THE BD-5 BULLETIN A quarterly publication by and for BD-5 enthusiasts the left hand corner of this page. Bulletin #23 Well You do the writing and Juan will Received! take care of the editing! It has now been two weeks since I Nosegear Parts completed the task of photocopying, stapling, tabbing, labeling and Located applying postage to some 857 issues April-June 2000 Issue 24 of the Bulletin, including 49 mailed Last month we talked about a to Canada and 68 others to various problem that is common to Gerdes countries around the world. nosegear struts that are not cleaned on a regular basis. Judging from the comments I've received, I think it is safe to describe Specifically, we talked about the the rebirth of the Bulletin as an degradation of the teflon disk, Inside this Issue unqualified success. spring and ball bearing that make up the centering mechanism of the · Bulletin #23 Welcomed! As you can see, this issue is greatly nosewheel castering system. We · Call for Authors expanded. Some of the material that thought that parts could not be 1 · Nosegear Parts Located you will see here is available on the located. Well, we were wrong. · Lester Berven's BD-5 web site, such as Les Berven's flight 2 Flight Test Program test report to the Society of Test Paul Ross of Alturdyne wrote to us Report Pilots. We have also included great in March and deservedly chided us · Alturair Introduces Spun news about the BD-5's main landing for not checking with him first. Sure 7 Aluminum Main Gear Legs gear, and a complete transcript of enough, Paul has the necessary parts the US Patent award to Jim Bede for kit. The cost? A whopping three · US Patent # 3,991,487, the Truck-A-Plane design in 1976. dollars and fifty cents. Call Paul at The Truck-A-Plane Enjoy! 619-449-1570, fax at 619-442-0841 8 or email him at any time at · BD-5 Vendor Listing Call for Authors [email protected] to get 19 · Misc Vendor Listing your kit. Do you enjoy writing and passing on · Late Breaking News On a personal note, as Editor and information for the enjoyment of Director of the Bulletin I am thrilled 20 others? Do you have a personal to finally have a direct line of computer? If so, here's your chance communication to Alturair. I have to gain notoriety and fame in the never really had a lot of contact with BD-5 community. Paul, whose company has been around since 1976, supplying BD-5 The Bulletin needs authors to write owners and builders with parts and articles about subjects related to the services. I am very happy that this BD-5. Some ideas: construction situation has now changed, The BD-5 Bulletin tips, avionics, electrical systems, Official Publication the BD-5 Network flight test reports, historical tidbits There's more about Alturair in this Juan Jimenez, Director & Editor and just about anything else you can edition of the Bulletin, including an Rich Perkins, Founder think of. PO Box 155293 important announcement about a Ft Worth TX 76155-0293 Interested? Email Juan Jimenez at new upgrade for the BD-5's landing gear design. Read on! [email protected] [email protected] or mail your manuscript to the address listed on . April - June 2000 Both a long wing (21.5 ft. span) and 5, N501BD, was being built at this a short wing (14.3 ft. span) are time. Because of the limited BD-5 Flight available. manpower available and the Test Program difficulty of making modifications to The BD-5 was first conceived in 1967 the fiberglass BD-5, Jim decided to Report as an ultralight, self-launched glider, stop development and testing of the but in searching for an acceptable fiberglass prototype and concentrate By Lester H. Berven, Chief Test Pilot, powerplant, it was found that the Bede Aircraft Inc. on getting N501BD in the air. It was high power to weight ratio of the also at this time that he decided to snowmobile type 2-cycle engine (Originally Published in the Journal of add some more manpower, and he would allow a very efficient powered the Society Of Experimental Test hired Burt Rutan as Director of aircraft and development was Pilots) Development and myself as Test channeled along these lines. Pilot in early 1972. Introduction Development Flight Tests The first all metal prototype, The BD-5 is an amateur-built N50lBD, differed from ship #1 not The first prototype BD-5, N500BD general aviation aircraft which only in the fuselage design but it was built in 1970. The fuselage was represents a new concept in sport also had an all-flying stabilator, an bolted aluminum angle framework aviation. The aircraft is purchased as American