Stall recovery procedures ATR 42
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On the A320 the stall rfecovery sequence (if stalling clean) is TOGA Thrust, flaps 1. Slats run out quite quickly and VLS (lowest selectable speed) drops by about 8 - 10 kts due to effects of slats. Hold the attitude and you lose no height.
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There's an urban legend at our outfit, that in the early days of the ATR some guys tried stalling it with the stall protection systems off during a test flight. To cut the long story short, they had to change their pants after landing 
Maybe I didn't make my point clear enough the first time around:
For purpose of stall recovery, flaps 15 are to be extended in ice accretion conditions only. It serves to increase stall margin.
Also spracht ATR FCOM
For purpose of stall recovery, flaps 15 are to be extended in ice accretion conditions only. It serves to increase stall margin.
Also spracht ATR FCOM
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Just to make sure that everybody gets the message about the Roselawn:
Instead of bitching around you all should rather go to the source (the finest IMHO which is the NTSB database and get the reports straight)
BTW: It clearly states that they encountered water droplets the size and bla bla which clearly exceeded the certification standards bla bla - In short it means they probably were in SEVERE ICING - quote.
Now the references:
Factual report - here:
http://www.ntsb.gov/ntsb/GenPDF.asp?...95MA001&rpt=fa
Probable cause - here:
http://www.ntsb.gov/ntsb/brief.asp?e...06X02420&key=1
Accident brief - here:
http://www.ntsb.gov/ntsb/GenPDF.asp?...95MA001&rpt=fi
I'll be back with the full narrative and if I can find it again with the know-how they got from the tests at the NASA icing branch.
error_401
Instead of bitching around you all should rather go to the source (the finest IMHO which is the NTSB database and get the reports straight)
BTW: It clearly states that they encountered water droplets the size and bla bla which clearly exceeded the certification standards bla bla - In short it means they probably were in SEVERE ICING - quote.
Now the references:
Factual report - here:
http://www.ntsb.gov/ntsb/GenPDF.asp?...95MA001&rpt=fa
Probable cause - here:
http://www.ntsb.gov/ntsb/brief.asp?e...06X02420&key=1
Accident brief - here:
http://www.ntsb.gov/ntsb/GenPDF.asp?...95MA001&rpt=fi
I'll be back with the full narrative and if I can find it again with the know-how they got from the tests at the NASA icing branch.
error_401
Last edited by error_401; 12th May 2006 at 15:28.
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My two pennies worth:
First of all stall (exceedence of AoA) is the first and foremost danger, recover that by reducing your AoA. Then you will find yourself with your seccond problem and that is altitude loss, for this we may (or may not if we're really unlucky) have engine power, this power (energy) is then converted into speed. To make this more effective let's get rid of unnessesary drag, so flaps to 15 degrees.
The speed at which you perform these tasks depends on your situation. If you have lots of altitude, use it in your recovery, if not I would be more power minded.
Last but not least, icing: No aircraft is certified to fly into icing conditions for a prolonged period of time whenever the supercooled droplets exceed 40 microns. So since I cannot measure the droplets, my way of operating when picking up ice: GET OUT OF THERE!
Use anti and de-ice to buy time, but either climb (3000 often is enough to get above ice accretion) or descent (if safe enough).
Good luck to all ATR drivers in the Wx
Nick
First of all stall (exceedence of AoA) is the first and foremost danger, recover that by reducing your AoA. Then you will find yourself with your seccond problem and that is altitude loss, for this we may (or may not if we're really unlucky) have engine power, this power (energy) is then converted into speed. To make this more effective let's get rid of unnessesary drag, so flaps to 15 degrees.
The speed at which you perform these tasks depends on your situation. If you have lots of altitude, use it in your recovery, if not I would be more power minded.
Last but not least, icing: No aircraft is certified to fly into icing conditions for a prolonged period of time whenever the supercooled droplets exceed 40 microns. So since I cannot measure the droplets, my way of operating when picking up ice: GET OUT OF THERE!
Use anti and de-ice to buy time, but either climb (3000 often is enough to get above ice accretion) or descent (if safe enough).
Good luck to all ATR drivers in the Wx
Nick
Originally Posted by error 401
It clearly states that they encountered water droplets the size and bla bla which clearly exceeded the certification standards bla bla
In short it means they were in f
SEVERE ICING
SEVERE ICING
According to FAA, during severe icing the rate of ice accumulation on an aircraft is such that de-icing/anti-icing equipment fails to reduce or control the hazard. Immediate diversion is necessary. So was it present at Roselawn? No - boots and heaters dealt with ice quite nicely, the ridge of ice that proved to be fatal formed on unprotected area behind the boot.
Hindsight is always 20/20 but does anyone think that crew should have considered routine hold with some icing as potentialy dangerous, when even designers and certifying authorities didn't know it was at the time?
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Clandestino,
That is exactly the danger with the ATR because the anti- and de-icing equipment is doing a terrific job. Nevertheless in icing conditions more than light you will start to accumulate ice all over the plane including the underside of the belly the pack inlets antennae etc. I'd like to know how much icing the boots on the ATR could really take... and make you believe everything is fine.
I have not been able to find your reference on FAA severe icing elsewhere than on the NOAA page.
The ridge that formed behind the boots on the Roselawn ATR may be strong evidence that they were flying in heavy icing conditions.
The real danger lies exactly in this equipment being so efficient that the crew may think they are safe. But runback ice is always a problem. So I fully agree with your last statement that at that time they probably could not have known.
I'm happy that ATR had to change the design of the boots and other measures which make the plane even safer. What probably led to the fact that icing incidents and accidents have nearly been eliminated on the ATR may be the specific procedure changes calling for: Leave severe icing conditions immediately.
Nick NOTOC,
I fully agree and actually do the same. As long as you see ice accumulate get out of it as long as you still can. Unfortunately ice has the tendency to build up on the window frame, wipers, ice evidence probe to quite remarkable sizes but will also brake off from time to time suggesting less icing than actually present. I usually start a timing at first ice accretion and after 10 minutes I'll get nervous if the accumulation is still strong.
That is exactly the danger with the ATR because the anti- and de-icing equipment is doing a terrific job. Nevertheless in icing conditions more than light you will start to accumulate ice all over the plane including the underside of the belly the pack inlets antennae etc. I'd like to know how much icing the boots on the ATR could really take... and make you believe everything is fine.
I have not been able to find your reference on FAA severe icing elsewhere than on the NOAA page.
The ridge that formed behind the boots on the Roselawn ATR may be strong evidence that they were flying in heavy icing conditions.
The real danger lies exactly in this equipment being so efficient that the crew may think they are safe. But runback ice is always a problem. So I fully agree with your last statement that at that time they probably could not have known.
I'm happy that ATR had to change the design of the boots and other measures which make the plane even safer. What probably led to the fact that icing incidents and accidents have nearly been eliminated on the ATR may be the specific procedure changes calling for: Leave severe icing conditions immediately.
Nick NOTOC,
I fully agree and actually do the same. As long as you see ice accumulate get out of it as long as you still can. Unfortunately ice has the tendency to build up on the window frame, wipers, ice evidence probe to quite remarkable sizes but will also brake off from time to time suggesting less icing than actually present. I usually start a timing at first ice accretion and after 10 minutes I'll get nervous if the accumulation is still strong.
