The Me 328 was originally conceived as a parasite aircraft to defend Luftwaffe bomber formations in World War II, the Messerschmitt Me 328 underwent a prolonged development process during which it was considered for various roles.
As the war drew to a close, the design was revisited as a potential Selbstopfer (suicide weapon) aircraft. However, it was ultimately deemed inappropriate even for this desperate use.
The small fighter was intended to be powered by pulsejets, but the inadequacies of these engines fundamentally compromised the viability of the Me 328 from the outset.
Initial gliding tests involved launching the aircraft from a Dornier 217, but the powered trials conducted in 1944 yielded unsatisfactory results.
Additionally, a further model, the Me 328C, was envisioned to be equipped with a Jumo 004 turbojet. Plans for this version and a proposed manned glider-bomb variant ultimately did not materialize.
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It was smaller than the He 162, and its structure was primarily made of wood. The aircraft was powered by a pair of Argus pulsejet engines, similar to those utilized by the V-1 flying bomb.
Two variants were planned: the Me 328A fighter and the Me 328 bomber, with cost estimates suggesting that four Me 328s could be manufactured for the price of one Fw 190 or Me 109 fighter.
Me 328 Background
Initially designed as the P.1073 in 1941, the Me 328 was intended as a parasite aircraft to defend Luftwaffe bomber formations against Allied fighters.
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Constructed predominantly from wood, the Me 328 was projected to cost significantly less than traditional German fighter aircraft like the Focke-Wulf Fw 190 or Bf 109.
Its proposed propulsion systems included a single Jumo 004 turbojet engine, two or four Argus As 014 pulsejets (similar to those used on the V-1 flying bomb), or even as an unpowered glider.
The Deutsche Forschungsanstalt für Segelflug (DFS – “German Research Institute for Sailplane Flight”) also participated in its development.
The aircraft made its first flight in the spring of 1944, equipped with two As 014 pulsejets. However, these engines proved to be quite problematic, causing excessive vibration, imbalance, and noise, which led to the suspension of the manned flight program after just a few trials.
Throughout its extended development period, the Me 328 was considered for various other roles; on Adolf Hitler’s insistence, it was evaluated as a potential bomber.
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As the war increasingly favored the Allies, the Me 328 was reconsidered as a Selbstopfer (suicide weapon) aircraft. However, it was ultimately judged unsuitable for even this desperate role. Consequently, the Me 328 never saw operational use.
Me 328 Used Pulsejet Technology
The origins of the Me 328 date back to early 1941 when Argus Motoren, a German engine manufacturer, approached Messerschmitt AG to share its advancements in pulsejet technology.
Despite the pulsejets’ projected thrust output of 500 kg being less than the 600 kg anticipated from early turbojet engines, the pulsejet’s significantly lighter weight of 80 kg compared to 600 kg was appealing.
Impressed, Messerschmitt quickly began integrating the Argus As 014 pulsejet engine into its aircraft designs, initially considering it for the Me 262, which would later become the world’s first production jet fighter. By May 1941, Messerschmitt’s project office had produced 21 designs, internally labeled as P.1079.
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The design settled on a twin-engine configuration to enhance flight performance, allowing for easy interchangeability of the propulsion units.
Each pulsejet was individually controllable by the pilot, equipped with functions for quick stopping, and integrated with gauges for monitoring fuel flow, capacity, and pressure.
Controls for power distribution and safety were installed alongside standard equipment. The cockpit, while relatively basic, was designed to allow for a future upgrade to a more advanced pressurized version without significant alterations to the aircraft.
Primarily Used Wood
Noted aviation author Dan Sharp commented on the design’s focus on minimizing costs and speeding up entry into service.
The aircraft primarily used wood in its construction and featured a gently swept wing for better high-speed performance, and a simple dive brake was also considered. However, even at this early stage, the design team had reservations about the aircraft’s stability.
