G5 Altitmeter Setting Question

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5QK

Pre-takeoff checklist
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5QK
My G5 altitmeter seems to be off two decimal points. For example, our AWOS is reporting 29.92, but my tape reads high when set to that. At 29.90, it is spot on with my stock altimeter and the proper field elevation at that spot on our field that is actual elevation.
Can this be reset somehow or does it need a trip to installer?
Thanks POA
 
5QK said:
My G5 altitmeter seems to be off two decimal points. For example, our AWOS is reporting 29.92, but my tape reads high when set to that. At 29.90, it is spot on with my stock altimeter and the proper field elevation at that spot on our field that is actual elevation.
Can this be reset somehow or does it need a trip to installer?
Thanks POA
Click to expand...

There's a calibration procedure, but it requires access to a pitot/static test set.
 
I thought mine was off at first, but it’s dead on with the GPS altitude on the ground (in multiple location) , so I concluded my analog altimeter was incorrect.
 
So how high does it read when the current baro press is dialed in? There is some reg somewhere that discusses an allowable 75ft error (for IFR ops I think??). I’m sure someone will come along to give us chapter and verse.
 
I've not worked with the G5 yet but explained to the people new to ADHRS that they now see with a micrometer rather than a yardstick.
 
They did the P.S. check at install, but maybe Bob W. is right. I'm getting too picky
 
If your ever not sure just verify with ATC, They used to get a kick out of me when we first started doing GPS powered approach cert flights, wondering what we were testing.

Fly Safe
 
0.02 is less than 0.07% of a full scale error. Sure you can recalibrate it but there's nothing to say it wouldn't have migrated back in a couple months anyways. There's also nothing to say that the pitot-static calibrator will be any more accurate. Since ±75ft max error is required, I'd call it good.
 
I’m surprised it’s 75ft. On an ILS, that’s a hell of a lot closer to the ground....
 
dreyna14 said:
0.02 is less than 0.07% of a full scale error. Sure you can recalibrate it but there's nothing to say it wouldn't have migrated back in a couple months anyways. There's also nothing to say that the pitot-static calibrator will be any more accurate. Since ±75ft max error is required, I'd call it good.
Click to expand...

To be fair, it is REALLY annoying when you have two altimeters that aren't reading the same altitude.
 
Any time my CFI would comment I was off my altitude, I’d just twist the alt adjust knob and it was all better. I suggest you use it and make the numbers match......
 
dans2992 said:
Looks pretty complete, but it’s still 70 ft at ground level...
Click to expand...

The friction test has the 70' error spec. at sea level. The table above shows the altitude in feet, the corresponding inches of mercury, with the allowable error. With interpolation, you would see there is a 70' tolerance at 9,000' ish. With the modern solid state sensors we have today the friction test is no longer a challenge like it could be with the mechanical altimeters.
 
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