I have two Air Band HT's, one IC-4AT and Sporty's A-300, and keep one in the airplane at all times.  Aside from emergency and back up use, such HT's are much cheaper than any fixed installation equipment.  Also there are quite a few 1940's and earlier airplanes as well as homebuilts flying that have no electrical system and an HT is the easiest way to have comm. I even recently picked up a booster amp to use with air band HT's.

 

I actually have three air band HT's.  One is a Sporty's that works Okay but for some strange reason on transmit the power requirement is now about 3 amps rather than the previous 500ma.

Wayne

WB5WSV