Category Archives: Reconnaissance

Reconnaissance

DFS 346 (Huma Models)

TYPE: High-speed, high-altitude reconnaissance aircraft

ACCOMMODATION: Pilot only, in prone position

POWER PLANT: One Walter HWK 109-509 liquid-fuel rocket, rated at 3,400 kp thrust

PERFORMANCE: 560 mph (verified), 1,723 mph (estimated)

COMMENT: The DFS 346 was a German rocket-powered swept-wing aircraft subsequently completed and flown in the Soviet Union after WW II. It was designed by Felix Kracht at the Deutsche Forschungsanstalt für Segelflug (DFS, “German Research Institute for Sailplanes”). The prototype was still unfinished by the end of the war and was taken to the Soviet Union where it was rebuilt, tested and flown.
The DFS-346 was a midwing design of all-metal construction. The front fuselage of the DFS 346 was a body of rotation based on the NACA-Profile 0012-0,66-50. The middle part was approximately cylindrical and narrowed to the cut off to accommodate vertically arrayed nozzles in back. Probably for volume and weight reasons the DFS-346 was equipped with landing skids, both in the original German design and in the later Soviet prototypes; this caused trouble several times.
The wings had a 45° swept NACA 0012-0,55-1,25 profile of 12% thickness. The continuously varying profile shape caused a stall in certain flight conditions, which caused complete loss of control. This was later corrected by use of fences on the top of the wings.
The DFS 346 was a parallel project to the DFS 228 high-altitude reconnaissance aircraft, designed under the direction of Felix Kracht and his team at DFS. While the DFS 228 was essentially of conventional sailplane design, the DFS 346 had highly-swept wings and a highly streamlined fuselage that its designers hoped would enable it to break the sound barrier.
Like its stablemate, it also featured a self-contained escape module for the pilot, a feature originally designed for the DFS 54 prior to the war. The pilot was to fly the machine from a prone position, a feature decided from experience with the first DFS 228 prototype. This was mainly because of the smaller cross-sectional area and easier sealing of the pressurized cabin, but it was also known to help with g-force handling.
The DFS 346 design was intended to be air-launched from the back of a large mother ship aircraft for air launch, the carrier aircraft being the Dornier Do 217K as with the DFS 228. After launch, the pilot would fire the Walter HWK 109-509B/C twin-chamber  engine to accelerate to a proposed speed of Mach 2.6 and altitude of 100,000 ft. This engine had two chambers — the main combustion chamber as used on the earlier HWK 509A motor; but capable of just over two short 2,000 kp of thrust at full power, and the lower-thrust “Marschofen”, (Cruise chamber = throttleable chamber of either 300 kp (B-version) or 400 kp (C-version) top thrust levels mounted beneath the main chamber. After reaching altitude, the speed could be maintained by short bursts of the lower “Marschofen” (cruise chamber).
In an operational use the plane would then glide over England for a photo-reconnaissance run, descending as it flew but still at a high speed. After the run was complete the engine would be briefly turned on again, to raise the altitude for a long low-speed glide back to a base in Germany or northern France.
Since the aircraft was to be of all-metal construction, the DFS lacked the facilities to build it and construction of the prototype was assigned to Siebel Werke located in Halle, where the first wind tunnel models and partially built prototype were captured by the advancing Red Army.
On 22 October 1946, the Soviet OKB-2 (Design Bureau 2), under the direction of Hans Rössing and Alexandr Bereznyak, was tasked with continuing its development. The captured DFS 346, now simply called “Samolyot 346” (“Samolyot” = Aircraft) to distance it from its German origins, was completed and tested in TsAGI wind tunnel T-101. Tests revealed some aerodynamic deficiencies which would result in unrecoverable stalls at certain angles of attack. This phenomenon involved a loss of longitudinal stability of the airframe. After the wind tunnel tests, two wing fences were installed on a more advanced, longer version of the DFS-346, the purpose of fences was to interrupt the spanwise movement of airflow that would otherwise bring the boundary-layer breakdown and transition from attached to stalled airflow with loss of lift and increase of drag.
