BD-4 NEWSLETTER #26 - May, 1998  

Roger Mellema
17605 SE 288 Place
Kent, WA 98042, Ph:253-631-5324
rmellema [AT] halcyon.com (or: roger.d.mellema [AT] boeing.com)
http://www.halcyon.com/www2/rmellema/BDindex.htmi

Greetings!
Spring is already here and EAA '98 will be following close on its heels. There must be a lot of BD-4 work going on across the nation as my mail and number of telephone calls has been down. Another BD-4 anniversary is coming up this year. It has been 29 years since the introduction of the BD-4 at Rockford and 30 years since the first flight of N624BD (August 2, 1968). If you haven't yet, send a picture of your BD-4 to Dan Marucci (8 Topaz Drive, Franklin Park, NJ 08823, Ph: 908.398.1897, email: dmarucci [AT] mfgfkln.cosmair.com). He is trying to work up a booklet with pictures of all the BD-4s. He has not had a good enough response to his mailing - so get with it if you want your airplane included.

Please note the change to my phone number at the top of this page. They decided to give us all new area codes! There are getting to be WAY to many people on this earth!

Memorial Day Picnic:
As usual, we will be having a BD-4 (and other plane freaks) get-together at my house on May 25, 1998. This is an "uncoordinated" potluck so bring whatever you prefer in large enough quantities to feed you and your guests.

The place is: Crest Airpark which is southeast of SeaTac airport near Seattle, WA. The time is: from 12 noon on - we usually eat about 2 PM.

BD-4 History: A little bit of history on this anniversary eve.

For those of you who don't know the history of Jim Bede and his contribution to homebuilt aviation, the following history is excerpted from the 1988 20th Anniversary booklet.

The Company:
Bede Aircraft, Incorporated, was founded in 1958 to design aircraft specifically for amateur construction, and to supply complete materials for the construction of such designs.

The company began with offices located at Cuyahoga County Airport near Cleveland, Ohio, and with a warehousing and prototype workshop facility located at Harper, Kansas.

In 1971 Bede aircraft, Inc., moved its warehousing facility to Wichita, Kansas but the prototype engineering test center remained in Harper, Kansas.

The Sales of the BD-4 were grwoing at a steady rate, and with the introduction of the BD-5, the company continued to expand. By mid 1972 the need for a larger organization became necessary and the company was regrouped at Newton, Kansas.

At this time about 70 persons were employed at the Newton headquarters, and four persons at the Cleveland office.

The BD-4 was the first airplane to be made available to the homebuilding enthusiast with good quality control and really complete detailed drawings.

The BD-4 was accepted as an outstanding design and a break-through in aircraft construction methods for the homebuilder.

James R. Bede:
Jamer Richard Bede was born in Erie, Pennsylvania on Aril 17, 1933. He graduated from West Technical School in Cleveland in 1952 and attended Fenn College and the University of Wichita receiving his Aeronautical Engineer Bachelor of Science Degree in 1957. Buring this time he entered and won a competition for the Institute of Aeronautical Sciences with a paper entitled "Steam Jet Assist Take-off Engines," which presented an original idea on a new concept of auxiliary power boosts for aircraft using super heated steam as the propellant. Jim designed, built and tested the new engine whilr writing the paper.

After graduation, Jim worked at North American Avation, Columbus, Ohio, as a performance Engineer on the FJ4 and AJ3 aircraft. Following this he and his father, James A. Bede formed their own company, Bede Aircraft Corporation in 1960, for which Jim became president and chief engineer.

Jim started flying at the age of fourteen. Flying lessons, one half hour at a time in a J3 cub, were earned by delivering newspapers. He accumulated enough hours to solo by age sixteen and was issued a student pilot's license on that birthday.

By age seventeen Jim obtained his private pilot's license and bought his first airplane, a Stinson Voyager. It took two years to recover and rebuild the airplane and rebuild the engine.

The Stinson was eventually replaced by a Globe Swift, a Cessna 195 and a Beechcraft Travelair. Jim subsequently acquired both single and multi-engine ratings.

Bede Designs:

Jim's first design to be flown in 1961 was a twin engine pusher-propeller aircraft. It was powered by two O-300 Continental engines driving a single three blade shrouded propeller.

Suction boundary layer control was used and the airplane demonstrated speed as low as 40 mph. This airplane now resides at the EAA museum.

The BD-1 was completed in July 1963. It was a low-wing single-engine, two seater sport aircraft. It was the first light aircraft to use a method of structural bonding that had only previously been used in supersonic jet aircraft. It also used aluminum tube spars and simple torque tube activated ailerons. This airplane was first flown in May of 1964 and went on to full certification as the Grumman-American Aviation "Yankee".

This aircraft started as an engineering exercise and first flew in March 1967. It was a singleseater, high aspect ratio, single-engine endurance aircraft designed for a nonstop around the world non-refueled flight.

Jim flew the BD-2 on a closed-circuit flight in November 1969 to capture three world endurance records. A distance of 8974 miles was covered in 70 hours, 15 minutes, before a total electrical failure terminated the flight.

