737-800 Flight Deck Smoke on TO after deice
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737-800 Flight Deck Smoke on TO after deice
Hi folks,
I was wondering if anyone else had ever experienced this. We were in a fully loaded -800 departing on a snow covered runway that required Flap 25 Bleeds Off. We deiced with Type I and IV with the engines running and the APU off and then restarted it 2 or 3 mins after leaving the deice bay. We left the bleeds on the engines until just before take off (as is specified in our company FOM). We then switched the bleeds to the APU (packs auto, isolation valve closed, eng bleeds off, APU bleed on).
On the take off roll at about 120 kts we suddenly got a strong odour followed by a lot a smoke in the flight deck. We were pretty close to V1 with a slippery runway that spills out onto a highway, so we continued. The smoke dissipated over the next 1-2 mins. The FA's and PAX did not notice anything in the back (which makes sense as the Right Pack was essentially off with the iso valve closed).
I did not love taking off into the pitch black, 1/2 mile and 200ft in -fzra with smoke billowing out of the vents. Has anyone seen this before? Given the location of the APU inlet and that the APU was off for deicing, it seems strange that we would get this much fluid into the APU bleed system.
I was wondering if anyone else had ever experienced this. We were in a fully loaded -800 departing on a snow covered runway that required Flap 25 Bleeds Off. We deiced with Type I and IV with the engines running and the APU off and then restarted it 2 or 3 mins after leaving the deice bay. We left the bleeds on the engines until just before take off (as is specified in our company FOM). We then switched the bleeds to the APU (packs auto, isolation valve closed, eng bleeds off, APU bleed on).
On the take off roll at about 120 kts we suddenly got a strong odour followed by a lot a smoke in the flight deck. We were pretty close to V1 with a slippery runway that spills out onto a highway, so we continued. The smoke dissipated over the next 1-2 mins. The FA's and PAX did not notice anything in the back (which makes sense as the Right Pack was essentially off with the iso valve closed).
I did not love taking off into the pitch black, 1/2 mile and 200ft in -fzra with smoke billowing out of the vents. Has anyone seen this before? Given the location of the APU inlet and that the APU was off for deicing, it seems strange that we would get this much fluid into the APU bleed system.
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Obviously the right decision,so well done.
It never happened to me apart from the occasional light smell.
It is possible that the deicer aimed at your APU inlet quite well...
It never happened to me apart from the occasional light smell.
It is possible that the deicer aimed at your APU inlet quite well...
Submit an ASR.
This could have resulted in a rejected take-off on a very dodgy runway surface with a potentially catastrophic over-run. It would probably not have been pretty.
If the de-ice operative is unaware/has forgotten about not spraying fluid on certain areas of aircraft, then some retraining is required - report it as soon as possible.
This could have resulted in a rejected take-off on a very dodgy runway surface with a potentially catastrophic over-run. It would probably not have been pretty.
If the de-ice operative is unaware/has forgotten about not spraying fluid on certain areas of aircraft, then some retraining is required - report it as soon as possible.
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That was a really messed up situation, for sure. Great you're here to tell the story without further traumas.
I never did a de-ice/anti-ice procedure in my entire career ! That's a very unlikely procedure here in South America.
However, looks like the cenario you faced is warned by boeing in the supplementary procedure which regards this kind of procedure.
SP 16.8
CAUTION:After de-icing, the use of APU bleed air during takeoff may cause smoke in the airplane.
All the best !
I never did a de-ice/anti-ice procedure in my entire career ! That's a very unlikely procedure here in South America.
However, looks like the cenario you faced is warned by boeing in the supplementary procedure which regards this kind of procedure.
SP 16.8
CAUTION:After de-icing, the use of APU bleed air during takeoff may cause smoke in the airplane.
All the best !
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Good Call
A others have noted, it looks like you made a VERY good choice. At your noted speed and under those conditions, I would not want to execute an RTO. We do not know the rest of your weather situation, but The Schedule does NOT govern safety. Another choice might have been to deny boarding and delay until conditions improved. OPS will always be a little pissed off if/when we do that, but they do not ride or drive the planes. What is safe enough for you ought to be safe enough for your pax and your family. When saying NO is necessary, do it and move on! 
