Custom Fuel Management System

Jettison test of the three propellants.

Conventional aircraft use only one type of fuel (aviation gasoline or jet fuel). Propellant consumption is automatically calculated and managed by the simulator.

Like the real X-15A-2 rocket plane, the X-15A-2 SE addon uses three different types of propellants, all pressurized by helium:

anhydrous (waterless) ammonia (NH 3 ) as the main engine fuel;
liquid oxygen (LOX) as the oxidizer;
and hydrogen peroxide (H 2 O 2 ) as a monopropellant for the engine turbopump, the APUs and the ballistic control system.

For this reason, the X-15A-2 addon uses a specially designed three-propellant fuel management system that bypasses the simulator's fuel management system.

FSX "Settings - Realism" page. The interface is similar in Prepar3D®.

This special system requires the "Unlimited fuel" option to be selected in the simulator's realism settings to work properly:

Under "Aircraft" (or "Vehicle") in the simulator's top menu bar, select REALISM SETTINGS.
On the "Settings – Realism" page, under "Engines", select the UNLIMITED FUEL option.

For more details, refer to the recommended settings for your simulation platform.

Important

Do not use "CTRL+E" to start the engine — The simulator's autostart command ("CTRL+E") should not be used to start the X-15A-2 engine. For a quick start, use the automatic ignition sequence start button [76, fig. 5-1], located on the main instrument panel, instead. This is similar to pressing "CTRL+E" with conventional aircraft. However, the red button initiates all X-15A-2 rocket aircraft systems, including the special three-propellant fuel management system.