REFLECTOR: Calibrating the static port

[Al Gietzen]

Scott;

Straighten me out here:

 

At the runway, Set your altimeter to field elevation. 

 

Now fly the airplane at cruise speed as close to the runway as you are

comfortable.  50 ft is a good safe altitude.  

Note the altitude.  Your altimeter should indicate  50 ft above field

elevation. 

 

IF NOT:

 

If your altimeter shows a lower altitude this means the static port is

in a low pressure zone relative to the real or unaffected pressure.

 

If the port pressure is too low, wouldn't it be indicating altitude too
high?

 

Usually this requires a ridge behind the port to raise the pressure. Put

a thin piece of aluminum  tape right behind the port.  Fly again.   It

may require  multiple layers, it may require  tape in front of the hole.

Its a trial and error process.

 

If it shows a higher altitude, the the same as above but start with the

tape strip ahead of the port to lower the relative pressure.

 

And vice versa?

 

Mine was off 400 ft(high) at cruise.  No wonder the ground seemed so low

in the pattern! 3 layers of aluminum tape ahead of the  static holes got

it spot on, and my indicated airspeed now agreed with my GPS's computed

airspeed(not ground speed!).

 

Flying at cruise speed just above the runway requires calm attentive

piloting.  Don't do this  as part of a known low pass with  people 

watching and waving.   Too distracting.  Don't do it.  This is flight

testing and serious business.   Have one person  near the runway to

estimate how high you are as you make the pass to verify your altitude.

 

Scott

 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.tvbf.org/mailman/private/reflector/attachments/20090224/0231763b/attachment.htm