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Thanks for the replies. In regards to:
The good call ... I can't take credit as I was the FO. I was just recently awarded my upgrade however, so this incident was particularly poignient to me. The captain had coincidentally just completed his upgrade 4 weeks ago and did a fabulous job of keeping cool and continuing.
Safety ... we are a Canadian carrier well equipped to handle this weather and with a very progressive safety culture. It was well within our training, experience and comfort zone and there's no pressure to go at our company. It's a good point to bring up though. Sometimes it's best to just sit the weather out.
B737SPF and the SP ... I am very interested in this Supplementary Procedure you refered to. There are no restrictions in any of the company or Boeing documentation we have available. Could you elaborate on the specifics of the document you were referring to? Is this a company or Boeing document?
This incident is filtering through the safety system but the initial feed back was that this happens from time to time. I have a feeling they do not appreciate how much smoke was produced. I have had a whiff of odour and maybe a wisp of smoke before. This was many orders of magnitude greater than any other deice related event I have experienced in the last 15 years. The more I thought about it, the less it makes sense that it was simply residual de-ice fluid from poor deicing. The APU was shut down, thus the door closed. The APU inlet is on the lower half of the fuselage cross section. Gravity naturally drains fluid away so I cannot imagine much of a mechanism by which residual fluid would be ingested after deicing is complete and the APU is started (which took place several minutes after de icing).
I wonder if it is possible that the Type IV fluid could be injested by the APU as it shears off the wing during the takeoff roll. The inlet IS positioned such that I could see this being possible. This would explain why it came on so suddenly at the 100-120 kt speed range (where Type IV fluid will be departing the wing surface on mass). I wonder if this might be the reason that B737SPF's Supplementary Procudure exists.
Any thoughts on this?
The good call ... I can't take credit as I was the FO. I was just recently awarded my upgrade however, so this incident was particularly poignient to me. The captain had coincidentally just completed his upgrade 4 weeks ago and did a fabulous job of keeping cool and continuing.
Safety ... we are a Canadian carrier well equipped to handle this weather and with a very progressive safety culture. It was well within our training, experience and comfort zone and there's no pressure to go at our company. It's a good point to bring up though. Sometimes it's best to just sit the weather out.
B737SPF and the SP ... I am very interested in this Supplementary Procedure you refered to. There are no restrictions in any of the company or Boeing documentation we have available. Could you elaborate on the specifics of the document you were referring to? Is this a company or Boeing document?
This incident is filtering through the safety system but the initial feed back was that this happens from time to time. I have a feeling they do not appreciate how much smoke was produced. I have had a whiff of odour and maybe a wisp of smoke before. This was many orders of magnitude greater than any other deice related event I have experienced in the last 15 years. The more I thought about it, the less it makes sense that it was simply residual de-ice fluid from poor deicing. The APU was shut down, thus the door closed. The APU inlet is on the lower half of the fuselage cross section. Gravity naturally drains fluid away so I cannot imagine much of a mechanism by which residual fluid would be ingested after deicing is complete and the APU is started (which took place several minutes after de icing).
I wonder if it is possible that the Type IV fluid could be injested by the APU as it shears off the wing during the takeoff roll. The inlet IS positioned such that I could see this being possible. This would explain why it came on so suddenly at the 100-120 kt speed range (where Type IV fluid will be departing the wing surface on mass). I wonder if this might be the reason that B737SPF's Supplementary Procudure exists.
Any thoughts on this?
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Flyingchanges, do you have any documents referencing the policy to not use APU bleed air after deicing? Is it something your company has put in place or is it straight from Boeing?
We have no such restrictions. I wonder if this is something that somehow got missed by our Flight Ops folks. All our NG's have the higher thrust rated engines so we rarely do bleed off takeoffs, particularly in the winter. I wonder if this is something that has slipped through the cracks.
We have no such restrictions. I wonder if this is something that somehow got missed by our Flight Ops folks. All our NG's have the higher thrust rated engines so we rarely do bleed off takeoffs, particularly in the winter. I wonder if this is something that has slipped through the cracks.
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At another Canadian carrier, operating the -800 exclusively...
Our deicing checklist specifically states that if performance requires a no engine bleed takeoff (after de-icing), to use the unpressurized takeoff procedure found in FCOM supplementary procedures (section 2).
