BD-5 Information Memo - No. 5


Flight Tests

The BD-5 has flown. Our prototype aircraft, N500BD made its first flight on September 13. These flights were made at an ex-naval air station at Hutchinson, Kansas. Although very little engineering information was obtained on these first flight tests we were quite pleased with the results. The aircraft had a good solid feeling about it and the wrist action control stick was most ideal. All flights were made with the gear down because we found the fiberglass spring that we used on the nosewheel strut was too flexible and would give a porpoising effect when we would hit dips on the runway. Although not dangerous we could not accept this condition. We initially made changes to stiffen the strut but this only partially solved the problem.

The next change we made was to eliminate the fiberglass spring completely and make a rigid structure. At this point we also changed from the small solid wheel to a larger pneumatic tire the same size as the main wheels. This solved the porpoising problem but found the ride to be just a little hard. So as not to delay the first flights any longer we elected to continue testing at Hutchinson, Kansas, where the runway is exceptionally smooth. With the larger diameter nosewheel it was not possible at that point to retract the gear in the original gear well. We did, however, learn what we wanted to, and are now making the appropriate changes to the aircraft.

Some of the other changes we are making is to move the location of the main gear relative to the CG of the aircraft. This will reduce the weight in the nose gear and at the same time provide easier and smoother nose gear rotation on takeoff.

Another interesting thing we learned in flight test occurred on our early high speed runs. Our exhaust system simply had the exhaust pipe coming out of the side of the aircraft. The exhaust was discharged at nearly right angles to the side of the fuselage. Although we considered this installation as just a temporary one, we did not foresee any problems. What did occur, however, was the fact that when the engine was running at full throttle the exhaust does come out at a pretty high velocity. The result was a jet reaction of an estimated two to three pounds of thrust. We discovered, therefore, when we would lift the nose gear off the ground that the aircraft had a slight tendency to go to the left because the exhaust pipe in the aft portion of the fuselage was producing thrust to create a slight turning tendency. A simple redesign of the exhaust pipe rectified the problem but we are studying the jet reaction of the exhaust very thoroughly to see what potential performance gains we might obtain at high speed.

Although on all of the flights the aircraft became airborne below 60 MPH IAS we are going to refrain from quoting any performance figures until we have obtained complete information and have calibrated all of our instrumentation.

Delivery Schedules

We have been able to establish January 31, 1972 as the beginning of our production. We have programmed a very active schedule from now until that time to evaluate and test both the aircraft and its structure and make final refinements well before the January 31 date. In coordination with this program we are establishing our production suppliers and will have completely organized our facility and have all materials well stocked so that we may begin a very active delivery schedule. We have had additional personnel join our company who will plan and direct this operation. We have established a production rate of 300 aircraft to be delivered in February and 500 aircraft every month thereafter. Since the interest in the BD-5 has been rapidly growing we are prepared to increase this production rate appreciably so that we can insure a relatively early delivery of all initial orders.

Those of you who have a BD-5 already on order will be notified at least 120 days in advance of when your aircraft will be ready for shipment to you. We will be shipping your aircraft in a complete package. All materials and parts will have been inspected and complete in every respect. When you receive your aircraft there should be no delay in preventing you from starting fabrication immediately. For those of you who may choose to come to Kansas and pick-up your aircraft instead of having it shipped commercially, we would like to request that you give us at least two weeks notice. In the future newsletters we will publish shipping charges by both motor freight and air so that you may know the cost of shipping. The exact sizes and weights of the complete aircraft will be spelled out. We have established a firm policy of not making any shipments until all items are complete. If for some reason we cannot make shipment of your aircraft within the week specified, we will voluntarily impose a penalty of 10 percent annual interest of the cost of your order, for any delay that is a result of material shortages of packaging delays. We do not want to be held responsible for delays due to acts of God, war or other outside factors that are beyond our control. We are simply volunteering this penalty on ourselves because we intend on meeting our delivery schedules but will not do that at the inconvenience of our customer.

All flight test information must also be corrected to indicate what the results would be at maximum gross weight on a standard day. It is only in this manner that we would be at maximum gross weight on a standard day. If we release information that is only partially complete the exact performance may actually be considerably different. For example, our airspeed indicator on the first flight did indicate below 60 mph when we became airborne. This could easily, however, be 5 MPH or even more in error. We have established a very comprehensive flight test program and we are following it through to completion. We know everyone is interested in flight test figures but the only ones that mean anything are the accurate ones.

We are exceptionally pleased with the flight tests so far and we are now even more convinced that our final results will be very close to our design goals. One thing we can guarantee everybody right now is that the BD-5 will give them performance they could not obtain from any other aircraft up until this design.

