The BD-5 flight test program is ready to get into high gear. It is an easy thing to say that an aircraft is undergoing flight tests. In some ways when a person designs and builds his own little homebuilt and he goes out to put on some flying hours, he can easily say that he is doing flight test work. This can simply mean that he takes the airplane up, flies it around, enjoys the scenery, shoots a lot of touch-and-go landings to where he is pretty sharp, and maybe does a few stalls, levels the aircraft out and goes to full throttle to see what its top speed would be. After putting in first or one hundred hours, you might hear the remark that the aircraft has been completely "proven out."
Maybe for some designs this is okay. But in reality the "test pilot" has only explored a very narrow region to which that airplane could be subjected in flight. For example, the change in the center of gravity of the aircraft can easily occur for different loading conditions and this has a definite effect on how the airplane handles. Exact engine performance on hot days, cold days, with carburetor heat on, with it off, at steep angle of climb, and for different carburetor air inlet conditions you also have a pronounced effect on the aircraft's performance.
Most of the time (and it is true for factory aircraft), the basic controls of the aircraft are never modified from an original concept to the final or production design. Therefore, exactly how the airplane handles for elevator responses or aileron deflection at high speeds or slow flight is simply just the way it comes out. In other words, if the elevator will allow the airplane to porpoise a little bit while landing at high speeds nothing is ever done to correct it. It is simply written off as a characteristic of the airplane. Only in a few cases where handling characteristics truly become dangerous is there a crash program undertaken to correct the problem.
In the development of military aircraft, on the other hand, the science of flight tests for perfecting an aircraft's handling qualities has been developed to a fine degree. In these cases a new aircraft is put through very extensive flight evaluation tests, and the results thoroughly studied. Very sophisticated instrumentation and telemetering is used to gather extensive engineering information. The end result is that the aircraft could have excellent handling qualities, and the exact performance under any configuration is thoroughly known. The BD-5 is going to be put through this type of program. We do not have the complicated telemetering instrumentation, nor a lot of sophisticated in-flight measuring equipment, but the BD-5 is, of course, considerably simpler and far less complicated than a modern military aircraft.
There are many relatively simple ways of collecting important engineering information without a huge investment in equipment. But the planning of each flight, the preparation of the aircraft, the actual flying, the data collection and data reduction takes a proper crew, and it takes time. With Mr. Burt Rutan being assigned as director of development tests, we think our program will move into high gear and we will be ale to do the job in a first class manner. As we mentioned in the previous newsletter, Burt was stationed at Edwards Air Force Base doing exactly what we mentioned above on the F-4 and F-15 programs. The first all-metal BD-5 is within weeks of completion. The second aircraft is not far behind. We will also complete a third aircraft and will use all three for the complete flight test program.
We have three milestones to accomplish. The first is when we have completed the basic flight test program to where we know the overall design is complete. At this point, we will clear the aircraft for delivery to customers. In other words, shipments will begin. Approximately a month and one half to two months later will have complete enough high speed tests and preliminary spin tests as well as performing maneuvers up to 80% of the design load factors. At this milestone, we will give an okay for customers to fly their aircraft, but with certain limited flight conditions. Two to three months after this we will clear the aircraft for full operation. We will have completed all flutter and V-max conditions, and we will have performed maneuvers which will subject the airplane to structural loads up to 100% of its design limitations. High altitude performance, rough field operation and all other unusual conditions will have been tested. We think in this manner you will not only be assured of a strong, safe aircraft, but you will have had all the performance and handling characteristics evaluated in the most ideal and desired way.
The next subject I want to discuss is a question I am sure you have all been asking. Just how soon will we start making deliveries on the BD-5? Well, the exact delivery date hinges on two points; first, the availability of our large engines, and second the completion of flight tests to the first milestone mentioned. With regards to the engines, Kiekhaefer Aeromarine has been unable to deliver any of the large engines at this time. They have given us a firm commitment for delivery of the large engines to be 50 units by the end of April, 500 by May 15, and 1,000 by June 15. We will receive 1,000 engines per month thereafter. We can receive a six month supply of 40 and 55 HP engines in May, but since the majority of our customers want the larger engines, our production rate will be pretty much controlled by that engine.
Our first milestone in the flight test program should occur in May or first week of June at the latest. It is conceivable that this could even be accomplished by mid-April. In any event, all other materials have been ordered and are now arrive at our warehouse facility here in Kansas. At this point we see no other items causing us further delay.
It might be possible for us to ship at a rate even faster that we can receive engines. This means that there is a possibility we could ship material packages complete less the engine. We are having our production people study this and we may find that the paperwork and added handling would make the idea of shipping the aircraft less engine, following later with the shipment of the engine, to be totally impractical. Also, the freight charges for the customer would be somewhat higher. We would, however, like to know your opinion. If you would rather wait and have everything shipped at one time, we can do this. If, on the other hand, you would prefer to receive everything, less the engine, we can consider it.
We are going to send out a questionnaire within the next week to everyone who has a BD-5 on order. This matter regarding shipment without engine will be one of the questions. We would also like to know one other bit of information; building your aircraft generally becomes a family effort, and we would like those of you who have a family to list your spouse's first name and the name of your children, with their birthdays, if you care to. We would like to send each of them a birthday card to let them know that we who build and design airplanes are not all crazy.
We would like to reconfirm what we have said in earlier communications: that those of you who have already paid the balance on your aircraft will receive a delay in shipment of your aircraft from when it is scheduled and will definitely receive interest on this money for the delayed period. This interest is at an annual rate of 10%. In a short time we will be notifying all our customers when we expect to be making deliveries on their aircraft, based upon their priority numbers. We sure cannot wait to start making deliveries, but we have got to make certain that all essential things are right before we do.
James R. Bede, President, Bede Aircraft, Inc.
Last Update: 6/2/97
Web Author: Juan Jiménez
Copyright © 1997 by Juan Jiménez - ALL RIGHTS RESERVED