The reason for this is to avoid the exact situation you've described.
Our deicing checklist specifically states that if performance requires a no engine bleed takeoff (after de-icing), to use the unpressurized takeoff procedure found in FCOM supplementary procedures (section 2).
The reason for this is to avoid the exact situation you've described.
Last edited by lowspeedaluminium; 1st Jan 2016 at 00:25.
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Thanks LowSpeed. That is good to know. I found a copy of the Adverse Weather section of the Boeing FCOM online (a document we don't have in our library as we have a company specific FOM). While it does not forbid an APU bleeds takeoff after deice, it does contain the Caution that B737SFP mentioned earlier (APU Bleed TO after deice may cause smoke) so this seems like the obvious policy to put in place. As much as taking off unpressurized is an annoyance, smoke is dangerously distracting and probably not the healthiest thing for crew and pax to be breathing.
I'm going to run this up the food chain. Thanks for the comments folks. It's been very helpful.
I'm going to run this up the food chain. Thanks for the comments folks. It's been very helpful.
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Submit an ASR.
This could have resulted in a rejected take-off on a very dodgy runway surface with a potentially catastrophic over-run. It would probably not have been pretty.
If the de-ice operative is unaware/has forgotten about not spraying fluid on certain areas of aircraft, then some retraining is required - report it as soon as possible.
This could have resulted in a rejected take-off on a very dodgy runway surface with a potentially catastrophic over-run. It would probably not have been pretty.
If the de-ice operative is unaware/has forgotten about not spraying fluid on certain areas of aircraft, then some retraining is required - report it as soon as possible.
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Sounds like a well handled situation.
I think what B737SFP is referring to is the FCOM1 Supplementary Procedure for deicing which should be on or around page SP 16.8/9.
My operator has no restrictions on an engine bleeds takeoff after anti-icing that I know of and publishes no specific guidance; the only warning I'm aware of is that in the SP section that smoke may occur during takeoff. The amount of times such a procedure is required (i.e. bleeds off takeoff after deicing) is probably why we haven't had any specific guidance whereas a Canadian operator is sure to have much more exposure and experience.
I think your hypothesis about the fluid shedding from the wing at higher speeds is credible. I suppose another possibility is fluid that was used to treat the runway surface being ingested due to the amount of spray being thrown up by the wheels and engines during the takeoff roll.
I think what B737SFP is referring to is the FCOM1 Supplementary Procedure for deicing which should be on or around page SP 16.8/9.
My operator has no restrictions on an engine bleeds takeoff after anti-icing that I know of and publishes no specific guidance; the only warning I'm aware of is that in the SP section that smoke may occur during takeoff. The amount of times such a procedure is required (i.e. bleeds off takeoff after deicing) is probably why we haven't had any specific guidance whereas a Canadian operator is sure to have much more exposure and experience.
I think your hypothesis about the fluid shedding from the wing at higher speeds is credible. I suppose another possibility is fluid that was used to treat the runway surface being ingested due to the amount of spray being thrown up by the wheels and engines during the takeoff roll.
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Thanks 737aviator. They do use some anti ice fluid here in Canada now to try to help manage runway contamination (if you want to nerd out on ice control chemicals there's an AC on it below) so maybe it could be injested too, but you got me thinking about how much residual Type IV there is on a day like that sitting on the runway after having sheared off the previously departed aircraft. In the daytime you can sometimes see a green slick part way down the runway where most aircraft reach the shear speed for the fluid. So perhaps that could be kicked up as well.
Either way, now that I have been forced to consider the APU inlet's position it's no wonder fluid finds its way in there. I imagine it probably find its way there from any of the avenues mentioned: poor application by the deice truck (unlikely in this case), fluid streaming aft on takeoff after shearing off the wings and perhaps even getting kicked up off the runway onto the fuselage where it could stream back (I don't think it should be able to spray directly into the intake as it has a deflector but I don't think this would protect from fluid flowing along the skin).
Anyway, I for one will not be taking off on the APU bleeds again if there is any deice fluid anywhere.
Cheers.