Optional Equipment

The following is a list of optional equipment that will be available for delivery with the first aircraft: 
Long Wings (Extra Set)
Short Wings (Extra Set)
Variable Speed Drive System
Electrical System
 (Including electrical starter, battery, rectifier, wire circuit breaker switches and terminals.)

In addition to these items, all three engines will be available at the start of production. The 32 HP engine comes with the basic aircraft. The 40 HP will cost $90 additional. The 70 HP including drive system and larger propeller costs $710 additional.

The price for the optional engines is based upon our current volume. We do find, however, that if we had approximately 2,500 orders we could make a substantial reduction of the optional engine prices. We are, therefore, putting on a drive to obtain new orders so that when we place our initial engine order we can get them at the lowest possible price.

We, therefore, would appreciate if it you are interested in the BD-5 please place your order within the next thirty days or if you already have an aircraft ordered and then find a friend who would be interested. If we reach our goal, we will supply the 40 HP engine at no cost to the basic $1,800 price and we will be able to supply the 70 HP engine for $450 additional. We feel that this is a significant savings that could be of benefit to all.

We would like to remind everyone that we voluntarily canceled our price increase from $1,800 to $1,950 on the basic airplane to go along with President Nixon's price freeze. When the price freeze is over, however, we will go back up to the $1,950 figure. So now is really the best time to place your order. There will be a number of additional optional equipment available and we will announce these items and their cost as soon as we get firm price figures.


We have decided to definitely establish BD-5 dealer sale outlets throughout the country. It will be possible, therefore, in the future for all BD-5 owners to obtain assistance, service, optional equipment, as well as complete aircraft from their local dealer. All those who are interested in possibly obtaining a dealership should write directly at our office in Newton, Kansas, to the attention of Mr. Vic Oliver, advising us of your desire and give basic information about such dealerships. We will not be assigning dealer outlets until the first of next year and requirements will be finalized in late November. Those of you who are interested will be contacted at this time for complete information.

Increased Gross Weight

The BD-5 production aircraft will all have an increased gross weight from what was originally published. All configurations will now have a maximum gross weight of 600 lbs. The normal operating gross weight will be 550 lbs. After completion of thorough flight tests on the prototype aircraft, we will publish new performance figures based upon the higher gross weights.

With the increased gross weight we did not, however, want to affect the stalling speeds. The production BD-5's will, therefore, have increased wing area to provide essentially the same stalling speeds. With the increased wing area, cruising speeds will be reduced somewhat. Depending upon the configuration the loss in cruising speed will be between four to seven MPH.

We have found from those who have already ordered the BD-5 that there is considerable interest in optional equipment. The electrical system, instruments, avionics, etc. affect the empty weight of the aircraft. Also by going to the newer and better Kiekhaefer engines the aircraft's basic empty weight is also increased. It is for these reasons that we have upped the gross weight of the aircraft. A BD-5 owner can now install this type of equipment and still have a practical useful load. With the increased gross weight, takeoff and climb performance will be affected adversely. For those convinced these performance characteristics are critical, our recommendation is to maintain as light as possible empty weight and operate their aircraft at values below maximum gross weight. Under these conditions, takeoff and climb performances will not be appreciably affected. We are beefing-up the aircraft's structure so that the maximum G-load capability will be essentially unaffected.

Metal Fuselage

A major design improvement is now capable for the BD-5. Because of the high interest shown in the BD-5 and with a lot of hard work in our engineering, we were able to solve some tricky problems of manufacturing an all-metal fuselage. With all design problems solved. we now will be able to produce the BD-5 utilizing an all-metal fuselage. The result is we can have a stronger, lighter and easier to fabricate airplane.

The original design called for seven fiberglass components molded with compound curves in such a way that they would form the complete outer fuselage surface. With this arrangement it was necessary to design an all-metal internal structure that carried all primary and secondary loads. For a number of technical reasons we did not feel it was advisable to use the fiberglass shell as part of the basic structure to carry any loads. Now that we are capable of going with an all-metal fuselage skin we have eliminated a major portion of the internal structure and allow a major portion of the flight loads to be carried by the metal skin. This greatly simplifies the internal structure and the complexity of building the fuselage. It also provides us with more room for the cockpit and engine compartments. It results in a substantial savings of as much as 22 percent of the aircraft fuselage weight which can be utilized as useful load. With the BD-5 now being made entirely of metal we can assure the structure of having an essentially unlimited life.

