• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.

BD5 - 007 plane

#1
I have been wondering if the flite test group might be interested in another challenge. My nephew and I watched a few 007 cd's and the BD5 with the jet in the rear was very exciting to watch. The challenge is to design a BD5 with a 24 grm motor in the rear instead of a jet.
 

rcspaceflight

creator of virtual planes
#2
Is this the plane?




This photo shows it with a prop, for some reason:


It seems like this plane would be a lot better off with the prop in the front. Even though the tail is very short, it may still require a lot of weight in the nose to get the CG right. Plus planes tend to be squirrelly being pushed instead of pulled. It would also be awkward to have the prop right there at the control surfaces. You'd lose thrust when using those controls.
 

earthsciteach

Moderator
Moderator
#3
The BD-5 is a very short coupled airplane, but it is balanced and flies quite well. The engine sits very close to cg, as does the pilot, so there isn't a need for heavy ballast in the nose. And, pusher planes fly very well. Elevator/rudder deflection should be fairly minor and the prop will still pull the air it needs.

Now, certainly a brushless out runner will provide a challenge in balancing because it will sit toward the rear, unless it can be incorporated into the fuse and shaft extended. A brushless in runner may be the way to go with this plane.
 

rcspaceflight

creator of virtual planes
#4
It still seems like it would be squirrelly. Like a Gee-Bee. Especially with how thin the cord of this plane is.

But you're right about trying to bring the motor in towards the CG. Just like the photo I posted with the prop version.
 

earthsciteach

Moderator
Moderator
#5
Yep, squirrelly would be an issue, unless dialed in. I doubt an rc version could be built scale, particularly in terms of chord, without it being a very HOT airplane.
 
#6
I submit to both you gentlemen that an rc bd5 is very doable, although not exactly a desirable model to fly....sort of one of those " if I can just get the damn thing on the ground in piece I swear I'm going straight home" a quick YouTube search will serve testament to the disbelievers.
 

xuzme720

Dedicated foam bender
Mentor
#7
I submit to both you gentlemen that an rc bd5 is very doable, although not exactly a desirable model to fly....sort of one of those " if I can just get the damn thing on the ground in piece I swear I'm going straight home" a quick YouTube search will serve testament to the disbelievers.
Sounds like my mini GeeBee when I messed up and had the throws too high. Had the dual rates set and flipped it to high by accident one time while launching. Talk about squirrelly! I reduced the throws permanently to keep that from happening again...still have DR but at a much more manageable level...
 
#8
rcspaceflight - when the first BD5 cane out as designed by John BeeDee the plane did in fact have an engine in the rear with the streamline proppeller.