Pilot P51

My Feedback: (6)

Bo
That is a good looking plane. One of the guys in our club has one and I almost bought one until I saw the DA that was going to come out in a twin. KMP now has a DC 3 110" WS all composite ARF. It is a limited addition and high dollar $1000.00 but it is a good looking plane. Check out their web site.
Have a Merry Christmas and will talk to ya later

Walt

mrbassman

Well, had my first engine out condition yesterday. Five minutes into the 9th flight the left engine say "adios". Well, once that engine quit it was like someone hung a 10 pound weight off that left wing. Kicked in right rudder trim but I could not get that plane to turn right no matter what I did. I had to make a very gentle left turn to get back to the field, which put me behind the pits, (not good), I still couldn't get lined up with the runway, it went in on some very soft brush, very little damage, was fixed in about 2 hours.


I'm actually glad it happened, because if it doesn't happen, I'll never know how to deal with it. That's why I'm flying this. I must admit, I was less than impressed with the engine out characteristics, since this is supposed to be quite manageable with an engine out from what I've been reading.

My concern right now is why did the engine quit? I ran that engine right after this happened, and I tried to make that engine quit and I couldn't. I was banging that throttle stick as fast as I could and that engine wouldn't quit. I'm beginning to think maybe it sucked in something?

Should have it out today, we'll see what happens.
Ken

Newalan

Hi,

The similar sort of thing happened to me 2 months ago, I managed to land OK because I had a lot of height, and throttled back the good engine to half and using the rudder it was manageable ( I had set my rudder for a lot of throw on dual rate and that is what I used)

I have had same happen again, but this time the whole thing was less dramatic as I have two cheap Gyros fitted one on the rudder and one on the Aileron. As soon as the Engine quits the model yaws, the gyro pick it up by putting correct and timely input, the wing drops and the aileron gyro pick that one up. I was able to keep the throttle to almost 90% and land the model.

I have read reports that some guy tested a twin with two gyros and even completed a take off and landing with a single engine. I am not brave enough to try that, but apparently with gyro it is possible.

boingram

Newalan,

Please tell us a little more about the gyros.

Thanks,

Bo

Newalan

Hi Bo,

If using two Gyros you need to use Hobbico “Aero Gyro� or the Futaba GYA351 (FUTM0817) which supports 2-channel input and output for a single axis. This is because most Gyros will not work if connected to a "Y" lead and you require to use two different channels to operate for example your Ailerons (not so critical for rudder since that uses a single servo therefore a cheap Gyro will do, but not the Heading Hold type)

The technique of using gyros on a twin and flying a twin is very well explained by a guy who calls himself TwinMan he has a lengthy article. at: [link=http://www.rcwarbirds.com/Techniques/Technigues.htm#t2]http://www.rcwarbirds.com/Techniques/Technigues.htm#t2[/link]

To save you looking for it I have copied and pasted all the relevant details below: The article below is by a guy called Twinman I have used the advise he gave and it works.

I have previously explained how losing an engine on a twin can result in an inverted flat spin faster than you can imagine. It’s worse on Warbirds with high wing loading and wide engine spacing (P-38, B-25, etc)

I have decided to see if the problem can be solved by using two gyro’s on the plane. One gyro on the rudder, and a dual inlet/ outlet Hobbico “Aero Gyro� on the ailerons. This in mind, and for the glory of Bayou City Flyers (I hope Greenwood is getting this), I programmed my kit bashed Twin Ugly using a 8 channel Futaba to intentionally cause an engine failure and possible crash! Via a rotary dial channel, my copilot, and son Kyle, (who was only too happy to deliberately cause a crash) was able to bring one engine from full power to an idle on my command. As a side bonus this allowed me to sync the engines at idle very easily. After the initial setup and trim in flight I noticed a much more stable aircraft. Maneuvers became really rock solid. Hanging on the prop straight up was almost hands free. Now for the test. I flew level at half throttle, pulled the nose straight up and went to full power. At this time I signaled to the copilot (who was dying to help) to cut one engine to idle. This should have caused an immediate inverted snap roll. It did not. The plane slowly yawed toward the retarded engine. (I said retarded engine not pilot!) I then applied down elevator and flew three laps around the field, at various power levels, in a tense but controlled manner. The plane was flying at almost a 30 degree yaw angle in level flight, but fly it did and it should not have. I signaled my copilot (who had his mouth open in amazement or disappointment!) to bring the idling engine back up to speed. The engine promptly died! Naturally there was a cross wind, and I’m starting to have chest pains! The landing however was uneventful.