The XBD-2 was the forerunner of the BD-3, a 300 mph six-place executive aircraft. Certification costs prevented this design from going into production.

This design flew in August, 1968. This single-engine two-place / four place airplane introduced homebuilders to an easy-to-construct, high performance airplane at relatively low cost.

The "Panel-Rib" method of wing construction was introduced in which the molded fiberglass "module" ribs are stacked onto an extruded tubular aluminum main spar and bonded together with structural epoxy. A "panel-rib" consists of the rib and about 11 inches of wing skin all formed as a single piece.

The first BD-5 prototype was flown in September 1971. The aviation world saw in this small, lightweight, single-seat homebuilt, a chance to own a low cost, super high performance sport aircraft that looked different from anything else available.

The BD-6 is a single seat, 2 / 4-stroke powered airplane that closely resembles a BD-4 in configuration and in construction method.

The BD-7 is a 4 place, conventionally powered airplane that closely resembles a BD-5.

The BD-8 is a single seat, IO-360 powered, all-out aerobatic airplane. It featured differential elevator control for high roll rate capability.

Don't know. Could it have been the Light weight airplane seen at Oshkosh that used a chemically milled BD-4 spar?

The two-place tandem, jet powered personal rocket. Supposedly capable of Mach 1+ but never developed to that stage.

The modern mostly composite two-place BD-5 look-alike. Jim is shopping around for someone who can make the production molds for this and the BD-14 airplanes.

The modern mostly composite four-place BD-5 look-alike.

Jim visited Seattle recently and is talking about a six-place airplane that is built using BD-4 technology. Indeed, Jim said that it initially was to be called the BD-6.

"Build Your Own Airplane" books:
With the total shortage of these great books Hugo Schneider can now supply great copies for $70 apiece. I looked at these at Oshkosh and you can build a complete BD-4 with just this book.
May - Sep: PO Box 262, Brooklyn, MI 49230 Ph: 517.592.5202
Oct. -Apr: 17200 W. Bell Rd. #823, Surprise, AZ 85374 Ph: 602.214.1676

Another BD-4 about to leave the nest: Steve Knight (P.O. Box 990, Edwards, CO 81632 Ph: 303.926.2003) <knight [AT] vail.net>

Just wanted to let you know that N11960 is no longer a garage queen, it has made the journey to the airport. Nice to see it all together! Going to Waterloo IA to fly with Joe Pfiffner in his BD, hope to get 4 or 5 hours in. Hope to see you at Oshkosh for the 30TH anniversary. Thanks for all your help along the way.

Internet:
I am really impressed with the number of people who have contacted me through and because of the internet! It seems that when people learn about 'search engines' they immediately start looking up past dreams.

After this newsletter is out the "BD-4 Homepage" will get an improved presence on the web. This is both to help spread the BD-4 word, and to cut down on my workload answering Email messages. The number of weekly messages that concern the BD-4 (and require some time from me) is about 20. That comes out to around 1000 messages per year and about 2 months of full time work (pleasure, but the pay is low!).

Jerry Grant (Ph: 601.873.6708) has just finished laying up his gear (with advice from Chuck). There are 120 layers of glass in them and he laid it up 20 layers at a shot. He worked very hard to maintain the correct ratio of epoxy to glass and is confident that his main gear worries are over.

There are a lot of 'lessons-learned' that these builders would be happy to share with you - please call.

Flush Fuel Drains: T. M. Weston dmw1 [AT] mn.uswest.neb
My fuel drains are flush with the bottom of the wing. I am going to have a machine shop make me new drains, I will use the original inside plungers with heavier springs.
Also I found fuel level senders at NAPA. I think I will have to mount them on top of the wing instead of inside but the ohm readings match my gauges. The part number is NAPA #701-1573 and 701-1574. You have to take them apart to rebend the bracket so that it will work with the adjustable float. So far I think they are going to work out real well. Close working quarters in the wing though.

Chevy 4.3L: Gary Raabel (120 Hillside Ct., Stoddard, WI 54658 Ph: 608.457.2562)
All the engine systems, gauges, and fuel systems are complete and working. The engine runs super. Now for clean-up, windows, inspection panels, and preparing for the paint shop. Now for wings and wing extensions. Ed. An enclosed picture shows the engine installation. It looks great with the aluminum heads, NW Aero PSRU, the 3-into-1 exhaust headers, and lots of MSD ignition boxes.

A Better Nosegear system (continued):
In the last newsletter there was some discussion (started with Keith Anthony and nosegear shimmy problems) about connecting the nosegear to the engine mount.

This is a drawing of the RV-6 method of installing the nosegear. It slightly complicates the engine mount but look at how it simplifies the fuselage reinforcement.

