REFLECTOR:A (re)volting problem

Dave Black reflector@tvbf.org
Wed, 01 Oct 2003 20:46:42 -0400


Chuck,

> Now, all I have to do is figure out how hot is hot enough at 12v.  I assume
> it wouldn't really have to be particularly hot.

This is an area I do not have expertise in. Pitots are small and out in the
breeze, so they will require a good deal more heat than a similar item sitting
on your patio. Obviously, some manufacturers think a great amount of heat is
required. But then, this pitot tube may have been designed for a jet going
600kts at FL300. It's a cinch it was not designed for a Velocity. 

> What to do?  What to do?

Reminds me of my instrument flight instructor. One day he put me through a
series of Unusual Attitude maneuvers. In each case, I was able to quickly
bring the aircraft back to stabilized straight-and-level flight. On one test,
when he handed the plane over to me I did absolutely nothing. Nothing. After
about 10 seconds, the instructor said "Aren't you going to do anything?"

I replied "I will as soon as I see something which needs to be done." 

He gave me another 10 seconds, then admitted he'd handed the plane back to me
already completely straight and level. He explained 9 out of 10 students will
do something in that situation, even though it's incorrect.

So I think you're in a similar situation. Think about how you'll handle it if
the lower heat presents a problem. But don't DO anything until you actually
see a problem. 

Remember: The Pitot Tube connects only to the airspeed indicator. So in worst
case, you'd lose only the airspeed. While airspeed is important in descent and
landing, you could probably land safely without it. Anyway, as you descend,
the air will get warmer, so any ice may melt with the heat you've got. Once
you actually experience ice even with the pitot tube heated, THEN you should
make corrections.

Do nothing at this time.
(That's my opinion)

Dave Black
Shortwing RG