This test did prove that the concept works. The gyro’s, as used here, do not take control of the plane but rather dampen unexpected actions sufficiently to allow you time to react. If you have to rely on your reflexes to do this you are already about a second or two behind the plane which, in a lot of cases, is too late!
As a side note I used the Hobbico “Aero Gyro� because it allowed me to use separate channels for the two aileron servos so I could mix in aileron differential. You could also couple the elevator and ailerons for more positive elevator control. This gyro also allows me the option of turning it off in flight as needed for aerobatics.
Are gyros the answer? Nothing replaces ability, but they do allow you to relax a little while flying twins. I have already had my heart attack trying this and could use a little relaxation.
Additional. This concept was further used with great success, on an Areotech P-38 and was proved to be a viable way to control the P-38.

Twin Engine Saga: So You Want To Do Twins ? {Part 6} By Twinman
It has been five weeks of me trying to talk you out of trying twins. Still you won't listen, so I will write the final chapter. (Cheering is in bad taste) The old twin ugly has served it's purpose to be the test bed of these articles and now retired and in the hanger. No, it is undamaged!!!! The final test was to try the most difficult and dangerous maneuver for a twin engine airplane...The Single Engine Takeoff! The twin ugly has served well in these tests and so the decision to try the single engine takeoff was an easy one....Yeah, let's do something new!!!!! (Told you flying twins was a nutty idea!) Total time for the decision....2.5 seconds. One early (so as to have not too many witnesses) Saturday morning the old plane was fired up on twin engines and twin gyros (See Last Month Story on Gyros) for a refamiliarization flight. This went well by trying eight point rolls inverted low passes etc.. The plane was landed and one engine refueled and the other tank drained. Gyro for the ailerons set to maximum rate. My son and copilot Kyle ( always one for a good crash ) assisted to carry the doomed plane to the far end of the runway with the single engine at quarter throttle to maintain heat. The single engine run up and was held at the straight up position for the 10 second requirement, for safe take off. The plane was set on the runway (The peanut gallery was unusually quiet.. Or was taking side bets) Rudder and aileron set at 50 percent into the running engine, (This rapidly increased to 75% during the roll out) and with a deep breath, the plane was off at a very slow pace. Remember that one engine out is not half power, but a loss of up to 90% of the required power for flight and climbing. The plane was held to the ground the full length of the runway to gain maximum air speed and so control at lift off. I pulled up around 20 feet from the end of the field and began the slow climb for altitude. ( Your Friend) Controls were sluggish to say the least, but controllable.

I made a turn into the engine( Not recommended and difficult as the plane wants to turn away). First concern was to put as much space between the plane and the ground as possible. After three circuits around the field, I decided that it was time to land. (OK, my hands were shaking so bad that I was having trouble holding the transmitter.) The peanut gallery seemed unconvinced that one flight was actually a test of skill, so a second flight was attempted.( My son is concerned that insanity is hereditary, I assured him that only hair loss is!) The second flight was as uneventful as the first( OK so it was just as terrifying as the first) It was going OK until the peanut gallery (One half of my club...to name but a few of my "friends") started screaming to LOOP IT,ROLL IT.