Flying in Canada / Insurance: Andreas Meyer <meyer [AT] hpanix.an.hp.com>

I live north of Boston, i.e. not too far from the Canadian border, and it is my intention to fly this plane in Canada too. I have relatives up there and I am currently flying with my C-120 up there on weekends, so being able to fly in Canada is rather important to me. It was brought to my attention that I may not be able to do that if I don't also get the BD-4 inspected and/or certified up in Canada. Since you live near Canada too I figured that you may have some good insight into this and may know what is involved. If I do end up building the BD-4 my intentions are to use an automotive powerplant (Chevy 4.3), to stretch the fuselage a little bit and go with metal wings. How would those changes the original plans impact my chances of getting approval up in Canada?

Second question is about insurance. From reading your past newsletters it seems like there was a time where insurance companies were not willing to insure BD-4s for any price because of fuel problems. Have those issues been resolved and are insurance rates on BD-4s comparable to other planes in the same category?

Thanks in advance for any answers you may be able to provide.

Ed. In this area of the states we have to deal with Victoria, BC. They require homebuilts to have written permission to enter Canada. A fellow flyer recently reported that permission can be obtained very quickly and everything you need is faxed to you.

There was no mention of auto engines versus certified engines. There should be no difference in the procedure as auto engines are being approved for Canadian homebuilts.
BD-4 insurance has been a touchy point for a long time. It centers around two things: first they had a problem with the flap/aileron attachment to the wing, and now they reject because of the fuel system. Steve Mahoney, who has used Avemco before,

was recently rejected due to 'no header tank'. Here is someone who has lots of time with the system as it is, has been insured before, but now is persona non grata.
There have been some problems with the newly built airplanes and the fuel system. Usually the cause is not building per plans. There have some really complicated fuel systems proposed but the original system is still the best. The only difference from a Cessna system is that we have no dihedral. Out placard against "take-off with less than 1/4 fuel" solves that problem.

The biggest problem now is some self proclaimed expert who 'designed' a header tank system for John Bracher. He then was so proud of his untested monstrosity that he burdened the world with it. He wrote letters to the EAA and proclaimed the present system to be dangerous and that his header system was the complete fix.
Steve Mahoney is attempting to change Avemco's attitude. He has since found insurance elsewhere but hates to see such stupidity promoted.

Propellers: Allan Franko <allanfC [AT] CancerBoard.ab.ca>

I have a suggestion for a newsletter topic: propellers. I thought I knew a bit about propeller selection, but a recent experience with my BD-4 made it clear that there's a lot that I don't understand. Perhaps my observations might contribute to a discussion of the virtues of various propellers on a BD-4. For example, I'm potentially interested in a Warp drive, or maybe an inflight adjustable No Prop, and I'd really like to hear about experiences people have had with them on BD4s.

When I bought my BD-4 (C-GAJ13, taildragger, Lycoming O-320, 160 hp, extended wings, no fairings of any sort), it had a metal Sensenich EM8 propeller, 74" diameter (had been cut down 2"), 60" pitch. With this propeller on a standard day at 3500 feet, 1450 lbs total weight, I saw about 1200 fpm climb at 110 mph indicated, and a top speed of 151 mph (which agreed well with my GPS) at 2750 rpm. Maximum static RPM (at 2500 feet) was 2300. Following up an AD on that prop, I learned that Sensenich had never done a vibration analysis for an EM8 prop on a Lycoming O-320. The factory strongly recommended that I remove the propeller.

A fellow BD-4 owner had a Colin Walker wood prop which he wasn't using, and he offered to sell it to me for much less than any metal prop I could find, so I tried it. I thought I knew that wood propellers are less efficient than metal props, but I was hoping that I wouldn't lose too much performance. The prop is 68" in diameter, 67" pitch (and it saved me 25 pounds!). The maximum static RPM went up to 2400, suggesting that the prop flexes considerably or that the pitch rating was badly wrong. On the other hand, it develops a lot less thrust at taxi speeds, as both initial acceleration and normal taxing speed require an extra 200 RPM. Under the same flight conditions as above, my climb rate went down to 900 fpm, despite the fact that the climb RPM went up a bit (I think). The real surprise was the top speed, which went up to 159 mph at 2700! Since the power output can't be much different, this wood prop must be substantially more efficient than the metal prop (by as much as 15%). My usual cruise conditions are 130 indicated at 8500 to 11500, and I think I'm getting slightly lower fuel consumption as well.

Aside from performance, a big question with all wood props (and composite props, I suppose) is durability in rain. Walker makes the first 1/4" of the leading edge out of a slightly flexible plastic of some sort, which has held up perfectly to roughly an hour of flight in light to moderate rain (I have about 50 hours on the prop). However, he didn't extend the plastic far enough inboard, because I've got some erosion of the paint on the leading edge extending about 3" inboard from the end of the plastic.

Another issue: Sensenich told me that the EM8 prop is very inefficient on a Lycoming O-320 (another reason to remove it), which my experience appears to verify. I happen to have an EMS on my 180 hp Pitts Special. Why isn't the prop equally inefficient on that engine?

Ed. You do ask the hard questions! Obviously, the right answer is: keep using the wood prop.

