Germany (1944)
Rocket-Powered Interceptor Prototype – 1 Built

The Me 163 showed to have great potential as a fast rocket-powered interceptor, but its design had some shortcomings. These included a limited view from the cockpit, lacking of landing gear, increased fuel storage, etc. The German companies Messerschmitt and later Junkers tried to resolve this by implementing a number of improvements to its design leading to the Me 163D of which only a few prototypes were built given the late start of the program.

History 

The Me 163 small size, while reducing the overall cost of the aircraft, enforced limitation of the fuel that could be stored inside which in turn led to a limited operational powered flight time of fewer than 8 minutes. In combat operations, this proved to be insufficient but no auxiliary tanks could be added to the Me 163 wings not inside of it. Another issue was the lack of proper landing gear. The Me 163 was instead forced to use a two-wheel dolly. Once the aircraft was in the air, the dolly was jettisoned. On occasion, there were accidents regarding this system when for example the dolly refused to be detached from the aircraft or even worse when it bounced off the ground and hit the aircraft from below. On the landing, the Me 163 were to use a simple retractable landing skid, placed beneath the fuselage. After landing the aircraft was immobile and essentially an easy target for enemy crafts.  For this reason, a normal retracting landing gear unit was desirable but once again due to Me 163 small size impossible to install.

To redress the previously mentioned issues engineers at Messerschmitt began working on an improved version named Me 163C. It incorporated a longer fuselage, extended cockpit, having an engine with two combustion chambers, and other modifications. The work on this version was rather slow and by war end not much was done on it besides a few incomplete airframes.

Parallel with the Me 163C development another project was carried out in early 1944 once again by Messerschmitt. This project was initially designated as Me 163D and was to have substantial numbers of improvements mostly regarding the overall shape of the aircraft, engine use, weaponry etc. For testing this new concept of substantially extending the aircraft fuselage if it was feasible at all. One or two (depending on the source) Me 163 (BV13 and BV18) was to be experimentally modified with an extended fuselage. In addition, experimental landing gear was also to be added. The testing of this rebuilt aircraft proved to be feasible and so the work on a fully built prototype began in earnest.

Name

The Me 163D project, due to Messerschmitt being simply overburdened with the Me 262 production, would instead be given to Junkers company. Once in their hands, the project was renamed Ju 248. The Me 163D obviously had an identity crisis as in late 1944 it was once again given back to Messerschmitt. Once back to its original designers, the project once again changed its name, this time to Me 263. As all three designations are basically correct for this aircraft, this article will use the original Me 163D designation for the sake of simplicity and to avoid any possible confusion.

First Prototype

Despite being originally designed by Messerschmitt, it was actually assembled in Junkers factories sometime during August 1944 or in early 1945 (the sources are not clear here). After that it would be returned to Messerschmitt where it was planned to examine and test its overall performance. While it was intended to have an increase in fuel capacity and an improved engine, the first prototype had actually no engine installed at that time. The Me 163D V1 (DV-PA) prototype was also provided with a new retractable tricycle landing gear which was to help with the mobility during the ground drive.

Given that no engine was fitted to the Me 163D, first flight testing was done as a glider, in late 1944. After these were conducted the prototype was in a series of wind-tunnel testings. The results of these two test trials (flight and wind tunnel) showed that the Me 163D was not capable of safely achieving dive speeds that were greater than its normal flight speed. In this regard, it was inferior to the original Me 163 aircraft which could achieve extensive dive speed but still managed to preserve good flight controls. The Messerschmitt engineers at this phase even considered redesigning the rear tail unit, but nothing came of it. The tricycle landing gear units did not offer good mobility on the ground, this was mainly due to it being too narrow. The Germans had plans to test using a parachute that was to be released during landing to help reduce the need for a long airfield. If this was tested or even installed on a Me 163D is unknown.

Technical characteristics

The Me 163D like its predecessor was designed as a high-speed, rocket-powered, swept-wing tailless aircraft. Given its experimental nature and its late development into the war, not much is known about its precise technical characteristics. Its overall construction would probably be similar to the previous versions, with a fuselage being built of metal and wooden wings.

The semi-monocoque construction fuselage was longer and was now 7.88 m ( 25 ft 10 in) compared to the original 5.84 m (9 ft 2 in) length. It had a good overall aerodynamic shape. The wings were swept to the back at a 19° angle, compared to the Me 163B 23.3° angle.

The pilot cockpit received a new ‘bubble-shaped canopy. This provided the pilot with a much greater field of view. Given that it was intended to operate at great heights, the Me 163 D cockpit was to be pressurized and for this was bolted to the fuselage.

