"A two-seater can have as good a performance as a single seater and, with a crew of two - pilot and navigator - should be able to out-perform the single seater."
"The Harbinger should have a good future and a long life. It is not an ultimate or an extreme design. It is meant for good performance in all sorts of weather and all sorts of places."
These comment,; were made in May 1948 by Waclaw Czerwinski and Beverley S. Shenstone, the joint designers of the Harbinger. They had prepared a design for entry in the 13GA design competition of that year for a two-seater trainer, which would have a cross-country performance. there were twenty designs entered and the Harbinger came fifth. The winner was a side-by-side two-seater by Hugh Kendal and known as K1 (Crabpot). The side-by-side arrangement was thought more suitable at the time for training purposes and the K I embodied many new ideas, but it subsequently proved unsuccessful and no longer exists.
Historical Photographs - click the image below for details
The Harbinger design and construction employs well known principles and aimed at a relatively light airframe of clean lines but with strutted wings. Sweeping forward the centre part of the shoulder wing gives the rear pilot an excellent view, something which was a failing of' the 1935 German Kranich then in widespread use throughout Europe. The equipped weight was estimated at just over 564lbs. This figure was optimistic and there are a number of reasons why the Harbinger Mk2 eventually weighed over 700lbs.
What of the Harbinger designers?
The late Beverley Shenstone, born in Canada, had worked during the 1920s for Junkers on the single-engined metal aircraft (the W.30) which was later to develop into the technically excellent Ju 52. He had then transferred to Supermarine to work on the prototype Spitfire. After the war he was to become British European Airways Chief Engineer.
He was always interested in gliders and produced many papers on sailplane design.
The other contributor to the design was the Pole Waclaw Czerwinski. Few people in Britain have heard of him, and yet he was one of the four Polish sailplane designers before the War, and probably the best of them! The following high performance sailplanes were Czerwinski's design: CW5 (1934), CW7 (1935), PWS 101 (1937), PWS 102 (1938), PWS 103 (1939).
Some readers may have seen pictures of the two magnificent PWS 101 single-seaters taking part in the Wasserkuppe International Meeting of 1937. These designs by Czerwinski, and other Polish sailplanes entered, were judged second only to the German aircraft for their technical excellence. On the first day Mynarski flew a PWS 101 351 km to Hamburg together with three German competitors, one being Hanna Reitsch, who was flying the prototype Reiher. At the Wasserkuppe In 1937 a CW5 achieved best altitude after a climb in cloud in competition.
For a flight of 578km across Poland in a PWS 101, T.Gora was awarded the Lilienthal Medal for the most meritorious performance of 1938. The following year saw the construction of three examples of the PWS 102 "Rekin" (Shark) and another design by Czerwinski, which was the equivalent of the Reiher. But before it could achieve real fame, war broke out and most Polish sailplanes, as they were based in the east of the country, were removed by the Russians to Moscow and never heard of again.
When the Germans invaded Poland in 1939, Czerwinski was able to escape to Canada and there, whilst working for A. V Roe Canada, met Beverley Shenstone. In Canada in 1945 he reproduced his earlier design, the Salamander, under the name of Sparrow, and then produced an improved version known as the Robin. Shenstone and Czerwinski were also together involved in 1949 with the design of the Loudon sailplane, which was built at the University of Toronto as an engineering exercise for fourth year students. The Loudon incorporated a steel tube wing root diagonal internal strut similar to that in the Harbinger.
Fred Coleman, who was a an engineer and a member of the Derby and Lancs Gliding Club, had been gliding since 1929 and was responsible for building the British Harbinger. Later it would be designated by Czerwinski as Mark 2 to distinguish it from the Canadian one, construction of which was started about the same time. Coleman had built a Grunau Baby, "Black Diamond", taking two years to build it in 1936, and this aircraft, BGA 277, much restored and without the 4-piece wing it originally possessed, is still flying today. To build a two-seater sailplane is a very considerable task. To build a new design, in fact a prototype where the plans are being completed, some materials not available, and at long range to the designers needed someone of considerable ability and tenacity. Fred Coleman was just such a person. He received some help from Gerry Smith, an employee at Rolls-Royce, former CFI of the Derby and Lancs G.C. and a former member of a BGA Test group, and from friends Mr. Shadlock and also Harry Ashton (see note on the right) who coverd the wings using 'Medapolin', a type of linen
A relative reports about
At the time of the Harbinger MKII build, Harry worked at AWA (later I believe this became Hawker Siddeley Dynamics) in Whitley, Coventry where he was employed as the superintendent of the experimental machine shop. Some of his work here involved work on the 'Blue Steel' stand off missile carried by the 'V' Bomber force. Harry met Fred Coleman when learning to fly gliders, I believe that it was Fred who taught Harry to fly and from this they became friends right up until the time Harry died of cancer at the beginning of 1966.
In early February 1949, Coleman, having paid Czerwinski a licence fee, received the wing drawings, and having already arranged in advance to purchase his materials from A. V. Roe & Co. Ltd., commenced work on the sailplane. He also designed and built an all-metal trailer (Timber was rationed and could only be bought on licence at the time.) to take it and planned to have the Harbinger completed and flying first for 1952 and later in the 1954 International Gliding Competition to be held at Camphill. The trailer was completed in December 1951.
