Introduction
During the later stages of World War Two, as the Allied daylight-bombing offensive on Nazi Germany was gaining momentum, a requirement was issued by the RLM (German State Ministry of Aviation) for a short-endurance local-defense interceptor.
 |
This requirement could be summarized as follows:
-Fast Reaction interceptor
-High rate of climb
-Fast speed, both in climb & diving flight
-Good maneuverability
-Heavy offensive armament
-Easily & quickly manufactured to meet the urgent demand
There were many proposed designs to meet this (and other similar) requirement but three of the best known are discussed here. These are:
-Messerscmitt Me-163 Komet
-Bachem Ba-349 Natter (Adder)
-Heinkel He-162 Volksjager (People's Fighter)
 |
The rocket powered Me-163 Komet interceptor was basically designed around the Walter 109 liquid fueled rocket motor. This gave the aircraft greater performance than anything else in the flying at that time, but the high fuel consumption kept operational flight times in the 5 to 10 minute range.
(Note: The Me-163 nearly broke the sound barrier in testing.)
The Me-163 was almost impossible to shoot down & flew fantastically with excellent handling & agility. On the approach of the enemy bombers, it would launch on a trolley that was then jettisoned once airborne. The Komet would climb rapidly (16,500 feet/min) & then swoop down through the bomber formation & fire its twin 30mm cannon. This procedure would be repeated until the fuel was spent & then the aircraft would glide back to earth, landing on a skid fixed under the fuselage. It was only during this unpowered descent that the Komet was vulnerable to attack by the fighter escorts.
More Me-163 pilots were killed by accidents due to the complexity of the rocket motor & the volatility of the fuel than by allied fighters.
Some serious issues were:
-Limited range & combat endurance
-Casualties often resulted from explosions & collisions on landing - residues of the two volatile & highly reactive rocket fuels (hydrogen peroxide & hydrazine hydrate) often sloshed together from the impact of the skid landing
-Restricted visibility from the cockpit during combat
 |
Due to the pressing need to get such a devastating warplane into service, these design issues were largely ignored. However, a refined design was begun shortly after the Me-163 entered service. Incorporated into this aircraft was a version of the Walter motor that had a smaller secondary combustion chamber to permit a degree of cruise, larger & safer fuel tanks, retractable undercarriage & a cut down rear fuselage with a bubble canopy for better pilot visibility.
This model was being developed as the Me-263 but never saw active service. It was quite a complex & expensive aircraft to manufacture and to maintain.
 |
The main engine was the same liquid-fuelled unit used by the Komet.
For launch, four additional solid-fuelled booster motors were attached to the sides of the rear fuselage. The rear fuselage with rocket motor was jettisoned after use, recovered via parachute & reused.
 |
There was constant trouble with the ejection system & Allied troops took over the factory & launch site before any combat missions could be flown.
The concept was acceptable (considering the circumstances) & the aircraft had several advantages over the Komet. These were:
-Made largely of wood therefore inexpensive
-Simple construction - easily & quickly manufactured
-Superior climb rate (36,400 feet/min)
-Faster reaction & launch time.
 |
Although He-162 was designed under a separate requirement it is worth mentioning here as a comparison as it shows another example of the German design innovation. This aircraft was designed to the requirement for what was commonly called the Volksjager (People's Fighter) program.
 |
-Be built of wood & other non-strategic materials
-Have a simple structure capable of being manufactured by semi-skilled & unskilled labour
-Be easy to fly, to be piloted by pilots whose only previous flying experience was glider training
This was the most conventional of the three designs, & was powered by a comparatively reliable BMW turbojet engine. (Heinkel were leaders in this field, having flown the worlds first jet-powered aircraft in 1939.)
 |
The armament consisted of two 30mm cannon (same as the Komet) but later versions switched to smaller 20mm weapons due to a lack of strength in the forward fuselage.
The He-162 design incorporated some pioneer features. These included:
-An innovative hydraulic & spring operated landing gear system
-A one-piece blown acrylic canopy
-Explosive powered ejection seat
-Use of adhesives in construction
 |
The ejection seat was never properly tested due to the rush to get the aircraft into service, but did add an element of safety into the design.
The use of adhesives in bonding the wooden components was a good feature, although this had drawbacks due to the use of sub-standard adhesives (hastily developed due to the major adhesive plant being bombed and destroyed) & several aircraft came apart in flight.
 |
 |
The Ba-349 was a major departure from conventional design thinking and it may well have worked. There was insufficient time to remedy all of its faults.
The He-162 appears to have been the most sensible design & more emphasis was applied to reliability and safety than was given to the other designs.
These three types (although not as much with the Komet) were quickly conceived, designed, prototyped & flown in a short space of time. The original RLM requirement called for a very advanced aircraft & it seems unreasonable to expect to develop such an aircraft in such a short time.
However, these aircraft (along with other types) & their designers did much useful research into rocket & jet propulsion. Russia & the USA, in particular, heavily based their early jet developments on the German wartime work.
bravenet.com