It is with the greatest of pleasure that I welcome this opportunity to talk to you about the BKB, my father's amazing little sailplane, the real story of which has been clouded for so long. If you have heard of the BKB, it's likely to have been in connection with words like tumbling, aerobatics, and unpredictability. Some of you, especially if you are young or new to the sport of gliding, may not have heard of it all. There is much to tell about the BKB, but I suspect I'll raise more questions than I'll answer.
I have a mission here today and that is primarily to correct some serious and prevalent misconceptions about who designed and built the BKB. But my mission has a second and very important part also, and that is to obtain more information about this very unique aircraft; how it performed in its later years, what caused it to crash, and could it really tumble? I'd like also to revive some interest in the BKB, especially academic and analytical.
But first it's important to tell you that this little sailplane was designed by my father, Stefan Brochocki, an aeronautical engineer at Canadair Ltd. Fred Bodek, also of Canadair, assisted in designing some of the controls. (Fred later worked for Boeing and was involved in designing the landing gear for the 747.) The BKB-1 was flown in Quebec and Ontario, Canada, long before it came to Seattle and well before Witold Kasper put his hand to the controls of it. Kasper, as you probably know, was well known in the Seattle area for his amazing stunt flying in the BKB in the 60's. He also claimed to be its designer and builder, and generated an enormous amount of publicity to that effect along with his Bekas and Kasper Wing based on the BKB.
The BKB was an experimental design inspired by the Horten sailplane, and was created to serve a specific need in Canadian gliding in the 50's, It was a high performance, tailless aircraft with a glide ratio of 29:1, despite having a low aspect ratio of 10:1. Dave Webb, several time Canadian gliding champion was one of the test pilots who flew it. On one occasion, he was able to compare its performance directly to that of his own Skylark 2B. Dave was flying the BKB at the same time as a friend was flying the Skylark. The BKB outperformed the other aircraft between thermals with a flatter glide angle in the 50-75 knots region. (The documentation presented to TWITT includes a comparison of its performance to that of the Fauvel.)
It was most famous for its alleged ability to perform controlled tumbles and recover; not exactly what it was designed for, but perhaps, if true, a serendipitous quirk (an aero-isoclinic wing perhaps?) that bears further investigation. At the end of this presentation, you'll see a very short film clip of the BKB in flight and you may judge for yourself whether it is truly performing the fabled tumbles. (Note: Since this presentation I have located two people who claim to have seen it tumble, one of them being a pilot who flew the BKB and performed the tumbles in it.).
At this point, it's worth it to recount a brief overview of events in the development and testing of the sailplane BKB-1:
The BKB-1 Story
The BKB design concept began with Stefan Brochocki's interest in gliding in his native country of Poland in pre-war days. He had become inspired by the silhouette of the Horten glider and, over time, he came to realize aspects of the Horten that could be improved upon. But it was not until 1953 that he began to put his ideas on paper in the form of a design.
In Canada, in the 1950's, Stefan belonged to various gliding clubs, in particular the Montreal Soaring Association, which flew out of Hawkesbury, Ont. near the Quebec -Ontario border, just on the edge of the Laurentian Mountains. Stefan was disappointed by the lack of suitable aircraft to fly. Many of the gliders were old and in need of repair, and there were too few of them to fill the needs of the local gliding enthusiasts. It seemed that gliding in that area was not exactly on the cutting edge of the sport. With his ideas in mind of improving on the inspirational Horten, Stefan set out to design a new glider which would suit the needs of his club.
Stefan's new wing was designed with the following objectives: to fill a gap in Eastern Ontario soaring by providing a design that strayed from the traditional design, but which was inexpensive to build, easy to handle in flight, and easy to maintain. For a more aerodynamic explanation of the design objectives, I would refer you to Stefan's letter of Nov. 10, 1961, to Dr. J.J. Cornish at Mississippi State University. This and other documents are included in the material I will be leaving with TWITT for its library.
His design was met with enthusiasm at Canadair Ltd. where he was employed, and where he immediately attracted two volunteers in forming a partnership for the construction of the new craft - Fred Bodek, who worked in the design department, and Witold Kasprzyk, an inspector, working as a liaison between design and manufacturing. For Brochocki and Kasprzyk (later known as Kasper), it was a renewal of an old acquaintance, the latter having been Stefan's gliding instructor in Poland. In 1954 the partnership was formed, each member with his specific duties. Bodek and Kasprzyk were to finance the project, Stefan to provide design and drawings and create the type record, while Bodek was to provide some of the excellent illustrations and some design of the craft's technical features. All three were to be involved in the construction which started in 1955 in Kasprzyk's basement.