Well, not having good sense to ignore the challenge, I climbed as high as possible. This is a difficult process on one engine. Yes, the plane did both loop and roll on command. One low life commented that a real pilot would have done as low level inverted pass! Call me woosy,,, No way!!!!! Seriously, the tests conducted with the twin gyroscopes are, in my opinion, a complete success, and will be added to two P-38's I and my son are finishing as we speak. No, the gyros are not necessary for all twins and I don't use them on my other two twins, but if you are going to start with twin engine airplanes, and even think about the P-38 ( Understand an ARF is coming) or any other heavily loaded high powered twin and expensive war bird, I would really like to recommend them as cheap insurance. Good Luck and see you at the field...I'm the one with the twin electric fans on my Aggie hat!!!!!

Prairie Mike

I haven't read any comments about "minimun single engine control speed". Are there any full size multi engine pilots on this forum who would like to explain the concept?
you can maintain control with an engine out as long as you have sufficicent airspeed. I've done it several times with my dual ace. I even made a
low speed (but not too low) go-around and climbout on a single engine.
With the twinstar I made a single engine takeoff. Was on asphalt for that one though. If you get the airspeed too low, NOTHING will help you.

don't ask me how I know that................

Pilot P51

My Feedback: (6)

Mike
I am a full scale pilot and I have a twin with over 35 years of flying. The major difference between flying a twin and single engine is knowing how to manage the flight if one engine loses power. On normal takeoffs we use the manufactures recommend rotation speed (Vr) or liftoff speed (Vlof). On each aircraft the speeds are different.
Minimum Control Speed (Vmc) is designated by a red radial line near the low speed end on the airspeed indicator. When you lose an engine, the pilot will need to stop the turn that results when the critical engine is lost to within 20 degrees of the original heading, using maximum rudder and a maximum of five degrees angle of bank into the working engine. This will maintain a straight flight.
Vmc is also determined with maximum available takeoff power, Propeller windmilling in takeoff pitch or(feathered) and maximum takeoff weight.
There are a number of things the pilot has to do when flying a scale twin verses flying a R/C plane when it comes to flying with one engine. The main thing is to get the plane on the ground in one piece.
Another helpful hint in flying an R/C twin, when you do lose the engine try to make your turns in the same direction the engine is running to get back to the runway, if possible. The plane will want to yaw or turn into the engine that has stopped working. Turning in the opposite direction you have a less chance of spinning the plane into the ground when making the turns.
I have seen this happen more than once. Were a pilot will recover from a lost engine but as soon as he starts his turn back to the runway he turns the plane and into the ground it goes.

I hope this helps in what you were asking about Single engine control speed.
Walt

TED 1

Interesting to read all the information on engine out experiences with the dual ace. I have been flying 2 of them....one with the original nacelles and OS LA-40s for power, and one with home made custom nacelles and OS FS.52 four stokes. The 2 strokers are using 10 x 6 props and the 4 strokers 11 x 7s. The latter has much better performance even though the 40s supposedly have more power. I will include a picture of the 2 airplanes. I have about 225 flights on the one with the 2 strokes and about 30 on the other one. I have had 4-5 engine outs on the 2 strokes and just some falters with the 4 strokes, but none where the engine totally died. My experiences have left both planes in tact with no crashes. I have actually flown a couple laps before landing one time. Here are my observations. Mentally, be ready to chop the throttle on the good engine if things go bad. I am not the most adept with the rudder (as I suspect many RC pilots are) as with the ailerons, so my natural instinct is to correct for the yaw condition with ailerons. That will work, but.....be extremely careful turning into the dead engine. The first time I tried that I went into one of those spins where the dead engine wing just dropped and luckily I quickly cut power and was high enough to pick up speed and resume flying. I slowly brought the power back up and turned by just letting off the aileron correction I had applied and she began turning toward the dead engine. I have since applied more rudder for correction and that definately helps. The next dicey thing is when you are lined up for landing and chop the power. You must immediately go to neutral on the controls or that thing is going to take off toward the engine with power due to the correction you had been feeding in. Now, when I have an engine failure I correct and reduce power so she flies straight while trying to maintain altitude until I am ready to land. The faster you are going when the engine quits the easier it will be. The time I flew the two laps it quit at high speed during a dive and initially I thought it just went out of trim.
One of the 4 strokers faltered once rigfht after lift off and luckily came back on or I think I would have lost it.

