BD-5 - Why is it so engrained in our psyches?

[Regdor]

Why not drive an internal Fan directly off an air cooled engine and place the thrust line exit on center mass .....

 

[raytol]

I think the BD-5 would have been safer if the wings had been moved up to just under the canopy and leave the HS down where it is now. The original prototype had a V tail which would have worked well if it had been sized correctly.

 

[David L. Downey]

Lest we forget, Bede basically did it again with the BD-12/14 fiasco. It was announced that deposits would go into escrow. Turns out it wasn't. Bede spent all the money.

Was pretty good friends with a magazine editor back then. He had been through the BD-5 era, and was LIVID that Bede was trying again with the BD-12. The development of the plane got zero coverage in the magazine. It got ink only one time...when the prototype crashed. CG issues, I believe it was on the first flight.

I've heard Bede described as "95% of the great designer". Needed someone else to do that last 5%.

Had dinner with him, in the 90s, with a friend who was the leading light in the BD-4 area. He seemed a bit wary of me....

Ron Wanttaja

Any chance your friend was Roger Mellema? Very nice guy. RIP

 

[cblink.007]

Is there any way we can get you to come to the ESA event in Tehachapi this Labor Day?

DM in your box!

 

[PMD]

Wow.

I was very aware of the subsidies the school received. I was referring to absence of financial assistance I received, as most of my demographic is mostly ineligible...but that debate is for another forum.

In any case, what I did pay was worth it...and is far, far less than what most new graduates get strapped with today. If you're curious, I can connect you with a junior engineer of ours who is over $205k in loan debt; he can tell you all about how the taxpayer helped him out...

I digress.

Having paid for 23 years of post secondary education for our 2 kids - granted in a different country but similar environment - I know the feeling of the out-of-pocket, but when I compare that to the MILLIONS of actual cost to the institution and it funding sources I think it was a bargain not to be disregarded. Heck, just one of big kid's research tools was in the BILLIONS!!! (but obviously shared with others).

Sorry if I seem to come across a bit harshly, but the cost of education to taxpayers and other sponsors has bloated horribly vs. the drift of a student body there for the degree, not the education. I don't see us getting our value for the money (to tie that into the J Bede theme).

 

[Wanttaja]

Any chance your friend was Roger Mellema? Very nice guy. RIP

Yep. We still met at his hangar for Chapter 441 meetings for 20 years after his death.

Ron Wanttaja

 

[Two Bolts]

Very interesting thread.
I remember when he brought the 5 to market or lets say Oshkosh back in the early 70's. They flew the Jet version, but had issues late in the week where the clam shell stuck and landed short and sheared off landing light, but very little damage to the plane. I also thought that he had another plane the following year that was the same design as the 5 but bigger. I passed it up on a trailer on the way to Oshkosh. BD7J??--had it as static display but taking orders.
He was also involved in the American Yankee. I thought that was also his design but the government took it away

 

[Wanttaja]

Very interesting thread.
I remember when he brought the 5 to market or lets say Oshkosh back in the early 70's. They flew the Jet version, but had issues late in the week where the clam shell stuck and landed short and sheared off landing light, but very little damage to the plane. I also thought that he had another plane the following year that was the same design as the 5 but bigger. I passed it up on a trailer on the way to Oshkosh. BD7J??--had it as static display but taking orders.

I found the BD-7 tucked into a hangar at a small field near here, about 30 years ago. Never saw it again.

Ron Wanttaja

 

[Rob de Bie]

Has anyone here ordered the 'BD-5: Original Plans' PDF as advertised here?

BD -5 | Bedecorp

Are the drawing of sufficient resolution for study? And what version(s) do they cover? Thanks in advance!

Rob

 

[TFF]

The plans are more like an assembly manual. If I remember, the pictures were pretty good. Similar to the BD4 manual. I’m sure there is templates for brackets and some measurements, but a plane can’t be built from scratch from them. Tab A into Slot B, not blueprints.

 

[BoKu]

Has anyone here ordered the 'BD-5: Original Plans' PDF as advertised here?

BD -5 | Bedecorp

Are the drawing of sufficient resolution for study? And what version(s) do they cover? Thanks in advance!

I have. They cover the BD-5A and BD-5B. I thought them well worth the money. They seem fairly complete and are well-drawn, though their presentation sometimes makes it difficult to understand the relationship between the parts.

It's been a while since I looked, but I believe they omit most if not all of the powerplant installation

 

[Tiger Tim]

I believe they omit most if not all of the powerplant installation

Sounds very on-brand

 

[pfarber]

How old are you? we used to read reports, way back in the '70s, of builders getting into trouble with PIO. You know what that is, right?

Do you touch down a 172 at 65 MPH? You're an accident waiting to happen. Besides, 65 MPH in a 172 is not the same as 65 MPH in an airplane half the size, a little over a quarter of the wing area, and just over a quarter of the weight. Its Vso is higher than the 172's.

65 MPH in a sedan is not the same as 65 MPH in a go-kart. Try a small homebuilt sometime.

Lol sure... Ive crashed every landing becuase i dont stall it out (not even the FAA is hot on stalling it out).