Because of the many difficulties encountered, the Harbinger Mk2 was not ready until September 1957, when serious centre of gravity discrepancies became apparent. As Coleman's construction was virtually completed, he suggested a relatively simple solution: to lengthen the fuselage by 15 inches between the two pilots. After considerable correspondence with Czerwinski, consultation with Shenstone, who was by now in England, and fresh stress calculation in respect of the proposed greatly enlarged cockpit opening, Czerwinski agreed , although his own solution, subsequently incorporated in the Canadian MkI, was somewhat different, in that he suggested that the wing centre section forward sweep be reduced by three degrees.
By 7th June 1958 the modified Harbinger was ready for further weighing. An engineering assessment was made, found satisfactory, and so, on the 26th July the preliminary test flights were made at Hucknall, Nottinghamshire, with Gerry 0. Smith the test pilot. No adjustments were found necessary.
The aircraft was taken to Camphill and flew regularly until on the 28th June 1959, whilst being flown by Fred Coleman with a passenger over Bradwell Edge, Great Hucklow, it suffered a mid-air collision with a Slingsby Prefect flown by Brian Hollingsworth. Sadly the Prefect pilot was killed. More damage was caused to the Harbinger in the subsequent forced landing at the bottom of the hill than in the collision. Fred Coleman suffered damage to his ankle and other injuries. At this time the Harbinger had not yet received a full Certificate of Airworthiness.
It was another three years before the Harbinger became airborne again, totally without modification except for a new front canopy and wheel brake operating on the exterior of the tyre. Some pre-collision flight testing had been carried out by the BGA No.5 Test Group but later, post-collision flight testing was carried out in July and August 1962 by Bedford Sailplane and Design Group at Twinwood Farm, Bedfordshire, headed by Harry Midwood and including Joe Caiger and Peter Bisgood. The Harbinger received a Category Certificate soon afterwards.
In July 1965 the Harbinger was entered in the Northern Gliding Competition at Doncaster, coming 9th out of 16, being the top placed two-seater and beating both the Blanik and the Slingsby Eagle. The pilots in the Northerns were the late Charles Christianson and the late Alec McCaskle. On the 9th July 1966 a flight of 8 hours 55 minutes duration was made from a winch launch at Camphill, using thermal and wave lift. The pilots this time were Christianson and Spooner.Technical Merits
The Harbinger's light wings and simplicity made rigging possible within ten minutes by three people. As the struts bear much of the load, it was possible to design much lighter main spars and a shallow depth of profile at the wing root. The minimum chord and depth of' wing-root profile have reduced the danger of wing-root/fuselage (armpit) turbulence, a constant worry for designers wishing to produce a cheap aircraft. Where there is likelihood of trouble, the area has to be diminished. This solution was also used by the designers of the Westland Lysander and pre-war PZL fighters. The Harbinger's designers sought to find very simple solutions to basic structural problems.
The aircraft has two square steel tubular wing attachment frames built into plywood frames, which form part of the essentially wooden fuselage. The wing attachment frames take the wing loads, the rear frame being attached to a steel diagonal tripod within the wing. There are steel tubes within the struts. Since all are connected within a system of triangles and rectangles, a very strong structure results.
Because of the limited size of Coleman's workshop, (his spare bedroom), he built the fuselage in three separate sections before removing the bedroom window frame to transport them to his specially lengthened garage for final assembly as a fuselage.
Click 3 views to enlarge
Above - The Canadian Harbinger with a modified wing angle of sweep due to centre of gravity problems
Above - Fred Colemans answer to the centre of gravity issue was to extend the nose and controls by 15 inches.
Rear seat visibility and ease of rigging are much improved over those of the Kranich 2b 1. The Harbinger's empty weight is 738lb with 25lb ballast. This makes it about as heavy as the Kranich 2b 2, although some Kranich 2b Is weighed only 630lb. The wings of the Harbinger are much lighter and can be lifted by two people.
The aircraft features slotted ailerons and segmented airbrakes and whilst slightly under-ruddered at slow speed, the general characteristics are of a docile yet good soaring sailplane. Because of the high all-up weight, excessive speed on approach and landing can result in a lengthy ground run. On the ground the tail is heavy (approx 85lb to lift).
Beverly Shenstone may have been responsible for the Harbinger's excellent engineering design, but it is the lines of Czerwinski's famous sailplanes that transpire in the Harbinger. This aircraft remains one of the few material tokens of the fine fleet of pre-war sailplanes that once graced the skies of Poland.
Mk 2 Harbinger - with spoliers
Construction in Canada of a Harbinger Mk 1 started in 1949 but, after passing through the hands of four sets of builders over 28 years, the final assembly of this Harbinger began at Pendleton, Ontario in 1975 and flew later that year. Although well ahead of its time in 1947, by 1975 the Harbinger required further modification and development and was discontinued. Between 1975 and 1977 the aircraft made over 30 flights, the longest being over three hours, with a grand total of 25 hours and 45 minutes being flown. The Harbinger was donated to the Canada Aviation Museum at Rockcliffe, Ottowa in 1988. It remains listed but unseen in storage in a side annexe and differs in numerous details from the British Mk2 in its appearance, with a slightly swept-back wing, shorter fuselage and "bunny" nose profile.
Mk 1 Harbinger - Registration C-FZCS - Home-built - Manufacture Date: 1975 Construction #: C1