Planes > Jets

SR71 Blackbird first public show Duxford 2010

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Happy Days:
Interesting to hear that John.

The reason I was asking about twin prop planes is because I was thinking of getting one. 8)

I find the concept interesting, and I’m looking for a new challenge.  :wink: (Don’t think flying powered twins/multi propped planes will overtake my love of flying gliders though.)

The problem I face is one of cost. I’d almost certainly buy ARTF and not having any spare outrunners/esc’s, they would have to be purchased as well. So I’d probably be looking in the region of 500 quid.
If the project then went tits up on first flight I’d be pretty miffed! :cry:  :cry:  

Something to think about though…………HHHHmmmmm……………… :?:

K.

gerryb:
john is right about getting the eng's as close to centre line as possible. the cat is basically a pylon mounted wing, so it's very easy to get the eng's in there. i resurrected an old 'twintub', (yea, that's what it was called), a few years ago. 7ft span, parasol wing. took off on 2x 25 2-strokes, would fly around on one eng without a bother. the key was keeping the eng's close to c/l.  i then bought a hobbico 'twinstar' from tower hobbies,  flew very well, i'd certainly recommed it. it was designed for 2x25's but with a few mod's, i'm sure it could be converted to el. check out t. h. website for video.
i had a few eng out's with the twinstar. the chances of saving it depend on several things...
1   total concentration on the model all the time.
2   identify which eng has died as quickly as possible (that means              immediately!)
3   throttle back and get the rudder into the live eng . this will yaw the dead eng wing forward and (hopefully) prevent the live eng wing from banking so steeply that a crash is inevitable.    
4    when flying twins, always bring a black bag with you!

gerryb:
keith,
re tuning both eng's...
you're way beyond me on the tech's of freq's, harmonics etc. i just tune each eng to peak rev's then back off a notch or two on the main needle. then i stand over the c/l of the model and listen to the sound of each eng. a little tweaking is usually all that is required to get both eng's 'on song'. a bit of practise and you will know when things are right. patience and time spent on those eng's will reward you with a satisfying flight and a big grin on your face.
i have no knowledge or experience at all on el twins.[/quote]

Happy Days:
Well, thank you for all that info Ger. (Clearly you are a very adept typist as well as a skilled rc pilot!)

It seems that flying twins is a risky affair. I saw a vid on You Tube the other day of a twin taking off. I’m not sure exactly what happened (I suspect it was your number 3 Ger.) but immediately the plane lifted off the ground the right wing rose, rolling the plane onto it’s left side and crashing before the thing had  passed the end of the runway. :cry:  Pretty sickening stuff!

In my case I’d definitely go electric, I have no experience, starting equipment, or desire to use ic. It does seem like a good challenge. I shall have to think long and hard about this matter. :?:  :?:

Thank you both for taking the time to input on this topic. :clap:

Keith

JohnPearson:
Hi Guys

Quick post today, the SR71 completed it's first test flight, all went well with the model and it flew great.

Well done Ian Robb

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