thumbs up to the crew from another pilot that fly's an old heap.
mad_jock,
Think Trim Stab's first comment was tongue-in-cheek!
Thanks for your insight into current ops on the F27. It's a very long time since I had to contemplate feathering a Dart prop. The modern turb-props seem to feather every time the engine is shut down, which is kind of the designers?
(For any uninitiated readers:
jet-jockeys usually have it easier; if only because the momentum of the fan takes a while to be lost, and no feathering is needed to avoid the instant drag of a CSD-driven prop going into full-fine pitch.)
Do you agree it seems unlikely that a blade would be shed as a RESULT of autofeather of the prop following an engine failure (and consequent loss of torque or oil pressure)? Unless 3 blades feathered and one didn't...
My money is still on a fatigue failure of the blade as the primary failure.
Think Trim Stab's first comment was tongue-in-cheek!
Thanks for your insight into current ops on the F27. It's a very long time since I had to contemplate feathering a Dart prop. The modern turb-props seem to feather every time the engine is shut down, which is kind of the designers?
(For any uninitiated readers:
jet-jockeys usually have it easier; if only because the momentum of the fan takes a while to be lost, and no feathering is needed to avoid the instant drag of a CSD-driven prop going into full-fine pitch.) Do you agree it seems unlikely that a blade would be shed as a RESULT of autofeather of the prop following an engine failure (and consequent loss of torque or oil pressure)? Unless 3 blades feathered and one didn't...
My money is still on a fatigue failure of the blade as the primary failure.
Auto-feather is normally meant to apply only to a prop's pitch setings while attached to an engine. The engine itself doesn't need to decrease its drag but does need to decrease the spinning power to the prop drive turbine (fuel chop)
The reason for auto feathering is to reduce the frontal drag against an engine that is no longer offsetting this drag with thrust.
The prop drag is way more than the drag of the non running engine missing the prop. My only question earlier had to do with the amount of increased drag in this incident from the obviously distorted cowlings.
Not much the pilots can do other than fly the aircraft and manage the yaw in a difficult approach phase.
The reason for auto feathering is to reduce the frontal drag against an engine that is no longer offsetting this drag with thrust.
The prop drag is way more than the drag of the non running engine missing the prop. My only question earlier had to do with the amount of increased drag in this incident from the obviously distorted cowlings.
Not much the pilots can do other than fly the aircraft and manage the yaw in a difficult approach phase.
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F27 looses propeller
There is more to this story as the gear box came off as well (see picture ). This reminds me of a Texas Convair operator flying RDa10 powered water methanol injected engines. They used wet take-offs even on the longest runways and developed gearbox casing cracks. The incident in Paris surely seems to point at over use of water methanol assisted take offs every time. 
Last edited by Yankee Whisky; 1st Nov 2013 at 13:37.
'Morning, lomapaseo,
Judging from the photo, the outboard cowling certainly has flipped backwards. Bit like the tail airbrake on a DH/HS/BAe146. That would increase the Vmca...
BTW, the Dart is a single-shaft engine, so no free-turbine.
Judging from the photo, the outboard cowling certainly has flipped backwards. Bit like the tail airbrake on a DH/HS/BAe146. That would increase the Vmca...
BTW, the Dart is a single-shaft engine, so no free-turbine.
Quote:
...if you look at the salvage photograph the propellor blades look as if they are not feathered.
Agreed, N707ZS. BTW, can you see 2 of the 4 blades, or 3?
...if you look at the salvage photograph the propellor blades look as if they are not feathered.
Agreed, N707ZS. BTW, can you see 2 of the 4 blades, or 3?
BTW, the Dart is a single-shaft engine, so no free-turbine.
By the time the gearbox had left exposing the compressor no compressor load as well , might as well be a free turbine
all small stuff in the scheme of things, still must find what failed first and why in this case.
Bad karma if the fuselage is in the center position of this pic
"Mildly" Eccentric Stardriver
Like I said, it's been a long time, but I'm pretty sure the F27 didn't have autofeather, and it certainly didn't have a yaw-damper. My comment about glass was merely to observe that these guys were able to "think outside the box",and I can't see where Pailot77 is coming from regarding SOPs. I don't think "total loss of the front half of the engine" is covered by the checklist.
