Symmetric sails four thrusters jet plane

Wings can be created from symmetric sails utilizing drag as an upward force. This allows planes to fly upside down like real ones. This plane is built using this technique.

Four thrusters give it cruising speed of up to 85 m/s when using gasoline (it can accelerate more during some maneuvers). It can reach and maintain cruising altitude without active input from the pilot.

Additionally two redstone accumulators can control flaps and thrusters to achieve cruising regimes at different speeds. By lowering thrusters power and deploying flaps to increase angle of attack hence lift-drag force you can cruise at lower speed than max 85 m/s.

Plane mechanisms are powerd by two engines. You need to start only one of them and the other will start automatically. Crankwheel can be acessed through one of the trapdoors under the wing. Behind same trapdoor is lever, controling clutch, that needs to be powered to disengage all plane mechanisms when starting the engine. After starting the engine and depowering clutch plane should be ready.

Plane's fuel tank can be acessed directly from underneath, but it's better to use hose connector. It can be found near the engine.

Plane is supposed to use "Drive by Wire", but connections aren't saved in schematic. You have to recreate them yourself. All four flap bearings and two redstone accumulators can be found behind trapdoors. I trust you to figure out how to wire them, which gives you freedom to tune it to your liking.