Yes, you can open up the frequencies a *little* bit -- but this will let you cover FRM/GMRS, and possibly *some* police and public utility.  The thing transmits FM only, so no aircraft band -- aircraft is AM only.
For this type of info, check out 
www.mods.dk.  They have mods for every known amateur radio and scanner.
Yaesu makes a radio that is a combination air band transmitter, and a dual-band HT.  And it is also waterproof.  But you still have to keep it charged.