RevGQ

Question: How much rudder throw did you have dialed in?

rexracer

I have a pair of Saito 45's. They'll turn a 12x5 at over 9500rpm. Do you think they'll fly this plane ok?

old bird

Rex racer, I'm flying the Dual Ace with a pair of Magnum .52 4-strokes. It flies just fine with 12-6 APC props or 10-7 Graupner 3 blade props. I'll bet your Saitos are making more power than the Maggies. I get right at 9000 rpm with either prop. Our field is at 5000' and the plane has plenty of power for BIG loops and is pretty fast too. This is our first twin and we love it.

Best regards, old bird.

craigie

My Feedback: (69)

I have a Dual Ace and am very interested in the idea of using gyros. Can someone give me additional information about the use of gyros including where to mount them, connections and set up.

Thank You
Craigie

Capt. Crackup

My Feedback: (1)

Hey Guys, I almost have mine put together. Using Thunder Tiger 46 2 strokes. It may be a short while before it flies because I'm still waiting on my new RDS8000 radio to get here. In the mean time,,,,, How has everyone been mounting the fuel tanks? Are you cutting the nacelles out and padding or "pressing" the tanks into the ply holders? Also, how is everyone transporting the Dual Ace. Thanks Skip D

boingram

I have over a hundred flights on my DA and I just press fit the tanks in the nacells. I use two squirts of Armorall in my fuel to relieve any foaming (old modeling trick).

No harder to transport than a 60-size sport plane.

Bo

Pilot P51

My Feedback: (6)

I went with bigger tanks, they are press fit with foam on the bottom. I had to shave out the nacells to make them fit. Read back on this thread I posted how I did it. As far as transporting, I have a big trailer with racks built so I have no problem. With the wing not being one piece it can be a hassel to transport.

Walt

Capt. Crackup

My Feedback: (1)

Thanks Bo and Walt for the rapid response. I just sold a C 160 Transall and those tanks were hard mounted. Didn't have any problems..... I have observed others with ARF trainers and such that had press in tank designs and they worked as well. Years back, hard mounting tanks was a strict no no. I heard of the Armorall trick but was reluctant to use it because I heard that the silicone would contaminate the glow plug. I don't know if it is true but from what I understand the fuels today run much more anti-foaming agents than years ago. Thanks again. Skip D

mrbassman

Hi Skip, I was able to put the Sullivan 10oz flex tanks in mine. What I did was open up the hole in the firewall for the plastic cap of the tank to fit in. I was able to get some padding on the tanks and they fit snug, not tight. Make sure your props and spinners are balanced and you shouldn't have a problem with fuel foaming, I've yet to have that problem. Balance it at 100mm, not the 85 as the manual says, that's wrong. I put in a bit more elevator throw than the manual calls for, I heard about guys "running out of elevator" on landings. Playing the throttle and elevator just right, I can land mine slow enough that someone can jog alongside next to it. Never used flaperons yet, don't need them.

I'm using Evolution 46's with Graupner 10-7 3 blades, if those TT 46's are the same, you'll be flying around at half throttle, maybe a bit less. With the 10oz tanks, I can stay up for 13 minutes and still have plenty of reserve for go arounds.

I did put a dedicated servo for the nose wheel, it's a cheap servo, but the nose wheel takes a good pounding and I didn't want to tear up a $40 servo.

The only thing I will do is make a new rudder a bit larger than the original. I find it not to be too effective. If you lose the left engine, which is the worst of the two to lose, the extra rudder will definately help. Also go with a pull-pull system on the rudder.

Hope this helps, I know that thanks to everyone on this thread, I didn't have to learn some things the hard way.

