I've spent the last year building an 8' span B-2 Bomber. It was my first scale/scratch built Airplane but it is pretty nice. It's built up balsa/ply/carbon fiber. w/flat black Monocoat and a O,S, 70 Surpass on the nose. It's impressive.
The experienced pilot I chose to fly it for the first time arranged to use a local Gen Aviation Airport due to the long runways.
The B-2 took off great and climbed out flat and at a good rate. He made a couple of good turns and I heard the engine rpm's go to about half. Well I warned him about letting it go to slow. The designer warned me that if we get it too slow then it will turn over fast and dive until air speed comes back. He stalled once and I told him to increase airspeed he did but cut it back again and sure enough it stalled again. I told him again to get the air speed up - he was maneuvering to try a frantic landing slowed it down "again" and sure enough it went over but didn't have the altitude to make it. SMACK!!!
It hit a soft slope with tall weeds but broke the engine and mount out and surrounding structure is a mess but fixable. I learned working on the real B-2 that anything can be fixed. We discussed what he thought was the problem but I've been in this hobby long enough to know when excess heat and distractions are the cause of a crash. I'm pretty sure that if we were on our own field on a cooler day it would have been different.

I've finally gotten some pics to show you guys. My B-2 is rebuilt and ready to fly tomorrow "weather permitting". The new test pilot seems to be pretty talented and we are using one of our club fields instead of the General Aviation Airport. I put in an FMA Direct CoPilot and I think it will help to tame this beast. Thanks Deltatech.

More pics!

More pics!

Just curious, but why did you build a plane you can't or won't fly?
It's a huge project to spend a year on something, you could have had three or four much smaller planes in the air, crashed and rebuilt in that timeframe?

When you ask someone else to fly your plane, you always run the risk that their judgement of tough situations will be different than what you would have done...on the other hand, if you would have done it differently, maybe that explains why you aren't ready to fly your own plane..kinda like a catch-22.

There could be a million reasons for it, but, IMHO it's a mistake to trust anyone to fly your plane if you aren't prepared for it to crash.
I had an instructor take up my first trainer and land it telling me I needed to beef up the undercarriage, the pushrods and use a better trim scheme for visability. After that, I had the confidence to fly my own planes.

try a larger engine, a .70 sounds WAY too small to power a plane that size with such low lift... its a crash waiting to happen. if it was staling when you cut the power half then its probably under powered try like a 1.2 or higher... IMO ofcourse

Thanks for the response hockeypilot. You bring up some standard topics in R/C Aviation and some not so standard. To answer your first question I would rather fail at something very hard rather than succeed at something very easy.[:-] I've gotten alot more out of this project than I would have ever gotten out of a garage full of ARF'S "no offense to ARF enthusiasts I have a few of my own". I guess you have never really challenged yourself.
The B-2 is all rebuilt and ready to go and I'm sure that it will be fine. Like I said earlier it flew great I just have to keep the speed up. I've been in this sport long enough to know the most simple concepts. When I total one of my own planes it does not phase me.
I guess that you never did anything really worth while and thats why you don't understand why I spent so much time and money on a project that is far from a failure. I have an engineering background and when you build something that is unproven and no one in the U.S. has had the courage to attempt then you have to expect a few bugs to work out. If you start out with a good foundation things usally work out. Deltatech

Delta---take it easy...you have to admit you sounded like a beginner in your original posting. I'm not trying to sound smug or tell you what to do..sorry.
I have been flying for 19 years and have scratch built, bought kits, bought an ARF and of course, crashed and rebuilt. I have done almost all aspects of the airplane thing.
I have challenged myself and have pushed my limits, that's not the point of my reply to your post, I think you were out of line to hit me that hard in your posting.
Good luck with your B-2 and lighten up.

Thanks for the response Balsa Master. A flying wing needs significantly less power to fly than a conventional aluminum tube A/C. The entire ship has lifting properties none of the structure is just along for the ride. A conventional airplane has a fuselage and tail group that don't contribute to lift at all - these parts are "just along for the ride" so they require significantly more power for flight. Nasa built an amazing R/C airplane testing the idea of using a flying wing / blended wing lifting body as an Airliner. The A/C was huge maybe 18/20 feet span but the engine they used was a paltry I think 90 size 2stroke. I've seen video on RCU of this amazing Aircraft flying maybe someone will find it and attach a link. Thanks again for the advise. Deltatech[sm=cool.gif]

yea... up when i poste that my comp was at 16 color and the whole pic was black and white and very blury, i confused B1 and B2 since i couldent see pic. but even though theres no fuse if its stalls that bad does it not make sence to add more power?

not to mention that the whole plane is staticly unstable which is why the real one has computer controles that trim the flaps 360+ times a second...

just pointing this out so that your semi offensive ego can be um... checked?

and as a mater of fact from your original post i had no idea that you could fly at all so to get offended when your skills are questioned is a little harsh.

