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designed by Hans Jacobs
In describing this sailplane, one has no small responsibility, as it was the most successful mass produced high performance sailplane in the World before the Ka 6.
Hans Jacobs designed the prototype Weihe in 1938, after his Reiher of 1937 and before the Olympia Meise of 1939. As Hans Jacobs had been taught sailplane design by Alexander Lippisch, designer of many gliders during the 1920s and the Fafnjr of 1930 and Fafnir 2 "Sao Paulo" of 1934, one can state that the Weihe was another of a long line of saliplanes which were influenced by the Fafnir. The clean, simple beauty of the Weihe would make it a worthy exhibit in an exhibition of Greek art.
The machine started its great career in 1938 and set up its last World Record in 1959, over 20 years later. This is even more remarkable because very few countries were able to build this machine again because of its construction cost in the austere period after 1945.
Described below are four different types of Weihe:-
The Weihe is constructed in the normal fashion for that time, i.e. a Baltic (Polish) pine structure covered with birch ply. The fuselage is a normal semi-monocoque tube construction The parachute box is removable to give access to the luggage space. In th e same space are the fittings for a water tank to hold 40 litres (8.8 gallons), with drain cock . The advantage of this ballast for higher speed ranges, to increase the cruising speed, is well known. In addition, the luggage space is large enough to hold three oxygen containers for altitude flights.
The wing is unusual in that it has only a single spar, there being no rear or drag spar. An aileron spar is supported from the main spar-by a stressed box, on which are mounted the air brakes. These are of DFS type, rotating open and shut on a tube. The air brakes do not open to 90 degrees to the wing surface, probably because the designer felt that the wing was not rigid enough in torsion because of its single spar construction, combined with high aspect ratio. This means that they are inefficient, especially at low speed and large fields were needed to land in. The Weihe used to soar at Lasham with the air-brakes out and it would still pass other gliders in the climb
The dive brakes restrict the Weihe's speed to 190 k.p.h. They have little drag effect when the machine is flown slowly. In fact they have a steadying effect and the machine will climb well in lift with the air brakes out at between 34 and 38 m.p.h. The dive brakes become more effective when flying speed was increased. The sinking speed in a slip with air brakes out is 5 metres per second.
The outstanding feature of the Weihe is its quick and easy rigging and de-rigging. The wing, and wing attachment fittings are so well designed and engineered that rigging the aircraft can be done with three people (one of them strong) in 7 minutes and the de-rig in 5 minutes, during which someone or something was required to hold the fuselage vertical. Two levers on either side of the decking of the fuselage, drive home, simultanaously, the two wing/fuselage bolts. Then it was necessary to couple the controls and to raise both wing tips simultanaously, so that a single main spar main pin could be inserted and locked, on the centreline of the fuselage on the upper surface of the wings. It is doubtful whether the system of the main fittings has ever been improved on. It has never appeared on any other machine, possibly due to its perfection and cost of production.
Wings are hung from the glider before lifting and locking into position
The tailplane was secured by a single central vertical bolt, onto which a wing-nut vas screwed and locked. It vas only necessary to couple the elevator underneath the tailplane in the fuselage. A trimming device actuated by the pilot was coupled by an operating arm which was inserted into a small bracket ensuring it lined up during rigging.
Regarding the finish. In Germany 1938 - 45 the open frame areas were fabric covered and usually painted with red dope undercoat and then standard NSFK cream over everything, plywood and fabric too, quite opaque. This was mainly to combat ultra violet light attacking the fabric, of course. It was sometimes done to lay very lightweight fabric over the ply skins at this time, with painted finish on top, quite thick with primers and undercoats so you couldn't see the fabric underneath.
One of the RAF Weihes had clear doped fabric surfaces, but all the plywood skins were painted cream. There was another RAF example with clear fabric but dark green plywood and 'scalloped' edges on the wing and tail; very pretty. The Surrey Club had a Weihe that had all deep yellow flying surfaces, opaque, and red fuselage.
