JohnBuckner

My Feedback: (1)

The Flight plan - Take off with left Propellor removed (worst case senario with normal rotation engines) climb to three left circuits (worst case senario with left engine out) of the pattern with a left barrell roll (worst case senario with left engine out) on the second and an approach and landing on the third.


The Airplane - Sig Kaydet Seniorita bashed into a twin, The nacelles are also completely removable so the airplane can be aerotowed with a nose release as a glider. Engines are OS .25FX with Performance Specialties Ultra Thrust pipes. Props are APC 9x4 And fuel is 15% Powermaster 18% total oil.

Thrustlines - This airplane is fully adjustable quickly for out thrust from zero to ten degrees out. This to suit a wide variety of pilots. This flight the out thrust set at four degrees out both sides the normal best setting for a pilot with experiance. There is no onboard gyro or device.

Conditions - Temperature 96F degrees, Field elevation 3450MSL, Density altitude at the time of the flight: 4600 feetMSL. Runway required for takeoff was approximately 200 feet. Predictably there was a planned for swing in takeoff heading of around eighty degrees untill the rudder had sufficicent authority and you see this in the vidio, also it was neccessary for the helper to give the airplane a shove to get intial rolling in the dirt.

Here is the vidio:

http://video.google.com/videoplay?do...06427302&hl=en


John

Edit I negleted to mention full rudder high rate (about 35 degrees) was used manually through out the takeoff untill it just before liftoff where it was relaxed a little. At lift off and initial climb full was reapplied until speed was up a bit and the ballance of the flight was around half right rudder. Rudder trim was deliberately not applied since this always causes problems on power reduction for the landing when you really don,t want to be fighting trim.

fancman

My Feedback: (16)

What's your point? I'd love to see you try that with a OV 10 Bronco or Cessna 310.

wingspar

My Feedback: (3)

I'm trying to figure what the point of all this is too.

Dave

Villa

Hi JohnBuckner
Great job. I know that is an exciting accomplishment. To prevent boredom we try all sorts of things. Taking off on one engine is not only an interesting and difficult effort, but it gives you an easy way to practice one engine out flying. I designed and built a side-by-side twin like yours, but mine was a SPAD and used two .28 Magnum engines. Because our field is grass, I could not always take off on one engine; too much rolling resistance. It took all kinds of tricks to mother that thing into the air. A good head wind was always welcomed. I know you are having a good time. That is the point.

LaCerne

My Feedback: (16)

I think the point is that this is an RC forum and he is trying something different. Some might ask what is the point of hovering an airplane.

Neat trick JB. I hope to try that sometime with my twinair, if I ever finish it!

Have fun!

Larsen

clabro

My Feedback: (4)

I totally agree, the point was to have fun and prove that it is possible to successfully fly an entire flight on one engine. The fact that this was accomplished twice (I just didn't show both attempts in the video) says a lot for the plane and the pilot. The neat thing about that plane is that both nacelles pop off and it becomes a glider (that actually glides quite well). It's great fun with aerotow, here's another video with it minus the engines.

http://video.google.com/videoplay?do...37609334854372

twinman

My Feedback: (2)

I TOTALLY agree that this is a VERY good exercise and the fact that you made it with all the rudder input necessary to do this and not rely on trim and other makes all the more important and a good learning tool.
The point is that it is very good practice for engine out.
Note,,,personal experience..the first time I did this,,had helper hold the plane..tail dragger, while I went to full power one only one engine. DO NOT DO THIS!!. You must have speed over the rudder to hold a somewhat straight line on roll out and increase the rudder as you build speed. Full power and let go...an instant 90 degree turn...EXCITING,,but not recommended or safe!!
Congratulations.

Rip n Bank

Not trying to put this test down at all, but it seems that taking off with only one engine operating on a twin is a pretty neat "trick."

Learning to FLY a twin that is already airborne, but just lost an engine, is an important "skill", and, I believe, much more representative of what any owner of an RC twin really needs to be able to do.

BTW, I, too, would like to see this accomplished with different twins, say, a P-38 or a B-25!

I think a more practical (and undoubtely, less expensive!) test, and practice, would be to have the engines on separate channels, with one that can be reduced to idle with a switch throw. Take her up three-mistakes-high and flip the switch. That'll give you very close to single-engine flight characteristics, yet, in a pinch (read: you blow it), you could throttle up the idling engine and safely recover the aircraft.

