Another Dragon issue
 

Well, I was flying my X-Treme Jets Dragon yesterday at a Giant Scale event at our club. You may recall that I lost the canopy due to unknown reasons 2 weeks ago and Skymaster/XTJ replaced it in time for this event. Kudos to SM for that.

It was my second flight of the day, approximately the 20th flight on the Dragon. My friend Nir (Yakboy) was spotting and Doane (Kingair41) was nearby. Erik (erik r) was announcing at the time. I took off normally and completed the first lap and went into a full power climb. The Dragon got to about 700 feet and was still going over 100mph when I rolled into a split S. Except when I neutralized the ailerons the Dragon kept rolling. I immediatly reduced power and in an instant the airplane was nose down and spinning. I tried adding power and in an instant the airplane was heading towards the area where the spectators were sitting. I reduced power and was able to point it down in order to intentionaly crash the model. Either Doane or Nir, I don't know which, said "shut it down". I did and then I was able to regain marginal control. At this point the airplane was at about 100 feet and on the down wind end of the runway and is still had loads of energy. Nir calmly told me to "just fly the plane" which I did although it seemed to handle really weird. It may of been me because at that point I was pretty shook up. I was able to glide the model to the other end of the runway, perhaps 500 or 600 feet and make a 180 degree turn and still have a good approach although still moving fast. I kept the flaps and gear up thinking that I didn't want any extra drag. But as I approached the threshold Doane barked "full flaps". Thank god he did! I blew the flaps and gear and put it down pretty far beyone the centerline (by design) and really smooth. But still to fast. After a brief rollout it bounced and hit again with the nose gear which took some damage as did the front of the fuselage. But nothing that Dan (split s) can't fix. Upon approaching the airplane we noticed that one third of the windshield was missing which we first assumed was from the bounce. But upon further inspection I found the pieces wedged in the rear of the front compartment by the fuel tanks. I would assume that if that happened on the bounce that they would either be outside the airplane or laying inside right under where it broke since it was not moving very fast then the nose hit.

The point of all this? I believe (but will never know) that it broke in the air and the sudden air pressure inside caused a severe handling problem at all but the slowest speeds. The new canopy was reinforced so as not to loose it again and the new method of attachment worked to good. The first time that it came off was due to an opening in the top of the windhield which let air in and it instantly blew the canopy off so I never even felt it. I put more glue under the windshield except it cracked this time.

Again, this is my theory of why the event occured, I will never know. I am also treating this like a radio problem and will be sending the RX back to be checked, will change the switch, batteries and inspect all servos and servo leads and extentions just in case my theory is wrong. BTW, much thanks to Nir, Doane and Erik for your support!

Jim

Here is a picture.

RE: Another Dragon issue
 

Hey my friend,
That's what we're here for. To support our fellow jet flyers. It could have been worse, a lot worse. But you managed the jet properly and got it down with minimal damage.
It'll be in the air again soon with all systems checked and ready to go.

Doane

RE: Another Dragon issue
 

I warned you! It's the aliens.

Nice save...good friends!

George

RE: Another Dragon issue
 

How thin is the canopy windshield?

Dave

RE: Another Dragon issue
 

Thanks Doane! You too George!

Dave, the windshield is .020 thick. Which I'm sure would be more than adequate if it weren't so brittle and was glued in properly. It is so brittle that if I bend it in half it doesn't bend, it breaks.

Every corner of this airplane needs to be checked and double checked. Such a great flying airplane, but, you know the rest.

Jim

RE: Another Dragon issue
 

What radio were you useing? I had a similar incident that i put down to radio? JR 12X with 1221 RX? but perhaps not? similarly my brand new DRAGON only 3 flights old was flying great when after 1 succesful flight this day I fuelled up for another and about 2 mins into the flight seemed to give a shudder and became instantly without any control at all? repeated attempts at regaining control and switching turbine off proved fruitless? consequently the impact and ensueing fire destroyed eveyrthing (I mean every dam thing) thus not allowing me any insite into cause
I have been flying my flash with the same radio without incidence ever since? perhaps 8 flights, but very nervous! Also now reading about the amount of dragons that have met there demise for various structural weaknesses has given me mixed messages as to the real cause?? Also 3 weeks after the crash I recieved in the mail a tail former/fin upgrade for the Dragon from extreme, which I felt was a little disconcerting Ian