No ACCIDENT was rooted in PIO. Not the ones i read. The. Handling was not an issue. Stupid pilots, crappy MX, bad builds sure. But the only real issue was the drive shaft.

Show me some accidents direct related to oscillations. None of the dozen i read mentioned it.

 

[BJC]

No ACCIDENT was rooted in PIO. Not the ones i read. The. Handling was not an issue. Stupid pilots, crappy MX, bad builds sure. But the only real issue was the drive shaft.

Show me some accidents direct related to oscillations. None of the dozen i read mentioned it.

See BD-5 - Why is it so engrained in our psyches?


BJC

 

[pylon500]

Lol sure... Ive crashed every landing becuase i dont stall it out (not even the FAA is hot on stalling it out).

No ACCIDENT was rooted in PIO. Not the ones i read. The. Handling was not an issue. Stupid pilots, crappy MX, bad builds sure. But the only real issue was the drive shaft.

Show me some accidents direct related to oscillations. None of the dozen i read mentioned it.

I suspect you may have read reports that state words to the effect that 'the position of the drive shaft and prop can cause crashes on take-off'. This is due to the high thrust line over a short coupled body requiring a fairly noticeable amount of elevator to rotate. Without the drag of the wheel 'on the ground' the aircraft could continue to pitch up and, while it doesn't really pitch up too much, the view from the cockpit can suddenly be just sky. The pilot pushes (instead of easing) the stick forward, and with the pitching moment of the high thrust line (and probably a little flap), the ground appears very suddenly which causes the pilot to pull back suddenly. One of three things happens next; 1/ the pilot pitches down again and hits the ground (many first flights); 2/ the pilot manages to miss the ground on the second PIO and starts to jockey the throttle in a hope of stabilising the PIO's, reducing speed and induces a stall close to the ground; 3/ the pilot realises what's going on and freezes the elevator to damp the PIO's and then determines what the visual of his climbing attitude will be and climbs away.
I wonder how many Lake Buccaneer pilots flew BD-5's, I know Richard Bach had one of each and seemed to have got away with it.

 

[PMD]

I wonder how many Lake Buccaneer pilots flew BD-5's, I know Richard Bach had one of each and seemed to have got away with it.

Please try to take this with the understanding I am not just trying to be a sarcastic jerk, but a huge part of such problems come from ab initio training being done in exceedingly benign aircraft with dump-truck like controls and response. The solution IMHO is that all instruction should be done in a BD1 (or similar....but there IS no "similar" basic trainer, so BD1=AA1) would produce a pilot body with some sort of appreciation for and feel for aircraft that have controls that actually DO something rather than just to hang onto while it crashes.

Of course, we can thank no one other than J. Bede hisself for that.

 

[SpruceForest]

Back in the day, you had fighter jocks, helo drivers, and glider guiders that had been forced to develop the sort of control touch that small/high control sensitivity/highly responsive aircraft required. These days, sim work could take a lot of the risk out of initial flights for something like a BD-5ish aircraft.

A few years back on 'Drag Your Spawn to Work Day', I had the privilege of doing the sim demo/'kid flies jet' work because a) I could operate our research cockpit sims, and b) I could still fit into a 46L zoom bag. A significant portion of those 9-13 year olds had the sort of control touch almost never seen back in the previous century beyond those that had been graduated from a good UPT program on fighter or helo track. And not a single one of those kids could resist the urge to drive the sim through buildings, other aircraft, or under one or more of Seattle's bridges.

OK... maybe sim not such a good idea.

 

[Tiger Tim]

Example: Each wing panel has a tubular spar that slips over a 6" long carrythrough tube that protrudes from the fuselage at the side of body. The wing panel is secured to that carrythrough with a single 1/4" bolt through one wall of the spar and carrythrough. All wing forces due to lift, and all the forces due to drag and thrust, are reacted by the 6" overlap (essentially 2 tube diameters). All wing torsion forces due to pitching moment are reacted by that single 1/4" bolt through one wall of the tube.

Wild to think that the ones that were disassembled and trailered between air shows for years didn’t wear out that minimal attachment.

 

[PMD]

A significant portion of those 9-13 year olds had the sort of control touch almost never seen back in the previous century beyond those that had been graduated from a good UPT program on fighter or helo track. And not a single one of those kids could resist the urge to drive the sim through buildings, other aircraft, or under one or more of Seattle's bridges.

Our youngest has become a rock star in the world of arthroscopic surgery and when asked about her incredible manual control she usually credits it to many hours of Mario with Dad. I think the 15 years of piano might have been just as important - but to restate my case: it is valuable for pilots to HAVE experience in REAL WORLD highly responsive control. They can always dumb down to spam cans and iron boat anchors that are so boring that they must be flown by george.

 

[PMD]

Wild to think that the ones that were disassembled and trailered between air shows for years didn’t wear out that minimal attachment.

AA1-AA5 wings are attached in same way. The fit is not 0/0 but a bit sloppy and adjusted with shims. Still amazed that fretting does not seem to be a factor long term. Having once tried to cut down a small forest with an AA-1 I can tell you that those spars and carry-through are bloody well STRONG!!!!!