K&A L-39 with Retracts? - RC Groups
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Feb 09, 2002, 12:45 AM
I'll fly anything...
GlasairAllen's Avatar

K&A L-39 with Retracts?

Has anyone fitted a K&A L-39 Albatros with retracts?

I have been flying quite a bit at my local flying club's field and I'm really getting spoiled by the long paved runway. Lately I find the idea of packing up the bungee, pedal launcher and driving to a park that may or may not have people playing soccer on it increasingly unapealing. I would love to take the L-39 to the flying field and use the runway.

If I decide to do this I'll probably get another kit and lighten it up a bit to compensate for the weight of the retracts.

Anyone done this with positive results?
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Mar 06, 2002, 10:01 PM
I'll fly anything...
GlasairAllen's Avatar

K&A Albatros Retracts

Well, I'm about to do an experiment with the K&A Albatros. Today I put fixed gear on it just to see if it will ROG ... or how much of the runway (and battery) it burns up getting off the ground.

If this works I'll get another kit and do it with retracts.

Stay tuned...

(no photos, the camera lost it's mind today and did not save the photos of the L-39 sitting on it's gear)
Mar 06, 2002, 10:55 PM
EDF all the way!
bruff's Avatar


Contact Robert at EJF he has a new set of metal retracts that are smaller than the micro Spring Air's. I'm putting a set in a F-86. Good Luck!
Bob Ruff
Mar 07, 2002, 12:02 AM
Registered User
ScottS's Avatar
How do you plan to get retracts in that thin wing?

I think ROG would mostly depend on how much power and runway. I know I could put wheels on mine and ROG, but I like getting 50+ mph without turning the motor on. I also think the drag would limit top speed with fixed gear.
Mar 07, 2002, 10:34 AM
I'll fly anything...
GlasairAllen's Avatar


Photo of the Alby on gear
Mar 07, 2002, 10:36 AM
I'll fly anything...
GlasairAllen's Avatar

Re: Retracts

Originally posted by bruff
Contact Robert at EJF he has a new set of metal retracts that are smaller than the micro Spring Air's. I'm putting a set in a F-86. Good Luck!
Bob Ruff
I've seen Robert's retracts and they look great. I'll probably use them on my YF-23. ...But pneumatic retracts seem a little overkill for a model this size. Also I can't imagine that they are any lighter than Robart's little micro mechanical retracts ... are they?
Mar 07, 2002, 11:11 AM
Dude, where's My Plane?
JasonJ's Avatar
Ehhh, why not just make a little dolly for it, then it can just lift off and leave the wheels on the ground where they belong . Maybe when you get good enough at landing it on a dime, you can try to land on the dolly .
Hey how about this, make a Dolly out of a RC car and get your buddy to drive it down the strip while you man the sticks .
We could call it the Buggy launch!
That would be cool!
Mar 07, 2002, 11:46 AM
Registered User
I put mechanical retracts on my f86. Used great planes 30 size retracts - figured it would be needed on a 6-7 pound plane and a grass runway. I havent flown it yet. Each retract weighted 1.75 ounces. Figure that .75 of this was the wire landing gear, which you would need anyway on a paved runway. So retracts add about 3 ounces plus 2 servos to operate-figure 4-5 ounce penalty for mechanical retracts. Shouldnt effect flight much

How much lighter are the pneumatic ones???
Mar 07, 2002, 11:31 PM
I'll fly anything...
GlasairAllen's Avatar

Well, it's over for the L-39

My L-39 now hangs in the hall of shame in our shop

Here's what happened. The gear was installed as a test only so I did not bother making the nose gear stearable. I figured that our runway is wide enough that I could yank it off the ground (soft/short field takeoff style) before it wandered off the pavement. On the first takeoff attempt it rolled about 50 feet and was starting to get close to takeoff speed when it left the pavement and went into the rough. I shut down the power and let it bouce to a stop.

Nothing was damaged so I decided that I'd just try to hand launch it (never done it before by myself, have had others launch it for me with mixed results). ... A good run and throw as hard as I could while trying to keep one hand on my JR 10X, the plane bobbed and floundered for a few feet and them did a belly-flop on the paved runway. Of course the landing gear was a total loss, but worse than that the fuselage has millions of little stress cracks now. It's probably fixable but I'm already right at the limit of max flying weight for this thing and I know that repairing it will only add more weight.

I'm ordering another one from K&A tomorrow. It's a great plane and I want to fly it again. I have not given up on ROG ... the next one I build will have retracts ... and a steerable nosewheel

... hmmm, maybe a few Estes rocket JATO rockets next time

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