The big difference between the two props is that the wood usually flexes better and gives you some 'constant speed' characteristics (flatter pitch when loaded heavily - takeoff, and greater pitch when loaded lighter- cruise). The other big difference is the required hub depth with a wood prop which results in a thicker airfoil section near the center.

The improved climb with the metal prop could be due in part to the longer length (68 to 74 inches gives 30% more disk area).

Anyone else want to relate experiences and make some guesses?

Auto Engines: John Steers and "Crisenbery Engineering, Inc."

John Steere now has his SuperCharged 3.8 L Ford running. One of the problems he has is a cast aluminum oil pan that 'weeps'oil. He asked people on the internet about way to solve that problem and he got the following interesting response from Crisenbery Engineering:

"Read the thread on this on rec.aviation.homebuilt, and I noticed a potential error. The 3.8L Ford S/C package was set up for approximately 12 psi boost not 12 in-Hg of boost (with an intercooler). There are about 2 in-hg per psi. Max. boost is controlled by the belt ratio. Therefore if you have not changed the pulley in the drive system you are going to get the full 12 psi at WOT. (full load) at about 4000 engine rpm. The boost vs. rpm at WOT (wide-open-throttle) varies due to differences between the shape of the volumetric efficiency curves for the engine and blower. If you do not have the intercooler in the system you will get much more than 12 psi boost with the stock pulley ratio (the intercooler cools the charge and thus lowers pressure). Stock overall drive ratio is 2.4:1 as I recall.

The by-pass valve controls the load that the blower comes in at. The standard bypass will begin to close at approximately 10 in-hg of inlet vacuum and be fully closed by 3 in-Hg.

You didn't say which model year engine you had, but the 94 and later superchargers were more efficient, especially on the low end and mid-range due to going to coated rotors, to identify them they will have the same metallic gray coating that is on the outside of the castings. The earlier blowers have rotors that are bare aluminum. The 94 blower also has improved porting on the inlet side. the 94 will give the lowest temperature rise for a given boost pressure and is the one you want to use.

As for the pan leak I agree the best bet is try to get it replaced. If you are stuck with it the key to using an anerobic is get a wicking type, some said 290 Loctite, this may or may not be right, check with a supplier. The thin anerobic will wick into the porosity in the casting if you have it prepared properly. I have had some luck using this on castings.

If you pull the pan to have it leak impregnated, I would not go with the sodium silicate, most OEMs got away from this some time ago for a few very good reasons. find a job shop that will impregnate it with a resin sealer, one brand name I recall is Resorcinol 90C. The sodium silicate sealers will stop leaks but get very hard and if deposits are left and break loose they can really mess up tight clearance components. Sodium silicate also reduces heat transfer through the aluminum (some aluminum heads are impregnated with it to do exactly this) less heat transfer through the head means increase bhp). You don't really want decreased heat transfer through the pan or to get sodium silicate in the bearings.
The boost numbers I gave you are based on in-car figures with a stock T-bird exhaust. A fairly low restriction exhaust system on an aircraft (the T-bird is AWFUL even for a car) will give a lower boost pressure due to decreased system restriction. however, you will be getting more bhp at the flywheel so don't worry. You have to understand that the blower used (Eaton corp. is the inventor/builder of the blower) is a positive displacement pump and boost pressure comes from the system (restriction) it is hooked up to.

You don't want to run the stock drive ratio without an intercooler, I did mention that boost will be higher but your charge air temps will go out of sight. if you run this system without an intercooler you must slow the blower down and probably limit boost to 6 to 8 psi max.

The T-bird engines were rated at (as I remember) 210 @4000 for the 89-93 and 225 @4000 for the 94 to end of run. Maximum bhp is not at 4000 for this engine, it is at about 4700 (varies from engine to engine). Peak bhp is at least 20-25 over the rated as I remember the dyno curves. The reason for rating these engines at 4000 rpm was based on getting around some government requirements." . . . . . . . . .Crisenbery Engineering

Thanks for the input. I am using an engine pulled out of a 90 T-Bird, by Ford. They supposedly pulled several out to use the vehicles to test the new modular V8. I purchased one of them, so I have an essentially "new" engine.

I have retained the T-Bird intercooler, but removed the heavy end castings, replacing them with custom plenums fabricated from sheet aluminum. I also replaced the heavy cast aluminum tubes with flexible stainless steel tubing, wrapped with a self-fusing silicone rubber tape, rated up to 5000 F. I had tried SCEET tubing which is rated to handle the temperature and pressure, but the accordion effect was not manageable at idle vacuum.

I have retained the standard pulley ratio for the blower drive, but changed the remaining pulleys to reduce the alternator, water pump, and air pump (used as an instrument vacuum source) rpm.

Thanks again for the input. I wasn't aware of the peak HP rating. You seem to be very familiar with this engine. . . . John Steere

Ed: Alternate pulleys can be obtained from: Auto Specialties, Inc., 13313 Redfish #106, Stafford, TX 77477 Ph: 713.721.8056. He will use the part number: ASP-037-3.0. This combination slows the accessories to a better speed - full charge occurs at 950 rpm. They also supply mace air flow sensor for the SC engine.