Ken

old bird

Bo Ingram, the Armorall as an anti-foaming agent is a new one on me, as I am fairly new to the hobby-sport. Would you care to elaborate a bit? Is it two squirts per tankfull or two squirts per gallon. I don't have a foaming problem in the Dual Ace but I do have it in our GP Seawind, and other seaplanes with tight engine pods are prone to the foaming problem.

Best Regards from old bird.

Capt. Crackup

My Feedback: (1)

Hey Guys, I put my Dual Ace on the balance rig today and it balanced right at 105mm. I'll leave it like it is and mount my receiver up forward. When I looked at the engines closely, I noticed down thrust on both sides , OK. but on the right engine there appears to be left thrust. Has anyone else noticed similar on theirs? I think tomorrow I'll put some washers under the mount and take that side thrust out.
I think right thrust or none would be OK but I don't like the left. Any thoughts? Skip D

chrishwegner

My Feedback: (38)

I don't think that I would take out the out thrust of the engines. They were designed that way to minimize the yaw problems in case of an engine out situation. If you look closer you will probably see out thrust on both engines. Just my thoughts.
Chris

boingram

...a couple of squirts per gallon...Clarence Lee has signed off on this so I assume it's OK. Been doin' it for years.

Bo

Capt. Crackup

My Feedback: (1)

Hey Chris, I said on the right engine there was left thrust.. It is pointing in. I've seen no thrust and out thrust on twins. On my DA there appears to be a very small amount of out thrust on the left engine, and a fair amount of in on the right.
Bo, I'll keep that Amourall deal in mind in case I have foaming issues.
Thanks.Skip D

chrishwegner

My Feedback: (38)

Skip,
Sorry for the mixup. I don't know my left from my right so I normally carry a rock in my right hand to tell the difference. I had to drop it to type that reply.
I have a 11 inch prop on my DA and setting it horizontal I measured each end back to the leading edge of the wing and found that there was about 3/16" of out thrust on both engines.
I have a DA , a TF Ccessna 310, a Nosen 310, a Twinstar and a Twin air all have varying degrees of out thrust.
Could you have mounted the engine boxes on the wrong side? I checked the installation manual and did not find any mention of which is right and which is left. Hope this helps.
Chris

Capt. Crackup

My Feedback: (1)

Hey Chris, There is a angle on the back of the nacelle boxes that corresponds to the trailing edge of the wing. So its pretty much impossible to get them wrong. I verified the angles and there's about 1 degree out on the left and there was about 2 degrees in on the right. I shimmed the right engine mount with some flat aluminum stock and flat washers. Total shim is about .025" I now have about 2 degrees out on the right engine. So I'm happy now, at least it seems to match yours. I have been flying and just recently sold a C 160 Transall which had zero side thrust. I still have and fly a Twinstar with about 2-3 degrees out. Because of those airplanes and of course single engines, I was concerned when I saw the in thrust.......I guess we'll see what happens. I am pretty much done with the Dual Ace except installing the radio and doing final adjustments/setup to the servos. As I said before I'm waiting on a new Airtronics RDS 8000 to come in, as I'm converting over to Spread Spectrum. Until then, I'll continue to watch this forum and hopefully be flying soon.........Later Skip D


Also here's a short video of my Transall. I'm sorry it's not a Dual Ace, and I hope it doesn't bother anyone. But if your interested here it is. Hopefully I'll have one shortly of my DA.


http://www.rcuvideos.com/item/96N5T1FMM39XC8HL

rastus21

Well flew mine today. It was very succesful. Flew very smooth, and surprisingly slow on approach, very easy to handle plane, just a nice smooth sport plane.

All standard, and found the kit to go together very easily with out trauma. Great price here in OZ, really a winner.

Using OS 55 ax, nice and quick, just the way I like em. Rolls beautifully on low rates, and very stable in the pitch axis, benign stall. All good. I already love this plane, and I'm using it as a twin trainer for a bid WW2 twin.

Cheers

Matt