On Feb 21, 9:10*pm, Peter Clark
wrote:
Not neccessarily. *You'd have to check the equipment list - if only 1
were required operational it would say 1, if both were required (I
don't see why in the case of redundant fuel guages in the same tank
but anyway) it would say 2. *Example, the KOEL for the Piper Malibu
Mirage which has 2 alternators installed lists 1 as required
operational for IFR and 2 are required if flight into known icing is
anticipated (one will run things fine unless you need the heated
windshield, lift transducer, etc).

Yup, no disagreement. I just meant that an inop gauge (in addition to
a legal, working one for the same tank) doesn't automatically violate
91.205b9.