This solution was used on the majority of the Soviet planes with sweptback wings of the 1950s and 1960s. In the meantime, the escape capsule system was tested from a North American B-25J “Mitchel” piston engine medium bomber and proved promising. Despite results from studies showing that the plane would not have been able to pass even Mach 1, it was ordered to proceed with construction and further testing.
In 1947, an entirely new 346 prototype was constructed, incorporating refinements suggested by the tests. This was designated “346-P” (“P” for planer = “glider”). No provision was made for a power plant, but ballast was added to simulate the weight of an engine and fuel. This was carried to altitude by a Boeing B-29 “Superfortress” captured in Vladivostok and successfully flown by Wolfgang Ziese in a series of tests. This led to the construction of three more prototypes, intended to lead to powered flight of the type.
Newly built “346-1“ incorporated minor aerodynamic refinements over the 346-P, and was first flown by Ziese on September 30, 1948, with dummy engines installed. The glider was released at an altitude of 9700 m, and the pilot realized that he hardly could maintain control of the aircraft. Consequently, while attempting to land, he descended too fast (his speed was later estimated at 310 km/h). After first touching the ground he bounced up to a height of 3–4 m and flew 700–800 m. At the second descent, the landing ski collapsed and the fuselage hit the ground hard.
The pilot seat structure and safety belt proved to be very unreliable, because at the end of a rough braking course Ziese was thrown forward and struck the canopy with his head, losing consciousness. Luckily, he wasn’t seriously injured, and after treatment in hospital he was able to return to flying. Accident investigation research team came to the conclusion that the crash was a result of pilot error, who failed to fully release the landing skid. This accident showed that the aircraft handling was still very unpredictable, as a result, all rocket-powered flights were postponed until pilots were able to effectively control the aircraft in unpowered descent, requiring further glide flights.
The damaged 346-1 was later repaired and modified to 346-2 version. It was successfully flown by test pilot P.Kazmin in 1950-1951 winter, but nonetheless these flights also ended “on fuselage”. Furthermore, after the last flight of these series, the airframe again required major repairs. On 10 May 1951, Ziese returned to the program, flying final unpowered test flights with the 346-2, and from 6 June, unpowered tests of the 346-3 without accidents.
By the mid-1951 346-3 was completed, and Ziese flew it under power for the first time on 13 August 1951, using only one of the engines. Continuing concerns about the aircraft’s stability at high speeds had led to a speed limit of Mach 0.9 being placed during test flights. Ziese flew it again on 2 September and 14 September. On this last flight, however, things went drastically wrong. Separating from the carrier plane at 9,300 meters (30,500 ft) above Lukovici airfield, the pilot fired the engine and accelerated to a speed of 900 km/h (560 mph). The rocket engine worked as expected, and 346-3, quickly accelerating, started ascending and soon had flown in very close proximity of its carrier aircraft. Ziese then reported that the plane was not responding to the controls, and was losing altitude. Ground control commanded him to bail out. He used the escape capsule to leave the stricken aircraft at 6,500 meters (21,000 ft) and landed safely by parachute. With the loss of this aircraft, the 346 program was abandoned (Ref.:24).

