[VSKYLABS Test-Pilot Notes] issued 27 August 2024
The answer is…YES!
The Heinkel He-162 A-2 Volksjäger was powered by the BMW 003 E-2 series turbojet, a 1st generation axial flow jet engine, which was equipped with a variable cross-section area exhaust nozzle.
The variable cross-section area mechanism featured an adjustable inner-diffuser cone, capable of shifting its position mechanically.
By shifting its position forward or aft, it increased or reduced the cross-section area of the exhaust jet-pipe. This mechanism allowed the utilization of the maximum allowable power during the flight, depending on the aircraft's speed and altitude, and prevented ‘choked nozzle’ at high flow velocities.
*Modern variable-area nozzles are capable of ‘transforming’ the exhaust nozzle into a ‘Converging-Diverging’ geometry, allowing the nozzle jet flow speed to exceed supersonic velocity. The early variable cross-section area mechanism of the BMW 003 turbojet operated only within the ‘converging’ range of nozzle geometry.
The adjustable nozzle control was manual, and the pilot had to set the nozzle position (cross-section) according to the given phases of flight. The index positions were marked on the dorsal mounting fin extension, located underneath and aft of the engine, allowing to recognize the nozzle position externally.
The adjustable exhaust nozzle had four positions, which the pilot set using a multi-position knob in the cockpit.
Adjustable nozzle position index:
A - Normal idle / Start-up.
H - Normal flight above 8 km (altitude).
S - Normal flight below 8 km (altitude).
F - High-speed flight from 0-4 km (altitude) and above 650 km/h (airspeed).