Most of us have seen Ray Ward's Super BD-4 and its auto engine and rear scoop but this one is a good bit different.

First of all it has a nose wheel! It is hard enough to get an auto engine in with a taildragger. The nosewheel almost demands that the radiator be somewhere other than the engine compartment and that is what John has done. The first question most people ask when they see this configuration is: what did he do with the elevator control tube? That brings me to the best part of this configuration - the radiator is totally under the airframe. It is specially built so that it is quite wide and thick but is short vertically.
The inlet looks to be in a good position. It has a very wide inlet port. The only thing that may be difficult is to maintain attached flow on the aft side of the installation.

Cabin Heaters and Oil Coolers:
One of the several advantages of water cooled auto engines is the availability of hot water that can be used for heating the cabin. It turns out that there are other uses for the heater core.

Cabin heat for my BD was initially of the 'exhaust heat riser' type. This was due to the availability of the old air valve on the firewall and also the need to 'smell' the engine. When initially flying the V-6, the smell emanating from the engine compartment told me a lot about what was happening under the hood.

As last Oshkosh approached, there was still some worry about cooling capacity and with that, oil temperatures. Because the engine coolant cools the oil with a 'liquid-to-liquid' heat exchanger, hot coolant also usually means hot oil. It seemed apparent that a little more radiator would be welcome and especially if it also ensured lower oil temperatures.

The solution was a bit of kismet. First, run the coolant through the heater core full time as is done on most modern cars and direct the heated air into the cabin (if needed) or overboard. Second, after the coolant has been 'cooled' by running through the heater core, use it to feed the oil heat exchanger. The heater core used is a 'two-pass' and will cool the coolant more than a common radiator. This lower temperature coolant running through the oil heat exchanger drastically improved the whole cooling system. In fact, even in the heat of the mid-west, the oil temperature never got above about 210° F.

Flight Test Quirks:
A fellow auto engine enthusiast reminded me that my 'engine overheat detector' as installed during flight test was never covered in the newsletter. I had never seen this done but it was inspired by the famous Mr. Blanton.

Dave Blanton had trouble telling when his test engines were detonating during high manifold / low rpm conditions. Instead of going the electronic route, he plumbed the crankcase breather tube so that its output was visible from the cockpit. When detonation occurred, the black smoke coming from the breather notified him to back off and save the engine.

During initial ground tests with my auto engine I was shocked to learn that most of my coolant was lost during a taxi to the other end of the airport and back. I had absolutely no idea it had happened as the coolant temperatures seemed reasonable. My solution was to plumb the coolant overflow line up so that it squirted onto the right side of the windshield. You would not believe how much trouble this simple modification saved me during the 50+ hours of flight test! Nothing gets your attention better than green stuff squirting all over your windshield!

The airplane is painted with a pure polyurethane paint that is impervious to coolant (yes, I checked first!).

Alternative Torque Tube Bearings: Robert Bollinger (2000 N. Court St., No. 13D, Fairfield, IA 52556 Ph: 515.472.0598)

Robert found a possibly better solution to the very expensive aileron / flap torque tube bearings specified by Bede. They are "plastic open radial ball bearings" that are self lubricating, resist corrosion, and can be used up to 1000 rpm, from -60° to +230° F. The balls are stainless steel or glass.

The inner diameter is 1 ", the outer diameter is 1.62", and they are 1 /2" wide.

Our use of the specified aerospace quality bearings requires very little strength and our major problem with the bearings is lubrication. Every grease / oil I have tried seems to get gummy and the tube starts to slip inside the inner race.

Order part #6455K43 (K88 for glass balls), from McMaster-Carr, Ph: 908.329.3200, Fax: 908.329.3772. They are located in New Brunswick, NJ. Oh, by the way, they cost $4.00 apiece!

New HI-Vo Chain Reduction: Aero Kinetics, 7702 288th St. So., Roy, WA 98580 Ph: 360.458.8775

I have discovered a Hi-Vo chain drive that looks right for my SuperCharged V-6. I like the belted PSRUs but they do not fit well on the SC V-6. This unit really fits right, is smaller, weighs about the same, and is cheaper. and never has to be adjusted. All of the bearings run continuously in an oil bath. This is preferable to the grease packed bearings in a belt drive.

Milo Burroughs and his wife, Wenjin Jia, have been producing PSRUs for several years but prefer to stay at a low volume that does not interfere too much with their life. Delivery time is at least 120 days.

The PSRU comes dirty, right off the mills. You have to clean it up and install a few things. "Our kits consist of all the fabricated components to make up a PSRU, with all machining and welding completed. The kit does not contain common hardware (i.e. nuts, bolts, bearings, chain, etc.) and they must be purchased separately by the buyer".

The price is these 'kits' is about $2000 for the 200 hp version.

