Telemaster Sales UK

On 29th April1917 a man with the same name as me was shot down and killed by Baron Manfred von Richtofen, the "Red Baron," while flying a BE2e artillery observation and reconnaissance aircraft. His was to be the last of the BE2s which MvR downed. The BE2s were too slow to run away, too stable to out- manoeuvre a German fighter and too badly armed to be able to fight them on equal terms. I am in the process of building a replica of my namesake's aircraft but when a complete one turned up in a local bereavement sale, I just had to have it!

It has a scale working exhaust and is powered by an OS 70FL.

This is a brief video of my fifth or sixth flight with it. I'm still getting used to it; it's not a very stable flight but I'm trying several alterations to improve matters starting with introducing some aileron differential. The best part of the flight was the landing and taxi back to the pits which the camera man missed!

https://vimeo.com/123989510 Apologies to French speakers for my forgetting the French for "fourteen."

abufletcher

Fantastic model! I'd like to see and/or hear more about it. Do you have a build thread somewhere? How did you do the functional exhaust? Plan-built or scratch-built? And, of course, photos if ya got'em!

Telemaster Sales UK

This particular model was built from a Practical Scale kit. The builder was a retired Head Teacher; is that a"School Principal" in American parlance? I never met the man, but apparently he was married to another head teacher and they had no children, so there was no shortage of disposable income. Which probably accounts for the 463 aeromodelling items he left behind him when he died, that's counting a box of at least fifty plans as one item! Two of his clubmates have made a list of everything and it has been circulated to members of local flying clubs before it goes on eBay. That's how I got to know about it. Although I was in the course of building my own model, I just had to buy it!

It was originally designed by Roy Scott in the late Sixties or early Seventies and is finished as per the box art as an aircraft from No2 Squadron. I've always planned to build the model for the reasons stated above, and must have had the plan for years. I bought it from one of the foremost British scale modellers, either Dennis Bryant or Brian Taylor IIRC. Having decided to retire to rural France I sold a number of surplus possessions and noticed that Flying Scale Models were not only selling the plan but they also sold a plan pack with all of the ribs and formers cut out for you. I bought a plan pack and started the build. The formers seemed to be too wide until I cut slots in the ply doublers to form a mortice and tenon joint. These slots are not shown on the plans so prospective builders watch out for this! I stopped building once I'd finished the fuselage because I thought that it would be better to take the model to France with most of its components in a cardboard box rather than to attempt not to break a pair of uncovered biplane wings! However, when I was last in France I was flying a small electric powered sports model at a club near Gueret. In the club house were lots of used magazines including the August 1971 edition of RC Modeller which features a build article of this very model! They let me take it away! Pictures of my fuselage and of the "Bereavement BE2" attached.

As for the model I bought from the bereavement sale, it's covered in dyed silk. Some claim that it had never flown, others that it had only flown once. Be that as it may, the oil from the exhaust has stained a great deal of the covering which leads me to wonder whether he ever fuel proofed the model. The model has been widely admired and the staining is said to give it a weathered appearance! The functional exhaust was part of the kit. It takes the form of an aluminium cylinder across the engine bearers and held to a former with metal straps, with an inlet pipe on the right and the two scale exhaust stacks coming out of it. I have a right-angle knuckle on the engine and connect the engine to the silencer with a straight piece of silicone. I plan to fit a Laser to "my" model and will probably get Just Engines to fabricate an exhaust to suit. I will cover mine in Solartex and fit a bomb dropping function which is shown on the plan.

The plan and cut parts are available here: http://adhpublishing.com/shop/store/products/royal-aircraft-factory-b-e-2e-plan325/




PS. Once when I was flying it I thought about converting my BE2e to an RE8. They had the same wing and tail after all, but as I wasn't very smooth with this one, I thought that things could be worse with the smaller fin of the RE8!

Telemaster Sales UK

Good day gentlemen. Since I put up the last post, I've sold up in England and retired to the middle of France where the weather's much better!

I flew the model for the first time in France last Sunday afternoon. Sunday was a busy day for me as I'd spent the morning at a motor cycle charity event. The model wasn't easy to fly. I suspect a rearward balance point and will add some lead to the nose.

Meanwhile here's a few pictures of the model. I love that over-wing exhaust! This was provided as part of the kit.

