• Radar. Some kind of working station to spot incoming planes or helicopters, specifying direction, speed and location.
  Extras:
  If a plane flies at 15 blocks up or less from the ground, it won't be spotted by the radar. Example: when approaching an enemy base, you could fly low to avoid being spotted by the radar, but risk being seen by players, or you could enter from above to use a parachute, but be spotted by the radar.

The radar emits a redstone signal when it detects a plane or helicopter. The signal strenghtens as it gets closer.

• More space needed for takeoff. Currently, any plane or helicopter can take off from anywhere. For planes, they should need at least 24 blocks of runway to take off, and helicopters would need a flat surface to land.

• Climate effects. Like in point 2, planes and helicopters can take off from anywhere and at any time. I think planes and helicopters should be harder to control and take more time to steer, but, in return, radars wouldn't be able to spot planes or helicopters flying in rain or thunder
  Extra: During a thunderstorm, planes/helicopters have a low chance of being struck by lightning while on the air, that increases with altitude. If a plane/helicopter has the armor upgrade, the chance increases.

• Anti-Air guns. Or, in turn, any kind of way for players to take down planes while in the ground. This could be its own standalone mod.

MrCrayfish's Gun Mod compatibility.

• Missile compatibility. With the dispenser upgrade, missiles would be able to be launched from the dispenser.

Talking about missiles...

• Guided missiles. With the Radar upgrade, the dispenser upgrade and a special kind of missile (WIP), planes could launch guided missiles. The plane should focus for a couple of seconds to lock in. A Locking SFX would play while this happens, while the beeping gets quicker as the locking proceeds. After the plane locks in, the pilot would be able to shoot the guided missile, although the plane would need for the target to stay in their FOV.
  As for the target of the attack, if they have the Radar upgrade too, the plane would pick up when it's locked by another plane. The player would be able to either try to evade the missile or leave the plane.

• Warnings. With the HUD upgrade, the player would recieve warnings on the middle-top of the screen. These warnings would be:

• Low fuel. When the plane has fuel for 2 minutes of flying time or less, the warning would appear on the screen as:
  [ LOW FUEL - FIND LZ ]

• Low health, for when the plane is below 20% HP.
  [ LOW HEALTH ]

• Locked, for when a plane is locked by another plane.
  [ LOCKED ]
  Extras: There could be a fourth warning, but positive, for when your plane is locked in to another one ([ LOCKED IN ]), although I prefer for the beeping to get very fast.
  A separate upgrade could include the beeping for warnings, being a note block.

What I'd like to see is more universal options for the dispenser and for the TNT dropping mechanic. It'd be really cool to be able to drop Packed TNT from the Xplosives mod, or to use modded arrow types with the shooter upgrade. Ideally, I'd like to be able to use any TNT as a bomb and anything with unique dispenser behavior as a shootable. EDIT: This would also effectively add #75.