Weihes were built in several countries. The ones that came from Czechoslovakia seem to have been thrown together. They did not even scarf the plywood fuselage skins but overlapped them and this shows clearly through the paint. (Some, it is said, had no glue in the main spar laminations so they were extremely dangerous to fly unless virtually rebuilt. The German ones were much better made, but many of the wartime ones were built with urea-formaldehyde glues which began to break down after while.
1. PRE-PRODUCTION WEIHE (WEIHE 1) 1938-39
Two prototypes registered D-11-184 and D-11-185 took part in the 1938 Rhön Contest, These machines differed from the production models in that they had considerably less dihedral, smaller cockpit canopies, a smaller elevator trimmer, different fuselage/wing fittings. There were other slight differences. It is probable that about 7 of these pre-production Weihes were built by the firm of Schweyer during 1938-39, These Weihes had room behind the pilot for a water ballast tank of 40 litres capacity and space for 3 oxygene bottles.
2a. PRODUCTION WEIHE 1940
The Weihe was one of the types selected to be developed by DFS for use by the N.S, Flieger Korps. Other types were the SG 38 (DFS 14), Grunau Baby (DFS 49) the Meise Olympia (DFS 70), the Kranich (DFS 30). The production Weihe seemed to have a slightly less refined shape than the prototype. This machine had in 1945, a 10-15% improved performance over any other sailplane then in production. This performance was only marginally improved on by the French with their AIR 100, produced in l947, and the Slingsby SKY which, built in 1951, only achieved limited production. The DFS Weihe was built during the war in Germany, in Czechoslovakia (by Mraz or Avia), in Poland, in Sweden 1943, and probably in Spain. After the war it was built in Spain (probably at Ruesca) and in France. 30 Weihes were built at the Victor Minie Aeronautique at Saint Cyr during 1949/50, These are known as VMA 200 Milans, and are identical to the DFS Weihe. Many Spanish Weihes had been built by 1951. These were also identical to the DFS Weihe.
2b - THE JACOBS SCHWEYER WEIHE
Hans Jacobs stopped working for DFS during 1940 and started supervising production of Weihes at the Schweyer Flugzeigbau. Here he was able to further simplify the Weihe design for cheaper and quicker production. The 1943 J.S. Weihe at Dunstable had its fuselage covered with ply that was only scarfed along one edge (or perhaps on no edges at all). The resultant joint was then sanded down, giving the fuselage a telescopic tube effect. The joint was filled to give a smooth surface. Also written on the machine were the words "Hans Sieg, Moebelfabrik" (Furniture Factory). This might indicate dispersal of production at the time.
The wartime price of the Weihe was only 4,800RM, Hans Jacobs in 1945 said that he had built 280 Weihes but that the parts for another 100 were at he Swiss owned firm of Kittelberger, Rheinau-Hoebert, Nr, Bregenz. In 1943 the Jacobs Schweyer firm was taken off glider production and put onto building wooden tail units for ME 109s and ME 262s.. These were conversions from existing metal structures and were almost certainly never used. The firm was also engaged in building dummy U-boats (radar decoys) and. ME 328s..
Parts of pre-production and production Weihes were not interchangeable without considerable modification.
During latter years some Weihes in Germany, Switzerland and the U.S.A. have been much refined around their wing fuselage joints and forward fuselages. So much so that on some of them it is now impossible to lower both wingtips to the ground without damage to wing roots, top of fuselage arid fittings. Because of this refinement it is possible that on these Weihes the practically-tested max. L/D of 1:29 of the older Weihes, has been improved to 1:31, as stated in the book 'Die Beruhmstesten Segelflugzeuge' Georg Brlltting. Some of these modified Weihes now have been fitted with fixed landing wheels and have had their landing skids removed.
The machine handles superbly and climbs well, with its good lateral stability in thermals. Rate of roll is slow by modern standards but this is no inconvenience once a pilot is familiar with the machine. The gliding angle becomes rather steep if the speed is increased to above 55 knots. Stalling speed - below 30 knots. One feels that one is flying a machine of great quality, in fact, it flies you.
Other flights on this day:
Also 19 pilots flew over 300 Kms to the two Berlin airfields.
On another day in poorer weather, Hoffman fllew a Weihe 410 Kms to near Rotterdam. Späte was again 1st. on this day, landing his Reiher at Rotterdam Airport - 415 Kms.
