411A
Nobody is suggesting, “idle thrust will provide ADEQUATE bleed air for COMPLETE anti-icing protection for wing anti-ice or engine anti-ice on the ground”
If you re-read my original post, you will see that we are discussing a known history of possible adverse effects vs benefits of using wing anti-icing on the ground. Over the years the advice for its use has changed, possibly more than once. The ambiguity this has created is demonstrated by the fact that operators are still divided as to its correct use.
For you to dismiss this subject in the terms you have done so, demonstrates a worryingly ostrich-like mentality and, unless you simplified your explanation for us, a poor understanding of either the system or the problem.
As I understand it, with wing A/I selected on, hot bleed air will flow to the leading edges unless either an overtemp/overpressure condition exists or if either thrust lever is advanced beyond the T/O warning setting, a thrust lever angle that I guess would probably give at least 50% N1. Even with normal taxy power settings, the leading edge will heat up. Early last year there was much discussion about the thermal stability of thin layers of de-icing fluid (see article in Aero 8, Oct 1999). The upshot of it was that because of differences in SAE and ISO standards of all, but particularly type IV, fluid it could not be guaranteed that the fluid would not have partially dried out before the hold-over time had expired.
My question is: Has this issue been sorted out yet and if so what was the conclusion?
S & L
http://www.boeing.com/commercial/aer..._textonly.html
Edited to add link to Aero 8
S & L
[This message has been edited by CaptainSandL (edited 02 January 2001).]