Airwarrior

It looks a lot to me like it's tail heavy. A bit of noseweight should help a lot!

Telemaster Sales UK

I bolted 165 grammes of lead under the engine yesterday. We'll see what difference that makes next calm day.

Stachel

Wonderful work! Glad to have found this thread, I'm building the same model from the same woodpack from FSM. And yes, that former was an interesting problem! Here's a picture of my efforts, don't mean to hijack your thread, I'll start my own when I get things along a bit better.
Lyle

Telemaster Sales UK

Hijack away! I doubt that I'll be doing much to my model over the next few months. I am currently renting a house but am seriously thinking of buying one, so another house-move may be on the cards.

Curiously, I ceased to be the only Englishman in the club a few weeks ago when Daniel Hunn joined. Daniel has taken early retirement from working in hospital laboratories and is a good builder and flyer. Guess what his winter project is going to be! That's right a Roy Scott BE2!

This time next year we could have three BE2s in the air escorted by a Flair SE5A, all to the same scale! .

Stachel

Hello again!
I am back at work on my Be2e, happily gluing formers and stringers in place on the fuselage. I was looking at several plans for the plane and noticed that the model plans has the top wing's incidence at a somewhat surprising 4.5 degrees. The bottom wing is at a lower inclination, something closer to 3 degrees. The drawings I saw in the Datafile show much less incidence. I'm wondering if lowering that incidence would tame the model? The one they are flying in New Zealand is said to have lovely flight characteristics! Thoughts?

Telemaster Sales UK

Hi Stachel!

When I last flew the BE2e, as photographed in post 4, I had added 165 grammes of lead under the engine. I found it very difficult to fly and only just managed to recover it from some OOC situations. Before adding the lead I fitted four strips of Solartrim under the wing to delineate the cog range. The model now balances nose down with my finger tips below either piece of Solar trim. Picture attached.

I'm beginning to wonder whether there is a problem with the incidences. The tailplane is set at quite a positive angle of attack as was the case on the original aircraft so there's nothing we can do about that. Furthermore, I felt less in control of the aircraft in August than I did when I flew it when it was filmed in England. Control movements too great?

I think I'll bolt it all up again and give it to Roger Aubard to fly. He's the best pilot in the club but I think I'll wait for a warm and calm day next Spring. He once finished tenth in the French National Glider championships and has competed in competition aerobatics too, so he should be able to manage it. Maybe we'll also get it up on a table and give it an aerodynamic analysis in the club hut.

TFF

That is the scale model dilemma. Wing incidences on big planes are there to gain more lift by making the wing have more of a positive angle of attack. When the looks of the incidence is prominent you can have a choice of what looks good or flies good; many pick a point in between. Models usually can just fly on the airfoil. Maybe 1 deg different between top and bottom wing to help stall, but too much makes the plane have divergent flying qualities. Models fly in such a slow sped range that one wing starting to stall while the other is still flying at a flying speed that is normal can happen if the incidences are too aggressive.

Stachel

I went and did some reading and found in Centenary Datafile 165 The RAF BE2E at War! by Paul Hare where it's stated, "These wings were rigged at a constant 4.5 degree angle of incidence,without washout, the design team believing that tip stalls would be eliminated by the outwardly-raked tips." So, it seems the plans are correct. The airfoil is not scale, though...modified for a flying model. Every thin airfoil I've seen on drawings seems to have been designed with severe positive incidence, i.e. the Bleriot XI. On the opposite end are the thick airfoils from Fokker and Junkers, where there is little incidence at all. Is there a formula for determining incidence with airfoil thickness factored in?

I'm not a mathematician in any way, shape or form and yet I seem to be wandering far from my comfort zone along the shore!

jumpinjan

That cannot be the CG! Is that what the plans call for?
Jan

Telemaster Sales UK

The centre of gravity is marked just forward of the rear cabane strut on the plan. I am just a little nose heavy.

jumpinjan

It cannot be there, I did a quick & rough illustration on what is really going on with Center-of-Lift & CG. It is more like in the middle of the top wing cord.
I'm not going to give a tutorial on balancing a biplane here, you should get an idea on how to find it by the picture....Jan
My CG point seems to be right in the observer's seat, which makes sense. Maybe that's were it's suppose to be then.

