cfm 56 anti ice procedures

[plattsburgher]

USAF KC-135Rs use the CFM 56-100 engines. I think that our flight manual anti-ice procedure is wrong (we are supposed to have it on any time in visible moisture and below 10C in flight). As a minimum, I think that there should be a lower temperature limit so that we don't cruise for hours with the anti-ice on when there is no chance of icing.

Can anyone with experience with this type of engine, or something close to it, tell me what your company procedures are?

Thanks in advance.

 

[KeroseneSnorter]

That is not just the CFM 56's, 10C and below in vis. moisture for anti ice is now the official FAA temperature for anti ice systems to be on.

Every airline uses these limits.


Some of the worst ice I have ever been in has been at +8 and 9 C.

RAT indicators are not exact, and there are all kind of variables which can result in ice accumulating well above 0 c

 

[Guppiedriver]

The procedure for the CFM 56 is anti-ice on during during all flight operations in visible moisture at temperatures between 10 C and -40 C, except during cruise and climb when temps are below -40 C.

 

[plattsburgher]

Sorry, I reread the post and I think I wasn't clear. The 10C limit is fine as a maximum. I am interested in what everybody else does as far as a lower limit (as in -40). Cruising at something like 390 in a high cirrus and standard atmosphere is way too cold for engine ice to occur, but current USAF procedure would have us leave it on until we were in the clear, however long that might take.

Thanks for the prompt reply.

 

[Ted Striker]

If it's colder than -40C, we don't have to have it on. That's on an RJ, but still pretty standard from what I understand. Too cold for ice.

 

[KeroseneSnorter]

Sorry for the confusion, -40 is what we use also.

 

[Steeler Fan]

Same thing on the B-717...

Most Airline Guys in my AF Reserve Unit use -40 SAT as the lowest temp for Eng A/I On

 

[C40_Pilot]

same...

Same for us. We have the CFM 56 engine with the same engine ice procedures.

 

[LiveFreeorDie]

KC-135

KC-135 procedures screwed up? No way. Worst ops manuals ever written. Never seen more useless trash put out. Four changes to address what color lights to use while tanking. As if it hasn't worked just fine for 40 years... Oh well get what you pay for and no one is spending money on 135 pubs.



_LFD