TAS Now Reading WAY Low

[melkel2000]

I've been flying my D-180 for about 3 years now with no issues...or so I thought.

About a year ago, I noticed that my TAS was indicating about 4-5 mph slower than what was "normal" in my airplane. I didn't worry about it too much but I always wondered why this happened.

Fast forward to yesterday. My TAS was showing 20+ mph low plus the winds were all wonky, showing very high at one point and showing a tail wind in opposite directions (every pilot's dream). I took the plane down yesterday after my flight to complete my condition inspection so it's good timing.

After reading some posts, I suspect a leak in the system. I'm thinking it's something that has been wearing or loosening over time.

My question is, if a leak is the likely culprit, is the pitot line or the static line more suspect?

By the way, this is installed in an RV-9A.

 

[kurtfly]

TAS needs Indicated Air Speed, Temperature, and Pressure altitude. 
Is the IAS also ~20 kts low?  Look at these to determine the root cause.

Static leaks can usually be proven by opening / closing air vents when in flight. If you see a change in altitude when opening or closing an air vent you have a leak.

 

[rvator51]

I am not sure what is most likely, but I also wonder if you should check for condensation in your lines too?

 

[GalinHdz]

If only your TAS is off then the problem is probably in the Pitot system. If both your TAS and altitude is off then the problem is in the static system.

 

[melkel2000]

Well, I finally got around to working on the plane last weekend. I started with the easiest pitot connection to get to (in the wing) checked for the security of the lines, and this is what I found:



Yep, that was the problem. I'm not sure how it pulled out from the back of the connector. Weird, but I replaced the connection hardware and everything works fine again.

Thanks for the help.