DFS 228 V1 (Huma Models)

TYPE: Rocket powered high-altitude reconnaissance aircraft

ACCOMMODATION: Pilot only in prone position in pressurized cockpit

POWER PLANT: One Walter HWK 109-509 bi-fuel liquid rocket engine, rated at 1,650 kp at 40,000 ft

PERFORMANCE: 435 mph at 75,459 ft

COMMENT:   Beginning in 1940, the DFS (Deutsches Forschungsinstitut für Segelflug, German Research Institute for Sailplanes) started an ambitious program to achieve supersonic flight. Since the only engines powerful enough and available at the time were rocket engines, it was realized that the solution was to have the assault on the sound barrier take place at a high altitude. It was decided to divide the program into three sections:
The first part was concerned with developing and testing of the pressurized cockpit section, the method of pilot escape in case of emergency and performance testing of rocket engines at high altitudes.
The second part was to discover the performance of various sweptback wing configurations. The DFS acquired the Heinkel P.1068 designs for a four-engined turbojet bomber with various wing sweep angles.
The third and last part was to actually build a supersonic aircraft with information learned in the above two steps, which was eventually to become the DFS 346.
The DFS decided to design a new aircraft (although much was learned in an earlier design, the DFS 54) to investigate the first part of their three-step program. Thus, in 1941, the RLM assigned the number 228 to the aircraft, and requested that the DFS 228 also be designed for high-altitude reconnaissance duties as well as research work.
The first prototype of the DFS 228 (coded D-IBFQ) was completed in 1943 by the DFS, although the control sections and landing skid were built by Schmetz Company. The fuselage of the DFS 228 V1 consisted of three circular sections: the nose section containing the cockpit; a center section which contained the landing skid, fuel tanks and a Zeiss infra-red camera; and the tail section with the Walter HWK 509A-1 or A-2 rocket engine. The wing was attached at the mid-fuselage point, and featured 4.5 degrees of dihedral. Wooden construction was used for the entire wing, with a single laminated wooden spar running from wingtip to wingtip, wooden ribs and a plywood covering.  Wide-span divided ailerons were fitted to the wing (the inner section acted as landing flaps), and lift spoilers were also fitted to the upper and lower wings. A conventional tail unit was used, also with all wooden construction. Landing was done on a retractable skid. Since the DFS 228 was to operate in extremely high altitudes, a completely pressurized cockpit was designed. Although it was thought at first that the pressure cabin could be of wooden construction, a metal compartment was built after the wooden one failed to hold sufficient pressure. The nose section was double-walled constructed with aluminum foil insulation. The V1 prototype had a conventional seated pilot’s position, but the V2 and later aircraft were to have a prone pilot position, due to the difficulty of of sealing such a large compartment with the pilot seated upright. All glazed areas were made of double layered Plexiglas and were provided with warm air circulation between layers to prevent frosting of the Plexiglas.
After pressure sealing problems became apparent on the V1 cockpit, it was decided to go with a prone pilot. An adjustable horizontal couch was provided for the pilot to lay on; all controls, oxygen supplies and cockpit equipment mounted directly to the steel tube structure which was then attached directly to the main fuselage bulkhead at the back of the cockpit. This also had the added advantage of keeping the pressurized area small. Thus it was easier to keep sealed. The new cockpit arrangement was incorporated in to the DFS 228 V2 and later aircraft.
A very interesting flight plan was arranged for the operational recognizance DFS 228. It was to be mounted above (or could be towed behind) a carrier aircraft (usually a Do 217K), where it was then carried to approximately 32.808 feet. Upon release, the DFS 228 would then ignite its rocket engine until an altitude of about 75.460-82.021 feet was reached. By this time, the DFS 228 would be over its photographic target area and after its reconnaissance mission was fulfilled, the aircraft would then make a long glide back to base.
In the case of an emergency at high altitudes, the complete pressurized nose section (with all life support equipment attached) could be jettisoned by firing four explosive bolts, or it could take place automatically when the cockpit pressure dropped below a minimum level. An automatic parachute would then deploy to stabilize and slow the descent. When a safe altitude was reached, the pilot was ejected by compressed air, and would then descend to the ground using his personal parachute. This escape procedure was successfully tested by the Soviets after the war, with a captured DFS 346, which had a similar escape system.
DFS 228 V1 flight trials were made at Hörsching, southwest of Linz, by the DFS and also by Erprobungsstelle Rechlin in late 1944. Over 40 test flights were made, and although powered flight was to take place in February 1945, none were actually made using rocket power, and none exceeded 32.808 feet. It was in these tests that the upright pilot’s position was found to be unsuitable for proper cockpit pressurization. The decision was made to go with the prone position cockpit, and was included into the DFS 228 V2, which was built and also flight tested.
The main faults found with the 228 were that it suffered from poor aileron effectiveness at high altitudes and that the elevators were very sensitive. Other than the early pressurization problems, the general handling was satisfactory and the problems would not hamper the intended role of the aircraft. A potential problem could have arisen with the use of the Walter HWK 509A1 or A-2 rocket engines, due to the fact that the flight profile meant for the rocket engine to be intermittently operated, and the possibility existed of valves and pumps freezing up at the extreme altitudes and low temperatures in which the flight was to take place. Of course, newer rocket engines were continually being developed, and perhaps some sort of heating system or the possibility of using M-Stoff and A-Stoff (methanol and oxygen) for fuels, which could have operated at much lower temperatures, could have been developed.
Although powered flight had not been attempted at the time of Germany’s collapse, the construction of a pre-production batch of 10 DFS 228A-0 aircraft had begun at Griesheim, near Darmstadt.
The DFS 228 V2 was destroyed at Hörsching in May 1945, only the forward section had parts worth salvaging. The DFS 228 V1 survived the war, and was surrendered at Ainring in the US Zone of Occupation. On June 18, 1945, it was taken by road to the US Air Technical Intelligence Unit at Stuttgart. It was later sent to the RAE Farnborough in June 1946, and although allegedly was sent to the scrap pile in 1947, another report has the DFS 229 V1 being sent to Slingsby Sailplanes Ltd. at Kirkbymoorside in Yorkshire. Strangely enough, Slingsby offered a design for their T44, a stratospheric research sailplane which incorporated several DFS 228 features, including the detachable pressurized cockpit section (Ref.: 17).

