IFR cert

[kevin O]

I was unsuccessful in getting an answer from MGL so appreciate seeing the response. Just to clarify to an earlier post, the AFS glass was certified with no issues. Problem is that if another altimeter is sitting there it must be certified. I believe one can address this by placarding VFR only on the altimeter. No I am not an accountant. must think like one.

[stanbrv]

Did the AFS system need to be calibrated? I have not found the procedure to do so in my AFS manual.

Stan Blanton

[orchidman]

Originally Posted by stanbrv

Did the AFS system need to be calibrated? I have not found the procedure to do so in my AFS manual.

Stan Blanton

Setting offsets is in the manual. Mine was within 10 feet so no offset was required.

[Rainier Lamers]

To clarify:
Right from the beginning all our altimeters would be able to display actual altitudes down to -700 ft. This is AFTER correction for local pressure.
This means they are well within range of the requirements from a logical perspective.
However, the IFR certification requires -1000ft relative to a local pressure of 29.92 inches which of course makes sense for a mechanical altimeter to ensure that you will be able to dail in a local pressure such that an airfield at sea-level at high pressure will show the correct elevation.
The IFR certification makes no allowance for a system where local pressure is adjusted at measurement source rather than "tweaking" the actual display output.

Anyway, it's not a train smash as it is all done in software. I will be releasing free software updates for all our instruments (Inifinity and Velcolity singles as well as EFIS systems) to allow display of altitude to -1200 ft at any desired local pressure setting should you need this...

Rainier
CEO MGL Avionics

[kevin O]

Has this software been released?

[Mouser]

Originally Posted by kevin O

Has this software been released?

I can't speak for the ALT-1, but the latest Odyssey EFIS software allows for -1200' display: http://www.stratomaster.com/html/odyssey_updates.html

[Dave Cole]

The Winter 2-1/4 inch alitimter with a typical three-hand movement appears to be a good choice for a small back-up altimiter. However, if you are intending to maintain IFR certification of your pitot-static system, I believe the back-up will have to meet the same requirements for accuracy as the primairy.

Unfortunately, the Winter 4 FGH40 performance specifications show an unacceptable indication error of plus or minus 120 feet at 8000 feet, and twice that much at 15,000 feet. (I found the specificaitons on the Cumulus Soaring website at www.cumulus-soaring.com ).

It looks like the MGL ALT-1 or ALT-2 may still be the best choice.