Maiden flight skymaster Gripen in Norway (Full Version)

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rookie -> Maiden flight skymaster Gripen in Norway (8/16/2004 1:40 AM)

I received my Skymaster Gripen a month and ahalf ago. I had ordered the gray camo version and was very happy indeed upon opening the box and seeing the finish. It was beautiful.Well spent money i thought until i started building it.
Dissapointment nr 1.
The paint imediatly started to chip of if you were'nt very carefull handling the plane.Bad prep work pror to painting. The gel coat had'nt been properly scuffed and primed prior to painting.
I always look for a builders manual before i start construction and read it from beginning to end.There was none included in the kit.
I received a link to a manual of sorts from skymaster which i found extremly lacking in detail and information.It did not even mention were the hardwood blocks in the elevons were located. It was only thru dumb luck that i mounted the rod horns correctly. Imagine what could happen if a novice were to build this airplane?
I built my airplane according to the sketchy info supplied from skymaster and were things were unclear i consulted a friend who has built 2 skymaster kits and is now starting on his third.

The day came for the maiden flight.
I loaded up my truck with my prescious gripen and my trusty old Rookie + all the gear nesesary for a god days flying and then went to pick up another friend of mine who happens to be Norways most experienced and accomplished model airplane pilot.
He had promised to help me with the first flight.
We arrived at the field and i started asembly of my gripen.Then followed all obligatory checks. CG.Control throws. All sett up according the manual supplied by skymaster.Then onto tanks and fueling,checking for leaks,integrity of tanks,fuel drainage etc.
Next was engine start, radio range test, taxi tests. Everything was found to be in perfect working order.
back to depo, refueling and battery checks.
Engine start of we trundel along the taxi way out to the runway. Full power was applied.
Dissapointment number 2.
Upon rotating the plane and climbing out it became appearant that it was severely tail heavy and nearly stalled.
We got the nose down and accumulated speed and got up to safe altitude.The airplane was nowhere near what you could call stable in flight. pitchy as all hell!!!
We flew a couple of rounds whilst debating a safe way to put the airplane back on the ground. while entering into a large right hand turn at 75 % throttle with a low bank angle the airplane deepstalls and enters into a flat spin subsequently tumbling slowly into the ground.

Again i repeat: the airplane was sett up as described in the manual for normal flight, suplied by skymaster.

Conclusion: CG as described in the manual must be completly wrong.
control throws must be reduced by at least 50 percent both ways on the canard and the elevons reduced by at least 30% on elevator an aileron fuctions. I recommend that CG be moved forwards by at least 5 centimeters for normal flight"mode" and an additonal 3 centimeters for "beginner mode".

Damage:
The underside looks like **** with paint having peeled of all over the place. the fuselage has several rips and tears in it where the wingspars enter the fuse. Engine hatch is cracked and has several holes in it after the engine mounting blocks came lose in the impact
with the turbine smacking through it in several places. The aft end of the fuse has several places with burnt paint caused by a hot turbine roling freely around inside it.In other words my airplane looks like a 20 year old russian fighter which has nor had any TLC for said period.

Salvageable?
Yes,but i dont know if i'm going to bother having lost faith in the product. We'll see..........

Erik Tornøe



George -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 2:56 AM)

Erik, sorry to hear your ordeal. While I found the online manual not so helpful, I did set CG and throws accordingly and the Gripen flew absolutely perfect. The CG was in between the recommended beginners and advanced measurement with it being slightly behind the front (beginners) mark. We are still in the first few flights and getting the throws ironed out. The aileron roll is fast at the recommended throw if that's what you like. The elevator is very close and the canards are effective. The recommend you land with 50% canard throw. Again, I'm still working out the throws and these are my preliminary findings until i get more time on it.

Not a rep, just one of the first to assemble and fly the production kit.

