Michael9865
Elite member
Looking good. Tip tanks look sweet
Aero L-39 Albatros - 50mm EDF jet
almost means not
New member
WOW!
We just got started in foam dtfb building with FliteTest stuff this summer. My son is 12.
By some coincidence and years of work, Ethan was selected to fly in an L-39 at Oshkosh this year.
We have been trying to figure out how to design an L-39 and get it painted (or skinned) like his airplane (race 777).
This summer, we would like to take it and deliver it to him in Atlanta.
almost means not
New member
do you need a beta tester for the design? I have the page open to order FMS 50mm 4s.
almost means not
New member
I've also been thinking about larger radius curves than the crease folds. I want to try removing about 1/2 inch of interior paper and running the curve that way. In testing, that yields a more smooth curve, but much harder to make exact measurements. It might make the intakes and canopy look a bit more 'scale'. Still, I am immensely impressed with what you have created.
Grifflyer
WWII fanatic
Wow, thanks!! but the design is complete, the last thing I need to do is get a video together so I can make a release it similar to FT which should be soon, but if you are really anxious I could PM you the plans in advance.
Grifflyer
WWII fanatic
I just got out to fly yesterday and for a few seconds it flew pretty good then it went down, I think what happened is I'm so use to launching the FT long EZ almost vertically that I did the same to the prop L-39 and once I got it leveled out it had stalled then it plopped to the ground. I got some repairs to make which should be done by the next weekend.
charlesrc2
Active member
Awesome flyer!! I've been wanting to build one.
Grifflyer
WWII fanatic
Quick update, I just got out to fly the prop version a couple of days ago with a heavier battery and It flies like a dream!! If all goes as planned I hope to have the plane released this weekend.
The Aero L-39 Albatros is a Czechoslovakian high performance jet trainer developed in the 1960's. The L-39 has served with over 30 air forces around the world, and is the one of the most widely used trainers. Today the L-39 is used in the Reno air races jet class, flown by demonstration teams such as the Breitling Jet Team of France, and are privately owned by jet enthusiasts.
With this in mind I wanted to create a relatively easy to fly jet the was versatile and had a wide flight envelope. So after four months of work I give you the Grifflyer Aero L-39, a sport jet built out of two sheets of foam board that can be built as an electric ducted fan jet or as a pusher prop jet using standard components found in the Flite Test F pack.
Video:
Overview-
Speed-
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.
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.
Stalls-
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.
Aerobatics-
The aerobatic ability of this plane limited to the basics, Loops, Rolls, Inverted, Split S's etc.
Take offs-
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.
Landing-
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.
Skill level-
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.
Specs:
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
Plans:
Aero L-39 Albatros Plans
Instructions:
(coming soon)
Gallery:
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You have done an excellent job on this @Grifflyer - nice work young man!
DamoRC
Grifflyer
WWII fanatic
Thank you very much!!
AircPirateNinsei
airc-pirates.com
It's awesome! All you need now is some stickers!
Paracodespoder
Elite member
Wow, nice looking build you got yourself there! Another to add to the build list
Grifflyer
WWII fanatic
Yes