RE: Another Dragon issue
 

I could be wrong, however that small hole blown in the windscreen would not have caused the problem as you described it. A lot less forgiving airplanes have lost entire canopies, and not had the issues flying you had described. I myself had canopies blow off, or gear doors blow open, and though such an incident may throw the plane off axis, it should not cause you to loose control like that .. Sounds more like a radio issue from the way you describe it... Hopefully you find the cause before next time the plane goes up, especially as radio problems could be intermittent and hard to diagnose ... anyway, glad you have your plane in one (repairable ) piece [8D] ..I was hoping to make the event in PA, but i ran late picking my son up by Pittsburgh and it was late today as we got home [&o]

all the best,


~V~

RE: Another Dragon issue
 

If u are flying JR, then plz do a search for the JR 2.4 lockout thread (sorry, i dont recall the exact title) and u will see many similar stories. Enough stories to scare me off of JR/spectrum.

My gut, fwiw, doesn't subscribe to the windshield theory...but of course u are a much better judge for having been on the sticks at the time.

RE: Another Dragon issue
 

The window didn't cause the problem. I've had windows go (animal strikes!) and never seen anything like this.

JR/Spektrum does not have a lock out problem, I've used it since day one in 2006, never had one. I have 40+ models with costs between $100 and several thousand $, I would not use anything else. My friends who mainly fly jets have not had a problem, some of them fly a lot!!.
I've sold hundreds of JR/Spektrum radios through my business, to some very clever and not so clever people. I see and hear of very few problems and any problems could be resolved or proved and I can't think of a radio (Rx/Tx issue with JR and only a few on the cheap Spektrum park type Rx's). Generally its not the system, its the "set up" batteries, switch/power source, cheap leads or servos....people only ever give 10% of the story, so I ignore the threads talking about problems.
I'm gad you saved your model and hope you find a solution. What servos do you fly?

Dave Wilshere

RE: Another Dragon issue
 

Dave,

Could you please explain the numerous JR/Spektrum unbinding issues I have read about and personally experienced. Luckily, mine happened on the ground. My setup was using a JR 10SXII with the Spektrum conversion module and the AR9000 receiver with three remotes. Dual A123 2S 2300mah batteries run through separate Electrodynamics HD switches, no regulators. This happened while in the garage, and the system had been powered up for a couple of minutes. Without any command, my flaps lowered which was part of the fail-safe I had setup along with turbine shutdown... turbine was not running at the time. At this point, I had absolutely no link, and I thought ... what is going on. The link never came back, and it took a rebind to restore the link.. Nothing else was done before the rebind... not even a battery charge and the system worked fine afterward. I could not make it duplicate the problem. It's just like it chose that random moment to lose the bind. The plane had just been flown two flights the day before with fully charged batteries without issue... so low batteries was not the problem.

Ronnie

RE: Another Dragon issue
 

I gotta agree: the loss of any of that canopy material could not in any way I can think of cause un-commanded rolling of the airframe. Think about it: rolling requires a force applied orthoganally to the plane's X-Y plane, outboard, away from the center-line (to give it some moment arm). No way a hole in the canopy can do that. That is why we have ailerons out on the outboard area on the wing.

RE: Another Dragon issue
 

wojtek, sorry you couldn't make it! We had a great turnout both Friday and Saturday. Rains came for Sunday but a great time was had by everyone. Hopefully you will make the Jet Jamboree in October??? 4 days this year!

I was flying a JR 11X. The RX was a AR9000 with 2 satellites. The servos are Hitec 7955 TG all around. Except for this the model flies like it's on rails all the time. Cross wind landings have been a non event.

It sure seemed to be a radio issue. But it could have been the windshield that threw it off enough that it got me behind the plane. It could have been a little wind that got me behind the plane. It could have been me that snapped it and then got behind in control as it spiraled down. I will never know. This is why I am treating it like a radio issue and will completely replace any possible culprit like switch, RX, batteries, etc. All servos will be removed and checked. Satellites will be positioned in other positions. The current RX will be sent to Horizon for a check up. You guys get it, right?

Another piece to this puzzle is this. On the fourth flight of this airplane it did an uncommanded roll at the top of a huge loop. It was a bit windy. I thought it was a radio issue so I immediatly landed. The RX was NOT blinking (it would indicate a power failure if it was) and the data logger showed 6 lost frames and 0 on both satellites. Everyone who saw it said they thought I had got to slow and the wind blew it over. At the time I had a JR9303 TX. The point is that I would say that this added info rules out the new TX.