Fairings for the BD-4 (Fred Hinsch):
This is for those of you out there who have been flying your airplanes without fairings, like me, mainly for reasons of procrastination. Well, if your airplane is at the airport and may even be sitting outside (mine is) you can still have fairings on it and improve its looks and performance.

What you want to make:
1. Wing root and flap fairings (this can be a single fairing)
2. Gear leg fairings (they could be bent of alclad sheet)
3. Gear leg fairing to fuselage
4. Gear leg to wheelpants (this assumes you have them) There may be other fairings you can make but I will stick to these.

What you will need:
- Modeling clay. About 25 lbs should do it. You can buy this at hobby shops or
ceramic shops.
- Foam blocks (3 inch thick pink stuff is what I used)
- Two yards of 6 ounce fiberglass cloth
- One yard of 2.5 ounce fiberglass cloth
- 16 feet by 4 inches of 6 ounce fiberglass tape
- One quart container (the ice cream type) of zeothix. It is a filler that stops the mix from running too much.
- One pint of microballoons
- Three 500 ml kits of Coldcure. This is a 2-part polyester resin that will cure outside in any temperature you would care to work in. Or any equivalent product.
- A small can of paste wax (polyester resin will not stick to it).
- three 1 inch wide paint brushes (for spreading the resin mix on the mold).

Lets go do it:
In my case my Bede is at the airport and has been for a long time. I wasn't about to take it home to do this. So off I went to the airport on a good day with all my supplies and tools. I had already installed leg fairings of metal so the fairings I was looking at were the upper and lower ones.

I took a creeper board for lying under the airplane and a pail of water (the claymold must remain damp until you lay up your cloth). To save some clay, I used the foam, carved to a rough outline of the future fairing and glued to the spots around the leg fairing. I found that masking tape also works. Spread a coat of wax on the airplane paint around the edges of the mold to protect it.

The clay work took hours! Molding it over the top of the foam, filling all voids, Now and then it needs to be sprayed with water. A spatula comes in handy to smooth out the mold. Under the floor I spread it out in a half circle, but on top it meets the sidechannel and is drawn forward and aft to make it look streamlined. I don't need to tell you that the flatter you make the curves the larger this thing will get! So use your own judgment here.

I cut out all the pieces of cloth first, then mixed the resin adding lots of the thickener (this was going to be overhead - yuck). I wetted the cloth first and man was that a mess! However, I did manage to do it without getting it all over myself. Wear rubber surgical gloves to protect your hands during the glassing. The next day the glass is hard.

I cut it at the back edge with a linoleum knife and carefully loosened it with a hacksaw blade. I did not try to save the mold (or the clay for that matter).

Back in the workshop after doing the process twice, the fairing was cleaned and lightly sanded and another lay-up was made with 6 ounce cloth. The third and final one is the 2.5 ounce cloth and micro balloons in the mix ( this makes it self leveling. Any dips after that are filled with Featherfill.

To install these fairings I used sheet metal screws underneath. On top none are needed. The cut back edge needs a metal doubler underneath for screws to go into.

The bottom fairings are basically done the same way. Mine enclose the brake calipers and attach to the wheel pants with nutplates and stainless steel screws.

My next project were the wingroot fairings. Very little clay is needed here, only the juncture between the side angle of the windshield and the wing leading edge need a clay mold. Are you still with me? Good.

The 4 inch wide tape is laid over the top of the wing and fuselage. Again two layers of the tape (but only one at the airport). I used no 2.5 ounce here, only another layer of glass with microballoons. I have a metal wing and used Handywrap (yes, you read this right) under it to lay the glass onto. From the leading edge it goes under a little way and over the top of the side window. The whole thing goes back over the top of the flaps too.

The finished fairing looks great. If you have a glass wing, you may want to bond it to the wing itself. Of course you must sand off some paint. Again, use judgment how much to overlap it onto the fuselage side! My fairing, of course, is portable because the wing is metal, but it is attached to the wing. You don't want water running into the cockpit.

Winter is coming soon and I may think up some other fairings by next spring, so if you feel inspired now - get to it! . . .F. H.

New Engine:
What do we all need? More airplanes!!

I have been chaffing for the last couple of years as my prime airplane is always "under test". The 3.8 L V-6 has given superb service but the "system" always seems to need a little more tweaking and thus is always "in test' and therefore not available to "go anywhere" or "give someone a ride" on the spur of the moment.

The next step is to start work on the SuperCharged V-6 and this would again plunge N76VR deeper in the experimental category for some time. The other thing that has been bothering me for some time is the availability of an adjustable propeller that can handle the power from the SC engine (up to 270 hp?). The only good solution is called "MT" and it sets you back a cool $11,0001 Not what you would call "auto engine economy".

The solution to these problems came with the opportunity to buy an O-360 Lycoming with constant speed prop. It has no log books but looks and runs like it has less than 600 hours on it. It also came on a fuselage with a gyro panel and basic radios. This allows me to put the O-360 in N76VR and then use the other fuselage (rough) as an SC engine test bed. I have always dreaded losing my "good" fuselage in an off airport landing (yes, I know - it could still happen!).

