Thread: 2.125" analog FDIAS "sticking" on takeoff

my flight design 2 1/4'' airspeed indicator just (250 hours) started "sticking" on takeoff. This started a few flights ago, indicating zero airspeed until I approach some speed, then "jumping" up to speed. The dynon has not agreed and does not stick, so I assume its not the pitot static system they share. Has anyone had a similar thing? They want $660 for a new airspeed indicator, so I would rather find another solution. -WF

same here.... mine sometimes sticks until 40kts.... then all is OK. 'figure it's some sort of mechanical thing, as it seems to jump up earlier if I tap on the gauge. No Dynon.

Tim

FD wants $660 for a new 1 1/4" analog airspeed indicator, so I took the airspeed indicator apart (supervised, of course) and went over all the internal parts with rubbing alcohol on a q-tip. I saw nothing broken, but did pick up some dirt. I applied a tiny bit of machine oil on a toothpick to the moving pieces that rub together, only where they rub. Put it back together and viola! No sticking. The hardest part was putting back those tiny little screws that hold the back end on the thing. Had to stick the little screws, head first, in a hole I dug in the end of a pencil eraser, then used the pencil like a screw driver. - WF

'looks like that will be the plan for me, too. Thanx for the info! This forum is the best.

tim

I flew last weekend and my 3" Falcon airspeed indicator was stuck until I tapped it then it was 10 knots low compared to the Dynon. An old camera repair trick is to go over all the sliding/pivoting points with an artist's brush moistened with acetone, then lubricate with the proper oil. I presume that would be a fine instrument oil.

I also noticed that Chief had a UMA 3" airspeed indicator for less than $200. I might see if I can get a FD approval to substitute that for the Falcon.

Here's a neat setup for testing an airspeed indicator:

http://www.iflyez.com/manometer.shtml