AT THE 1939 RHÖN CONTEST
(above) - Graf von Treuberg, who was the youngest pilot in the competition,was placed 4th
3rd place was won by a Weihe flown by Treuter.
OTHER NOTABLE WEIHE FLIGHTS
55 hours 51 mins Duration Flight by Ernst Jachtmann from the 22nd to the 24th September 1943 over Brüsterort on the Baltic. See the following clip of the flight:
Over 53 hours Duration Flight by Juez (Spain) in pre-production Weihe registartion EC-RZZ over Monflorite, Huesca, Spain during 1943
The above two Duration Records were not recognised by the FAI as it was policy not to recognise war-time records. These Duration Records were marginally exceeded by the French in 1952.
THE MOST FAMOUS WEIHE
WORLD SPEED RECORD OVER A 200 Km COURSE was flown by the Jugoslav Klancnik in 1956. This was the first speed over a 200 Kms course record to be recognised.
DAILY TASK WINNER DURING 1956 WORLD CHAMPIONSHIPS at St. Jan, France, The Swiss pilot Muller won a task in a Weihe he had built himself.
WORLD GAIN OF HEIGHT RECORD of 9665 m The Weihe's final World Record. This was flown by Karl Bauer over the Teck in a thunderstorm on the 20th June 1959, in a wartime production Weihe.
DURING THE LATE 1940s AND 1950s Weihes broke National Records too numerous to mention in many countries. I have no details of Weihe or Milan performances in France. Almost certainly many flights over 500 Kms must have been achieved. At La Ferte Alais, near Paris , a Mdm de Brugada set up a French 300 Km triangle speed record for women in a Milan (speed approx. 35 m.p.h.).
One must also remember the efforts of Georg Raddatz who set up a German Goal Flight Record of 385 Kms from Brunswick to Bruchsa on the 2nd June 1955.
Two Weihes came to Britain after 1945 from the Wasserkuppe and many British Records were broken by these two machines:--
BGA. No. 433 (previous reg. G-ALKG) - see photo taken 1947 of Philip Wills at Dunstable) was built in Czechoslovakia in 1942 and brought to England after the war. The wings and tail were re-skinned completely with the plywood grain laid diagonall. The ply skins had no fabric, just clear varnish of a very high gloss the fabric covering being clear doped. The fuselage and fin was a deep turquoise green equiped with drop off dolly wheels. Registration letters were imposed by the bureaucracy for a few months 1946 - 7 only and were soon cleaned off. , and was later was sold to New Zealand where it became ZK-GAE. After repair it was flown by Philip Wills a Distance Record of 233 miles, to a Height Record of 15,800 ft and later to another Height Record of over 30,000 ft over New Zealand.
BGA No. 448 (previous reg. G-ALJW and LO+WQ) see photo and note the poor quality of the plywood planking) built by Jacobs Schweyer in 1943 was flown by Lorne Welch from Redhill to Brussels - 210 miles - and to almost 30,000 ft. by John Williamson in a thunderstorm. The first machine also set up all the New Zealand National Records when being flown by Dick Georgeson. H.C.N. (Nick) Goodhart gained his 500 Km Diamond in a Weihe in Texas.
With these two came a spare pair of wings, which with some fuselage parts and fittings were made into a third machine. This became BGA 642 (previous reg. G-ALMG). This machine was sold in 1949 to the U.S.A where it was registered as N1900M. and where it won the 1959 US Nationals. - see photo below and also read the owners history of the glider published in the VGC Magazine
A further JS Weihe BGA 650, came into Britain at that time,. It was registered in 1950 and flown by the Siamese Prince Bira. This machine left the country shortly afterward with Prince Bira. Another Weihe came from the RAF in Germany during the 1950s and went to Jock Forbes: when he emigrated to the U.S.A. the machine went with him.
During the 1960s, possibly as many as five Swedish built Weihes came to Britain with two more German built machines. One of the German rnachines was destroyed by spinning-in after its rebuild by a member of the RAF Chilterns Gliding Club at RAF Benson.