Features:
- Terrain-following autopilot and cruise autopilot
- Automatic aerial refueling
- Fully functional cockpit
- Pitch and roll rate controls

Instructions:
AG1: Cockpit open/close
AG2: Autopilot on/off
AG3: If autopilot on, cycle between altitude (MSL) and terrain following (AGL) pitch modes
AG4: If autopilot on, cycle between flying level, to a target, or to a heading
AG5: Refuel / formation autopilot (only throttle and pitch, use AG2 to toggle automatic or manual turning)
AG6: Master arm weapons
AG7: Eject
AG8: Engine on/off
VTOL: Adjust autopilot heading
TRIM: Adjust autopilot altitude (whichever mode is active will adjust, toggle AG3 to switch)

The status screen in the cockpit reminds you how each thing is being controlled if you forget. If you run into problems, you can always eject and try again.

Examples:
- Low altitude bomb run: Takeoff toward the carrier near Wright Airport and target one of the destroyers. Activate AG6 to arm bombs and AG2 / AG3 to turn on autopilot. The jet will track the target while automatically maintaining altitude above any terrain or water. Use the targeting camera on the front of the jet to zoom in and fine-tune your bomb drop.
- Tanker connection: start on any runway. Spawn a tanker flying roughly in front of you at any bank angle you like, just make sure the speed is relatively fast so your jet doesn't stall. Give the tanker a head start then take off. Set Air-to-Air mode and target the tanker. Activate AG5 and AG2 to automatically form up on the tanker. Enjoy formation, then turn off AG2 to give yourself some turning control to connect to the fuel hose. To disconnect, activate brakes and turn off AG2 and AG5 before you turn away. (This mode is great for flying formation with other random aircraft too)
- Bumpy ride: fly toward some uneven terrain and activate AG2 and AG3. The jet will maintain the terrain height you set.
- Cruise: Set a desired heading and altitude using VTOL and TRIM. Activate AG2.

Coding stuff if you want to add to your own airplanes:
-Terrain Following Radar:
Sample the terrain height beneath you, then sample it again a short time later (h1, h2, and their slopes m1, m2 over dt). Depending on the steepness of the terrain, fit a line or a parabola through your two known points and extend it to a third point ahead of you (agl-cur). Control your pitch attitude to avoid hitting terrain at this hypothetical future point. The math for this is in the variables h1 through h3-poly.

-Rate Controls:
The aircraft is slightly unstable in pitch, but this controller did a good job of making it fairly agile without stalling and spinning any time you try to turn. It also avoids the need for D > 0 in PID controllers which makes planes very shaky in this game. This also allows you to replace pitch-command with anything (the autopilots here use a PID(difference-between-target-and-current-altitudes, vertical-velocity, P, I, D) for pitch-command)

PID(pitch-command x sensitivity-multiplier x pitch-rate-limiter,PitchRate/25,0.35,0,0)

pitch-command [-1,1]: (Pitch, or replace with autopilot i.e. a controller that matches vertical velocity to the difference between current and target altitude)
sensitivity multiplier (i.e. less sensitive when landing or refueling)
pitch-rate-limiter [0,1]: proportion of the commanded pitch that gets sent to the control surface, gives it 100% response for some proportion of the AOA range, then it drops linearly to prevent stall - mine was (abs(AngleOfAttack)>split x aoa-stall?-(1/((1-split) x aoa-stall)) x abs(AngleOfAttack)-split x aoa-stall)+1):1)