Berlin B-9 by Kora Models
1/48 scale
Kit No. 4809
Cost: $50.00
Decals: One version – Experimental aircraft test flown in 1943
Comments: Cast resin with vacuform canopy and photo-etch details; re-issue of Master-X kit first released in 1996
History
The Berlin B-9 was a twin-engined experimental aircraft developed by Akaflieg Berlin and Flugtechnische Fachgruppe in 1943. It was built to investigate the feasibility of a cockpit designed so that the pilot could fly the aircraft from a prone position. This was especially important for ground attack aircraft and dive bombers, whose aerial maneuvers in combat produced G forces that could cause a pilot to black out. Akaflieg Berlin, aware that a pilot who can withstand high acceleration under combat conditions has a great advantage, sought to prove that an aircraft providing a pilot such an advantage could not only be built, but operated within a flight envelope that could make it an effective combat aircraft.
The data underlying the design of the B-9 revealed that a fighter pilot in a traditional sitting position can usually withstand 5G’s, or five times the force of gravity, but a fighter pilot lying prone can withstand 12G’s, and can engage in more extreme aerobatics without fear of losing consciousness. This would give such a pilot a critical advantage in a turning dogfight or a dive bombing attack. Flight testing was carried out from July to October 1943, during which time around thirty pilots had the opportunity to fly it. The test flights were conducted without major problems and only one accident was recorded.
The B-9’s cockpit was laid out for a pilot lying in the prone position, featuring a long cushion on which he could lay on his stomach, facing a glazed nose allowing him greatly improved visibility. This required a flight control system that a pilot could operate in that prone position, and without the need for advanced training. Fundamental changes to what were then traditional flight controls were ruled out — for example, the B-9 employed a control column instead of a control wheel. The cockpit was laid out in a definite right and left side pattern, to eliminate the need for the pilot to cross his hands under any circumstances.
In the Berlin B-9, the right hand was used to control the elevators and ailerons, and to release the pilot’s harness and activate the canopy release lever. The controls on the left-hand side of the cockpit were the throttles, engine instruments (fire warning, fire extinguisher, emergency pump, ignition switches), undercarriage (select lever, ratchet), and flaps. The feet, in the same fashion as in a conventional sitting position, operated the rudder and brakes. The pedals were activated when the pilot extended his toes.
Experience gained during the development of the Berlin B-9 proved that those controls that were not essential for safe flight could be located behind the line of the pilot’s shoulder. For that reason, the flight and engine monitoring instruments were reflected in a mirror so as not to take up valuable cockpit space in front of the pilot: Distance indicator, altimeter, variometer (rate of climb indicator), compass, electric turn and bank indicator, two engine tachometers, oil and fuel pressure gauges, airspeed indicator, and undercarriage position indicator lights.
Flight Testing
Test pilots reported that the prone position was generally comfortable, although on occasion there was a request for softer upholstery. Many pilots experienced muscle fatigue in the neck and shoulders from constantly having to lift their heads, and from moving the upper arms and the incorrect positioning of the parachute harness. Flying in a combination of winter equipment and heavy furs was noted as tiring, which did not bode well for service on the Eastern Front.
Pilots who flew the aircraft often soon adjusted to the prone position and were able to make 90-minute flights without discomfort. They considered a chin support bothersome in horizontal flight. The cockpit configuration without the chin support and the parachute on the pilot’s back was favored by most pilots, although under high G loads, flight surgeons viewed the chin support as imperative. The control column, initially horizontal, was changed to the vertical which pilots reported as more comfortable.
Test pilots initially felt the forces needed to control the aircraft were too low, partly due to the B-9’s relatively light weight; most pilots were used to controlling much heavier aircraft, which required a certain amount of physical force on the controls. As a result, the gearing of the rudder control was changed to increase the load needed to move the rudder in flight. Several pilots took some time to get used to the feel of the rudder.
No problem was encountered with the amount of force needed to operate the elevators. To assist the pilot in orienting himself, there were horizontal and inclined lines drawn on the windshield and the side windows of the canopy. Flight testing proved that this type of aircraft was well suited for bomber, ground attack, high speed reconnaissance and possibly even in a high-speed fighter role. But it was also noticed that, due to the somewhat restricted view, the use of low speed prone pilot aircraft without air support was not recommended. Despite being designed to withstand forces of up to 25 G, the maximum achieved was only 8.5 G. One of the reasons for this was the use of low rotational speed propellers. The B-9 produced a body of data that was instrumental in the design of the Henschel Hs 132, a prone position jet-powered dive bomber that was nearing the flight testing stage when World War II came to a close.
Specifications
Crew: One
Length: 6.06 m (19 ft 11 in)
Wingspan: 9.4 m (30 ft 10 in)
Height: 2.32 m (7 ft 7 in)
Wing area: 11.9 m2 (128 sq ft)
Empty weight: 940 kg (2,072 lb)
Gross weight: 1,115 kg (2,458 lb)
Fuel capacity: 95L
Powerplant: 2 × Hirth HM 500 in-line engines, capable of 77 kW (103 hp) each
Maximum speed: 250 km/h (160 mph)
Service ceiling: 4,000 m (13,000 ft)
The Kit
Kora Models Berlin B-9 consists of 27 beige cast resin parts along with a small photo etch fret, a single vacuform canopy and a small length of wire. The instructions consist of a single exploded drawing of the kit parts and a three view color plate showing a simple paint scheme of RLM 71 (Dark Green) over RLM 65 (Light Blue). Decals are provided for a single test aircraft bearing civil registration characters.
The major kit parts (fuselage, wing and tail surfaces) all bear engraved panel lines and lay the groundwork for a kit that can potentially look quite detailed. The fuselage is simple and consists of two halves, and the wing is a single cast resin piece that will only require a little sanding. There is no sidewall detail on the interior surfaces of the fuselage, and no real attempt to show any of the cockpit instrumentation. The cockpit consists of a floor, a cushion nearly as long as a prone man, an appropriately short control yoke, rudder pedals, and what may be a separately mounted chin rest. The glazed greenhouse nose consists of two clear vacuform parts that will have to be cemented together and to the fuselage with great care. Likewise for the main landing gear and propellers, since a slip with a razor saw could cause real damage.
The engine nacelles are nicely detailed, consisting of two parts each that are also attached to resin blocks. Putty will definitely be required for these parts. The wheels of the main landing gear are nicely detailed and feature radial tread, and the tail wheel may require extensive and patient clean up, since it is a delicate part and appears to be attached rather solidly to its resin block. The wire provided in the kit appears to be for a pitot tube which protruded from the nose, and also possibly support struts for the elevators in the tail assembly. Since it is far from straight, an aftermarket replacement may be best.
Markings
The kit decals are for a single test aircraft, registration D -ECAY. There are also what appear to be examples of the Akaflieg Berlin logo, and a pair of swastikas for the tail. While not terribly exciting, they appear to be quite serviceable.
Conclusion
This is a highly unusual kit that has a direct link to an actual Luft ’46 aircraft, the Henschel Hs 132, that was in development when WWII ended. Highly recommended for its historical interest.
References
www.luft46.com
www.plane-encyclopedia.com
www.wikipedia.org