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By December 1941, discussions with the Reichsluftfahrtministerium (RLM), the German Reich Aviation Ministry, identified the P.1079 primarily as a fighter.
It was envisioned as an economical, simple escort fighter that could be towed aloft by bombers like the Heinkel He 177 or Junkers Ju 388 using a semi-rigid bar, or alternatively, mounted on a Me 264 in a Mistel configuration.
Initially, three variants were proposed: an unpowered glider, one equipped with Argus As 014 pulsejets, and another with a single Jumo 004 turbojet engine.
Messerschmitt envisioned the aircraft serving multiple roles, including fighter, reconnaissance, bomber, and interceptor.
In February 1942, the project moved to the Deutsche Forschungsanstalt für Segelflug (DFS – “German Research Institute for Sailplane Flight”) for further development. The designation Me 328 was first applied to the aircraft in March of that year, marking the commencement of production on three prototypes.
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Subsequently, two specific versions were proposed: the Me 328A as a fighter and the Me 328B as a bomber. It was estimated that four Me 328s could be constructed for the price of a single Focke-Wulf Fw 190 or Bf 109.
At one point, the concept of towing the Me 328 behind the Me 264 for protective purposes was also considered, aiming to reduce costs and production challenges by utilizing as many components from the in-production Me 262 and Me 209 as possible.
Me 328 Testing Program
Test pilot Hanna Reitsch led a comprehensive testing program for the two prototypes of the glider version of the Me 328, releasing them from their carrier aircraft at altitudes between 3,000 and 6,000 meters (9,800–19,700 ft).
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Successful ground launches were conducted using both cable-type catapults and rocket-assisted carriages on rails.
Despite a reduced wingspan, the aircraft exhibited very satisfactory performance, leading to plans for constructing up to 1,000 units to serve as disposable bombers, piloted by volunteers from 5/KG200, also known as the Leonidas Squadron.
Seven prototypes, each equipped with a pair of Argus As 014 pulsejets (the same engines used in the V-1 flying bomb), were constructed by the glider manufacturer Jacobs-Schweyer of Darmstadt.
These prototypes were intended to function as fighter aircraft, armed with two 20 mm MG 151/20 cannons.
However, it soon became evident during static testing that they suffered from the same significant issue that plagued the early V-1 flying bombs—excessive vibration.
Reports indicated that two prototypes were destroyed by in-flight structural failures caused by these vibrations.
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The persistent engine problems led officials to believe that the project was unlikely to succeed, prompting the suspension of the manned flight program in mid-1944 after only a few test flights.
Aviation author Dan Sharp highlighted that another major reason for the Me 328’s suspension was the superior performance of turbojet development, which made aircraft like the Me 262, which utilized these advanced engines, more appealing.
The Me 328 had Undesirable Traits
The Me 328 faced numerous challenges primarily due to its pulsejet engines, which did not perform well at medium to high altitudes where most air combat was expected, due to lower air pressure.
Additionally, these engines were extremely loud, allowing the aircraft to be heard from miles away, a highly undesirable trait for a combat aircraft.
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The vibration issues were exacerbated by the fact that the twin-engine setup caused each pulsejet to operate at its own unique thrust cycle, creating oscillations that led to inherent instability from asymmetry and resonance.
These vibrations were detrimental not only to the pilot’s health but also to the aircraft’s structural integrity.
In September 1943, discussions between Willy Messerschmitt and Rudolf Seitz explored the possibility of transitioning the Me 328 to turbojet propulsion.
Despite these challenges, development persisted with design innovations borrowed from other Messerschmitt programs, like the P2092 single-jet fighter proposals.
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At one point, a projected model of the Me 328 increased the number of pulsejets to four, with the additional engines mounted below the wings, in addition to the original pair on pylons above the rear fuselage.
Fieseler Fi 103R
Bomber variants of both setups were proposed, and development continued under Adolf Hitler’s direction well beyond any practical use of the aircraft.
