I have an old E-Flite F15 twin EDF (from 10 years ago) that I am about to fly. When it was going last, as soon as the nose lifted off, keeping it on the runway centerline was pretty hopeless.
I wonder if I held down elevator until I was ready to rotate, would that work?
A valid technique? (A bit like a tail-dragger in reverse? )

The wind is going to decide if you can fly as you will need it right down the runway if you don’t have working rudders.
Pushing down elevator is not a real solution.
Install a rudder servo (or two).

shorten the nose strut about 1/4-1/2 inch.
get it to a 0 or 1-2 deg negative angle of attack, then stay off the elevator until it has reached full flying speed.

Better still,
Chuck it!

Yes you can hold some down elevator to keep the nose on the ground. Not much as you don't want to wheel barrow before take off..If there is hard cross winds keep the elevator neutral. Cross winds can be a pain with no rudder but can be dealt with. Hold aleron into the wind and let it build up as much speed as possible before rotating. No flaps if you have them.. I have many 70mm size jets with out rudder and cross winds are common at our field..

Sure. That is why the only real plane made without working rudders (the Aircoupe) was so wildly successful. Unspinnable, easy to fly and only one pedal on the floor!
What a concept!

No, just spend $3 bucks and put in a servo to make it work like rudders were intended.

That would be easy if the kit was designed for rudders which is was not...And I wouldn't trust a 3 Buck servo in a paper plane..But that is just my opinion...That is also not what he was asking....

Adding rudders to a foam model is about as easy as it gets.
I answered his question earlier.

Plenty of cheap servos out that work well. Here is one for example that has flown in a number of my 90mm and twin 70mm jets.

Thanks chaps - I am going to try those suggestions (no room at all in this plane for servos and rudders). It flew fine 10 years ago - I am thinking a gyro on the nosewheel and down ele might do it.

Originally Posted by randallp

Thanks chaps - I am going to try those suggestions (no room at all in this plane for servos and rudders). It flew fine 10 years ago - I am thinking a gyro on the nosewheel and down ele might do it.

Gyro? Why not just a servo on the nose wheel............ without any rudders?

The nosewheel has a servo with gyro (in the FrSky Rx) on rudder channel. It gets off quick when it has a bit of speed just the initial bit of flight :-)

Originally Posted by turbonut

That would be easy if the kit was designed for rudders which is was not...And I wouldn't trust a 3 Buck servo in a paper plane..But that is just my opinion...That is also not what he was asking....

3 buck servo for rudder is fine since it does
just very little work on the ground. That is it...
Just me though :-)


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This was a very early (10 years ago) twin EDF
The thrust tubes allow no room plus the wight would mess it up.

It will be fine. Way over-thinking. Your initial instinct is correct. Hold the nose down with some elevator until you are a flying speed, then pull back to jump off the hard quickly.

You don't need rudders, I fly a Yellow F-15 with twins 90's and it takes off and flys around fine with no rudders. Would be nice to have them, but you certainly don't need them. I'm more interested why it's pulling one way. I'd make sure everything is straight, batteries are about the same, fans are putting out about the same

Check to make sure it's not tail heavy, the shorter nose gear is a good idea so it sits level. You don't need nose high on a F-15, it'll rotate very easily