Design Work on what would become the Me 328 can be traced back to early 1941 and an approach by the German engine manufacturer
Argus Motoren to the aircraft company
Messerschmitt AG to inform the latter of its recent advances with
pulsejet technology. By May 1941, no less than 21 designs had been drafted by the company's project office, which had internally designated them as
P.1079. A twin-engine arrangement was selected for its greater flight performance, the engine configuration used also permitted the propulsion units to be easily interchanged. Each pulsejet could be individually controlled by the pilot, including a quick-stop function; gauges indicating fuel-flow, fuel capacity, and pressure were present alongside controls for power distribution and safety alongside standard apparatus. The aircraft's construction was to be mainly of wood. A gently
swept wing was applied to the aircraft for its favourable high-speed qualities. A relatively simplistic
dive brake could also be incorporated. However, even at this stage, the design team expressed their uncertainty over the aircraft's stability. As early as December 1941, discussions with the
Reichsluftfahrtministerium (RLM) (the German Reich Aviation Ministry) considered the P.1079 to be primarily as a fighter aircraft. In such a capacity, it was intended to be deployed as a cost-effective and simplistic escort fighter, to either be towed aloft by a
Heinkel He 177 heavy bomber or
Junkers Ju 388 using a semi-rigid bar (the
Deichselschlepp, which was also considered for towing winged auxiliary
fuel tanks), or carried on a
Me 264 in a
Mistel type fashion. Three versions of the aircraft were initially proposed: an unpowered
glider, a version powered by Argus As 014 pulsejets, and a version powered by a single
Jumo 004 turbojet engine. Messerschmitt believed that the type would be capable of performing in several roles ranging from a fighter to
aerial reconnaissance,
bomber, and
interceptor aircraft. It was envisioned that costs and production difficulties could both be reduced by incorporating as many components as possible from the in-production Me 262 and
Me 209 aircraft. The engine problems were such that officials came to believe that the project would be difficult to bring to a successful conclusion, and the manned flight programme was suspended in mid-1944, after only a few test flights had been made. Many of the problems with the aircraft were due to its engines - pulsejet propulsion did not operate effectively at high to medium altitudes (where the majority of combat was anticipated to take place) due to the lower air pressure. Furthermore, these engines also generated a huge amount of noise, allowing observers to hear the aircraft from several miles away, which was not a desirable quality. The excessive vibration produced by the engine would be compounded by the fact that, in a twin-engined configuration, the two pulsejets would run at individual and unique thrust cycles, producing
oscillations that would inherently cause instability due to
asymmetry as well as
resonance. These vibrations were not only harmful to the pilot's health, but also threatened the aircraft's structural integrity. During September 1943,
Willy Messerschmitt and
Rudolf Seitz discussed switching the Me 328 to turbojet propulsion. The proposal to fit the Me 328 with a Jumo 004 turbojet was designated as the
Me 328C. Despite this, development work continued, incorporating design advances from other Messerschmitt programmes, such as the P.1092 single-jet fighter design proposals. however, the aircraft was not developed with any such use being intended. However, work was dropped in favour of the
Fieseler Fi 103R (Reichenberg).
Proposed roles A wide variety of roles were suggested for the aircraft, ranging from a
point-defence interceptor, to a version with
folding wings and twin pulsejets to be launched from a catapult on a
U-boat, Various modifications to the prototypes were made to evaluate their suitability for these missions, and different engine configurations were tested. Despite all this, the vibration problem simply could not be overcome and the program was abandoned in early 1944, even as production facilities were being readied to construct the aircraft at the Jacobs Schweyer sailplane factory in Darmstadt. According to the historian Thomas Powers, German officials explored the concept of using the Me 328 as a
parasite bomber within the
Amerika Bomber program. In this role, a single Me 328 was to be carried by or towed behind either an
Me 264 or a
Ju 390 to attack
New York City. Plans for this tactic — first proposed as much as nine months before
Heinkel's trans-Atlantic Amerika Bomber design competitor received its own RLM designation — were hatched from a meeting between
Generalfeldmarschall Erhard Milch and
Generalmajor Eccard Freiherr von Gablenz at Berlin on 12 May 1942. After release, the Me 328 pilot would release a bomb over
Manhattan and then ditch at sea near a U-boat. The idea was dropped in August 1942. ==Variants==