From: Fredmoreno@aol.com
Message-ID: <d0.d0a3ff58.25a6dce2@aol.com>
Date: Fri, 7 Jan 2000 01:08:34 EST
Subject: Ice on Lancair IV
To: lancair.list@olsusa.com
Mime-Version: 1.0

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I can provide two reports, one direct (I was there) and one indirect (a 
reliable reporter was there).

My experience was in a IVP.  Light rime knocks about 20 knots off right away 
as the laminar flow goes to turbulent with associated drag build up.  We did 
not add much more ice before exiting. The tail ices up much more quickly than 
the wing, as expected, due to its much smaller leading edge radius.  

The report I received was moderate icing that "welded" the elevator 
counterbalance horns to the vertical stabilizer removing any pitch control.  
After a while the stick was thumped downward by the pilot in attempt to break 
the ice, and the baggage went to the ceiling when the elevators broke loose.  
Luckily no outside loop in IMC followed, but apparently it was a thrill. 

The Lancair IV cruises with the elevator horns slightly above the top of the 
horizontal stabilizer, perhaps 1/4 inch.  If the leading edge of the horn is 
squared off, and the fit between the horns and the horizontal stabilizer is 
tight (less than 1/4 inch spacing), the "weld up" can occur quickly, in a few 
minutes of light icing.  

Several years ago I made a plea at the Lancair evening forum to round off the 
leading edge of elevator horns so that they would not collect ice on their 
leading edge when displaced slightly.  Last year at OSH I noted that most IVs 
still had squared off leading edges on the horns, presumably because it looks 
neat (even if it is draggy in cruise).  

However, losing it in IMC is not neat, nor is putting baggage on the ceiling. 
 Fix those elevator counterweight leading edges, or DON'T fly above the 
freezing level.  

'Nuff said.

Fred Moreno
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