SkyMaster Hawk
 

I would like to know if anybody out there has had any experience with this airplane. I was thnking of getting one, but I saw the manuel and was concern with the tail section of this airplane. If you look at the former and the plate that holds the vertical fin in place it looks very thin. The other problem that I see with the airplane is the elevator servo location. Its located in the rear of the airplane at the top of fuse on a plywood plate. Now with the pipe going next to that and we all know that heat rises you would have to be concern with that and hope that that plate does not get lose with the heat. If anybody knows any different please let me know as I would really like to get me one of these airplanes.
Thanks.

RE: SkyMaster Hawk
 

Hi Jose
I have flown my Skymaster Hawk quite a lot and had no troubles at all.
I don't think that any skymaster plane could be called under-engineered. When I when to the factory I was amazed to see how much actually goes into one of these models.
My Hawk (Well worn prototype model) Actually experienced rudder flutter when the rudder servo stripped in too fast a flick roll. The next pass was balls out and the rudder began to flutter which lead to the entire fin getting a flutter on. I slowed down right away and landed. I was amazed to see that all the fiberglass and woodwork inside was in one piece. I changed the servo and then had another 20 or so flights after this with no trouble.
As for the stab servo and plate. Don't work. If you are using the double walled skymaster pipe this area does not even get warm. I ran an entire tank through a hawk on Sunday on the ground (13 minuets) and at no point did the fuz get hot. This included some prolonged full throttle runs. Again The tailpipe is a little thicker than it needs to be and people are changing them for lighter ones but the skymaster one does the job well.
The only issues I have had with the model are the elevator set up and the flap set up.
We have two models here in the Uk that were set up with Futaba Digital tail servos (9350) The owners set them with the push rod on the furthest hole on the servo horn and midway down the elevator arm. This seemed fine but any load on the all flying stabs caused the stab to blow back. This looks like a case of bad geometry on the linkage but my one with the JR 8411 set up the same had no problems on the ground or in the air. My advice would be to make sure you set your elevator link up for maximum mechanical torque.
As for the flaps. On the hawk they are very powerful. Probably too powerful. Too much flap or flap deployed at too high a speed will result in a nose pitch down. This can be so severe that the elevator can not override the flaps. My advice is use the flap deflections in the manual as a maximum. And make sure you set the flap to elevator mix so that for every increase in flap deflection there is increase in elevator compensation. we had a case where a customer set his flap to elevator mix so that all of the up elevator trim came on in the last few clicks of flap. This was not good.
Lastly applying the flaps. You have to apply the flaps in stages and at slow speeds. It is no good motoring down wind and jamming in full flap. This will cause the model to pitch down. Instead on a up wind or gear pass start to slow the model and gradually apply a bit of flap. as you turn down wind apply a little more until you are on finals and you are applying full flap. What I suggest people do is take themodel up high and play with the flaps up there. get a feel for the model at height and see how nice it flys at slow speed. But under no circumstances apply too much flap too fast.

RE: SkyMaster Hawk
 

Do a search here on RCU, there has been some chatter in this jet and some great video / flying by Al`s hobbies in the UK. Any time there is a concern about heat in the tailpipe area i put about 3 coats of bvm heat shield on that area and problem solved. Not sure if this jet has a problem there but if you feel it necessary then do it.
V..

RE: SkyMaster Hawk
 

Thanks Ali,
Isaw the video of you flying this model and you did a great job, but then again every plane that I seen you fly through video it seems that you make them look very easy to fly. Some one brought the rear section to my attention so I just wanted to make sure before I ordered one. As far as the flap problem what would you recomend if I'm using a JR8103 where you don't have multiple flaps setting. Thanks.

RE: SkyMaster Hawk
 

No problem at all.
Am I right in thinking your radio only opertaes the flap on a switch? If so can it do it on a 3 position switch? And can it mix in the elevator. Excuse my ignorance I have only just started flying Jr and all I know is the MX22 and the 9X

RE: SkyMaster Hawk
 

Hey Jose

Next time we meet at the field i will show you how to setup your JR8103 radio to have two position FLAPS.

RE: SkyMaster Hawk
 

Ali

I am buildidng a Hawk with smoke system and I am a little concerned about the models weight.
at what weight do you fly your Hawk (the zero fuel weight)
I have mine now ready at 23 LBS (10,5 KGS)

thanks

RE: SkyMaster Hawk
 

"The tailpipe is a little thicker than it needs to be and people are changing them for lighter ones but the skymaster one does the job well". What part of the pipe do you think is a little thicker than needed Ali? The inner thrust tube or the outer ducting? I have one on the way, but not yet in hand. I hope it is the inner. I would far rather have a too thick thrust tube than worry about it collapsing after a toasty start!

RE: SkyMaster Hawk
 

Saber Guy Hi,
ali here 3demon is my home computer name . My Current hawk with a AMT Mercury, Two tail servos, tail former mod, Tail plate glassed in and Pilot weighs in at 11 kg with no fuel so your target weight is pretty spot on.
As for Tailpipe. The only reason why I changed mine was that I know from previous experience that the high eflux of the AMT Turbine lends itself to a different tailpipe than the Jet cat style constant diameter pipes. I had no problems at all with he normal Skymaster pipe when I used the P-120. The weight saving was a big advantage (Approx 1/3 rd of the weight) But the custom tailpipe was a lot more than 1/3 rd more expensive

RE: SkyMaster Hawk
 

So the pipe that you can buy with the Hawk (the one I guess I am getting), is it a thick INNER tube? Is that the tube you feel is thick? Or the outer tube? Thanks.

RE: SkyMaster Hawk
 

Thanks Ali,
You take a weight of my shoulder.

Hans