George



wojtek -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 4:12 AM)

Not trying to minimize on the problems you had rookie, but i had a very positive experience with building my SM gripen. The paint on mine is also the all grey, and is very nice and durable .. i had built this plane on a very small desk in my home office (too many projects going on in the garage, it a mess in there ! ) and banged it around quite a bit ... I found the plane built very very strong, and only out of my own paranoia I ended up reinforcing a few joints with some aeropoxy... I was hoping to maiden the plane this weekend, but the weather sucks here, and im not happy with the pipe I had made myself ( so i just ordered one from Airpac and am waiting for it) Only problem point i found was the gear doors that had to be trimmed shaped (under heat) to fit nicely ... however this is typical with doors moulded separately from the plane .. i would have preferred just cutting the doors out of the fuselage ... but no big deal .. I only used the online instruction for CG and controll throw references, as everything else went in intuitively .. i do see however you point for a beginer building this plane having some problems ...

again, sorry for the trouble you had with your plane, but i did find this to be an incredible deal in terms of quality and price ..... look for a review of this plane here on RCU in the near future ..


Wojtek



Aero65 -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 6:18 AM)

Hello Erik

I'm sorry to hear about your Gripen crashing, it is pretty amazing that even after spinning into the ground, the Gripen is still salvageable. One thing that I have found over the past year or so is that Skymaster Jets are though and durable.

I'm one of the test pilots for Airpac models and Skymaster in Hawaii, we have been flying the Gripen since November 2003.

Let me say first that I'm sure that you checked the CG before you flew, but my observations here are based on what you wrote in your post, it is not in anyway meant to question your ability to setup or build the airplane.

It sounds like the CG was too far aft, for whatever reason.

I have built or helped build / setup 3 Gripens and they have all been setup to have the cg at 140mm behind the leading edge of the wing.

Our test airplane had the cg as far back as 155mm from the leading edge of the wing. It would spin at that cg but you could recover, it would also do a really neat cobra type maneuver. (I have video let me know if you want to see it to compare with your accident ) It was more sensitive at this cg but flyable with some exponential.

Just today my friend flew the prototype Gripen 145 mm cg 5 times, I flew my gripen 3 times 147mm cg, even at 7mm back from the rear recommended cg it was very stable.

I measure my CG using a simple board with 2 holes drilled in to it. 2 dowels that are sanded to a very dull point are placed in the holes. We then tape a square of 1/16 in ply with mm markings on the ply to the bottom of the wing ( this is so the dowels will not damage the wings ) I will post a picture of it later.

In conclusion please double check your cg with no fuel ( UAT or hopper full ok ) and the gear down.

Please have faith in your Gripen it is a very fun airplane to fly, I'm sorry that you had such a bad experience with your first flight. I hope that you will have luck with it in the future. If you have any questions please feel free to contact me, I will gladly help you with whatever I can.

Here are some shot's from today. I hope they will inspire you to try it again.

The white one is powered by a Simjet 1700sp and the Red one is powered by a PST J600R.



rookie -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 7:26 AM)

Hi Duke,
Thanks for your reply. I have again measured the CG on my gripen and again its at 14 centimeters aft of leading edge,gear down.What control throws are you using on your gripens? Like you mentioned the roll rate was quick on mine.I also have the PST j 600 r in mine and my friend who was flying it said that there was ample power.I will take some pictures of mine and post them later.
have to go to work now

Erik Tornøe



Aero65 -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 9:38 AM)

Your Welcome Erik

I will find out the measurements tomorrow night as it is getting late here and Im going to bed soon.



KFalcon -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 9:50 AM)

That is terrible! I was getting ready to post another congrats post but I see that would have been bad in this case. Don't give up, if it is salvageable fix it. Good luck!



Hårek -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 4:35 PM)

Hi Erik.

That was really too bad....... Everyones nightmare..
I`ve been looking forward to see two Gripens at Rena next weekend..

I have also been in this situation before, but this was with a prop plane from Flair, a Cap 232.
But do you think there was a logical explanation from the dealer or producer?
Nope. Anyhow this prop-event was similar to yours.
Glad you warned me, as mine will be airborne at Rena (hopefully).
My understanding is that you won`t go for a second try with 140 mm, so what are you gonna do next time? If it can be rebuildt.. You have got some advices to fly at 140 mm even now.

So come on Gripen owners, what is your recommended CG setting!

This was just really too bad.. Sorry for you.

Regards

Gudmund



rookie -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 5:50 PM)

Hallo Gudmund.
Takk for sist! And thanks for your sympaties.
I think i will consult with some of the other guys here who have experience with setting up and flying canard jets.
Lets see what they say about this.
I would like to have some feedback from skymaster about this. We'll see.
I might be able to get it back together again for the Rena meet,but i'm not to keen on trying a second "maiden" up there.Besides i'm in the middle of selling my apartment(to many airplanes,not enough room)[:D]Kind of pushed for time.

