Stupid pitot tube question
 

Ok so say your flying along and only your pitot tube gets blocked (static still open). In the instrument flying handbook, it says it will act like an altimeter ie; climb higher=higher indicated airspeed. I see why that would be the case BUT wouldn't the pressure trapped in the pitot line escape out of the drain hole,causing it to go to zero?

Indeed. The IFH does not mention anything regarding a pitot blockage affecting the inlet only. However, if you were to have ice/bug/dirt/etc...and the drain hole was open, your ASI would indicate 0.

yep

anyone who has inadvertently taken off with a pitot cover on know this



Of course it wasn't me, but I've seen it and heard about it :rolleyes:

Actually your question is far from stupid if at all. That's interesting because they didn't teach that one on instrument ground school. I think it is such an important point. Suppose you are in IMC and your airspeed drops to 0 and you turn on pitot heat, nothing. You climb and descend to see if the airspeed will indeed act like an altimeter (like the book said it would), nothing. Either way the AI must be covered ASAP.

I took off in a Stearman once, with the pitot cover on and it was at least a half hour into the flight before I noticed the airspeed was zero :)

It happened to me. A few minutes after entering IMC the a/s went to zero. After landing I found some dirt in the front hole of the pitot tube.

haha thats awesome!

Pitot and Drain Block = AS freezes on last indicated airspeed, then goes up and down wth altitude.

Pitot Block an Drain Clear = AS drops to zero

Static Port Block = ALT Freezes on last indicated, AS reads low if you climb, and high if you descend.

THATS going on my kneeboard :)

Pitot Tube Advice- Never touch one when the pitot heat is on. I was helping a mechanic do an inspection the other day, and it is amazing how fast those things heat up. He flicked on the switch and yelled out "is it putting out heat" so like a moron I actually put my hand on it. After instantly pulling my hand off and waving it through the air while trying not to curse I managed to let him know that yes it is indeed heating up.