Hi Balsa Master. I didn't mean to offend you in any way. Your idea of more power is a good one I just want to make sure it will fly ok before I spend money on a more powerful engine. I've been looking into some O.S. 2stroke engines that produce two to three times the horse power of the 70FS and they weight the same. Sorry if I offended you and thanks for any further thoughts on any issue. Deltatech

yup, its just that you came off erm... as having a serious ego problem... thats all. as i said, i couldent see the pics. is it fully symetrical? and how long is it?

also can you post some biger pics to show off some of the details.

It does have a symetrical airfoil and I even designed it with the deep undercamber from the nose to halfway down the L/E Wing span is 8' long and the length is about 33" and it weights 13lbs. I wasn't able to post pics before because the file size was too large. I got a camera cell phone. The images are a little grainy but at least I can put some up.. When I get a chance I will post some new pics. Thanks again. Deltatech

thats BIG i still think the .7 is a little low but thats my opinion, (im the guy that likes to double the power on every thing though so that makes the topic some what usless). try saving images as 256 color bitmap then saving that image as a jpeg, it should cut back on some of the colors that no one will ever miss. (i think, im not sure but it cant hurt)

Nice work all around deltaforce.
You'll get it.

Thanks for the encouragment antslake.

I think I would have to agree with balsamaster. a .70 4stroke is too small. If you put a bigger engine on it, nonething says you have to use all the power. Just that it is there if you need it.

it is 8' its not exactly a park flyer, besides, you no you want to stick a 4.6+ on there *evil grin*

So have you abandon this project? I'm interested in what you uncovered in your subsequent flights, or if there have been any.

Hi dynodan thanks for the reply. Let's just say that I've taken a break and I'm getting back into it now. Today I took it too one of our grass fields. The mains handle the grass ok but the nose gear is too flexiable. I'm going to get a nose gear with a larger diameter leg and a second retract servo then try try again. I'm just trying to work the bugs out. thanks. Deltatech
P.S. no I haven't gotten off of the ground "yet".

Here is one of the flying wing project. Use wing gyros to help stablize the plane.

[link=http://www.amtjets.com/gallery_horten.html]More Pictures[/link]

More POWER! Way to much weight plus drag on that poor little 70 4 cycle. You should consider gyros for roll and pitch axis. This is not a simple project without a doubt which allmost allways means a little cost overrun or two. The stability provided by those gyros will more than out way the cost and time of rebuilds. Good Luck Yogi

Try an FMA Direct Co-Pilot. They can make almost anything flyable.

Balsabuster

Thats a nice job. I've built 3 bigbirds, the third being my own but its not finished yet. IMHO, building is just as much a part of this hobby as flying. I guess it depends on the individual, as to what they prefer to devote their time to.
No offense meant to anyone, (PLEASE!!!!) but I too would get an expert pilot to fly my plane for me if I had any doubts about my skills with an exotic model.
A few years ago I looked into scratch building a B-1 (I think thats the one with the wings that fold back during high speed flight). Part of my research was into who in my club had enough experiance with big, fast, very expensive planes, that I could trust my to teach me how to fly such a plane. Sadly, I found it had been done before, very nicely from fiberglass, and then crashed on its maiden flight. If I remember correctly, the article said the builder/owner also got a model jet pilot to fly his plane for him.
When I finish my 1/4 scale Mustang, I plan to get a .60 size or maby a little bigger Mustang and fly it until I feel confident about my skills with this type aircraft. Even then I may make the maiden flight with the Nosen on a buddy box with an instructor. I currently fly a .40 Midwest Aerostar that I built a lot of sport into. Its about as aerobatic as a high wing can be and a whole lot of fun. My first plane was a .40 Mustang and when I first started flying, I was so stressed out that it wasn't fun to fly and I prefered to build.
There is no shame in being careful, considering all that could go wrong and who could get hurt when an airplane gets away from the pilot. [sm=thumbup.gif]

Here's the opinion of some smartass kid who barely knows about powered delta wings
to me giros are somewhat like cheating, yeh know, being all stressed out about modern fighters and bombers robbing the pilots' job to fly themselves (i want to go to the air farce, but im scared UCAVs will take my future job away, that's all.)
I've been thinking, since slope flying wings like my Raider from wing warrior are inherently stable, even with only one winglet on...if flying wings are unstable without winglets, then i would consider safe asking these question:
Shouldnt some form of stabilators inside the intake of the engines provide some sort of stability? let's say an arfioled "X" just inside the intake. it would probably help.
it would be a good idea as well to have another simetrically airfoiled X just before the exhaust ends, and allowing control surfaces on the latter X, something like thrust vectoring, but much simpler--the exhaust X would serve as tail feathers as well as a horizontal and vertical satbilator.
There would be problems, i imagine, such as a small surface area and the fact that the exhaust air would be corckscrewing on its way out of the duct....
Well, that's a sugestion from someone who doesn't really sympathize with pilot aides--especially self-stabilizing planes [sm=idea.gif]