[Bill Phillips]

Question came up today at the Sat morning HangerRat coffee clutch. Certified EFIS box have encoder built in. We have all seen the Tec testing the steam altimeter and transponder, Pump up the box to simulate alt pressure, tap on it to get a reading. How it it done on a EFIS ? If a Tec guy can perform such a test on a certified EFIS if he does it to an "non certified" EFIS does that now make it certified for IFR? Some of us "old guys" have a hard time with some of this, but we're young enough to learn. Please respond or maybe we can find a 14 year old. They ALL know about computers, Happy New Year!, Bill

 

[Walt]

Bill,
It's done exactly the same way on an EFIS except there is no friction so you don't have to tap on it anymore!

Testing a non certified EFIS unit (non TSO'd) does not make it certified, but what we can certify is that it meets the requirment of CFR 91.411 (43 E) which is all that is required. The EFIS in this case simply takes the place of the altimeter and altitude encoder.

The only "certified" (TSO'd) equipment required is the transponder, the altitude encoder and altimeter are not required to be "TSO'd" for use in VFR or IFR.