radios don't do exactely as they are told. We have a Cherokee I teach
in that requires you to dial 1 MHz more than the freq (KX-170B). So for
118.32 you have to dial 119.32. I'd never allow such things in my
Mooney but you have to break even in the renal market.

-Robert, CFI

Write it up.. and don't use the airplane?? maybe when the "owner" realizes
he's loosing revenue for a bad radio.. he'll get it fixed... I would never
take an airplane IFR like that.. I hope the bad one is "radio #2".. We had a
repeat problem like that with a radio here in the Arrow.. After I refused to
take the rental for IFR refresher.. because you could not tell what
frequency you were on.. the FBO swapped out the radio. Had the same problem
with "LEDs" failing.. cant tell Freq or read the DME.. can't fly one IFR
approach around here without DME.. so I refused the rental... He put in an
KNS80.

BT