made Kiekhaefer 440cc covered with a molded fiberglass a complete materials package and is snowmobile engine, electrically shell. The wing structure was an assembled entirely by the retractable landing gear, and a aluminum tube-spar with aluminum owner/pilot. variable speed drive system. ribs and wing skins. This aircraft Upon completion, the BD-5 is had the original V-tail and was The cooling system for this engine licensed by the FAA in the powered by a 36 BHP Polaris installation was two NACA flush Experimental-Amateur Built snowmobile engine. scoops (one on each side of the Category. It is restricted to a local fuselage) from which the cooling air This fiberglass V-tailed prototype area defined in the aircraft operating was ducted down over the cylinder was first flown in September 1971 by limitations until it has flown 75 fins and out the rear of the fuselage Jim Bede. It made a total of 2 hours, at which time the local area in an exhaust/ejector duct. flights, both in ground effect just restriction is removed, and it is above the runway. These two flights operated in accordance with FAR 91 The initial ground testing of this for homebuilts. showed a serious deficiency in both aircraft began in May 1972 with an directional and longitudinal stability evaluation of engine starting and The BD-5 is basically a single-place, and control and a redesign of the tail cooling characteristics and with low low wing monoplane pusher with was begun immediately. speed taxi tests. These tests showed several unique design that the engine cooling was marginal The next configuration tried was a characteristics. It has removable on the ground and that the rudder swept conventional vertical fin with wings with a constant diameter tube was effective for taxiing above 25 a highly swept (60 degrees at the spar which fits over the center mph IAS and that the ailerons were L.E.) stabilizer/elevator. High-speed section, a two cylinder, two cycle, noticeable above 20 mph IAS. taxi tests with this configuration dual ignition, internally mounted showed very limited elevator power mid-engine which drives the High speed taxi tests were begun on for rotation and a large trim change wooden, fixed pitch prop through a 31 May and control effectiveness was with power due to the induced flow Gilmore belt reduction drive system evaluated in 5 mph increments up to from the propeller. with a 1.6 ratio. It has manually 80 mph IAS. We found, as before, that the ailerons and rudder were retractable landing gear, and a Because of the great interest in the combination push-rod/cable control very effective, but that the stabilator BD-5 and the large number of orders was not powerful enough to lift the system which is actuated with a side he was receiving, Jim had previously stick on the right console. nose, even at 80 mph (cg was 24% decided to pay for the tooling mac). necessary to produce a metal fuselage, and the first all-metal BD- 2 . The BD-5 Bulletin We then reballasted the aircraft to I pulled the power back to slow The new stabilator was ready for test 27% cg and tried it again. This time I down to a previously flyable air- on 8 July 1972. To check the stick could rotate by accelerating to 70, speed. As the airspeed decreased, free stability of the stabilator, we pulling the power back to idle and the controllability improved and I disconnected and locked the anti- applying full aft stick. Once the nose made a reasonably normal landing servo tab, and at 40 mph IAS came up I could add full power and in the remaining runway. After measured the stick force at full aft hold it there. By using this much discussion and more ground stick. This technique indicated a technique, I got the airspeed up to tests we decided the problem could very slightly stable tail, which was 80 mph IAS, made the first liftoff, have been caused by having the right where we wanted it. High flew down the runway at a height of aerodynamic center of the stabilator speed taxi tests showed a power-on about 5 feet and landed after about forward of the pivot. rotation speed of 50 mph IAS, and a 10 second flight. Both trim and power-off of 40 mph at a cg of 25% controllability seemed acceptable at Calculation showed it to be right on, mac. Once the nose-wheel was off, I 80 mph. but with the highly swept stabilator could hold it off down to 30 mph. the inflow from the prop would have Before the next flight, the main gear moved the center of pressure The next flight, on 11 July 1972, was was moved forward one inch and the inboard, and therefore forward.