More consideration for air vehicles

I often destroy my maverick instead of repairing it just because it's more convenient than flying to airport.
I would love at least one viable repair option in each city for aircraft besides airport:)

There are several Helipads apart from the airport ones in San Andreas like 1 in Bayside, 1 in Area 51 and 2 in Los Santos. I do think there should be more plane/Helicopter repair and refuel checkpoints. And about plane armour? The moment it comes out Seasparrow and Rustler will blast whole of San Andreas.

True about rustler and sparrow, I think  the solution could be making them gain less than double hp

Late to the party however, I feel no reason not to repair your air vehicles and also no reason to not be able to buy a plane. (For a super steep cost this could be a very good way to help clean the economy).

The ability to buy planes is an upcoming feature. There are already large checkpoints at the 3 main airports that repair and refuel your aircraft. These checkpoints will be given additional options in the future.