In 1956, negotiations with the Canadian Department of Transport began for inspection and certification of airworthiness. The prototype BKB-1 was completed in October of 1957 and revisions to the type record were made. With negotiations continuing through that year, the new wing was ready for testing. It received its temporary Certificate of Registration (CF-ZDK-X) and flight permit in September of 1959. (Note: Though considerable testing and modification was done in Canada it was never considered by my father to be complete and consequently, a permanent certificate was never issued.)
Kasprzyk had moved to Seattle in 1958 before the construction was completed and a new location had to be found to complete the work. The two remaining partners carried on with the work and the testing. Although short hops piloted by Stan Rys and Stefan were made with a car tow in the fall of '58, the BKB-1 did not make its official first flight until the fall of 1959 piloted by Dave Marsden of the National Research Council. Tragically, Stefan never flew the BKB again due to financial reasons and insurance costs. A slight injury sustained on one of those first "car hops" made an impact- he had a young family to support. He could not afford to have something happen to him.
Further testing was carried on by Marsden. Modifications and adjustments were made on an on-going basis, all of which are described in the Fight Test Reports section of this compilation. Bodek also flew the wing and said it was beautiful to fly. Dave Webb, Canadian gliding champion, was among the pilots who took it to the air. He completed a number of test flights, many of them lengthy. He was impressed with its potential and its amazing capabilities for such a low aspect ratio. But, he said, it was not a craft for beginners and suggested modifications, subsequently carried out, to the skid and towing arrangement which were needed to improve take-off and landing, and to prevent "porpoising" on rough terrain. (I believe there were further modifications made to the skid later.) Years later, he was to commission Stefan to design an aluminum version to be flown in competition. This design exists but Dave was not able to continue with his plans, so the design sits, not quite finalized, in Stefan's possession. Other pilots flying the BKB included George Adams, Gordon Hicks, and Hillier Kurlents.
Correspondence continued between Kasprzyk, now officially Kasper, and Stefan for several years. In 1960, from Kasper's letters, Stefan became aware that he was involved in another construction project and was planning to use the design and data of the BKB for as a basis for development. To protect his and Bodek's interests and the integrity of the design, Stefan drew up a document (A-1 in the collection of documents presented to TWITT) which prohibited Kasper from doing so. This important document, signed by Kasper, is in Stefan's possession. It became evident later, that Kasper completly ignored this agreement, and repeatedly violated its clauses.
Bodek, too, eventually moved to Seattle in 1960 to work at Boeing , and later worked in Barbados in charge of engineeing on a windmill project for the Brace Institute of McGill University. Left on his own to sustain the project, Stefan found himself overworked. His weekends were spent at the Pendleton Gliding Club, 90 miles away, his evenings working on drawings and modifications. The absences were taking a toll on his family. They had just purchased a new home, requiring landscaping and all the work that a new home entails. For financial reasons, insurance for him to continue test flying was out of the question. Without the financial backing and assistance of his partners, Stefan's resources of time, money, and energy were exhausted, and he had to make a decision about the future of his glider.
Kasper had been badgering him for years for news of the testing; Stefan was weary of his demands and decided that he would let the glider move to Seattle for further testing and the continued tuning that had been suggested in the test flight reports. In 1964, the Canadian registration was canceled and ownership was transferred to Kasper. It was a difficult decision, and one that was received with mixed feelings by his family. It was also a decision Stefan would come to regret in several ways. On the brighter side, he knew the BKB would not sit idle and development and testing hopefully would continue.
In 1960, Stefan was invited by Bev Shenstone, engineer with BEA London and British flying guru, to present a paper on the BKB to the 8th OSTIV Congress in Cologne, Germany. The paper, entitled A New Tailless Sailplane was presented by Bev in Stefan's stead in June of 1960. It was subsequently published in Swiss Aero Revue. Bev Shenstone was one of the most enthusiastic promoters of Stefan's work and arranged in 1959 for the inclusion of his design in Jayne's and The World's Sailplanes, Vol.2.
It is worth noting that at the same OSTIV Congress in 1960, Dezsö Györgyfalvy, of the Aerophysics Dept. of Mississippi State University, presented a paper entitled Performance Analysis of the Horten IV Flying Wing. Stefan felt vindicated by this critique of the Horten, for it cited many of the flaws that he had set out to overcome when he designed the BKB-1.
During these years, Stefan Brochocki received requests from all over the globe for information on the BKB. It had been well received internationally. Stefan's reputation as an aircraft designer grew with it. Requests were received for his advice on other aircraft design projects as well. In 1961, Professor Barry Neumann of McGill University asked Stefan to present at a Fluid Motion Seminar in the Dept. of Aeronautical Engineering at McGill. With pilot and friend, George Adams, he presented Introduction to a Canadian Sailplane.