Focke-Wulf Fw 186 (Planet Models, Resin)

TYPE: Autogiro, reconnaissance, observation

ACCOMMODATION: Pilot and observer

POWER PLANT: One Argus As 10c air-cooled inline piston engine, rated at 240 hp

PERFORMANCE: 103 mph

COMMENT: German helicopter development began with Focke-Wulf’s acquisition of the rights to manufacture Cierva autogyros during the 1920’s. Over 30 Cierva C.19 and C.30 autogyros were built during the late 1920’s and early 1930’s, and from this experience, Heinrich Focke, the engineering half of the Focke-Wulf company, decided to develop an original autogyro design to compete in the Luftwaffe’s contest to provide a utility-liaison aircraft. The Focke-Wulf entry, designated Fw 186, was essentially a Focke-Wulf Fw 56 “Stösser” (Goshawk) parasol wing advanced trainer, with wings removed, tail unit and landing gear redesigned, and configured for two seats in tandem. The engine remained unchanged, with a clutch arrangement installed to start the blades rotating for takeoff. An autogyro, similar in principle to today’s gyrocopters, uses the main power plant for forward thrust, while the rotors freewheel in flight. The aircraft could take off and land in very short distances, but it could not hover or take off and land vertically.
The first flight of the Focke-Wulf  Fw 186 was on July 1939 and although very successful, it was beaten out by the Fieseler Fi 156 “Storch” (Stork) for the Luftwaffe contract, and disappeared from the scene afterward. Only two examples were built (Ref.: Planet Models).

Henschel Hs 130E V3 (Antares Models, Resin)

TYPE: High-altitude reconnaissance aircraft

ACCOMMODATION: Crew of three

POWER PLANT: Two Daimler-Benz DB 603B liquid-cooled engines, rated at 1,860 hp at 6,900 ft each and one Daimler-Benz DB, rated at 1,475 hp driving “HZ-Anlange” supercharger in fuselage

