As a quick background, I flew RC back in the 70s and got good enough not to crash too often! I also have a little over 50 hours in light aircraft, so I understand aerodynamics.

I bought the HawkSky from Hobby Partz back in late April and it has been a complete failure to date. I did a lot of research prior to buying the plane as I wanted to have something beginner-proof due to the fact I hadn't flown for so long. Everything I read seemed to indicate this was a great choice. After it arrived, I realized just how true the comments about pathetic instructions were! However, it wasn't a difficult build (if you can call it a "build"). There's no real way you can get the wings or stab on the wrong way. Finally got it all together.

I confirmed the following:

Controls working correctly (that is, stick movements gave movement on the control surfaces the way they should)
Engine functioning correctly (the wash was going back, not forwards!)
CG slightly aft of the recommended range using supplied battery. Installing a 2200Mah battery brought the CG to almost right in the middle of the stated range

At the field, I again checked the controls - all OK. Fired up the engine, elevator trim slightly up, held in right hand slightly nose up (never installed the UC), launched with a smooth throw. The plane immediately nosedived into the ground. Swapped batteries - CD not slightly aft. Tried again - same result.

Went home and packed the front of the engine up about 1 degree, figuring is must have too much down thrust. Tried with both batteries - nosedive. Also tried with full up elevator trim. Nosedive. Tried with full up elevator. Nosedive, ripped the engine off the mount, mount off the fuse and destroyed the prop.

I'm getting nowhere with HP's tech support. Ha - they're more ignorant than I am and unable to read. I posted basically the same as I have here on their tech support and the idiot proceeds to give me a (poor) lecture in aerodynamics, basically saying I'd done something wrong.

So I have broken plane that won't fly. Has anyone any ideas or similar experiences? I'm stumped. Thanks.

First and foremost WELCOME to RCU !!!!
JUST to make sure we're all on the right page here... the Hawksky .. basically the same airplane as a Bixler... styrofoam airframe, brushless electric powered with a pusher motor configuration...
there are a couple of thing to be aware of... (I've got two bixlers and love them! very easy to throw in the car and fairly aerobatic when set up properly.)
you've mentioned that the prop is pushing air (as it should) .. but is the front of the prop still facing forward? (it should!) the front of the prop is the front of the prop, does NOT matter if the motor is mounted in a traditional tractor setup, or in a pusher configuration. the front of the prop should ALWAYS face the front of the airplane.

upthrust: again, since this is a pusher, in order to get more 'Upthrust' (advancing the throttle tends to push the NOSE of the airplane upwards) you would need to add washers to the TOP two motor mounting holes.
(that airframe has a considerable amount of DOWNthrust built in... double check that your 'upthrust' is not in fact DOWNthrust. )

additionally, since the motor is mounted way up higher than the aircraft centerline, adding throttle will momentarily cause the airplane to pitch DOWN.

one last thing.. my bixlers require a fair amount of up elevator on takeoff... once it's airborne that requirement goes away pretty quickly.

Hi Jim and thanks for the reply. This is the model in question - http://www.nitroplanes.com/60a-dy892...y-rtf-24g.html - don't know the Bixler, but did read many comparisons between it and the HS.

I've never owned or flown a pusher, nor a model with a pylon mounted engine, so I concede there may be aerodynamics I'm not aware of (I mentioned the bit about aerodynamics in my original post as the NP tech lectured me, not on high engine mount aerodynamics, but on elevator. aileron and rudder control - didn't need that again!! LOL!). The prop was factory installed so I assumed (in hindsight not wise!) that it was on the right way round. Though, from what I've read, having it on backwards will usually just cause a lack of thrust - correct me if I'm wrong. So, hopefully (haven't checked yet) the replacement one will have the front noted as such when I put the new one on.

Can you confirm the location of the washers please. I packed the front of the engine up - your post says top holes - mine only has 2 holes - one each side of the engine pylon. I figured packing the front endge tilts the engine towards being a helicopter so that should give upward lift - am I wrong?

I'll get it all repaired and try a left hand launch to try will a lot more up elevator than the trim allows for. Cheers.

VERY sorry for the delay in responding!!! yup, by the sound of it, you gave it MORE DOWNthrust. look at it this way: with the stock airframe, the motor already has a considerable amount of DOWNthrust.
remember, unlike a helicopter, the motor on this airplane is pushing air out the back... setting the prop so it's more like a helicopter will make the prop blow the airplane DOWNWARD.
looking at the motor / prop from the side of the airplane, you'd want to make LESS of an angle between the prop and the airframe centerline. (you'd want to decrease the motor's angle)
if you visualize this while looking at the airplane it should make sense, but DO feel free to post back if you're at all in doubt.
sorry again for the delay in responding!

Hi Op,
This is a great plane to get back into the hobby with. Yes, NP will not give the best tech service as you have found out, but that's part of the cost of doing business with them (ie the low cost of the plane). I've had a bunch of these (have one currently in use as a club trainer), in addition to the Sky Surfer, Bixler, and other Easy Star clones. I've never encountered the problem you are noting. It sounds like a balance issue, and forgive me for saying, perhaps reversed elevator control? I know you have prior experience, so just double checking on that. For the plane go nose in so quickly it's one of those two things I think. The motor already comes mounted and is balanced (to some degree) at the factory. I have never received one with the prop on though, that might be something new. I know you said thrust is coming back from the prop, but you might want to double check...switch it around just for ****es and giggles, you never know.

All of these types of planes should actually float/coast right out of your hand with a little push (balanced properly, and no motor on). Perhaps you have an area with tall grass you can try that in?

As another member mentioned, there is downthrust on the motor preset from the factory. About the worst thing I can say for this and similar planes is a habit of diving (slightly) when full throttle is applied suddenly. If I'm doing tricks near the ground (like touch and gos etc), I always plan a little up elevator right before punching the throttle. I don't know if any other way to counter that. Is there anyone else where you fly that could launch for you?

As you have already seen, a nice benefit of this plane is the ability to repair. Gotta love CA and kicker, or other types of quick set glue.

Hi Jim and Porcia

Appreciate both of you chiming in - thanks. Yes, NP hasn't a clue. The tech I was conversing with had an RC car as his/her avatar - I think that says enough... trying to talk planes!! Sheesh!

Porcia, yes the controls are working the way they should (ie. back stick, up elevator, etc). And the CG is definitely within the range specified in the (appalling) manual! This one not only came with the prop installed on the motor, but a spare as well (good job as I now have a busted original after the 3rd, or 4th, nosedive). Getting old one off, new one on could be yest another challenge as they're pressed onto the shaft.

Once I have done that and glued the fuse, which has split in 1/2 for about 6-8" behind the engine mount, I will try just gliding it. Also, as I mentioned in a post to Jim. I'll try a left hand launch (that will be interesting!) with full up elevator. It dived so dramatically that I don't see much else to do. If both these fail, I will strip out the gear and happily put a match to it - I'm really in no mood to fool with it anymore. I've been looking at the Delta Ray from Horizon - looks good too.

Cheers