Making an Aerobatics Flight Simulator with Opus 5

My last post, Building a Flight Simulator with Claude Code, Opus 5, was about building a flight simulator using Claude Code and Opus 5. That was a regular, vanilla flight simulator, with the bank angle limited to 30° in either direction to prevent the aircraft from rolling too far. It was also not designed for aerobatic manoeuvres.

It’s quite likely that some of you may not have got quite the adrenaline rush you were hoping for from that basic simulator. So, in this post, I have taken things a little further and built an aerobatics flight simulator, where you can try out a range of aerobatic manoeuvres and fly more adventurous sorties, much like you would in a real aerobatic aircraft.

The first and most fundamental change is that the Cessna 172 has been replaced with the aerobatic Super Decathlon. The Decathlon is highly suited for these aerobatic manoeuvres. A Cessna 172 is placarded against aerobatics and even if modelled perfectly accurately, would not work approproately.

Checkout the Aerobatics Flight Simulator (only desktop/laptop) at Aerobatics Simulator

My short video showcasing aerobatics of Decathlon – decathlon aerobatics

My initial attempts with Cessna 172 had multiple problems. A lot of this has been addressed with Super Decathlon in itself is more suited for such maneuvers

a) 360° roll on longitudinal axis.

The original flight simulator had a 30° bank limit. When I removed it, the aeroplane rolled — but it would not roll straight. The nose wandered in a circle, and every revolution it dropped a little further. After three rolls it was 55° nose down and accelerating.

The Aerobatics Simulator is keyboard-based and needs to run on a desktop or laptop. So a key press is an all-or-nothing input. A Pitts or an Extra rolls at 200–400°/s, so one keypress would carry you through a full revolution in about a second. The Decathlon rolls at about 100°/s, which is fast enough to be unmistakably aerobatic and slow enough that a keyboard can control it: a quarter roll is a quarter second of key, which a person can actually time. The aeroplane was chosen to fit the input device.

b) The vertical loop :

Pulling the yoke too hard (continuously pressing S) and the aircraft stalls, and instead of looping the aeroplane mushes upward and falls out. Pull too gently and the loop is enormous and slow and you run out of speed before the top.

It should be just about right. But that limit moves constantly, because a loop is a trade of speed for height and back again.

c) Viewing the loop : The `V` key opens a small second view in the corner, from a camera parked out to one side. It also draws your flight path as a line in the air behind you. Even from a fixed camera the aeroplane is a small object that mostly rotates on the spot; the trail is what actually draws the circle of a loop, so you can see whether it was round or egg-shaped.

The controls

Keyboard only, and as you’ll see further down, that constraint shaped almost every decision in the project.

Flying		View & panels
`↑` `↓`	Throttle up / down	`V`	Wing view + flight-path trail
`←` `→`	Roll left / right	`C`	Camera: chase → side → cockpit
`W` `S`	Pitch down / up	`N`	Moving map on / off
`Q` `E`	Yaw left / right (rudder)	`B`	Map range (2 / 5 / 15 km)
`Space`	Wheel brakes (on the ground)	`H`	Flight-coach hints
`G`	Landing gear up / down	`L`	Flight log / debrief
`R`	Reset to the runway	`M`	Mute engine
		`F`	Full screen

Shift and Ctrl also work for throttle if you’d rather keep your hand off the arrows.

And the three manoeuvres this post is about:

Manoeuvre	How
Loop	Build speed, then hold `S` and keep holding it all the way round
Roll	Hold `←` or `→` — it will keep rolling for as long as you hold it
Inverted	Roll to 180°, then hold `W` (forward stick) to stay level