PERFORMANCE: 379 mph at 45,900 ft

COMMENT: The Henschel Hs 130 was a high-altitude reconnaissance aircraft and bomber developed in WW II, but never used operationally, only existing as prototype airframes due to various mechanical faults.
Development of the Hs 130 began with two Hs 128 prototypes, which first flew on 11 April 1939, with the second prototype flying on 20 February 1940. Both prototypes were research aircraft, used for testing pressurized cabins, engine superchargers, and cantilever wings. Different engines powered the two prototypes; the V1 by Daimler-Benz DB 601s and the V2 by Junkers Jumo 201s. Both had fixed landing gear.
While trials of the two prototypes were not successful, the potential of a high altitude aircraft caught the attention of the commander of the Luftwaffe’s’s special reconnaissance unit. The interest in the Hs 128’s potential for high-altitude reconnaissance missions led the RLM (Reich Air Ministry) to instruct Henschel to continue development of the Hs 128 as a reconnaissance aircraft under the designation Hs 130A. Three prototype aircraft Hs 130As were built, the first flying on  May 1940. Five pre-production Hs 130A-0 followed, being delivered in early 1941, and featured Daimler-Benz DB 601R engines – each with a single-stage supercharger, retractable landing gear, and a bay in the rear to house two Rb75/30 cameras for reconnaissance. The five Hs 130A-0s subsequently underwent trials and testing, which revealed significant problems with the aircraft performance, and reliability problems which prevented operational use.
Two further modified Hs 130A-0s were produced under the designation Hs 130A-0/U6 and featured a greater wingspan, Daimler-Benz DB 605B engines, Hirth superchargers, GM-1 nitrous oxide power boosting, and under-wing drop tanks, and being ready for flight testing in November 1943, demonstrating an absolute ceiling of 50,570 ft. The Hs 130A-0/U6 variant as well as the other Hs 130A-0s proved unsatisfactory and were never flown operationally.
Further development of the Hs 130 led to bomber variants. The planned Hs 130B was almost the same as the Hs 130A, but with a bomb bay in place of the camera bay, but was never built. The Hs 130C was built as a competitor for the “Bomber B” project, and was very different from the Hs 130A, featuring a shorter wing span, remotely controlled defensive armament, a more extensively glazed but still pressurized cabin and up to 4,000 kg of bombs. Further development of the Hs 130 as a reconnaissance aircraft continued with the Hs 130D, which was planned to have DB 605 engines and a complex two-stage supercharger, but was again unbuilt.
The Hs 130E was a re-working of the Hs 130A with the “Höhen Zentrale” or “HZ-Anlage” (High-altitude gear center) in place of conventional superchargers. The “HZ-Anlage” operated by a third engine, a Daimler-Benz DB 605T, was installed in the fuselage  the only purpose of which was to power a large supercharger to supply air to the wing-mounted DB 603B engines.  Another difference from the Hs 130A was the nose, which was extended forward to offset the weight of the “HZ-Anlage” engine in the fuselage. Also underwing fuel tanks could be fitted to provide fuel for three engines, and air scoops were fitted under the fuselage to supply the fuselage engine.
Three prototype Henschel Hs 130Es were built; Hs 130E V1 first flew in September 1942, and could reach 41,010 ft when “HZ-Anlage” was employed. Hs 130E V2, first flown in November 1942, was lost on its seventh flight due to an engine fire; V3 was built to replace it. An order for seven pre-production Hs 130E-0s followed, first flying in May 1943, together with a production order was placed for 100 Hs 130E-1s which were to have a remotely controlled defensive armament and provisions for underwing bombs. The order was cancelled due to continuing problems suffered by the Hs 130E-0’s “HZ-Anlage” system. A four engine version Hs 130F was planned, which was hoped to solve the problems with “HZ-Anlage”, by using four supercharged BMW 801 radial engines, but was never built (Ref.: 24).

