Yes, you can. Here's a code snippet:
function ZILVehicle::onAdd(%this,%obj)
{
parent::onadd(%this,%obj);
%obj.mountable = true;
%obj.setWheelTire(0, Tire1);
%obj.setWheelTire(1, Tire1);
%obj.setWheelTire(2, Tire2);
%obj.setWheelTire(3, Tire2);
}
Add this after the part where you defined the datablock of your plane