TC Ice Control AC:
https://www.tc.gc.ca/eng/civilaviati...-300-1762.html
Either way, now that I have been forced to consider the APU inlet's position it's no wonder fluid finds its way in there. I imagine it probably find its way there from any of the avenues mentioned: poor application by the deice truck (unlikely in this case), fluid streaming aft on takeoff after shearing off the wings and perhaps even getting kicked up off the runway onto the fuselage where it could stream back (I don't think it should be able to spray directly into the intake as it has a deflector but I don't think this would protect from fluid flowing along the skin).
Anyway, I for one will not be taking off on the APU bleeds again if there is any deice fluid anywhere.
Cheers.
TC Ice Control AC:
https://www.tc.gc.ca/eng/civilaviati...-300-1762.html
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Majikthise, do you mind elaborating on which airport you experienced this leaving?
I work for a smaller charter operator up here that operates some relatively unique 4 engine jets (i'll let you figure that one out; i'm sure you'll figure out who
.
I've been noticing a disturbing trend of ridiculous excess Type IV applications on our aircraft out of some smaller centres (YMM, YXS, YXU to name a few) over the last couple years. Although our pilots have not been too concerned about it; I've spent many an hour flushing control surfaces. The usual pilot complaint is autopilot porpoising in cruise (this aircraft if quite susceptible to this with greasy Type IV floating in there).
Informally, our pilots have been keeping track of de-ice receipts, and fluid usage - I've seen variances of as much as 50 to 100 gallons at the extreme. It's usually quite obvious once a gallon or so drains out of the flap canoes.
At the larger airports, we usually don't have much problem with excess or incorrect application.
I work for a smaller charter operator up here that operates some relatively unique 4 engine jets (i'll let you figure that one out; i'm sure you'll figure out who
.I've been noticing a disturbing trend of ridiculous excess Type IV applications on our aircraft out of some smaller centres (YMM, YXS, YXU to name a few) over the last couple years. Although our pilots have not been too concerned about it; I've spent many an hour flushing control surfaces. The usual pilot complaint is autopilot porpoising in cruise (this aircraft if quite susceptible to this with greasy Type IV floating in there).
Informally, our pilots have been keeping track of de-ice receipts, and fluid usage - I've seen variances of as much as 50 to 100 gallons at the extreme. It's usually quite obvious once a gallon or so drains out of the flap canoes.
At the larger airports, we usually don't have much problem with excess or incorrect application.
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This was out of YYZ but I have not noticed any excessive spraying that I can think of. We have hydraulic controls so we don't usually have those kinds of issues with Type IV (I remember hearing some reports of trouble in the Dash 8 many years ago in a past life).
Sounds well handled, I can imagine it would be a somewhat disconcerting moment, even if you were well aware of the chance of smoke associated with APU bleed t/o after deicing, and had briefed accordingly before hand.
Certainly it would have got me a little unnerved. Definitely something to run up the food chain though, changing procedures so in future unpressurised takeoff rather than APU bleed takeoff would surely be better than a distracting or incapacitating amount of smoke
Certainly it would have got me a little unnerved. Definitely something to run up the food chain though, changing procedures so in future unpressurised takeoff rather than APU bleed takeoff would surely be better than a distracting or incapacitating amount of smoke
Why do you want to retrain the poor guy? If all the fuselage is covered with deicing fluid on take off run due to the wind it will run back? APU intake doors are opened so it sucked a bit.
We don't know exactly what happened in this case - it might be an aircraft design fault, but I doubt it. However, if too much fluid was sprayed, or fluid was sprayed where it shouldn't have been sprayed, then this information needs to be communicated to all people concerned to avoid a potentially fatal accident in the future.
Sometimes, fluid dripping down from the fin will run around the fuselage onto the APU inlet. The Airbus APU inlet is on the underside of the fuselage and has a 'fence' around it, so any fluid reaching it from above will be forced to drip down away from the inlet. We also do not take-off with the APU running. I don't know much about the Boeing APU inlet design, but the ones I have seen are on the side of the fuselage not underneath, which might make it more susceptible to fluid ingestion? I don't know.
By the way, when we, (a UK operator) deice, we don't spray "all the fuselage", just the wings, horizontal stabiliser, fin and rudder. So that might have been the cause of the problem in this case.