Keep the constructive innput coming guys!!!!


Erik



rookie -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 5:55 PM)

Hi Duke
Thank you again. I will make the airplane operational again and i will be needing as much detail as possible in order to avoid another
"exciting flight.


Erik



XCaliber -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 7:18 PM)

Eric,
Sorry about your Gripen.
I flew my Gripen with the CG in between the 140 & 110 mm mark and needed 5 clicks of up elevons for level flight. I think it is a little nose heavy with so much up trim. I didn't experience any bad habits with this setup. Just that I need to come in slower for landing.
I have it set for elevons & conards for takeoff and conards off when gear up.
It flew very smooth like this.
I have a P-120 dialed doun on it.
I need to do more flight to see if I need to move the CG slightly back.
Don't give up on the Gripen, it's a great jet for the $.
Xcaliber



lov2flyrc -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 7:19 PM)

Erik,
Very sorry to hear the misfortune you experienced with the maiden on the Gripen. There are however several now flying with the control throws and CG at the reccomended settings with flawless performance. I dont discount your ability to set the aircraft up properly but I do believe there must have been something faulty since the aircraft has proven to be very smooth and stable at the settings suggested. I do hope you can salvage your aircraft and try again. If there is anything I or skymaster can assist you with please dont hesitate to contact one of us (although, getting me right now may prove difficult for the next few days due to the severe storm that has passed thorough our state).
Todd



Rider-60 -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 8:04 PM)

Erik,
sorry about your loss.
It looks like everything was done as per the instructions so it should have flown ...if you are unfamiliar with delta/canards have you made sure that the canards operate in the good way (up elev= down canards) I think this is not really clear on skymaster's web instructions and a beginner could easily make a mistake here.
If you happen to repair it , just try to fly it without the canards operating, just to get the feel of the plane.
I 've got a rafale and a eurosport and that's what I did for the first flights.
Hope this help, take your time, repair and go fly it again , I'm sure it worth it, would be sad to just leave it like that in your basement!!

best regards
Florent



rookie -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 11:05 PM)

Hi Florent,
I assume that when you say "up elevator down canards" you are refering to the trailing edge of the canards?
Otherwise it defeits all logic and purpose of the canards?

Erik



seanreit -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 11:12 PM)

quote:

ORIGINAL: rookie

Hi Florent,
I assume that when you say "up elevator down canards" you are refering to the trailing edge of the canards?
Otherwise it defeits all logic and purpose of the canards?

Erik



Erik,

That's the funniest post I've read on here in a long while. Thank you!! .



rookie -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 11:15 PM)

Thanks for the reply Todd.
I have started to disasembele the aircraft to check it over.
Again, i am very interested in getting the details on the settups you fly yours with.I myself use the JR 9x transmitter.
If any of you are using the same i would apriciate a description of your programs.Do you know if anybody has fitted a working rudder
to it? I belive that if i had a rudder on mine it might have been able to stop the airplane from entering the flatspinn.
What do you think?

Erik



rookie -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 11:36 PM)

Thank you. I'll get it airborne again.

Erik



George -> RE: Maiden flight skymaster Gripen in Norway (8/16/2004 11:55 PM)

quote:

ORIGINAL: rookie

Do you know if anybody has fitted a working rudder
to it?
Erik


Yes, b/c we are in the US, we must have a working rudder. It was already cut out and ready for hinges. You must use a very thin servo (JR DS 168) or similiar. I honestly have not checked the effectiveness of the rudder in flight. I will make it a point to do so on the next outing.

As far as the flatspin, not sure, sounds like you may have been tail heavy by your description and it would have hard to come out of it if that was the case.

George



AirPac Models -> RE: Maiden flight skymaster Gripen in Norway (8/17/2004 12:17 AM)

Erik,
I’m sorry to hear about your plane. After reading your message, we double-checked the instruction manual and checked with a few other people who own the Gripen. There seems to be no errors on the instruction manual, and the 110 mm C.G. – 140 mm C.G. from the leading edge of the wing is correct. We’ve also had other Gripen owners confirm that the instructions are correct.

