BD-4 BUILDERS NORTHWEST

NEWSLETTER

Issue 8, July 1983

Dear BD-4 Builders and Owners,

Are you tired of being laughed at when you go to an EAA meeting and announce that you are building a BD-4? I've been laughed at several times and don't like at all! We BD-4 builders/owners know what a good airplane it is but no one else seems to. I guess the boxy look (remember the easy construction) and "flying milkstool" look of the tricycle gear have caused people to reject it as a real performer. We ourselves probably have added to the misconception as there seem to be a greater percentage of BD-4s that appear to be in a sad state of repair when compared to some of the other homebuilts. Maybe I'm just extra sensitive to sad looking BD-4s! I'm not trying to ding anyone - we all have our time and budget limits and many of us just want inexpensive transportation. and not a show stopper that you don't dare fly.

BUT------who would believe that a common (carefully faired in) BD-4 would have a chance at winning the prestigious CAFE 400? No one but a dedicated BD-4 flyer! The Lopresti Trophy for the Best Experimental, 1983 CAFE 400 race was announced as:  The biggest surprise of the 1983 CAFE 400 is Race Number 38 - Roger Mellema's BD-4, N76VR!

After several months of planning and many late nights of work in a cold open hangar - we did it! The BD-4 has been vindicated! We took first place in the 3 or more seat category by beating out the Defiant and a Dyke Delta. We got the Lopresti (president of Mooney Aircraft) trophy for beating out all other homebuilts. N76VR got 163 mph and 21.7 mpg over the 400 miles. We carried 808 lbs of cabin load and 35 gallons of gas (1/2 car gas and 1/2 100 octane aviation gas). The gross weight at take-off was approximately 2270 lbs. Climbs were at 65 percent power and cruise at 56 to 58 percent power. The cross country flights to and from the race gave a ground speed of about 190 and 20 mpg.

We should be able to do better on the race but we will save that for next year when everyone is out to get us. I didn't get a chance to prefly the course so my navigation wasn't perfect. I had trouble identifying two of the pylons and turned very wide to make sure I didn't cut them. I used full power for too long during take-off and also landed long and had to taxi a long way. I used an SRD Labs, MLX LORAN C receiver to help in navigation but didn't believe it when I should have - it would have helped a lot if I had flown the course first and verified the possible errors.

76VR originally indicated 174 mph, full power at sea level. It now indicates 204 mph under the same conditions. The airplane is so clean that I'm having trouble with pattern work. I usually flew a close-in down wind and base so that I could make the runway if the engine failed. Now I fly a standard pattern and still have trouble getting it down on the runway. A big problem is mixing with other traffic as it is uncomfortable to fly below 100 mph. I fly the pattern at 100 mph and slow to 80 mph on final.

The improvements I've made to N76VR are:

IMPROVEMENT	APPROXIMATE SPEED INCREASE
wheel pants
under wheelpant fairings
leg fairings
leg to fuselage fairings	16 mph
curved windshield	8 mph
tail wheelpant
removed/faired in antennas
sealed flaps and ailerons
put nav lights in tips
flap to fuselage fairing	6 mph

I did some flight test and the results are shown in figures 1 and 2. All tests were done at 2270 lbs.. The glide polar curve shows a best glide range speed of 119 mph(750 ft/min), and a minimum descent rate speed of 104 mph ('700 ft/min). This gives a glide ratio of about 14:1. This is a bit high as there is always some thrust from the engine. I did the test with the throttle pulled back to the stop and the prop in maximum coarse pitch. The climb performance chart shows a best climb angle speed of about 95 mph (850 ft min) and the best rate of climb speed of about 120 mph (1200 ft/min). My test flight data was pretty scattered for climb so I will have to do some more later. It is hard to believe how hard it is to get good data. You find the perfect morning, take someone with you to do the timing, carefully hold airspeeds, etc. Then when you plot the results you end up with dots all over your graph paper! The only number I really doubt is the best angle of climb speed as I would expect it to be somewhat lower. The data so far indicates an absolute ceiling of 16,000 feet. I don't believe that as I have been a good bit above it.

BUILD YOUR OWN AIRPLANE BOOK

Stephen's company no longer carries this book as they went out of business. The rights to the book have been sold and transferred through two or three different companies and I am still trying to track it down. More news when I get it.

For sale items.
Wayne Johnson has pneumatic pop rivet guns (POP Rivet brand) for sale for the extremely low price of $30.00 plus shipping. He is a new BD builder and is thinking about getting into the business of supplying spars. 3715 East Ave. T-8, Palmdale, CA 93550 His phone is 805-947-3345·
Dave Weaver wrote to say that his 90% complete BD-4 is for sale. The airframe and control system is complete. It is a tail dragger and the wings are not done. He wants to sell kits 1 through 5·
6N100 Margie Lane, St. Charles, II. 60174 PH 312-377-1591

The chart above was published by Bede to show the performance of N400BD. I have drawn on it my new sea level performance and also the results of my tests at 8000 feet. I sure wish I could get 75% at 8000 feet it looks like about 210 mph.