Crash Alaska

Hello all,

I'm thinking about getting into multi engine. I've heard all kinds of stories about the hazards (read horrors) that befall a plane that loses an engine in flight and this has always made me hesitate. What are some of the things you could do to an aircraft to assist with stability in the event of an engine failure?

Can anyone recommend an online store with a good selection of multi engine kits/ARFs? TIA

Dennis

mboland

I have just gone down the same path having purchased a VQ Models P-61 Black Widow ARF.
The next step was to read all I could find on twin engined planes, how best to set them up and how best to tune them.
What I have done is to add elements for reliability first, on board glow, fuel pumps. There are others such as Twin Sync but I had to draw the line somewhere.
Next I added a Gyro to the rudder. I already had one on the ailerons but after reading some articles on work some one did with twins and they even managed to take off and fly successfully on one engine, because they had fitted a gyro to the rudder. It will also catch the dreaded engine out spin at least until you have a chance to realise one engine is out and make suitable preparation s to land.
The Widow has had it's first disassembled inspection by our heavy model inspector and is now ready for ground trials.
First flight should be in a couple of weeks.

firedude0025

If looking for a glow unit for a twin Switch Glo is a great product that runs just off your Rx pack and can be toggled on/off with a switch or mixed in for low idle. works with 4.8 - 7.2V and one unit can handle both engines. (www.switchglo.com)

octane-link

I have heard the Twinstar makes a good first twin-engine plane, I am going to get one of these soon. They can be flown on one engine, there is a review of it on RCGroups where the pilot did lose an engine and flew just fine without realizing the engine died.

orygg

Hello, the first thing flying a multi engine is tune engine good and hear,dont nead twin sync or gyro if good tuning,butt remember tune down the stronges engin,if one stopp just fly it like a dead plane. Best regards orygg[sm=thumbup.gif]


PS Ripmax Harmony is a god plane begining werry stabel

ram3500-RCU

My Feedback: (221)

Here is my take on this.

Step one. Buy the best engines you can afford. Good, powerful, reliable engines like the OS AX line of engines. Both of the same vintage as well.

Step two. Run them in a little. Don't break them in in the air with a twin like you may a single engine plane. Just too many issues here. Even if it doesn't quit, a good long sag is enough to initiate a spin.

Step three. Try to mount them sideways versus inverted. If this can be done, IMO, no on-board glow is needed because of much less plug loading. Save the weight if possible, something else that will help you on one engine. The lighter the better as with all airplanes.

Step four. Tune each engine for the best run of that engine. Don't try to get identical tack readings on all the engines. If each engine is running as well as it can through it's RPM range, you are unlikely to loose one, which is far worse that a couple hundred or less RPMs that can easily be compensated for.

Step five. If you can swing it, install a gyro on the rudder. The biggest problem when an engine flames out is that first couple seconds while you try and figure out which one it is. Here is where most crashes begin. That gyro will give you time to gather it all together. And make that first engine-out turn in the correct direction. You DO NOT want to make that first turn into the dead engine. After you have figured out the correct amount of rudder to compensate, you keep the wings level and make almost flat turns. Use the ailerons to keep those wings level, not to turn. When you have all this figured out, it is possible to even turn into the dead engine with large sweeping turns, under almost full power on the good engine, but this depends on the plane and the size and shape of the rudders. Unless you are sure of all this, this should be avoided. With flat turns, and good rudder control, you DO NOT have to 'dead stick' your nice plane. Fly her in and give her a chance, carefully.

One more suggestion. Many of todays simulators have good programs for twin practice. You can even program some for random engine failure. This is great practice. As with full scale, failures are rare with good construction, equipment, and maintenance, but a good pilot is always prepared for the unexpected. My Uncle said he always had three possible emergency landing areas picked out ,as he flew across country, because it was faster to eliminate two than find one, in a crisis. This saved his life on one occasion.

octane-link

One note to add:

Mathematically, you want to fly with the dead engine high and leading. This gives you the ability to turn away from the dead engine and also fly at constant altitude and speed.

ram3500-RCU

My Feedback: (221)

Good point. I should have included that.

Crash Alaska

Thanks for the feedback. I am thinking of using 4 strokers instead of two. Anyone have any opinion of this? How effective is a rudder gyro for initial compensation of flameout. And as far as gyros go, do you refer to a standard heli heading gyro? I ask because I already fly helis and have several gyros. Thanks.

ram3500-RCU

My Feedback: (221)

I like 2-strokes for twins. More power with less weight and torque in the higher RPM range, and a better RPM range of control. The last thing you need with a flame out is a torquey engine. This may be just more personal opinion than anything else, but I have never crashed a twin in 38 years plus of flying RC. As for the gyro, I'll defer to some one who will probably explain this better that I.

mboland

I have tried a couple but the Futaba GY401 is a nice choice. You can also use the extra channel to change it from normal to HH and select sensitivity while in flight. The GY 240 is what I use in the Corsair but all adjustments have to be made manually.
The Aileron gyro is the one built into the Weatronic unit I am using.

octane-link

I have used the GY401 on a rudder, but for a different purpose, and it works very well. One note is to make sure the direction is correct, I can't tell you how many crashes we had due to that little switch!

jaka

Hi!
Get much some years flying and engine tuning experience before you try a twin.Then get reliable engines and set them right (by ear)! No scale twin please...just a sport airplane...and no gadgets like engine sync or gyro. And second most important thing to consider...Keep the plane light!