The Me 163D was to be powered by an improved Walter 109-509C rocket engine. It was provided by two combustion chambers.  While the sources are not clear if this engine was ever installed in the Me 163D, the estimated maximum speed was noted to be 950 km/h (590 mph) or up to 1,000 km/h (620 mph) depending on the source. It should also provide more economical consumption of fuel providing an operational range of some 160-220 km (100-140 mile) once again depending on the source. The operational flight endurance was increased from 7 minutes and 30 seconds to 15 minutes.

To overcome the previous Me 163B version’s lack of proper landing gear, the Me 163D was provided with the retractable tricycle landing gear. It consisted of a forward smaller and two larger wheels in the rear, just below the wing roots. All three of these retracted to the rear into the fuselage.

The fuel load consisted of 1040 liters (229 gallons) of T-Stoff and 492 liters of C-Stoff. The Me 163 was notorious for having only a limited endurance flight ofOnce the fuel was spent the pilots were to simply glide the aircraft back to the base.

The armament consisted of two 30 mm (1.18 in) MK 108 cannons, which were placed in the wing roots. Depending on the source the ammunition storage for each cannon ranged between 40 to 75 rounds.

Production

It is often mentioned in the sources that one complete and one partially complete prototype were built, by the war’s end. According to M. Griehl (Jet Planes of the Third Reich)  on the other hand, mentioned that at least three prototypes were built with less than 20 aircraft being in various states of construction when these were captured by the Allies in 1945.

Service

The limited operational test use of the Me 163D  and the German plans for it is not clear. Once again depending on the sources, there are mostly two versions. It appears that despite some faults in its design the Germans were willing to proceed with its further development. Given the end of the war, it should not be surprising that this was ever achieved. In another version, the work on the Me163D after some testing flight in February 1945 was officially terminated by the Luftwaffe officials. Mostly due to the fact that production of its unique and dangerous fuel is no longer possible.

The fate of these aircraft is not clear, given either information that these were either destroyed or captured by the Soviets. The latter option seems more likely as some sources suggest that the Soviets based on the Me 163D after the war developed their own version of it, the I-270. The project led nowhere and it would be abandoned.

• • Me 163D V1 – Completed prototype
  • Me 163D V2 –  Incomplete second prototype
  • Me 163D V3 –  Possible third prototype being built with additional 18 airframes

Conclusion

Given its experimental nature and its late introduction, it is quite difficult to make the final decision on the general properties of this aircraft. While it introduced some improvements in comparison to the previous version it also had issues regarding its reaching speed during dive flights. Despite offering the Germans a relatively cheap aircraft the whole Me 163 project by 1945 was essentially over given the general impossibility of production of its unique fuel. Nevertheless despite its downsides, the Me 163 whole series was certainly an interesting concept that had some merits that unfortunately for the Germans were never completely implemented.

Me 163D V1 Specifications
Wingspans	31 ft 2 in / 9.5 m
Length	25 ft 10 in / 7.88m
Height	ft  in  /  3.17 m
Wing Area	192.6 ft² /  17.91 m²
Engine	HWL 509  rocket engine
Empty Weight	4,400 lbs / 2,000 kg
Maximum Takeoff Weight	11,660 lbs / 5.300 kg
Maximum Speed	590 mph / 950 km/h
Operational range	100 mil / 160 km
Engine endurance	15 minutes
Maximum Service Ceiling	52,480 ft /  16,000 m
Crew	One pilot
Armament	Two 30 mm MK108 cannons

Gallery

Artist Conception of the Me 263 – by Carpaticus

Credits

• Written by Marko P.
• Edited by Henry H. & Ed J.
• Illustrated by Carpaticus

Source:

• D. Nešić (2008)  Naoružanje Drugog Svetsko Rata-Nemcaka. Beograd.
• E. T. Maloney and U. Feist (1968) Messerschmitt Me 163, Fallbrook
• M. Emmerling and J. Dressel  (1992) Messerschmitt Me 163 “Komet” Vol.II, Schiffer Military History
• J.R. Smith and A. L. Kay (1990) German AIrcraft of the Second World War, Putham
• http://www.walterwerke.co.uk/walter/me163d.htm
• W. Spate and R. P. Bateson (1971) Messerschmitt Me 163 Komet , Profile Publications
• M. Ziegler (1990) Messerschmitt Me 163 Komet, Schiffer Publishing
• D. SHarp (2015) Luftwaffe secret jets of the Third Reich, Mortons Media Group
• M. Griehl (1998) Jet Planes of the Third Reich, Monogram Aviation Publication