Wing anti ice

[Boelie]

Why are slats 1 & 8 not heated by the wing anti ice system?

greetz
Boelie

[sjap]

Mybe this is an answer?
http://www.b737.org.uk/iceandrain.htm

anybody?

[Dunny]

I would imagine it's just because icing in this area would not cause any significant problems to flight.

[troubleshooter]

I would imagine it's just because icing in this area would not cause any significant problems to flight.

That's what I've been told on the course. Ice build up on slats 1 and 8 has no significant effect on flight performance.

[lbh]

Hey

Slat 1 and 8 is propally not heated eather to just preserve bleed air or because some temperature sensitive components are taken from CL. So not to fry them off with a increased bleed demand? Boeing conpensated by programming a iceing logic in the SMYD.
If you get a lot of ice on the LE the A/C just becomes a little sloppy in roll due slats and pitch...since the is no anti ice on the stabilizer...
If you perform T/G in iceing conditions nosewheel stearing might also raise a problem...

Lasse

[Pete]

Because thats the way boeing wanted it.

[biswajit]

wing anti ice on slat #1 and no #8 not required as there is no ice formation there due to flexing during flight loads. notice the amount of flexing that occurs during flight by sitting near overwing exit sometime

[lbh]

Biswajit is that something you can documentate? Ive never heard that theory before...

[S&L]

Biswajit - that is incorrect. I can tell you from personal experience that ice forms, and remains, on the wing equally across its span. The photograph at http://www.b737.org.uk/iceandrain.htm#Wing_Anti_Ice shows the remaining ice after wing anti-ice has been used.

I was told by a Boeing TP that the reason was excessive bleed requirements, but Boeing would obviously never put that sort of negative comment in print.

I beleive that the MMA will have wing A/I along all slats because it may be operating in icing conditions for extended periods.

[biswajit]

if bleed is the reason then we have thrust conservation protection by the A/G logic and and the microswitches in the control stand that switches the WTAI off during T/O when the thrust lever is advanced.