BTW, I agree with you guys that think the windshield breaking is not the cause. I was simply giving you as much information as I could. My bet is on pilot error which induced a high speed snap or radio problem. And I am going with radio problem since I have logged 400 turbine flights in the past 2 years and have never come close to feeling as out of control as I did on Saturday.

So, there you have it. We will never know what happened and I am tearing out everything short of changing the motor and airframe and LG. If I still have a problem after this, the whole thing goes and I get an RC sailboat :D.

Jim

RE: Another Dragon issue
 

GREAT POST

the 'bash JR thing' has got very silly lately

RE: Another Dragon issue
 

Strange?? I guess this guy had radio issue also.

http://www.rcuniverse.com/forum/m_9929920/tm.htm

http://www.youtube.com/watch?v=cgGQXkORqoM

RE: Another Dragon issue
 

Depending on how the canopy decided to "depart the fix", it could have caused an uncommanded yaw that at higher speed turned into a rolling moment/spin......I seem to recall a friend of mine flying his Cook T-33 and this same thing happened and since the canopy came off and peeled to the side, it caused it to roll/flat spin right to the impact point....There are pictures of the canopy in flight just prior to the spin.....just my .02

RE: Another Dragon issue
 

NickC5FE, that does make sense. Whatever happened put me in a position similar to the Hawk video that was on RCU a while ago. The pilot was doing a loop with what looked like the gear down and maybe even flaps and it went into a high speed snap and crashed. Mine was similar but with enough altitude.

BTW, I do not blame JR if it was a radio issue. If it was radio it was a bad battery, bad switch, bad RX or just a bad install by me. It was NOT the fact that it was a JR 2.4 system.

Jim

RE: Another Dragon issue
 

Yeah, I could see that in the situation that you described (big canopy briefly to one side, causing a yawing moment), but not here. Here it is just a hole in the front, no big assymetry at all. I cannot see how this could cause any significant yaw/roll.

RE: Another Dragon issue
 

Hi,

Of course a departed canopy can cause control problems. I thought everybody knew that. Nobody can say for sure what happened in this case, but under the right circumstances, a partially departed canopy (i.e., a cracked and open one) can be the same thing or worse. Great (in a not-so-great way) video, though. Anyone know what camera he was using?

RE: Another Dragon issue
 

Dearly departed canopy ... dearly departed jet....

RE: Another Dragon issue
 

i think someone should make Airplanes400 a moderator on here .. he's fit for the role lol :D:D:D:D


~V~

RE: Another Dragon issue
 

hey jim ,seen the flite and was very glad u got it down safe, dont sell yourself short on the pilot skill part. i have one question for you. who flyes some of the most high dollar jets at our club.(billy) what radio does he use, how many planes have you seen go in by him. think of all the other stuff thats went in over the past year at our field, what radio where they holding in there hand. billy and i both fly the same brand and have never as much had a bump on it. it comes down to what you like ,but the proof is there in the number of flites me and bill have with no issues. i dont want to get in a pissing match on rcu about brand a v/s brand b but think about what i have said. be cool and cant wait for the jet meet got my elan almost done. later berk

RE: Another Dragon issue
 

Hi Berk,
Did Billy fly the F-5 yet? Beautiful jet.

Doane
By the way I'm the fellar that had the L-39 and the OV-10 Bronco this past weekend.

RE: Another Dragon issue
 

Airplanes400, you gotta be kidding, right? I don't want to start anything but you are morbid.

Berky, I know what you mean. I don't really know what to say. I want to stay with what I got, this is the first time I ever had a problem like this. I don't want to knock any brands because I really have nothing to base it on.

BTW, you and Billy are great flyers and maybe that's why you don't make any smoking holes! I do think that allot of guys are too quick to blame the radio!

Jim

RE: Another Dragon issue
 

hey doane, your bronco is bad *****. no he didnt fly it yet but we are going to the field alot next month, he got to fly the f-5 scorpion xl t-33 and the twin f-18 befor the jet meet. hope to see you out there. later berk

RE: Another Dragon issue
 

Going to hit every Saturday from now til then...hopefully. I might as well move down there. I see the guys at the field more than I do the wifey..

Doane