Shok

My Feedback: (28)

the springs are way too weak.

After the test flights we will address the issue. But yes it is a problem

speed is life

Just got an e-mail back from FlyEagle about the "soft" main gear struts:
[quote]
Hi James:
For the springs question, some people love the springs heavier, some people love normal. If you think the spring is too soft, there is one way can make it heavier. You can inject some gear oil (or lubricant) into struts. It will make strut to be stiff a little. You can try it. We have some customers used to do this way to make struts stiff.
Best regards,
James Chen
[quote]

Hmmm.....may have to wind my own heavier springs?

-Mike

Yann

Right Mike, That's also what I plan to do myself...

Yann

Shok

My Feedback: (28)

have to give that a shot

thanks

hpais

Hi Ronnie, thanks for the pointer to this thread.

Have you finished the L-39? How does it fly?

Would you recommend it as a first Jet? How acrobatic, agile is it in maneuvers, and also, how does it land?

thanks!

Hermann

autorot

hello,
My maiden flight,
http://www.jtso.fr/videos/L39-Seb.wmv

http://www.jtso.fr/component/content...jet-au-17.html
in french, use google translator...

All is ok, perfect landing (not on this video) engine is simjet 1200 6,5 kg (minimum) . ideal is MW54 class engine with 8-9 kg of thrust (merlin 90, G booster..Etc)
KJ 66 class engine (P80..etc) is too heavy and increase fuel.

Regards,

Sébastien

Shok

My Feedback: (28)

what were your throws and CG placement?


Also I think the ideal motor for this plane will be the P-70

Shok

My Feedback: (28)

you should upload that video to youtube

After 20 minutes I can only get the first 14 seconds of your video to play so far.

autorot

already on you tube, (www.jtso.fr and video)

http://www.youtube.com/watch?v=J8_ShUg3XAE

Best engine for this plane is merlin 90 or Gbooster.. not jet cat P70... (not enought thrust)
Regards,

Séabstein

Shok

My Feedback: (28)

I would think 17lbs of thrust should be adequate

Although it I'm sure it will lack vertical

autorot

the weigth of my L39 ready to take off with simjet 1200 (6.5 kg of thrust) and fuel is 11 kg so 24 lbs!!
17 lbs it's ok, no problem, i fly with less on this video (6.5 kg - 14 lbs) but you say BEST ENGINE .. so best engine for this plane is MW 54 class engine with 8-9 kg of thrust... like merlin or gbooster...or wren super sport

For CG, 105 mm like FEJ manual, and just 20 mm for elevator
Regards

sébastien

Shok

My Feedback: (28)

what about ailerons

autorot

all like FEJ manual...!

Yann

Almost there.
Thrust pipe and turbine are installed. I had to cut new beams to support the turbine.
Internal layout is also coming together.

Yann

Shok

My Feedback: (28)

Nice, I am still waiting on good weather to test fly.

Been very windy here [:'(]

autorot

Salut Yan,

tu me diras ce que cela donne avec le supersport? Avec le simjet 6.5kg , cÃ* suffit mais je pense que 8-9 est l'idéal.

Attention aux débattements de la profondeur, 15 mm suffit avec le centrage indiqué, et mais du différentiel aux ailerons, il a pas mal de lacet inverse

Bons vols,

sébastien

BluFox

My Feedback: (10)

Parts in question are for the aft mounting of the Jet Central jf50 Super Bee or a P-60. An option for the builder to choose from. No pipe required.

VT-90 Rabbit is going in mine.

Cheers,
Eric Clapp

Shok

My Feedback: (28)

Well we tried to make today the maiden.

Things did not go as planned.

First off, we had some problems with the rudder.
Suddenly now it's sticking, so it needs some work there.

Next the brakes just would not work.

The petromat was totally soaked from rain, making it very spongy.

Also the wind was gusting in the 30's and crossing.

I did get a chance to taxi it a bit.

Notice the nose gear spring...way too weak.
That will need attention.

As far as the P70 not being enough, well I easily acheived flying speed in about 250ft as can be seen in the video, when I almost lost control of it





[youtube]http://www.youtube.com/watch?v=deIlMMAk-NI[/youtube]

pittsflyer111b

Been almost a month since the last update.  Did you get the bird in the air yet?  Any flight assessments yet?

Love to hear some progress.

Bob

Shok

My Feedback: (28)

It is packed up and in the trailer heading to the Austin jet rally this week.
We will get the test flight in on friday

They have a nice runway there so it will be good

Shok

My Feedback: (28)

Well the plane finally flew on friday.
I was able only to get a few video clips off my digital camera.

The first flight was not all that great.
The plane seemed to have a lot of dead spots in control and seemed to "hunt" on roll axis.
The P70 was ok, but not nearly enough for this plane.
Lots of trim was needed and with flaps down, this plane does NOT slow down well.
It landed hot and rolled off the end of the runway losing one of the gear doors.

Back in the pit we discovered that some of the throws had changed a bit, or were there and not noticed.
Like one elevator at full throw was popping up more than the other, and one flap seemed to be drooping a bit.

We fixed these things and went back for another flight.
Now the plane felt much better. Flew almost hands off but still needed much more power in my opinion.
In turns it looses almost all it's speed and gets close to a tip stall because it is very heavy and highly wing loaded.
As it burned off fuel it handled better and better.
Finally on a low downwind pass over the runway it flamed out

The plane was doomed, because as soon as it started an immediate turn back toward the runway, it stalled and spun in.
Impacting nose first and destroying the plane.

On arrival at the scene the main tank was in parts and there was some fuel on the wreckage. Bu the UAT was totally empty.
After thinking about this a bit (ECU was broken, could not check shutdown reason), I am pretty sure of what happened.
I think maybe in the rough runoff on the first flight I might have knocked the clunk to the forward part of the tank.
In the second flight then we probably exhausted the UAT do too the clunk position.

Here are the short clips I have.
On the last pass you see, the plane crashed about 20 seconds later, I did not get it on tape, but I think someone at the field filmed it.



[youtube]http://www.youtube.com/watch?v=hbdYz0WM_q8[/youtube]

Yann

Mine is ready to go. The plane has been weathered and I had new springs custom made on oleos.
You'll see how the plane stands much higher off the ground.

Yann

aquaskiman

My Feedback: (46)

Shok that really sucks Sorry

hooker53

My Feedback: (106)

Shok,

I sure hate that for ya. Nurse your wounds and go at it again. I really hate that. I was glad to hear you got the L-39 and now this. Sometimes these birds just have a big X on them from the get-go. Is there any salvaged stuff you can use on the next one???  Hang in Dude!

Roy

Shok

My Feedback: (28)

yeah everything lived.

just need to replace the ecu case

Gear is all ok except the nose strut

motor checks out good