Also in 1961, Professor Neumann became the liaison between Stefan's group and Dr. J.J.Cornish to test the craft at Mississippi State University, where work had been done to test the Horten. MSU had wind tunnel testing capabilities not available in Canada, and the prospects were quite exciting. After a great deal of information sharing and correspondence, the effort had to be dropped because of logistics problems, distance and cost being some. (Please see the correspondence sections of the document binder.) /p>
Then in 1963, a disturbing letter arrived from Fred Bodek in Barbados shortly after Kasper had sent Al Wilson to Canada to pick up the plane. The letter described an article in the Boeing News. Despite the international interest surrounding Brochocki and the BKB, the Boeing news had carried a story of Kasper and "his" glider, the BKB-1, (technically he did own it). The article, entitled Employee's Glider Can't Fly- But It Does, has Kasper claiming, "My design is so stable, it can become boring to fly". He then proceeds to explain how he conceived of and developed the design over many years through some process of observing nature. No credit was given to his former partners. He didn't even mention their names. Brochocki and Bodek were not amused, but then, the Boeing News was just an employees' paper, and perhaps Kasper had just been carried away in his enthusiasm. After all, the work of the BKB and its designer and the partnership that produced it were already well-documented in respected publications, and Stefan had Kasper's signature regarding the matter. Stefan's interest was now consumed by sailboat design.
During this time Kasper and test pilot , Al Wilson, continued to fly the aircraft in Seattle. They made some adjustments to position of controls, reduced the hinge moment of the rudder to reduce pedal forces, and made the seat position adjustable.
Kasper was a gifted pilot who did some incredible (perhaps foolhardy?) aerobatic flying in the BKB and, if indeed the BKB did exhibit controllable tumbling as he claimed, then it is to his credit that he was able to discover that. It is all the more incredible that he was able to licence it for aerobatics. The BKB was not designed for aerobatics. You may recall that Stefan's original objective was to design an aircraft that was stable in flight. Since aircraft as a rule are not known to recover from a tumble and the ensuing stall, he had striven to avoid the possibility of tumbling in his design. Aircraft must be built to withstand much stronger forces to be licenced for aerobatics (at least in Canada this is true), and the BKB was not designed for this category of flight. It appears that by making stability the first priority, the BKB became sufficiently stable to recover from a tumble, (if indeed it did tumble).
Not much was heard about the BKB in the years following 1965, the last dated correspondence from Kasper. Soaring Magazine listed the BKB as designed by Stefan Brochocki and manufactured by the partnership in its May 1964 Directory of Active Sailplanes in the United States. It appeared that Kasper's design claims were either forgotten or generally disbelieved. However the Directory did mention that both Kasper and his test pilot, Al Wilson were individually working on their own designs based on the BKB.
Curtis McPhail, a pilot for Northwest Airlines, was killed in a crash in 1971 while piloting the BKB at Canaday Airport in Arlington, Washington. The story was reported in the Seattle Glider Council publication, Towline, and mentioned a brief history of the glider and the partnership that developed it. Stefan Brochocki was devastated at the loss of life. He tried to obtain details of the crash but nothing was received from Kasper. To this day he has been unable to ascertain the cause of the accident and subsequent loss of the pilot's life. He has never come to terms with it. Accidents can be expected in a risky sport, and somehow one can deal with them. But being left in the dark about the details is haunting and leaves no peace of mind in the long run. (TWITT library has provided one version of details of the crash.).
More stories began to surface about Kasper's claims regarding the BKB. In the Post-Intelligencer ( date & location unknown), he claims to be the developer of the control system and the "elevons", special adaptations of the wing designed by Brochocki. He makes further and greater claims in Soaring (Nov 1969) despite the magazine's previously- published crediting of the design to Brochocki. Lengthy articles were featured in US Sport Aviation Magazine (July 1973, Flight Testing the Bekas-N) and Canadian Sport Aviation Magazine (Spring 1984, Remarkable L/D Achieved by Short-span Tailless Sailplane) repeated in great detail Kasper's claims to the unique design of the BKB. Stefan wrote to publishers of the latter to set the record straight and was ignored.
In 1997, Bob Gairns of the Montreal Soaring Council wrote Stefan to notify him that Soaring (July 1997) had again published information describing Kasper as the designer of the BKB. Bob had contacted Soaring and furnished them with documents (1955 article in Free Flight by Stefan Brochocki) to refute this. He, too, never received an acknowledgment or thanks. (Bob Gairns passed away, tragically, last year at the age of 80, when the glider he was flying crashed.).
