Airspeed Indication

[cgruby]

Well with all the rebuilding done and brakes that are now manageable, I turn my attention to other things that need a little attention. I never have been totally satisfied with the my airspeed indications. It appears that the needle is all over the place causing me to not rely on it totally during approach and landing. Even at cruise, it's vacillating between 80, 70, where the GPS is rock solid.

I suspect I need a static system. Has anyone out there plumbed up on and have a good location for the ports?

Thanks,

[Dusty]

Try a very small restricter under the dash.
I had the same problem.
Rock solid now,possibly reading slightly low at speed and slightly high on approach.
Only a few kts out but ok

[cgruby]

Try a very small restricter under the dash.
I had the same problem.
Rock solid now,possibly reading slightly low at speed

Thanks a lot for the information. That sounds like a good fix. I wonder how critical and how small the hole size should be.

BTW, your plane looks a lot like mine. Have you got a larger picture?

[jiott]

I plumbed in a static port and my indicator is rock solid. On the model 7 the factory has a recommended static port location that is low on the left side and just ahead of the lift/push handle.

[Dusty]

Hi chuck
The hole can be very small,about the size of a pin.
It is effectively only a breather
Re photo,I recently posted some images on where I fly

[cgruby]

Thanks for the info. If simply restricting the pitot side doesn't tame oscillations, I'll install a static source. Isn't it amazing the things we do to make a simple airplane complicated.

[cgruby]

Hi chuck
The hole can be very small,about the size of a pin...

Thanks for the neat photos, our planes are somewhat similar.

[cgruby]

I added an orifice in the pitot line. I think the indications are more stable, but may have to use a smaller hole to really damp out all the oscillations.

[cgruby]

Well it's now a month and a brand new airspeed indicator later, and for the first time my airspeed is solid an accurate. It no longer wags at me like a windshield wiper. What a Godsend.

The old gauge exhibited the same reactions when I plumbed it up to my auto to check it out, so hence the new one.

[phintz]

I plumbed in a static port and my indicator is rock solid.....


When it built my series 6 , I placed my static port in the same location! My indicator is calm also.