In 1944, there was an attempt to revive the Me 328 as a piloted flying bomb based on the Me 328B, equipped with a 900 kg (2,000 lb) bomb, but this effort was abandoned in favor of the Fieseler Fi 103R (Reichenberg).
Two alternative revised versions were considered—one designated as the Me 328C to be equipped with a Jumo 004 turbojet, and another unnamed in-house proposal that featured two As 014 pulsejets on pylons mounted to the rear fuselage sides, fitted with a twin-tail empennage and a single-use Porsche 109-005 turbojet.
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However, none of these proposals materialized. According to Sharp, Reitsch had advocated for the use of the Me 328 as a suicide weapon, but the aircraft was not originally intended for such use.
Excerpt from German Jet Engine and Gas Turbine Development, 1930-45 by Antony L. Kay
“Assignments given to the DFS by the Forschungsfuhrung were within the fields of fundamental research and flight testing. In connection with the latter [a glider called DFS 230 acted as a testbed for 300mm diameter pulsejets and associated fuel systems prior to the development of the Me 328], a project for a cheap and simple high-speed aircraft came to the DFS for attention at the beginning of 1943.
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The aircraft, designated Me 328, was designed by the Messerschmitt AG as a low-level bomber and possible emergency day-fighter. Development was actually handed to the Jacob Schweyer Segelflugzeugbau, which worked in co-operation with the DFS and Messerschmitt company. Only ten (10) test aircraft were built, and the first (Me 328 V1) was mounted above a Dornier Do 217 E to measure forces acting on the Me 328 in flight. Later, the Me 328, without pulsejets, was released from the Dornier for gliding trials and proved to have barely acceptable flight characteristics.
Nevertheless, the programme was proceeded with, although early powered trials were scarcely encouraging either. In these trials, which the DFS performed from Hörsching airfield near Linz, two Argus pulsejets were mounted beneath the wings.
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In this position, the pulsejet tubes ended just forward of, and below, the tailplane of the aircraft, and several accidents occurred as a result of rear airframe structural failures caused by the acoustics of the pulsejet. The usual method for starting these powered flights was to tow the aircraft off the ground using a cable-type catapult. Once airborne, the Me 328 jettisoned its main wheels, and, later, landed on its retractable skid.
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In the hopes of minimising the detrimental effects of the pulsejet’s rhythmic exhaust explosions (which, apart from damage to the aircraft, were very uncomfortable for the pilot), tests were made with two pulsejets mounted on each side of the rear fuselage to exhaust beyond the tailplane. The principle of having the tail pipe extending beyond the airframe was exactly that applied in the case of the V1 flying bomb, of course. Even so, the new tests did not fully resolve the mounting of pulsejets on the Me 328, and the type never went into production.”
Designed to be Used as
The Me 328 was considered for a diverse range of roles, from a point-defense interceptor to a specialized version with folding wings and twin pulsejets designed for catapult launch from a U-boat, to a ground-attack aircraft.
There was even speculation that the Me 328 could be fitted for aerial refueling. Various adjustments were made to the prototypes to assess their compatibility with these different roles, and numerous engine configurations were explored.
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However, the persistent issue of excessive vibration was never resolved, leading to the program’s termination in early 1944, just as production facilities at the Jacobs Schweyer sailplane factory in Darmstadt were being prepared for its manufacture.
Historian Thomas Powers notes that German officials considered deploying the Me 328 as a parasite bomber within the Amerika Bomber program.
In this planned scenario, a single Me 328 would be carried or towed behind either an Me 264 or a Ju 390 for an attack on New York City.
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This strategy was developed from a meeting between Generalfeldmarschall Erhard Milch and Generalmajor Eccard Freiherr von Gablenz in Berlin on May 12, 1942, about nine months before a competing design by Heinkel received its own RLM designation for the trans-Atlantic Amerika Bomber project.
After its release, the Me 328 pilot was to drop a bomb over Manhattan and then ditch the aircraft at sea near a U-boat for recovery. This idea, however, was abandoned in August 1942.