Rip

clabro

My Feedback: (4)

Yes, that is likely all you'd ever *have* to do flying a twin. But these two flights were basically the worst case scenario with the left engine dead and flying from takeoff to landing that way. Completing the takeoff run and climbing out is a whole lot harder than having an engine die in the air when power can be brought back and the plane glided down. This situation would be almost identical to losing an engine on the takeoff run and if you can complete a takeoff with the left engine out, you'll have no problem recovering from an engine that dies in straight and level flight.

fancman

My Feedback: (16)

I still want to see this done with a real twin.....Bronco, P38, B25, Cessna 310 etc Then I'll be impressed.

maxpower1954

As a demonstration, in 1951 the prototype Aero Commander was flown from Oklahoma City to Washington DC with the left engine's propellor stowed in the baggage compartment. The event was covered heavily in the media.

In 1959, an Aero Commander 680 was ferried from Belize to Brownsville, Texas with the prop and engine cylinders stowed away in the cabin.

By the way the Aero Commander was designed by Ted Smith, of B-26 and Aerostar fame.

Well, I'm impressed! A friend of mine claims to have taken off on one engine in a DC-3...not that I'm calling him a liar, but having flown DC-3s myself it seems impossible...Russ Farris

JohnBuckner

My Feedback: (1)

Well while I certainly am dismayed that I have so severely insulted your 'Scale Sensitivity' with my lowly Unreal twin and posted a simple vidio but do be assured I have no interest at all in impressing you! I would highly recommend for you not push the play button any more to avoid any further stress.

John

fancman

My Feedback: (16)

No stress here my friend. Just saying that if you put enough horse power in a pinto to run a 12 second quarter mile......is it a big deal when it does?

JohnBuckner

My Feedback: (1)

I defy you to find anything in my post that is arogant or making "A Big Deal' to so insult your sensitivitys to the point that you do indeed attempt to belittle me and my airplane with your "REAL" remarks among others. Sir, there is nothing in that post except bland simple details of one flight period with zero editorial comment, Zip, Nada, None.

I wish you nothing but success with your P-38, OV-10 and B-25 and certainly hope you enjoy them as much as I have enjoyed my many other multi projects over the years both fantasy bashs and scale.

Rip n Bank

Guys, let's chill a bit here.

John, I was trying to be careful to couch my initial comment as not putting down your achievement of a single-engine take-off with a bashed twin, BUT I still submit that such a feat would not be repeatable with many other twin engine RC planes, including mine (a KMP B-25).

Fancman and I both brought up the other aircraft because they are "scale" replicas of real aircraft. As such, these aircraft (eg, 310, Bronco, DC-3, B-25 and SPECIALLY the P-38!) typically have less forgiving asymmetrical thrust lines (with an engine out), and resulting yaw, combined with proportionally smaller vertical stabilizer and rudder area with which to counter that yaw. Your purpose-built test aircraft did not have these limitations.

As I understand it, the minimum controllable airspeed (MCA) or Safe Single Engine Airspeed (SSES) is the speed, above which, you can counter the engine-out yaw with rudder. Below that speed, you cannot counter the yaw with rudder, nor can you use increased throttle on the remaining engine to re-obtain MCA. You can, however, trade altitude (if you have it) to regain MCA.

So, back to your single-engine twin take-off experiment, and why my B-25 could not do it. The take-off speed for both a real B-25, and, undoubtedly, the model, is typically well UNDER the MCA/SSES (eg, on the real Mitchell, take-offs are around 80-95 mph depending upon load; and the MCA/SSES is 140-145 mph). This "exposure" on take-off is typically why, unless there is an object to clear beyond the end of the runway, standard military take-off procedure in multi-engine aircraft is to "level off" (or climb very shallow) just after take-off and accelerate the aircraft to its MCA just as soon as possible, THEN begin a steeper climb out while keeping the airspeed above MCA. Once at a significant altitude, it becomes less critical to remain above MCA while you climb or cruise.

BTW, a great description of this climb vs airspeed trade-off can be read here: [link]http://www.b25.net/pages/spinningb25.html[/link]

Bottom line: my only realistic course of action with my B-25, were I to loose an engine right after take-off, would be to immediately idle down the remaining engine (emulating a deadstick), establish a glide slope, and "land" straight ahead. If there's more runway (rather unlikely), then leave the gear down. If it's weeds, then retract them and execute a "soft-as-possible" belly landing.

Then, once down, and hopefully in one piece, I'd undoubtedly have to go to the airfield porta-potty and ditch my underwear!

