heated pitot alignment

[miyu1975]

Last night I cut the hole for the pitot mast into the wing and also drilled the holes into the mast per instrx. But they came out very slightly crooked.. (I should have drawn a line on the mast so I could see it through the wing skin holes but I didnt) Didn't think to much of it at first but just was wondering if the pitot is not facing perfectly and directly forward will it read correctly. Now obviously if it was way off then I would not be asking as I am sure it would give bad airspeed data. The pitot, once installed, will only (like a 1/2 degree or so) slightly not facing directly forward. any help with this??..sorry no pics right now. What is the margin of err here?

 

[DGlaeser]

Not to worry...

If you're within a half a degree, you're probably as good or better than most
You've got to be WAY off to see inaccurate readings. I remember doing pitot sensitivity tests in the wind tunnel at WVU. I don't remember the results (loooong time ago) but remember that it took way more misalignment than I'd have thought before accuracy was affected. Asthetics are more sensitive than the aerodynamics.

 

[Kevin Horton]

Last night I cut the hole for the pitot mast into the wing and also drilled the holes into the mast per instrx. But they came out very slightly crooked.. (I should have drawn a line on the mast so I could see it through the wing skin holes but I didnt) Didn't think to much of it at first but just was wondering if the pitot is not facing perfectly and directly forward will it read correctly. Now obviously if it was way off then I would not be asking as I am sure it would give bad airspeed data. The pitot, once installed, will only (like a 1/2 degree or so) slightly not facing directly forward. any help with this??..sorry no pics right now. What is the margin of err here?

The NACA data I've seen showed that pitot tubes will indicate accurately if they are aligned within about 15 degrees of the local airflow. The angular value where the accuracy falls off depends on the details of the pitot tube design.

Build on.

 

[miyu1975]

shhhwww

ok thx...appreciated as usual.