The O-360 is well on its way toward being ready for installation. It is dressed up with an Ellison Throttle Body Injector and LightSpeed Ignition. The original BD-4 exhaust system will be modified to have the exhaust go out the rear of the cowl.

The new test bed BD-4 is stretched so the airplane will be balanced with the SC engine. I will continue to refine and finish this fuselage as testing and time permit.

The propeller is still a problem but one of these days Warp Drive will release the larger, thicker blades that are made for higher horsepower.

Improving the Flying Characteristics:
My ramblings in the last newsletter about the BD-4s adverse yaw characteristics (admittedly moderate or less) has moved some builders to action!

Carlos Serodio (Mozambique) and Lary Seibold (Seattle)*) have both modified the aileron counterbalance so that the "up-going" aileron (down-going counterbalances) creates as much or more drag than the "down-going" aileron on the other wing. this results in a pure roll being established without the need for much or any rudder input (especially for small aileron movements). This modification makes an inexpensive wing leveler auto-pilot much more useful.

My design of a "greater differential" mixer for the control stick (Newsletter # 23, page 2) is not necessary now. It had the associated worry of reducing the total aileron effectiveness where the use of these "managing the drag" systems have no such effect.

This system also has the possible advantage of "powering" the ailerons and making them lighter to the feel. The downside of this method is the possibility of "snatch". If the "spade" portion of the counterbalance is too large for the current airspeed, the ailerons will want to go to full deflection - not a pretty picture.

Another drawback is the need for a larger hole in the bottom of the wing tip for the "spade" to go into when the aileron is deployed downward.

Carlos Serodio's design (on the right, below) has a "u" shaped piece of 4130 steel in place of the regular counterbalance. This piece is about 3 inches wide at the forward end and tapers back to about 1 inch at the attachment to the torque tube. There is enough lead (the dark stuff) in the forward end to balance the aileron.

Carlos says that there is a tiny bit of adverse yaw when using just his ailerons.

Lary's design uses 4130 square tube welded to a tube that fits over the end of the torque tube (per Bede) on one end and a 3 by 4 inch steel plate on the other end. Lead is attached to the plate to balance the aileron.

Lary says there is no adverse yaw but the ailerons are very quick at high speed.*)

Both of these approaches have dual effects.
1. The large, blunt "face" that moves out into the airstream gives drag that hopefully is equal to the drag of the other aileron moving down.
2. Once the counterbalance moves down further, the air pressure against it will help "power" the ailerons. This could cause "aileron snatch" that could make the ailerons twitchy. A little "power" maybe good as the BD-4 ailerons are heavier than the other controls and this could give us a better overall control balance.

Below is a top view of the left, rear corner of a BD-4 wing (wing tip removed). The Seibold*) solution is on the left, the Serodio on the right.

The length of the 'counterbalance spade' (from torque tube forward) must be short enough that the aileron can reach maximum down deflection when the forward tip of the spade hits the top inside of the wing tip.

You must reinforce the wing tip due to the large hole cut in it for the spade. The area where the spade passes through should be boxed off from the bottom to the top of the wing tip. This will keep that junk you store in your wing tips from blocking your ailerons and will also keep air from finding its way from the bottom of the wing to the top (drag, you know).

My autopilot installation (Newsletter 25, page 6) was easiest to do if it were hooked to the ailerons. Didn't see an easy way to involve the rudders right away so thought the 'wing leveler' mode might work. It did. . . . . . . .and it didn't!
When lightly loaded and in still air, it will work but the adverse yaw really confuses it. It sees an error, puts in some aileron and the airplane nose goes the wrong way! This is due to the down aileron having more drag than the up aileron. On the way back and forth to Oshkosh I did conjure up a way to make it also spring load the rudder a bit to
kill the adverse yaw but have not installed it yet.

When Lary gets his BD-4's restricted hours flown off he has promised to come down here to Crest and let me have a little stick time. I will then decide on how big a spade should grace my BD. I will do it before Oshkosh so that the autopilot is more useful.

Wetter Water?:
If you have tried everything to get your auto engine to cool and you are just a little shy of being 'OK for Oshkosh', maybe this is the product to try!

This is a chemical additive for the liquid in the cooling system, a replacement for the commonly used glycol/water mix, and a replacement that does a better job in all respects except one --- Red Line's 'Water Wetter" is not an anti-freeze, and it offers no cold-weather protection.

While plain water has two- to three- times the thermal conductivity of straight glycol (it's also superior to the standard 50/50 mix of glycol and water), there is a problem. It is called "high surface tension". Under high loads, water tends to boil in localized spots, particularly inside the cylinder heads. These hot spots vaporize the water instantly, creating a series of vapor bubbles. In turn, these bubbles physically insulate the water jacket from the coolant. This phenomenon can occur even when the overall engine temperature is well below the actual boiling point.

