This is a simple stock to detect if player is using an heli/plane.
stock IsPlayerInFlying(playerid,vehicleid)
{
if(IsPlayerInVehicle(playerid,vehicleid))
{
switch(GetVehicleModel(vehicleid))
{
case 487, 488, 497, 460, 476, 511, 512, 513, 519, 520,548,553,577,592,593:
{
return true;
}
}
}
return false;
}
Credits to me.