Pitot Heat

Did I miss this in my training?

I thought Pitot Heat was only needed in icing conditions. Tom Haines column
in this months AOPA mag recommends turning it on in or near moisture at any
temperature. Is this a typical recommendation?

Is there an effect like a carburetor that could cause ice to from in the
pitot at above freezing ambient temperatures?

Since the heat is provided by a hot filament, having it on a lot
unnecessarily would make me worry about finding that it's not there when you
need it.

--
Roger Long

"Roger Long" om wrote in
message ...
Did I miss this in my training?

I thought Pitot Heat was only needed in icing conditions. Tom Haines
column
in this months AOPA mag recommends turning it on in or near moisture at
any
temperature. Is this a typical recommendation?

Is there an effect like a carburetor that could cause ice to from in the
pitot at above freezing ambient temperatures?

Since the heat is provided by a hot filament, having it on a lot
unnecessarily would make me worry about finding that it's not there when
you
need it.

High performance aircraft will normally have Pitot Ht on at all times from
take-off to touch-down, visible moisture or not.

Some pitot tubes do have a venturi effect that can cause ice to build when
above freezing ambient temperatures.

If you don't have a [Pitot Heat] annunciator light that will alert you to a
break in continuity of your heating element, you can just check your amp
gauge to look for a current draw when you cycle the switch to confirm your
heat is working in flight. On pre-flight you can *momentarily* activate the
pitot heat and then *carefully* check that the probe is warm.

Regards,
Mish

Gary Mishler wrote:

...snip...
High performance aircraft will normally have Pitot Ht on at all times from
take-off to touch-down, visible moisture or not.

...snip...

I assume one reason would be so that you keep the PT absolutely dry of
moisture so that it would not freeze when you climb above the Freezing
Level. Also I think you would be carrying a small amount of entrapped
air from the earth's surface (relatively warm and moist), which could
condense at the colder temperatures at altitude...

Does moisture alone screw up PT readings?

Icebound writes:

Does moisture alone screw up PT readings?

Part of the preflight checklist for my Warrior is to open up the pitot
and static drains beside the pilot seat to let out any moisture that
might have accumulated in the system, for what that's worth. I always
do it, and I've never seen any come out.


All the best,


David

Roger Long wrote:
Did I miss this in my training?

I thought Pitot Heat was only needed in icing conditions. Tom Haines column
in this months AOPA mag recommends turning it on in or near moisture at any
temperature. Is this a typical recommendation?



I asked my flight instructor that today and he said that if you can't
see visible moisture, you don't need pitot heat. I guess I can go along
with that for low-performance aircraft but something tells me there's
more to it. (I did read the Haines column, so maybe that's what got me
thinking.)

What's the life expectancy of a pitot tube heater?

-Scott

In article , David Megginson
wrote:
Part of the preflight checklist for my Warrior is to open up the pitot
and static drains beside the pilot seat to let out any moisture that
might have accumulated in the system, for what that's worth. I always
do it, and I've never seen any come out.

Test question: What is the maximum engine rpm permitted to perform this?
(The Turbo Arrow IV manual provides a limitation)

EDR writes:

Part of the preflight checklist for my Warrior is to open up the pitot
and static drains beside the pilot seat to let out any moisture that
might have accumulated in the system, for what that's worth. I always
do it, and I've never seen any come out.

Test question: What is the maximum engine rpm permitted to perform this?
(The Turbo Arrow IV manual provides a limitation)

I've never noticed a limitation, but then, I've never opened the
drains with the engine running.


All the best,


David

Icebound

On Sun, 02 Nov 2003 19:21:46 GMT, Icebound
wrote:

----clip----

Does moisture alone screw up PT readings?

----clip----

When you fly through rain does your airspeed quit?

Big John

"Roger Long" om wrote in
message ...
Did I miss this in my training?

I thought Pitot Heat was only needed in icing conditions. Tom Haines column
in this months AOPA mag recommends turning it on in or near moisture at any
temperature. Is this a typical recommendation?

Is there an effect like a carburetor that could cause ice to from in the
pitot at above freezing ambient temperatures?

Since the heat is provided by a hot filament, having it on a lot
unnecessarily would make me worry about finding that it's not there when you
need it.


Personally, I've lost my pitot/static insturments when flying through moderate
to heavy rain without pitot heat on a 70 degree day. Of course, I didn't HAVE
pitot heat to turn on, but I got them back about an hour after I got out of the
rain.

I assume what happened was I got a few drops of water in the pitot tube and it
got plugged, and I had to wait for it to evaporate or blow out. I would guess
that if I had pitot heat on, it would evaporate the water quicker and possibly
have avoided the problem.

For the record, I was flying a PA-12 at about 40 mph indicated when it first got
plugged.

--
Mike O'Malley

1000 or 1500 rpm ,have to check for sure, but that it the manifold pressure
release valve, and hold it for 5 seconds.


EDR wrote:

Test question: What is the maximum engine rpm permitted to perform this?
(The Turbo Arrow IV manual provides a limitation)