Telemaster Sales UK

Very interesting Jumpinjan. I assure you that the c of g is shown above the rear cabane strut on the plans. I could fit a bigger and heavier engine to bring the c of g forwards.

Alistair

I thought it looked like it needed more weight up front, but difficult to judge from a video.

I had a similar problem with an 90" wingspan RE8 I bought. Seller assured me it had flown and flown well. He was a liar.
Took off went almost vertical.(Tail plane incidence was a couple of degrees off to the plan) Managed to trim it with a lot of down elevator and it was horrible - similar to the way your BE2 is flying but much worse, skidding around all over the sky..

Re-rigged it to give it some dihedral (wing tips 1" up) and it finally flew well.

Until the scale brass elevator lever thingy in the fuse broke (because the soldering was poor) and it crashed.

Fed up with buying other peoples bodges, I decided from thereon I would make my own bodges, and started building !

p.s. Are you using a lot of rudder in flight and combining with ailerons for turns etc ? They do need a lot of rudder input for WW1 models (Sorry to teach you to suck eggs etc)

Telemaster Sales UK

I will try it with a more forward balance point by adding weight to the nose. The weight may include a Laser 80 or 90 or a Thunder Tiger 91FS all three of which are all currently unemployed, though the TT will require new bearings. I have these in stock but I have never got round to fitting them and the TT will be a better option if I want to use the overhead exhaust.

I am using bootfuls of rudder in the turns.

Alistair

Very nice looking model, the BE2 is very appealing, they look 'different', i've a hankering to either build one or an RE8 (I have a plan for a Martin Farndel RE8)

buzzard bait

It looks fabulous in the air and on the ground! I love the exhaust pouring out the stacks above the wing. Looks like you used rudder appropriately to get nice turns. Take off and initial climb suggested to me simply too much power. No BE2 ever took off that way. Back off on the throttle and let it float off the ground. The rest of it looked terrific.

There is much confusion about CG and incidences, and there shouldn't be.

When people call a plane "tail heavy" often the problem is simply poor trim. If down trim solves the problem then it wasn't tail heavy, it was just out of trim. Also, if backing off on the throttle solves the problem, then likewise, the plane was not tail heavy, it was out of trim. If you can't trim the stab, which is usually glued on, then you just use elevator trim. The positive incidence in your stab is probably a GOOD thing. The stab is probably affected by downwash from the wings and needs to be somewhat positive.

If a plane is unstable in pitch, then it truly is tail heavy. That is, suppose it swoops up when you give up elevator; then you give it some down and it goes increasingly down. You can't get the plane on an even keel because it diverges from any correction you give it; it keeps going up and down; you get very nervous and pray you get it down in one piece. That's tail heavy.

Sometimes a plane is stable in pitch, but makes you feel uncomfortable because it wobbles coming out of a turn sometimes, or sometimes you move the stick for a turn and does less than you expect. Sometimes moving the CG forward helps because it creates more side area in the back and less in the front. Of course that can be corrected other ways, but with a scale model you might not want to, so you move the CG forward to improve directional stability.

I've got more to say about this, but the post is getting long. Jim

buzzard bait

A plane may not be unstable in pitch, but it's just not as stable as you would like it to be. There are many tests you can do in the air, but for a plane like yours I think the easiest thing is to trim the elevator for level flight at a moderate cruise. Then push the stick forward, let the plane go into a moderate dive, and release the stick. If the plane keeps going straight toward the ground, the plane is neutral in pitch and probably uncomfortable to fly. Put some weight in the nose and try again. If it swoops up, it was nose heavy. Most people like it best when it comes out of a dive on its own somewhat gradually.

Jim

buzzard bait

I am not an aeronautical engineer, so I may not get every aspect of this exactly right, but as a practical matter, I think what I have learned (or what I think I have learned) from reading books and articles, and observing my models, gives useful results and helps me make sense of what happens at the flying field. So for what it may be worth, I’ll continue...