Kasper did indeed introduce other designs; his well-publicized Bekas and Kasper Wing. The Bekas was essentially the BKB. Kasper had attempted to increase its performance by increasing the wing span. By doing so, he ran into some difficulty because this further decreased the already low aspect ratio, causing instability. The wing became more elastic and lost its aero-isoclinic properties. As Stefan describes this situation, it became a case of the airplane flying the pilot. Kasper called it dynamic soaring. (Since this presentation I was able to locate a set of Kasper's plans for the Bekas and BKB-1a, included together on the same paper. I laid one of Stefan's original drawings of the BKB-1 wing over the top of Kasper's drawing of the same feature: they matched perfectly. Except for some gussets and modifications to the wing-tip rudders, it was essentially the same drawing with some details removed and some added. The extra length for the Bekas wing was not there in the drawing.).
All of these aircraft were developed from concepts initiated and tested on the BKB-1, violating design rights of the originator and contradicting Kasper's signed agreement with Stefan Brochocki. Over the years numerous articles continued to appear linking Kasper, and Kasper alone to the BKB-1. Present endeavours to set the record straight were initiated in 1994 by myself, and have, until the past year with the help of the Internet, proven difficult. Many individuals and organizations are now showing an interest in the real BKB story.
It is clear that despite the fact that the BKB no longer exists, there is much left to unfold in its story. The record needs to be set straight. Stefan Brochocki, his family, and those who have worked with him over the years and lent their invaluable assistance in many ways don't agree with Kasper's claim;
"Only a stupid fellow tells the truth." (Seattle Times, Sunday, Oct. 7, 1971).
If only Kasper were still here to face it!
THE FUTURE
It's clear that a great deal of public information currently available concerning the BKN is erroneous, and what I seek to accomplish is the absolute and sole connection of Stefan Brochocki with the aerodynamic design of the aircraft ,and in conjunction with Bodek insome mechanical aspects, in print and in the minds of the interested public. It must also be similarly acknowledged that subsequent designs by Witold Kasper with aspects resembling those of the BKB were based on that original design and violated an agreement he had made with Stefan Brochocki. Fred Bodek's contribution to the production as a whole must also be recognized.
Patents have been taken out by Kasper on various details of the BKB design. These patents are now being investigated with a view to the origins of their subject matter.
I don't seek to discredit Mr. Kasper for any legitimate contributions he may have made towards the refinement of the BKB design or performance, and I acknowledge the inspired flying he has done to test and promote this experimental aircraft. The fact that he failed to credit his partners while heaping praise upon himself alone is repugnant and incomprehensible. In assigning credit for the work on the BKB, Brochocki always referred to it as a partnership. In his address to the McGill Aeronautics Department in 1961 he wrote:
Speaking of the BKB-1 sailplane I am also speaking on behalf of my partners, Witold Kasprzyk and Fred Bodek, without whom this project would not have reached the flying stage." Let's restore Brochocki and Bodek to their deserved place in the story of the BKB.
The whole matter raises many questions, and it would be rewarding if there were parties interested enough to follow up. For example, I am unaware if Kasper's work was ever submitted for rigorous peer review. What I've seen in print generally appears to focus on Kasper's claims or those of public relations man, Horst Petzold. It's quite possible that there are performance analyses that my family has not seen. What we have been made aware of has generally been sent to us by concerned individuals who had happened upon one of Mr. Kasper's articles in some gliding magazine. I would welcome other resources, and I haven't yet had the time to access TWITT's library.
The BKB testing to ascertain its performance in relation to the original objectives of the designer was never fully completed, and it is regrettable that the rigorous testing it was to receive at Mississippi State University never came to pass. Consequently, there may have been design modifications still required but never attempted. After leaving Canada the BKB was commandeered for aerobatic uses. It became a stunt flyer, and it appears that its other capabilities, potential, or use as a tool in design research became of secondary importance to its role as a vehicle for publicity. This is not to say that the publicity was without merit, it just overshadowed the original objectives of the design.
What really happened to the BKB in America? What had it accomplished? What caused it's fatal crash? Was it properly maintained, and how did it become licenced for aerobatics? Were there other mishaps before the final one? What happened to it's remains? It would be extremely satisfying to Stefan Brochocki and his family to recover even a small piece of his project. Both Bodek and Brochocki have many questions they would like answered.
Having the opportunity to speak to this distinguished and interesting group of TWITT members has given all of us involved with the BKB the chance of hearing some answers and of acknowledging the correct facts in the matter of the little Canadian sailplane. There are many interested parties back home and across the continent who are anxious to know the outcome, and who realize your group's potential to acknowledge the truth and to encourage us in our endeavour. I thank you all.
Andy Kechkes of TWITT deserves my most whole-hearted thanks for the hours of time he has spent corresponding with me over the past 10 months and researching information and links to assist me. Without his kind help and encouragement, I would never have had this opportunity. And to John Mitchell, your telephone call made me realize I was on the right track. Many thanks. Iwould also like to extend my thanks to George Knight who has become a most valuable force in this project. I could not continue without his technical knowledge, assistance, and encouragement.
Text by Stefanie Brochocki