To form compound curves out of metal for the fuselage requires very expensive tooling. This tooling could not be justified if it was not for the considerable interest and orders that we have for the BD-5 already. Although the tooling is quite expensive, the rate at which these parts can be manufactures is considerably higher than production techniques for fiberglass. This means that we will b able to supply the BD-5 materials packages with an almost unlimited rate, thereby reducing delivery times for everybody's aircraft. We have now established the design so that the fuselage will come in eight separate components. Four right and four left pieces. The metal will be formed to shape and trimmed very close to the final butt lines. We have worked out a relatively simple way that the final fitting and assembly of this structure can be done by the most inexperienced homebuilder. A combination of bonding and blind rivets will be used to make the smooth structure. The blind aircraft-quality rivets are pulled with a simple pop rivet gun. It is a one-man operation not requiring complicated equipment.

With this design it will be possible to have two very large engine compartment doors, one on each side. The cockpit will be roomier in both width and height. Although the initial tooling cost for Bede Aircraft is quite high, we cannot visualize a better, safer way of fabricating the fuselage.


All BD-5's will be equipped with a new engine. The engine we have selected for our production BD-5's is manufactured by Kiekhaefer Aeromarine of Fond du Lac, Wisconsin. This is a very new and modern engine of both two cylinder and three cylinder sizes. They are similar in configuration to the original we intended for the BD-5 manufactured by Fuji Heavy Industries.

We have been convinced, however, in testing, that this completely American-manufactured engine is of exceptionally high quality. It is without question the best engine we have been able to find from any manufacturer. The internal parts are manufactured under exceptionally high tolerance and are completely interchangeable. There is no select match fitting of internal components. Furthermore, the design of the internal parts of the engine are so over-strength that we are assured of extremely high reliability. A new and improved cooling fin design permits the engine to produce a substantial increase in horsepower for the displacement. Our evaluation of the engine proved so successful that we are extremely excited about the adaptation of the Kiekhaefer engine in the BD-5. We are convinced that we will have the best possible lightweight engine for this aircraft.

We have found it desirable to use a single carburetor for the twin engine version. The cubic inch displacement on the engine is 433cc. The engine has the capability of producing either 32 HP or 40 HP under a different configuration. It comes equipped with a manual starter and is available with an electric starter as an optional feature. We have found the engine to be exceptionally easy to start and unbelievably smooth in all speed ranges from idle to maximum RPM. The basic engine will come equipped with a solid-state capacitor discharge ignition system. There are no moving parts or mechanical points to fail. The entire ignition system is a lightweight completely sealed unit.

We are expecting to develop dual ignition heads so that all engines can be modified for dual ignition. This will be available in the future as optional equipment. The three cylinder 648cc displacement engine is an amazing unit that produces a substantial amount of power for its size and weight. It comes equipped with a capacitor discharge ignition system, manual starter and electrical starter as an option. We believe that we will have a substantial increase in engine overhaul time and hope to come up with the exact figures from our testing bench. At the present time, however, we will quote only the need of a top overhaul at 300 hours. This will consist of merely removing the cylinder heads and replacing the piston rings. We believe a major overhaul of other items will not be required until possibly a thousand or more hours.

Fuel Tanks

Another design improvement that will be incorporated in the production aircraft is the elimination of fuel tanks from the fuselage compartment. The major portion of the fuel will be carried in the wing panels. We have come up with a technique that will allow the builder to very simply convert a a number of bays in the wing to fuel tanks.

We have also come up with a simple, foolproof design of fuel disconnect fittings so the BD-5 wings can still be easily and quickly removed. There will only be a very small header tank in the fuselage which will provide fuel for inverted flight and a simple and convenient gas gauge installation. With this design change two major benefits are derived: first, fuel capacity can be increased to a maximum of 14 gal. on each side for 28 gal. total; second, it provides additional fuselage space which can be utilized as a convenient and roomy baggage compartment. Exact size and dimensions will be available in the near future. Although the original arrangements had adequate provisions for fire prevention upon hard landings, this new arrangement provides even greater safety.


As many of you read in our Information Memo No. 4 we have established our BD-5 flight test center in Newton, Kansas. This will be headquarters for all BD-5 operations. You can call or visit our facility at any time. Our normal working hours are from 8 to 5 Monday through Friday. We are also open on Saturday for the major portion of the day. If you would like to visit the facility on Saturday we do request that you give us a call to confirm if someone will be available.

Newton, Kansas Airport is located approximately 22 miles due north of Wichita, and 1.5 miles east of Interstate 35 West. The phone number for this operation is (316) 283-6910. We request that you do not call collect because quite often people authorized to accept collect calls are not there. Furthermore, we are doing everything we can to keep our overhead as low as possible which in turn keeps the cost of the airplane down. Although if you visit our Newton facility and wish at that time to place an order you can do so. We do request, however, that if you are sending your order in you mail it directly to our main office in Cleveland, Ohio. In this manner your priority number will be processed immediately without delay.

Last Update: 8/3/98