VSI shows a very slight descent

[ryoder]

The VSI in my C shows a very slight descent while sitting on the ground.  I heard this is adjustable.  Is this something my IA can do?  He is waiting to get the ammeter and fuel gauges back so I'll ask him to make the adjustment if its possible.

[rob]

There's a screw on the bottom left side of the ASI that you can turn to adjust it. I'm almost certain the owner/pilot can make the adjustment.

Otherwise, adjust for the discrepancy in flight.

[Marauder]

This screw

[ryoder]

Wow. Can't believe I didn't know that. Thanks!

[carusoam]

Gravity has a tendency to make things droop...

-a-

[RobertGary1]

Also aggressive static testing is hard on them. You have to suck the static system up to 1,000 agl and hold it for a minute 43 appendix E That can tweak the vsi a bit.

-Robert

[Guest]

Gravity has a tendency to make things droop...

-a-

Only in older Mooney pilots!

Clarence

[Shadrach]

There's a screw on the bottom left side of the ASI that you can turn to adjust it. I'm almost certain the owner/pilot can make the adjustment.

Otherwise, adjust for the discrepancy in flight.

I was lectured to no end by a flight instructor about making this adjustment. I finally promised him that I would not, but I had no control over the hangar gnome that does weird little things to the plane. One time I caught the little sucker making sure my compass was full

of fluid.

[rob]

I was lectured to no end by a flight instructor about making this adjustment. I finally promised him that I would not, but I had no control over the hangar gnome that does weird little things to the plane. One time I caught the little sucker making sure my compass was full

of fluid.

Why were you lectured? I believe its a completely legal adjustment for a pilot to make. Does someone have evidence to the contrary?

[RobertGary1]

It's not listed as preventative maintenance. You would need manufacture instructions to make it legal even if you were and A&P. But unless the fsdo has it in for you you're probably ok

-Robert

[rob]

Really? It's essentially the same thing as adjusting the altimeter.

[Shadrach]

Really? It's essentially the same thing as adjusting the altimeter.

pretty much...the only difference is that one is an aneroid and the other is a diaphragm.

[Guest]

It's not listed as preventative maintenance. You would need manufacture instructions to make it legal even if you were and A&P. But unless the fsdo has it in for you you're probably ok

-Robert

You would have to make a log entry for the FSDO to know it had been adjusted.

Clarence

[Yetti]

if it was never broke, was it ever fixed

[63C]

The VSI in my C shows a very slight descent while sitting on the ground.  

 

I have exactly the same situation on my VSI. Thanks for all the comments. Learn something everyday!

[RobertGary1]

There used to be a place in NorCal where if you left your tach with a $50 bill it would mysteriously return working fanatically. The guy was known for doing amazing work but I heard he retired.

 

-Robert

[ryoder]

Leave your Mooney with me and a 24 pack of Miller Lite and it will leave clean and waxed.

[xrs135]

Leave your Mooney with me and a 24 pack of Miller Lite and it will leave clean and waxed.

LOL, and what is the drop off point?!

[Hank]

Leave your Mooney with me and a 24 pack of Miller Lite and it will leave clean and waxed.

I'm thinking Tampa's not that far away . . .

[ryoder]

I really do like cleaning and waxing cars and airplanes. Maybe I should start a detail shop when I retire.

[mike_elliott]

I really do like cleaning and waxing cars and airplanes. Maybe I should start a detail shop when I retire.

Your awful close to me, I may take you up on this! 

[Tommy]

Hijacking this thread

What about altimeter? Mine is under read by 25 to 50 feet (within IFR tolerance). Can it also be adjusted like VSI?

[Guest]

Hijacking this thread

What about altimeter? Mine is under read by 25 to 50 feet (within IFR tolerance). Can it also be adjusted like VSI?

It can be adjusted but not with a simple screw like the VSI. Generally it is an instrument shop job.

Clarence

[Tommy]

I see, oh well my bi-annual avionics check is coming up soon! Well get everything looked at plus IFR cert done!

[22 others]

While studying for my instrument written today, I discovered that the VSI is not a required piece of equipment for IFR flight. The practice test question asks what to do if you discover that the VSI reads 100 feet low while at the airport. The given answer was "use 100 feet low as the level flight indication."  Interesting tidbit.