This week on Friday’s Community Spotlight, we’re taking a look at a community member’s jet build.
If you’re a fan of foam board jets, this awesome looking foam board L-39 Albatros might be the next build for you. Grifflyer has been responsible for a number of great foam board designs and has even been featured here on the Spotlight once before with his P-39. So what does this new foam RC jet have to offer?
Free Plans: Download Here
Specs at a Glance
There are two versions of the L-39 that you can build. These are the EDF version and the Prop Version.
EDF Version
Wingspan- 26in. | 660mm.
Length- 27in. | 685mm.
Wing area- 143 sq. in. | 9.2 sq. dm.
Wing loading- 17.4 oz/sq. ft. | 52g/sq. dm.
Dry weight- 12 oz. | 340 grams
All up weight- 17oz. | 482 grams
CoG- 2 in. from leading edge | 51mm. from leading edge
Prop Version
Wingspan- 26in. | 660mm.
Length- 27in. | 685mm.
Wing area- 143 sq. in. | 9.2 sq. dm.
Wing loading- 15.8 oz/sq. ft. | 48 g/sq. dm.
Dry weight- 10.2 oz. | 289 grams
All up weight- 15.7 oz. | 445 grams
CoG- 1.5 in. from leading edge | 38mm. from leading edge
Flight Video
I find, to get a true idea of how a plane will perform, it’s best to see a video. Thankfully, Grifflyer has provided us with one! Take a look.
Flying Characteristics
Here’s the designer, Grifflyer himself, to explain how the L-39 flies and what you can expect when you take up the controls for the first time.
This thing looks fast - but how fast is it?
“Top speed is great when built as an EDF and slows down very well for landing, if built as a pusher prop jet the top end speed drops but your static thrust is much higher giving the plane a more "trainer" like feel.”
How would you describe the handling?
“When built as an EDF it tracks like an arrow and the controls are very smooth giving you the ability to fly like a pattern ship, but can become "snappy" and abrupt when you really start banging the sticks around. If you chose to build it with a pusher prop you'll find that it handles similar to a park flyer, but faster and less forgiving.”
How does it stall?
“If your plane stalls it will likely drop a wing but it is nowhere near entering a spin, all you have to do is level the wings and then power out. Due to the fact that a prop jet has more static thrust your recovery will eat up less altitude compared to the EDF setup.”
Can the L-39 do aerobatics?
“The aerobatic ability of this plane limited to the basics, Loops, Rolls, Inverted, Split S's etc.”
How do you launch the model?
“The method of launching the jet differs depending on how you choose to power it. If you built it with a ducted fan I suggest holding it right behind the trailing edge of the wing and tossing it from there. Let me rephrase that, don't give this a light gentle toss you need to get up to flying speed, because the ducted fan doesn't have enough static thrust to get it up to adequate airspeed before it hits the ground (ask me how I know
) On the contrary never launch it like this if you built it with a prop setup as you run the risk of the prop striking your hand, what I do is hold it right in front of the intakes and give it a nice underhand toss and let the motor do the rest.”
What does it take to land the plane?
“Landing this model is quite simple all you need to do is bleed almost all your airspeed and get it close enough to good 'ol terra firma to put ground effect to work, then right before to hid land flare the plane and you'll "ride" a cushion of air to the ground.”
What would you say the skill level is?
“This depends on which variant you'll be building if you want to go prop powered then I'd suggest being able to fly all four channels very comfortably, if you want to build it as an EDF then you'll want to learn how to fly faster planes.”
Closing Thoughts on the L-39
If you’re looking for an all-around fun and great looking EDF or pusher jet for your fleet, Grifflyer’s L-39 is an awesome choice. Its size and flying characteristics allow you to fly it in a park or small field whilst the optional pusher prop configuration empowers even relatively new RC pilots to have a go. Great job Grifflyer!
If you want to read more about other community projects, visit the Flite Test Forum or check out these articles:
Community Messerschmitt BF 109!
Article by James Whomsley
Editor of FliteTest.com
Contact: james@flitetest.com
YouTube Channel: www.youtube.com/projectairaviation
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If you have two you can hook them up in parallel and use less extra nose weight that way.
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Was a bit taken aback by the Weights tho... for 26" span flyers these are 16 oz !! models... That seems as Really heavy!
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I think the reason is that the wing loading on the l-39 is 17.4 oz./sq. ft. while something like the FT X-29 has a wing loading of 21.3 oz./sq ft. so it's actually not super heavy for its size.
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Good luck with the build.
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Each sheet of paper is 30x20 inches so you would want your plotter to be able to handle at least that much. If I remember correctly, this plane only requires two sheets of foam. If FT is willing I'd love for this to become an SBK. Good luck with your build!!
One other thing, if you're building this as an EDF I suggest you check out V2 of this design, it's basically the same plane and it flies the same, but it looks a whole lot better, easier to build, and looks a lot more like the real thing. https://forum.flitetest.com/index.php?threads/aero-l-39-albatros-v2-edf-jet.60299/
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Bonjour,
En quelle épaisseur faut il le construire?
Diiity
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