REFLECTOR:Heated Pitot and Ice

Chris Martin reflector@tvbf.org
Sat, 4 Oct 2003 21:11:15 -0700


Since everyone is talking about icing situations in their Velocities. I
thought I would resurrect my report that I printed last April for all of
you that missed it.

Chris Martin
--------------------
"Flying a Velocity in Icing Conditions, April 21, 2003"

I had an interesting IFR flight today  that I thought you all would be
interested in hearing about.
 
I needed to fly from Los Angeles to San Luis Obispo, CA and there was
marginal VFR. Clouds were reported with bases at 3,500 and tops at 7,000. I
asked a CFI friend to make the trip with me because I knew it would require
IFR and I am not rated. To make a long story short. We did some serious
cloud burrowing.
 
The icing level was 7,000 and we were at 8,000. After about 15 minutes, as
we poked in and out of the clouds, I noticed some minor build up of ice was
occurring. The first sign of it showed up at the tips of the vortelons, on
the sharpest edges. Within 30 minutes the rime ice was becoming 1/4 inch
thick on the leading edges of the winglets. Clear ice was beginning to show
just aft of the leading edge of the wing and on top of the carnard. At this
point I noticed the plane was loosing 20 knts of forward speed. We
penetrated a few more clouds and the buildup seemed to accelerate. The
speed of the plane was now reduced by 40 knts and the engine was beginning
to heat up. The cylinder head temps had risen from 370 F to 415F. This was
undoubtedly due to the arm pit scoops loading up with ice. I thought it was
time to call it quits and head for a lower elevation. We dropped to 7,000
and came out of the clouds. Canceled the IFR and squawked 1200 and dropped
further to 5,500 as the air temp rose from the low of 32 the ice began to
melt. As a few chunks came off, I lifted the nose and dropped the speed to
130knts to allow the ice to fall away as opposed to flying back into the
prop. Within 3 minutes we were clear of all the ice and resumed a normal
VFR cruise at 3,500 feet on to our destination.
 
I don't know how many of you have flown into real icing conditions. I
didn't think I ever would. But, given the right conditions, as I had today,
and the opportunity to drop out of it at anytime. I thought it was a
worthwhile opportunity to test the effects. The most interesting result was
the increased engine temps.
 
Just thought I would share the experience. I don't expect it to happen
again.