Rip

ram3500-RCU

My Feedback: (221)

"The Flight plan - Take off with left Propellor removed (worst case senario with normal rotation engines)"

Why not just leave the prop installed as it would be in an authentic engine out? Seams to me your test is skewed, lacking the drag of the left prop, and thus not the 'worst case senirio', nor the best test of your engine out skills.

JohnBuckner

My Feedback: (1)

It is what it is I never suggested to anyone any of the airplanes mentioned are capable of the same that was fancmans assumption when he went on the attack with his first post. As far as removing the left propellor well yes I did and noted such, probably out of force of habit to add a another inch of manifold pressure for Mother and Country!

It is disappointing that the multi engine forum here seemingly has deteriated to a level similar to the RCU AMA Forum where many regulars seem to be in the attack mode much of the time.

John

maxpower1954

I'm a newcomer to the multi-engine site - so, I'll tread lightly here.

I think it was quite an accomplishment. He did it for his own personal satisfaction, and wanted to share it with the rest of us. As far as removing the prop,
I don't think a non-windmilling prop on a model is any drag worth mentioning. He just wanted to demonstrate it was possible, and of course you guys are right...a full-size airplane (not "real" airplane; guess I'm sensitive to this ever since watching "Flight of the Phoenix" on TV in 1972) can't do it. Exceptions: the two Aero Commander occurences I mentioned in an earlier post. I'm not ready to risk it, but I think my Skylark 56 twin probably could from pavement.

It's a hobby, and it should be fun. Once upon a time I was a flight instructor in real airplanes (Uh, I meant full-size!) and I'll never forget my boss, shaking his head at me - he thought it was pointless flying R/C, since I was a already a pilot. Thirty years later, I'm still at it...models and the "real" thing.

Russ Farris

orygg

Hi i have taken off on one engine it is piper 31 navajo you nede lots off rudder butt this is a real plane

Rip n Bank

John,

With any posting of an "unusual" RC activity like you performed, you are typically going to get a wide range of comments and feedback; some positive and enthusiastic, some neutral, and sometimes a few even critical or questioning. It's the nature of forums, OK? No need to go to "DefCon 4" over it!

I joined in because of my recent acquisition of a KMP B-25. It will be a challenge to build, and to fly. (and to pay for, too!)

I've successfully flown a TF Gold Edition DC-3 (a buddy, who's also building a B-25, and I bought it used as our twin trainer) four to five times so far, but, admittedly, without having lost an engine (yet)!

It'll be months before my B-25 is ready to maiden, and I am doing everything I can to insure twin-engine reliability (eg, on-board glow for the pair of well-broken-in, well-tuned Saito 100's), and aircraft survivability in the case of engine-out (rudder gyro, and lots of practice ahead of time with the DC-3).

I was hoping to constructively discuss the challenges and limitations of twin-engine RC flying, especially around "loss of an engine", of which I'm still admittedly terrified!

Your original post seemed a natural lead-in for such a discussion, but, perhaps this is not the right multi-engine thread to explore this particular topic on...

Rip

ps2727

John,
That was a great job on the single-engined flight. Seems not everyone appreciates the complexities of assymetrical flight.
Paul

Deadeye

Very cool John! Ignore the negative posts. You don't even need to reply to them.

Villa

Hi JohnBuckner

Some people have a different view point and do not bother to introduce this difference into the discussion. They don't bother to clean up their comments to prevent them from being insulting. Can you imagine their opinions of my twin engine SPAD taking off on one engine? As others have suggested, just ignore them and don't respond.

kram-RCU

Rip n Bank:

Want some more input regarding engine-out flight on your B-25??

You can access a nicely filmed video (and audio) of me losing one of the Saito 100's on my KMP-25 last September at the Multi-Fly on You Tube: key words "Mark Taylor B-25"

If you want in-depth commentary, I'll be happy to respond after you watch it, but in a nutshell, your previous comments about "level it off and land it" were prophetic....by the time I got it leveled off, I had lost some altitude and my nerve for revving up and trying to go around on one engine in a "dirty" configuration, and I knew from (well, never mind how I knew) that tall, dry corn is very gentle for crash landings. So even in front of a twin-expert crowd, I didn't have the fortitude to throttle back up.



mt

Props4ever

Very impressive John,

I alway thought if one engine flight could ever be achieved on twin model. Now you have proved it as it's very much possible.
Amazing part was when you did rolls in this flight!. Flying twin is not that easy specially when there is good chance of losing an engine, yet doing rolls, its just impressive!, My hats off to you sir!!

I will try it once with my B25 and see how it goes, need more encouragement to do it..he he