Water Wetter does not raise the boiling point of water as a glycol/water mix would. But if the pressure cap is increased from 15 lbs to 23 lbs, the boiling point will be the same. Water Wetter also contains anti-corrosion properties for prolonging the life of everything metallic in the cooling system.

The "Wetter" works best with plain water (45° cooler than 50/50 glycol/water mix) but can be used with the anti-freeze mix although it is not as effective.

The final word is: run Water Wetter with water for your summer coolant in your auto - aero conversion.
Red Line Synthetic Oil Corp., 3450 Pacheco Blvd., Martinez, CA 94553 Ph: 415.228.7576

Tailwheel Springs:
Recent inquiries has spurred me to make drawings of my method of installing the tailwheel spring. Most tailwheel springs are too short for easy installation on the BD-4. The plans show a single aluminum angle to be used for bolting the front of the spring to and also to strengthen the lower rear fuselage. Even a 'doubled angle' is not strong enough to absorb the download caused by a moderately hard landing with maximum aft center of gravity loading. This problem has caused many builders to come up with heavy and cumbersome fixes.

One way of 'getting the stresses where they should be' is to make the 'front' of the spring longer so that it reaches station 216.5. This is where the rudder belcrank is located. The figure below shows how simple it is to install and brace this longer spring.

An alternate method would be for the angle to be replaced with a 'web' of 0.063" aluminum over the whole lower section of the 'frame' shown (cut out for the elevator pushpull). This part of the tailwheel spring only puts tension loads on these braces so there is really no reason they have to be rigid.

The rear of the spring should be connected just as shown in the plans. Be sure that the two bolts on the sides of the spring fit close aaainst it (shim if necessary).

There is a mandatory change to the rear of the fuselage to keep from fatiguing angle #28 (BD-4-1-05) shown below. This is the angle to which the rear of the spring attaches. If not strengthened, side forces on the tailwheel will rock the spring side-to-side and destroy the angle after a hundred hours or so. The steel 'U'channel spans the width of the tail and ties into the lower side longerons (#26 and #27)

I have been supplying single leaf tailwheel springs for some time and just had a new run made. These springs have been thoroughly tested and give just the right amount of springiness for the BD-4. $35.00 postage prepaid
The new longer tailwheel spring is fitted to the fuselage as shown in the figures below. The spring is 1.75 inches wide, 3/16 inches thick, and a total of 20.5 inches long. The proper size holes are drilled in each end of the spring. The bend in the spring is 39°. It is made to fit a Scott 3200 tailwheel.

BD-4 Glider?: Ray Ward
No, not another failed engine! Ray has just been thinking again and trying to find a market niche.

A close friend of his recently lost his medical and after some investigation, they discovered that he can still legally fly a motorglider (must fly solo). He wants to build a 2 place motorglider and is thinking of a 2-place BD-4, with 35' wing span, and with a small engine. Really sounds like a great idea - what a versatile airplane.

BD-4 Inspired Patents: Raymond D. Gilbert
Ray purchased a BD-4 built by Don Gray and had a great time flying it with his family but grounded when his son went to college (you know, tuition?). Even in storage the BD restimulated Ray's interest in patent work. The symmetry of the BD's flying elevator's cross section shape and the (then) current news of the gulf war with civilian air liner's moving large tonnages long distances over potentially unfriendly skies with the threat of possible missile damage to tail assemblies motivated Ray to work on possible solutions.

"The symmetry of the BD-4 elevator offered a not-so-obvious solution for an inoperative elevator drive : add spoilers to the top and bottom forebode surface of the elevators".

"Independently actuate the top surface spoilers to kill the lift of the top surfaces and allow the resulting downward-lift force of the bottom surface to raise the nose of the aircraft".

"Or, expose bottom surface spoilers to kill the downward-lift forces and let the remaining upward lifting surface forces pitch the nose down".

"If the elevator system has retained some capability of rotary motion, the forward location of major force of the unspoiled elevator surface will tend to rotate the elevator in an arc that is compatible with killing normal lift of the spoiled surface".

"My patent 5,445,346 offers a quick reacting backup pitch-control means for large aircraft. The BD-4 design might have been the prompting to cite a cable-connected, manual "armstrong method" as the most simple communication means between pilot and elevator surface".

Email Addresses:
I have had several requests for Email addresses of the builders. I am sure there are many more so please send me an Email to let me know.

Note: To prevent spam, the email address list has been removed from the HTML edition of this newsletter. In addition, all email addresses included in the text have been modified by replacing the '@' with ' [AT] '.

Rotordyne Gyro: R. Mellema & J. Huber
Yes, we finally realized a longtime dream of owning a flying a gyroplane! We lucked upon an ad at last year's Arlington airshow and went right out and bought this prototype bird. It is powered by an 0-290 D2 Lyc and a four blade Warp Drive prop. It has a 28 foot diameter rotor and we are in the process of changing it to 30 feet so that we can carry a second passenger. It definitely is different than flying a BD! These things are slow and have absolutely N O vertical performance.