BD-5 Customer Information Bulletin No. 3

Dear BD-5 Builder:

As I am sure some of you are eager for some information regarding spin tests, I've included a brief summary of an interview with Burt Rutan and Les Berven at the Flight Test Center last week:

Spin tests are now complete on the 1/4 scale model with encouraging results.

The tests have shown that the BD-5 is not prone to inadvertent spins, in fact, you really have to work at it to make it spin at all! Once a spin is achieved, the aircraft spins with a nose down attitude of 30° to 35°and recovers quite nicely from a fully-developed spin within one additional turn. A large variety of entry conditions revealed no tendencies for the aircraft to develop a flat spin.

These tests also helped determine the correct size and placement of the spin chute system to be used on the full size aircraft. Spin tests with the full-sized aircraft will begin soon.

Since the purpose of a spin test program is to determine the behavior of the aircraft in unusual flight attitudes (not to scare the hell out of the test pilot), the use of a scale model for the initial tests is becoming a well-established practice. For example, the spin tests on our nation's newest fighter plane, the F-15, are now being conducted with a radio-controlled scale model.

A new memo from the FAA states than an ELT is not required on aircraft equipped to carry not more than one person. This is as it should be, if you want one, fine... there is plenty of room in the BD-5 for an ELT. If you don't want one, don't buy one, it's up to you.

Everyone will be receiving the "Optional Equipment Catalog" very soon. Please do not write for panel layout drawings, wiring diagrams, antenna installation, etc. We will make these drawings available to you as soon as they are complete. Meanwhile, construction of your aircraft should continue. Do not wait for these drawings to close various parts of the aircraft. N502BD has been very busy in recent weeks proving out radio installations with internal and external antennas and more flights are scheduled.

As stated in an earlier bulletin, the Supplementary Package No. 4 is now being shipped. However, because of shortage of fiberglass materials, our supplier is unable to produce the wing root fairings at the rate originally promised. We still have quite a number on hand and will ship as fast as supply permits. We do not expect a delay of more than three weeks to complete shipments to the highest priority numbers.

Horizontal stabilizer plans will be mailed the week of February 11th. We will include with these plans the screws for FU29 and FU30, and the additional parts that were missing from the first few supplement packages. (BD-0004 x 36, only one was shipped and two are required).

Quick Tips

1. An engineering callout for a countersunk hole such as "No. 40 drill csk. 100° x .185" dia." simply means to countersink with a 100° cutter until a CCR264SS-3 rivet sits just flush with the surface. The CCR264SS-3 rivets have a head diameter of .185". Just remember to keep checking the depth of the countersink with whatever fastener is to be installed (rivet or screw) until it sits just flush with the surface and you've got it. Although the fwd. fuselage skins are thick enough to countersink, it might be best if those skins are dimpled (except for areas where the plans indicate the use of a countersink, such as nutplate rivets, etc.) Most people tend to countersink deeper than necessary and this is never a problem if the dimple dies are used. A properly installed flush rivet or screw should set just flush to .005" above the surface,neverbelow the surface.

Unless the plans specifically state otherwise, all parts of the BD-5 are to be bonded together with Pro Seal.

2. Paragraph 41, Page 1¹, calls out a .250" hole in FU7 and FU8. This should be a No. 12 hole. Also, the two rivets fwd. and one rivet aft of this hole should be moved down to just above the radius of FU7. If you've already drilled it in, replace the FU8 clips with new ones, install the rivets lower and drill the pivot hole in the clips with a No. 12 drill. The open holes in FU7 won't cause any problems.

3. Some ball rod ends in package 4S were marked with the wrong part number. You should have 2 female and 6 male rod ends, all 3/16" right hand thread.

4. All rivet packages contain a 10% overage; this includes nutplate rivets. If you run short in one package you should be able to borrow from another and still have plenty left. The long CCSR264SS-3-3 rivet can be used in place of the shorter -1 and -2 rivets. This overage applies to the rivets, not to screws, washers, bolts, etc.

5. You can dimple the engine compartment door and doublers for the 8/32 screws with a hammer and steel rod. Drill and csk. the end of the rod so that the screw sits flush. Round off the top edge of the countersunk hole with sandpaper to keep it from cutting into the door. Place the screw on an anvil, head down. Lay the door over the screw so the shank protrudes through the hole, place the rod over the screw and strike firmly once or twice with a hammer. You will need someone to hold a heavy piece of steel over the head of the screw to dimple the door frame (FU17 and FU18). Parts FU51, 52, 53 and 54 can be dimpled before riveting to the fuselage.

6. The double flush rivets along the fwd portion of the cockpit are simply standard solid rivets that are driven in holes that have been countersunk on both sides. As the rivet is driven, the butt forms in the countersink. These rivets can be installed with a ball peen hammer and a steel bucking bar.

7. Installing nutplates can be a frustrating experience unless you go about it properly. The best method is to shim the proper size screw with washers until it just reaches through the material and tightens in the nutplate with one and a half or two turns. Drill through the rivet holes using the nutplate as a drill guide then remove the screw and nutplate to countersink. Don't keep using the same nutplate if you have many to drill or the holes may become enlarged and ruin the nutplate. For ease of drilling, the nutplate can be placed on either side of the material then moved to the correct side for installation. However, if you use this method, don't get confused and countersink the wrong side of the material.

8. You will be required to do some trimming on the horizontal stabilizer spars. This will have to be done in several smaller cuts and finished with a file. A pair of left and right hand dutchman snips will be helpful although not absolutely necessary.

9. Finally, we would like to have a few black and white photos of your project and any fixtures you may have designed to simplify construction of your BD-5. We are starting a bi-monthly newsletter and would like to include the photos in the builder's section. Please include your name and priority number, city and state, on the back of the photo. Photos cannot be returned.

<signed>

Frank Andrews, BD-5 Sales Manager