However, according to your description on how your plane flew, it seems obvious that that your plane is tail heavy. We are not trying to question your building ability, but you might have someone more experienced to double check your C.G. set up. As explained in the instruction, we do recommend that you set up the C.G. closer to the front for those that are not as familiar with this plane in the beginning. As many have suggested, you may want to make sure the C.G. is in the gear down position with no fuel. You may also want to check Skymaster’s Norway dealer before test flying the plane again. I'm sure they'd be more then willing to help you out.

This Gripen is a fun and stable plane to fly, and you shouldn’t run into these problems with the proper setup. We do have a lot of our Gripens flying out there, and no one has run into any similar problems. After you've made your repairs and set everything up correctly, I'm sure you'll have a great time like all of the other Gripen owners worldwide. Don't let this small obstacle hold you back. [;)]

As far as the paint job goes, we’re not sure what type of finish you have. The U.S. version has a gel coat finish with no problem, but from what it sounds like, you may have received one with an exterior paint coat. I’ve already checked with Skymaster, and they are checking on the paint preparation to make sure that there no issues with the paint job.

We are now making changes to our instruction manual so that it is more detailed for those who are not as familiar with building planes. We'll be adding more specific information to help aid the building process. Skymaster is always grateful for the concerns of our customer to help us improve the characteristics of our planes and service



Mi-25 -> RE: Maiden flight skymaster Gripen in Norway (8/17/2004 4:41 AM)

Erik,
really sorry about your plane - a great shame...
Gents,
just a small but important point.
We all talk about '140mm back from the leading edge'. With a swept wing config. this could be difficult to understand - especially for someone who has never worked with this type of wing.
The reference point we are talking about is the point where the Wing Leading Edge joins the fuselage.

Shouldn't we be saying rather '140mm back from the Leading Edge Wing Root'? - just a thought.
Cheers
Leon



Rider-60 -> RE: Maiden flight skymaster Gripen in Norway (8/17/2004 8:38 AM)

Hi Erik,
yes sure I meant trailing edge for the canards, [;)]. just trying to understand what could have gone wrong....

Florent



SAP_2000 -> RE: Maiden flight skymaster Gripen in Norway (8/17/2004 10:32 AM)

Eric:

The Norwegian SM dealer was present and witnessed the maiden himself. As for the CG, it was checked on site by the most experienced pilot in Norway who flies model planes for a living. Also, Erik 'Rookie' is a very good builder, always with nice and tidy installations. His planes are always 100%. I am sure they all know that ''CG xx mm's back from LE of wing'' don't mean at the wing tips on swept wings...[;)]

Erik's plane has the two-tone camo scheme sprayed at the factory... Just as nice and detailed as on my F-18[:D]



rookie -> RE: Maiden flight skymaster Gripen in Norway (8/17/2004 8:21 PM)

Hi George,
I'm aware of the u.s. rules about rudder being obligatory and belive me its a good rule!!!
Here's the funny part: When i looked at the Gripen intialy it was advertised with working rudder.
When i took it out out of the box there was only the fin and the website i got referred to by Anton Lin stated that i had to cut it out myself and mount it.That made me a bit anoyed.Being a helicopter pilot as well, not having the rudder function makes me feel a little naked if you know what i mean. Besides it good for ground handling during takeoff and lining up for finals,etc....

Erik



rookie -> RE: Maiden flight skymaster Gripen in Norway (8/17/2004 8:27 PM)

By the way,dont forget to add a liability disclaimer with your kits otherwise somebody might sue you!
I would hate for that to happen as it would most likely discourage companies from continuing to develop
good ARF jets.

Erik



AirPac Models -> RE: Maiden flight skymaster Gripen in Norway (8/18/2004 4:27 AM)

Erik & Staale,

As I mentioned before, we are not questioning you building or flying capabilities. We are just trying to figure out the problem. Again, it does seem like it doesn’t have the proper C.G.. There are no errors made in our instructions, and it is difficult to determine the cause when there seems to be no errors made by all parties. Before you test fly the plane again, hopefully we will be able to find an answer from one of those people who are trying to help us out with this issue.

I also wanted to mention that your suggestion for the liability disclaimer is very important. We will see to it that all of our future kits have a copy included.



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