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?