I ran into induction icing often with my piston 4-P.  The alternate air door
would open, next the CHT's would then run hot, and then I had power back to
less than 20" to keep from overheating.  A K&N filter helped but did not
eliminate the problem.  I have talked to other long time Lancair 4 drivers
that have the same problem.  The alternate air system needs to work, and it
needs to be improved as hot cowl air makes for hot CHT's.  

I am building a turbine now and the induction air ice system is a mystery.
I am hoping enlarged inlets and alternate induction air ports coupled with a
fast climb rate will simply get me out of the ice before it builds up to a
problem.  People build 4's with very expensive and elaborate IFR panels but
if flown much in hard IFR ice will be a problem, and induction ice with the
resultant loss of power is the worst part of the problem.

Larry Klaas
2625 NW Ordway Ave
Bend, OR 97701-5497
Tel: 541-388-2420  Fax: 413-581-0178
Email: LDK@bendcable.com