Arado Ar 234R-1B (Dragon, Parts from Unicraft, Parts scratch-built

TYPE: High-speed, high-altitude reconnaissance aircraft. Project

ACCOMMODATION: Pilot only

POWER PLANT: One Walter HWK 509C liquid-fuel rocket engine, rated at 2,400 kp thrust (main chamber: 2,000 kp thrust, auxiliary chamber 400 kp thrust)

PERFORMANCE: 569 mph (estimated)

COMMENT: In 1944 the Arado design team proposed a two liquid-rocket engines powered reconnaissance versions of the Arado Ar 234 “Blitz” (Lightning) high-speed bomber. The Arado Ar 234R, as it was designated, would consist of a regular Arado Ar 234C frame but without turbojet engines. Instead two pods were installed under the wing, each containing a Walter HWK 109-509A bi-fuel rocket engine (project Ar 234R-1A). The second project Ar 234R-1B was to be powered by a Walter HWK 109-509C two chamber liquid-fuel rocket engine mounted in the rear section. Therefore a cowling would have been installed in the rear fuselage underneath the rudder. The upper rocket engine called “Steigofen” (Accelerate chamber) delivered 2,000 kp and was to be used for climbing to altitude while the lower rocket engine, “Marschofen” (Cruising chamber) delivered 400 kp thrust and was used to power the aircraft during horizontal flight. During return flight – over a distance of more than 155 miles ­– the aircraft flew as a glider without power. The wing had a laminar profile with its maximal thickness at 50 to 60% chord. The glide ratio was calculated to 1:14.
Because of the limited fuel capacity and short endurance of the rocket engines the Ar 234R-1b was to be towed by a Heinkel He 177 “Greif” heavy bomber. A possible reconnaissance mission in the London area was calculated as follows: After take-off from a Luftwaffe base near Paris the aircraft was towed to the operational altitude of app. 26,247 ft, reached near Calais. After release of towline with “Steigofen” at full throttle the aircraft was powered at a speed of app. 506 mph to an altitude of app. 55,775 ft. This height was reached in a few minutes app. near the coast of Dover. During horizontal flight intermittent ignition of the “Marschofen” accelerated the aircraft with 569 mph to the target (i. e. London). After photo mission the aircraft flew back to the coast of England at a speed of 541mph and the descent back to the home base was flown as a glider. The mission was estimated for 21 minutes.
Although the Arado Ar 234R-1B project was promising it was abandoned in favor of the DFS 228 reconnaissance rocket-driven glider giving even better ceiling of 75,460 ft (Ref: 16).

Messerschmitt Me 262A-1a/U3, NAGr 6 (Matchbox, Parts from Frank-Airmodel, Vacu-formed)

TYPE: Reconnaissance fighter

ACCOMMODATION: Pilot only

POWER PLANT: Two Junkers Jumo 004B-2 turbojet engines, rated at 900 kp each

PERFORMANCE: 510 mph at 32,800 ft

COMMENT: Another development of the Messerschmitt Me 262A-1a series was the Messerschmitt Me 262A-1a/U3 reconnaissance fighter. Several aircraft featured a bay in the nose for two side-by-side obliquely-mounted cameras. These could be two Rb 50/30s or an Rb 20/30 and a Rb 75/30. A small observation window was introduced into the floor of the cockpit. Due to the size of the cameras two bulge at both sides of the nose were installed. Because of the high speed all cannon armament was discarded. These aircraft were deployed to tactical reconnaissance groups (NAG = Nahaufklärergruppe) (Ref.: 7).

Blohm und Voss Bv. P.194.01-02 (Revell)

TYPE: Fighter, Dive bomber, Ground attack, and Reconnaissance aircraft. Project.

ACCOMMODATION: Pilot only

POWER PLANT: One BMW 801D engine, rated at 1,700 hp and one BMW 003 turbojet, rated at 800 kp

PERFORMANCE: 423 mph at 13,600 ft (estimated)

COMMENT: The Blohm & Voss Company had a great experience in designing asymmetrical aircraft as the Blohm  & Voss Bv 141,  Bv P.   176, Bv P.179, Bv P.204, and Bv P.237. In 1944 Blohm & Voss proposed new asymmetrical design to the RLM, which could be used as fighter, destroyer, dive bomber and reconnaissance, respectively. The design featured a mixed propulsion system with a piston engine in the main fuselage/ tail boom and a turbojet under a separated gondola that housed the cockpit.  The main advantage of that arrangement was an excellent and unobstructed view for the pilot and the reduction of torque moments along the vertical axis induced by the propeller of single engine aircraft. Several different designs were proposed, the Bv P.194.01-02, the Bv P.194.03-01, and the Bv P.194.00-101, changes regarding mainly in the layout of the turbojet engine. Due to the threatening defeat of Germany the Bv P.194 development was not pursued (Ref.: 16).