Now for incidence; but not biplanes, yet. You usually want the stab to have about the same incidence as the wing, or a bit less. The balance point must be ahead of the plane’s neutral point in order for the plane to be stable in pitch, so the stab must be able to produce some downward force to keep the nose from falling. It also helps in a stall, because a stab with a little less incidence will lift the tail as a plane goes into a stall, which makes the stall less severe. But the elevator affects the effective incidence of the stab, so if the stab isn’t ideal, you adjust with the elevator trim. Also, as mentioned, downwash from the wing(s) affects the actual incidence your stab “sees” on a given airplane, so a stab incidence that appears a bit positive may not have that effect.

Jim

buzzard bait

My apologies for turning your thead into this treatise! I have no excuses to offer, I just got carried away.

Now we have a problem, because aerodynamic forces are proportional to the square of the velocity. That means that if a plane is in trim at a given speed, increasing the speed will increase the lift of the wing in relation to the stab. The plane swoops up when you throttle up. That’s why I suggested that you just had too much power on take-off. Even if you could have managed the elevator stick better, it would be easier, and more scale-like, just to use less throttle.

This also shows the down side of making a plane nose heavy. The balance point is farther forward of the neutral point, so you need more downward force on the stab to keep it level. That creates drag, and it makes the airplane more responsive to changes in speed. The more nose-heavy, the more the plane will tend to climb when you increase the throttle, and the faster it will fall when you decrease it. This requires you to make more elevator corrections.

Down-thrust is sometimes used to decrease the amount of elevator correction needed for changes in power. Free flight models usually have quite a lot, because they must fly at full power or no power without any correction by a pilot.

Notice I haven’t mentioned incidence in relation to the fuselage at all. What matters most is the wing and the stab, and then the thrust line. Put a fuselage on top of those things at any angle you like. Of course, the angle of the fuselage affects the drag at a given speed. You don't really want to be hauling a sagging fuselage through the air. But my point is this: some people recommend adjusting a plane by reducing the angle of incidence of the wing, usually raising the trailing edge. This will have the same effect as trimming the stab, except for one thing...the thrust line of the engine in relation to wing and stab. Raising the trailing edge of the wing may help a problem, but it also reduces the down-thrust. Sometimes it changes the looks of a plane on the ground too.
Jim

buzzard bait

Now for biplanes. Here’s where I just have to tell you competing arguments, and you decide.

I think the most common idea, at least among modelers, is that for a plane with positive stagger, top wing ahead of bottom, the incidence of the top wing should be a little greater than that of the bottom. The idea is that the top wing will stall first, and the bottom wing will keep flying but the lift is farther back, so it will tend to prevent a stall, or make it less severe. Of course, that’s what a stab does too, so do you really need two stabs, one of which is the size of a wing and positioned to have less leverage than the aft stab? I never do this.

Another idea is that with positive stagger, the bottom wing flies in downwash from the top wing, so it should have MORE incidence. That way, the bottom wing has to do its share of the work. One guy who posts here as “Rodney” says he has found that also helps bipes “groove” better, for all the bipes he has tried (which are aerobatic types, like Aeromasters). This is what I do with my sport types.

The noted modeler and designer, Gordon Whitehead, who has published many scale bipe model plans, commenting on these two contradictory theories, simply puts the two wings at the same angle of incidence. I won't mess with Gordon's designs.

The truth is I have seen bipes fly successfully with all three set-ups.

Whatever you choose, the same principles in the post above still apply.

Sorry to be so long-winded. I hope this is of some use to someone! Thanks to anyone who actually read through all this.
Best regards, keep that beautiful bird in the air, no matter how you do it. Jim

Stachel

Hi Buzzard Bait,
I read it all! But it was interesting, so I don't need to get a medal. Thank you for putting these theories (more like axioms?) for us to study and apply to our models. Being that I'm building a Be2e right now, it's very important to try to get it right, since the plans seem wildly off in some details (CG being one).
The stab's angle of incidence looks as much as the top wing, about 4.5 degrees. The bottom wing measures out at 2.5 degrees. I like what Gordon Whitehead is saying about incidence, make both wings the same and go from there. I've gone and drawn on the plans the corrected incidence and what struts need to be lengthened. I am keeping the front cabane strut the same length and just dropping the trailing edge.
Telemaster's video of the Be2e in action is reason enough for me to build one--it's so captivating to see. No offense to fans of that Dutch plane builder, but I'm tired of seeing nothing but Fokker Dr.Is at shows!