Hello,
I have become proficient flying a HZ Super Cub. Felt confident enough to finally step up to an EDF foamie. Put together a Phase 3 Fantom EDF, a delta wing edf with twin vertical stabs and elevon control surfaces . Sadly it crashed on take off during maiden. Following a level hand launch at full throttle, I pulled back ever so slightly on stick to gain abit of altitude. The plane rolled over on its back and nosed right into the ground. The fuse is badly damaged, in more pieces that I care to count. CG and elevon throws were verified prior to flight. Wind was calm. Flying 2.4GHz. What did I do wrong?

Ken

You most likely stalled it by applying up elevator. You need to allow the plane (ANY plane) to build speed before climbing.


You said you had full power and that's good for part 1 of the take-off, but a healthy airspeed (part 2) wasn't there just yet for a gentle climb-out.

I say this as I assume your control surface servos are plugged into the proper ports of the RX.

I was thinking the same thing.

My initial thought is you pulled back on the elevator before it had proper flying speed and stalled. Since you did not have the chance to trim it out, it may have had just enough elevator to keep flying but on the edge of a stall. When that little bit of up elevator was applied, it was just enough to raise the nose, exceed the critical angle of attack for the airspeed being flow and one wing just gave up and quit flying. When it rolled over on its side there was not enough airspeed to fly knife edge (not to mention no rudder) which allowed the nose to fall through and meet head first with terrafirma who usually wins that battle.

IMHO, think you are trying to make too big of a jump in planes going from a 3-channel rudder/elevator plane to an EDF. You need to work up to the EDF by flying something with ailerons and aerobatic like a Formosa or similar type of plane. Learn to fly aerobatics first and master maneuvering the plane while working up to the EDF.

EDF's can be a handful - I did a maiden on one recently and fought it through most of the flight. It snap rolled and spun on me but luckily I was able to recover it literally less than 1' off the ground turning final. When I went to flair it snap rolled again but luckily it was only a couple of inches off the runway (I promptly landed it and told the owner to hand it on the wall).

Hogflyer

This may sound harsh, but if the throws were checked and the C.G. was checked then it may simply be you didn't have enough time under your belt to trim a model that needed trimming on its maiden flight. best to have a trainer/instructor put a first flight on an untried model - especially a fast one. A sleek ducted fan model doesn't allow you to try stick corrections at low altitude and if you fed in the wrong control . . .

You have to keep ahead of it - not react to it.

Planes like this don't get an ample supply of prop blast over the control surfaces, so everything has to be setup dead on perfect, no matter what your flying experience is. Fix it as best you can and keep trying. The aforementioned advice to allow the plane a shallow climb out is good. If the plane had more power, you would probably be very happy with it already. IMO, it's probably some underpowered POS.

The dreaded "tip stall"
Delta wing aircraft have quite different handling requirements to normal aspect ratio types.
Slow speed rolls with pitch are deadly. Any manoeuvre that results in roration about 2 axes can result in a "departure". It may be that you had just enough of a cross-wind component to flip you over at a critical point of flight.

You could try bungee launching.

That is the perfect crash senario for having the ailerons reversed. That's the first think I'd check...and double check....and check again.

Thanks
Barry

With my typhoon (3 D foamy), it can be a little squirrley during hand launches. I never need full throttle during hand or ground launch. Full throttle may have been too much power, about half throttle would've maybe given you some time to react to the roll. Were you using low rates or duel? Other than that, you will be suprized how many times a foamy can be glued back together with a hot glue gun and still fly! LOL! My typhoon is still flying after numerous falied hovering attempts, has broke behind the engine completely in half serveral times. A glue gun and clear package tape are a foamy flyers best friend. Anyway that's my 0.2 cents worth

I'll agree with Barry, Elevons too.

Bob

A 3D foamy and an edf are completely different animals and the edf needs full throttle to take off on a hand launch. I maidened one just yesterday, a Kyosho Illusion DF45 and it needed quite a bit of time flying straight and level out of my hand before I could pull up for a climb out. After it had the speed, it was a good flyer, but the edf's dont accelerate fast like a 3D plane, but they do acheive faster speeds.

The roll is the clue everyone is helping you with. Your up elevator became down elevator when it rolled. If you held up elevator you nosed it into the ground. But that's not the important thing. This model evidently has elevons.

It sounds like when you applied up elevator the airplane rolled either from incorrect mixing, or your input on the stick was not all elevator, you put in some aileron as well. I think it's either that, or the model was simply out of trim to begin with. Barry makes a good point about ailerons reversed. And Combatpigg is right that this probably wouldn't have happened if you had had more power, and others state this model needs speed to gain more speed. It certainly could have been a tip stall, but I'm thinking it wasn't because you don't describe enough angle of attack prior to the roll.

Think back to when it rolled, and what you did exactly prior to the roll. That's the key.

I definitely think it could have been a tip stall. When EDF is first launched, they usually struggle to fly for a little bit and sink before they start really flying. If this model was still sinking after the launch and had its nose pointed up with a little bit of elevator, then it could have easily reached critical AoA, tip stalled, and met terra firma. I think this problem would disappear if you let the model fly for a little longer and build up more speed.

As I remember , the plane was no more than 10 feet above the ground and moving in a nose down attitude when I pulled back slightly on the stick to try and correct and climb abit, instead it rolled over and instantly nosed directly into the ground. The plane was definitely moving forward at a good clip when it nosed in and impacted rather violently splintering the fuse into pieces. I judge this from the measurable distance I had to walk to recover the remains noting the plane was only in the air a few seconds.

Ken

It may have stalled. It may have been a control surface incorrectly mixed or a elevon/aileron servo wasn't connected which caused the roll. So you have to repair and fly it again to see! [8D]

I'm sure you'll ensure all control surfaces are neutral before the next flight, like you did the first time, and are functioning properly - Up/down elevator give exactly the same elevon throw.

At that point, as the others with experience with these models have said, it needs some speed to become stable and for the powerplant to do it's thing, so a good hefty level throw into a slight headwind seems to be the best approach. Or, you could throw it off a steep cliff :-) Just Kidding! It's a joke. But you would get nice initial airspeed.

Good luck and I hope you come back and tell us it flew successfully!

Thanks to all who responded. I very much appreciate the help and good advice!

Ken

Tip stall will happen on those at even higher speeds if your elevons have to much angle to them as well. I maiden a xpd8 I had built, let a more experienced pilot take it up after he gave me the nod on how it flew I took it made a couple of passes felt comfortable and went to climb up and do some spins and loops after giving full throttle for the climb from straight and level I went full up. the flaps were set to high it wiped all my lift and lawn darted from 100'

well you went from one extream to the other...slow down cowboy, the edfs are for experts...i lknow they look cool and fly fast but your not at that level yet so slow down and get the feel more!