Junkers Ju 388L-1 (Airmodel, Vacu, Parts from Italeri)

TYPE: Photographic-Reconnaissance Aircraft

ACCOMMODATION: Crew of three

POWER PLANT: Two BMW 801TJ rated at 1,890 h.p. each

PERFORMANCE:  383 m.p.h at 40,300 ft

COMMENT: The production Ju 388L-1 differed from the pre-production version Ju 388L-0 in several aspects. The wooden three-blade airscrews were replaced by VDM-Dural four-bladers, a FuG 217 “Neptun” tail-warning radar was installed and the “Waffentropfen WT81Z” (Weapon Drop), housing two fixed aft-firing MG 81 machine guns, were replaced by  a large wooden ventral pannier to accommodate both cameras and a jettisonable auxiliary fuel tank. A total of 47 Ju 388L reconnaissance aircraft were delivered

Junkers Ju 388L-0 (Airmodel, Vacu, parts from Italeri)

TYPE: Photographic Reconnaissance Aircraft

ACCOMMODATION: Crew of three

POWER PLANT: Two BMW 801TJ rated at 1,800 h.p. each

PERFORMANCE: 407 m.p.h. at 29,800 ft

COMMENT: This first version of the Ju 388 was derived from a Junkers Ju 188T-1.  In all 10 pre-production examples were finished. These were followed by  the Ju 388L-1

DFS 228A-0 on Dornier Do 217K-1 (Italeri, Huma)

TYPE: Rocket-powered high-altitude reconnaissance aircraft. Project

ACCOMMODATION: Pilot only in prone position in pressurized cabin

POWER PLANT: One Walter HWK 109-509 bi-fuel liquid rocket engine, rated at 1,650 kp at 40,000 ft

PERFORMANCE: 559 mph (estimated)

COMMENT: The rocket-powered high-altitude reconnaissance aircraft DFS 228 (Deutsche Forschungsanstalt für Segelflug, German Institute for Sailplane Flight) was designed to climb to altitudes up to 75,459 ft and was than – due to this extreme height – far beyond the operational limits of any other aircraft at its time.
The DFS 228 design was a mid-wing monoplane, using wood whenever possible, with the exception of the pressurized nose compartment, which was an all-metal construction. Fins were plywood covered, ailerons and rudder fabric covered. A landing skid was housed in the center fuselage and could be extended for landing. For take-off a “Mistel” (Mistletoe) pick a pack configuration with landing skids retracted on a carrier Dornier Do 217K was proposed. Equipped with Zeiss infrared camera the aircraft was to be used for powerless reconnaissance missions. To perform these missions the DFS 228 was carried to an altitude of 33,000 ft. After ignition of the Walter HWK 109-509 liquid-fuel rocket engine and separation from its carrier the aircraft was able to reach its service ceiling of app. 75,000 ft within five minutes. The actual reconnaissance mission was done in powerless flight. Descending to its release height of 33,000 ft the aircraft could cover a distance of app. 466 miles and another 218 miles until landing. In case of emergency the pressurized nose compartment, equipped with all life-supporting systems, could be jettisoned by means of four explosive bolts, the module descend to an altitude at which the pilot could survive without oxygen supply. The pilot was ejected through the front windscreen and at the same time a parachute was deployed to bring the pilot safely to the ground.
By the end of WW II one prototype had been built (DFS 228 V1) and flown but only as glider. A second prototype DFS 228 V2 was in advanced stage. However, flight testing was only performed in a non-powered glide and a height of 33,000 ft resp.75,000 ft was not exceeded (Ref 17, 24).