Hello guys

In need of info.
Yesterday my :cry: Avond F15 bought the dust ( write off )
Well I use Philip Avond KISS principle. No aileron ,rudder just kept it simple.Have been flying this for 2 great years.
During yesterday takeoff with strong cross wind my F15 clipped a low branch on the side of the runway and sling shot it back on the ground. Full left elevon but no effect at this takeoff speed.

I was wondering if I had ailerons on this plane would this react better at low speed as oppose to just elevons???

I am planning to buy another F15 ( maybe Santa can help me with this )

C Lim
Catapult launch??

I don't know if ailerons would have helped in this situation or not. Sounds like what you needed is a rudder. I'm not into doing knife-edges with a jet, so the only time I use rudder is on crosswind take offs and lining up with the runway on landings.

I wouldn't build a jet without a rudder. I've been out flying on crosswind days when other jet buddies couldn't take off without a rudder. Some may feel strongly about the KISS aproach, but considering the time and money invested in these birds I want the redundancy of ailerons and rudders in case a servo ever fails in flight. Also from what I've seen most planes fly better with ailerons than tailerons.

Joe

Talking with my good buddy, Gordon......I don't THINK(!) I am going to buy a kit where ailerons are not an option. The unfortunate thing is that rules out a lot of great planes (Avonds). Servos (along with everything else) do fail, and if one of the elevon servos fails....it's good night Irene. I know lots of people have had thousands of trouble free flights using elevons. I just won't be one of them.

I understand the KISS approach (especially the stupid part), but I am willing to sacrifice some simplicity for redundancy.

Bob

Have you checked with any Avonds F15 owners to see whether ailerons could be added easily ?

I know Tam lost his Avonds F-15 when one elevon came off - but he would probably have stuffed it anyway, even if he'd had ailerons (grin - just kiddin Tam !)

If you can't find your perfect aircraft, see whether you can find something that's close and modify it to be better !

Gordon

You know what?! You're fired as my mentor!

You know I didn't really mean that.......can I come down and what you glue some stuff?

Thanks for your input Guys!!!

That means doing some modifications if I find a new Avond F15 under the X-mas tree or I'll wait for Y/A New F15. Spoke to them already which will release it in March next year (finger crossed).

PS Has anyone modified their Avond F15 with aileron and rudder??
What throw did you put in the controls ???

Thanks in advance

C Lim
Happy landing

I forgot about that one! Do you remember if Yellow said their F-15 had ailerons? Thanks.

Bob

C Lim

I can't speak to the aileron question, but here's waht Avonds' says about recommended ruder throw on the F-15.
Johnny

Sounds to me that a chain saw to the tree would fix the problem.....

If you are going to have just elevons, then surely it makes sense to have two servos powering each elevon via a sloppy link. Full size aircraft never have their flying controls powered by just one system.

Great info's

Well I just spoke with Tam Jet and he will do a review on this plane very soon. My X-mas tree looks empty so I'm looking at the Eurofighter sport 3D and then the F15 next year.

C Lim
HaPpy Landing :spinnyeye

I would use at least 4-40 stuff or bigger on those rudder linkages insteat of 2-56. 2-56 stuff is too small!!

I have heard of more F15s written off, or badly damaged, because they did not have rudder control than any other cause, sounds like this is another, totally avoidable, write off !

Why do you guys continue to compromise on flight controls to the point of having NO aerodynamic control in the yaw axis and yet your aircraft has freedom in that axis. ?

By all means KISS but deleting flight controls has me baffled. My F15 has been flying for over three years with all models of JetCat and is a delight with tailerons (the tailerons provide all the pitch AND roll control needed) and rudders. Only mod I would do now is ganged 8411s on each stab. for redundance like my F4.

Add rudders, add a gyro and let the thing do beautifully straight takeoffs with very little pilot control input even in, reasonable, cross winds.
BRG, David Gladwin.

David, can you provide a picture on how you have ganged the servos? TIA

Bob

Dead easy. Connect one arm to stab. as usual. Then connect the second servo output arm using a rod and two clevises. to the first servo arm using holes in the arm which are in the same positions on both output arms.

As two servos will rarely give identical travels with the same receiver signal I very slightly enlarged the holes in the output arms where the two servos are connected to allow a little slop so the servos aren't fighting each other

With two JR8411s the F4 stab. has a mass of power making life easy for the servos, further reducing risk of failure. .

A JR matchbox could also be used. If one servo fails there every chance I will retain elevator control. Control redundancy, gives me a comfortable feeling !
BRG, David Gladwin.

Hi Guys,

I owned several Avonds F-15`s in the past and they were tough in cross winds. I remember taking off in a still cross wind and had to hold full opposite tailerons to fly straight!! This was before the "rudder rule" so the jet was not equipped with one. There is nothing like ail control to keep that outboard wing "down" in bad cross winds. The big undercamber wing and tall tails are very sensitive to cross winds. Otherwise the jet was simplicity at its best and the BEST landing jet you can ever buy, once the wheels touch down they are stuck, no bouncing ever.

Vin...

Flying Helis has taught me to use rudders all the time. I believe in active, properly set up rudders on our jet models. Cross wind take off/landing, knife edge and other manouvers need rudders!!!
Just got a built F15 w/o rudders and will install them asap!!

JHH sells the orginal (twin engine) version of the Avonds F-15, and it comes out of the box configured for ailerons. For those of you who want to put ailerons on your Avonds F15, and are not sure of the best way to do it, should give Larry Wolfe a call and he will get you squared away.

Regards,
Peter

One of our club members is flying the Avonds F-15 with ailerons he purchased earlier this year from Scott Marr, down in Texas.

The ailerons add a nice scale detail, and allow one to better keep the upwind wing down in a crosswind takeoff or landing. I have seen more than one F-15 end up on it's back in a stiff crosswind. Interestingly, it still has the tail waggle that all 15's and 16's seem to have, even though it is using the horizontal stabs only for pitch control. The installation is straight-forward with a flat-servo (forgot the #) buried in the wing with a pushrod out to the aileron.

Rudders, with all the throw you can get, complete the crosswind package.

Still, probably the best jet trainer around.

I have one of Philip's F-16's on order and am hoping it flys as well.

Tom

Apparently the GR1 tornado was initially built without a rudder. From what I read, the first crosswind approach brought the designers back to reality. Test pilots told them it needed a rudder.
If the use spoilers does not reduce the need for rudders, and they produce positive yaw in the turn, then elevons definately need help in the verticle plane. How many full size aircraft do we see without a rudder.
Dave

With the exception of the B2 and an early German jet flying wing, NONE ! Even the Wright brothers worked that out 100 years ago !.
BRG, David Gladwin.