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>I have purchased de-ice boots but so far have only fitted them to the

>surfaces and made the openings for the air/vacuum fittings.  Expect to

>install them March/April.  I purchased them from Chuck.  I understand

>that they are designed for laminar flow wing, Beech Star Ship, I think.

>Chuck reports no significant change in handling or speed.  Hope he is

>right, but normally there is a few knots given up for the benefit.

>

>Regards,

>

>Gary Rodgers



In 1995 I considered installing the BFG boots on my IV-P, but had concerns

about them disrupting the laminar flow over the wing. I called Rick

McWilliams, the designer of the IV's wing, to ask  about his opinion of

boots on the IV, and he was very much in doubt of the wing maintainig

laminar flow with boots installed. He told me that the maximum "ridge" or

discontinuity on the forward part of the wing has to be 0.002" or less to

maintain laminar flow. As far as remember the TE of the BFG boot, even

though it is a low drag faired boot, is 0.007". The boot itself is also not

totally smooth. Even with vacuum applied it is wavy which can disrupt

laminar flow.



Back then I also talked to a Starship support engineer at Beechcraft and if

my memory serves me right he told me that the starship wing cannot maintain

laminar flow with the boots.



According to Lancair the IV loses about 25 mph flying through rain - the

raindrops disrupt laminar flow (I'd be interested in hearing numbers from

people other than Lancair)



I don't know for sure that the boots will have a negative effect on

performance - the only way to find out would be an actual flight test.

That's why I was wondering if somebody on this maillist knows of anybody

who has flown a IV equipped with the boots.



Hannes TRNKA