Official Freewing 80mm EDF L-39 Albatros Thread

[DCORSAIR]

Not to toot my own horn, but that's a perfect comparison between Overdone and Done Right. The 90mm Yak-130 wasn't my project, and it shows compared to my L-39. Yak is still a fun flyer on 8s, though.



RCJetDude, what livery did you decide on? Are you doing an opening cockpit, too?

Yes I do like the Yak as well, it flies very well for me on the 6S and the 1680kv motor, I do enjoy it and plan on keeping it for awhile anyway, but I can see the L-39 getting more flight time...........:)

[Alpha]

For those of you who are curious, the Freewing L-39 is *roughly* a 1/11-ish scale model. As is well known, none of our RC models have exact scale proportions for a variety of reasons (material thickness, wing loading bias, etc). So we round up or down slightly and take the length/width/height into consideration. Any time we post a scale ratio, take it with a grain of salt because it's really just an overall estimate to give owners a general sense of relative size sitting next to their Freewing cousins on the flight line. In the air, almost all scale is lost so don't be afraid to post some heritage flight shots of these models in formation. It would look real enough in my book, anyway.

By its length, the Freewing L-39 is about 1/10.8 scale, which could be rounded to 1/11 scale. This puts it in line with approximate scale length of the 90mm F-16 (1:10.7), 80mm F-5 (1:11.2), and 90mm Eurofighter (1:11.4). The 80mm Mirage is ~1:11.8, which I round to 1:12. And the big A-10 is 1:10.3, which I round to 1:10. But technically all these aircraft are "close enough" if you squint.

[seaviper]

The philosophy used in the design and manufacture of the L-39 is just right in my opinion. For clubs like ours, who are relegated to flying out of a hay field, the 80mm series of jets have the right combination of weight and thrust to perform nicely. Add in those wide F-4 tires and trailing link struts and you have an all-terrain jet. Well done.

I look forward to other 80mm birds at this level of finish and performance.

[seaviper]

A cool L-39 video trying to re-create the Polaroid shot that Goose took in Top Gun....(no top gun music in this one)

[JazzmanB]

Not to toot my own horn, but that's a perfect comparison between Overdone and Done Right. The 90mm Yak-130 wasn't my project, and it shows compared to my L-39. Yak is still a fun flyer on 8s, though.



RCJetDude, what livery did you decide on? Are you doing an opening cockpit, too?

Id say the L39 is the best all around freewing jet released. My top 3 are L39, Avanti and Venom. Then would be f5 and 262. The l39 is tops because it has the scale looks, big presence and performance STOCK. In fact it has near unlimited vertical once you have momentum going and is the fastest freewing jet out of a dive no question. I just want to put low timing on the esc to draw the amps a bit down. The build quality is top notch too with the stiffest(that's what she said) foam wing ive seen and not to mention AMAZING paint job. Id recommend this edf to EVERYONE. :)

[bill34207]

The L-39 gets my vote for the best one so far, too. Jazzman I tried low timing on mine for a couple of flights this morning and couldn't tell that it made any difference in battery use. I brought along my programming card to the field and put it back to medium after the second flight.

[JazzmanB]

The L-39 gets my vote for the best one so far, too. Jazzman I tried low timing on mine for a couple of flights this morning and couldn't tell that it made any difference in battery use. I brought along my programming card to the field and put it back to medium after the second flight.

Got ya. What about battery temps? At this point if i dont go to a fms fan Im more concerned with that. While none of my batteries come out hot they do come out pretty warm. Ive usually landed with 20-30% after 4 minutes or so. The batteries come out warmer then any jet i have currently actually. Similar to the 90s with the 1550 kv .Even the 90mm flex jet they stay cool. Im good at throttle management too bit this 80 on medium timing loves amps:)

[Wiz1]

A cool L-39 video trying to re-create the Polaroid shot that Goose took in Top Gun....(no top gun music in this one)

Great video Seaviper. Thanks.

[bill34207]

Got ya. What about battery temps? At this point if i dont go to a fms fan Im more concerned with that. While none of my batteries come out hot they do come out pretty warm. Ive usually landed with 20-30% after 4 minutes or so. The batteries come out warmer then any jet i have currently actually. Similar to the 90s with the 1550 kv .Even the 90mm flex jet they stay cool. Im good at throttle management too bit this 80 on medium timing loves amps:)

The batteries were not super hot but they were warm to the touch. Warmer than if I'd had them in the Avanti for 4 minutes. The second flight where I thought I was being very frugal on the juice actually seemed to use more than with it on medium timing and the EC5 connectors were very warm. Battery cells were right around 3.72 per cell and lower than I like them to be. I'm more accustomed to 3.78 - 3.81 after landing.

[Hardway]

Headed to do the maiden right now. I have 8 Admiral 5000 packs and one 4000 PRO, so no excuses!!!!!!!!!! Get sum!! (I hope :Whew:) Report later....

[DCORSAIR]

Headed to do the maiden right now. I have 8 Admiral 5000 packs and one 4000 PRO, so no excuses!!!!!!!!!! Get sum!! (I hope :Whew:) Report later....

You won't have any trouble with it, if you can't fly the L-39 then you need to find another hobby....:):)

[Hardway]

Flies great..... CG at 103mm. I thought it might be a touch nose heavy, so I added 8 "clicks" of up before takeoff and it was perfect... Have the throws maxed, but with my expo settings, I couldn't get bad behavior unless I put them all in the corner at med-high speed. I did several outside snaps!!! LOL Knife edge has little to no coupling. Like an Extra or Lazer…. Stall is a non event with mush forward and then keeps flying if you have any throttle at all... Keeps flying forever on landing. Better have a long rollout on concrete.... A little down mix is good with flaps, but more of a pilot helper than necessary..... Overall, a great EDF... Flew it hard and had 3.72 per cell left after a 3 minute timer. That included me doing a taxi text, then clearing the timer, then having to go around once with a bad setup for the first approach... SO 4:00, maybe. Battery was warm, but all good!!!!! Winner!

[Felixs10]

Finally got a chance to maiden mine today . It flew great , no takeoff flaps and up in about 200 feet .I also own an avanti (which I love ) I believe the L39 is a tad faster. The Avanti is still easier to fly and land . I don’t think the 2 planes are as similar as advertised, but that’s not a bad thing either. This plane has no bad tendencies that I could could find . Roll out and landing speed is faster than the Avanti . The only thing I noticed was that from a moderate to high speed , if you chop the throttle , she climbs. This is the first time that a jet has done this to me.

I really like this plane ! It looks great on the ground and flys remarkable well ... good job Freewing .....

[bill34207]

Finally got a chance to maiden mine today . It flew great , no takeoff flaps and up in about 200 feet .I also own an avanti (which I love ) I believe the L39 is a tad faster. The Avanti is still easier to fly and land . I don’t think the 2 planes are as similar as advertised, but that’s not a bad thing either. This plane has no bad tendencies that I could could find . Roll out and landing speed is faster than the Avanti . The only thing I noticed was that from a moderate to high speed , if you chop the throttle , she climbs. This is the first time that a jet has done this to me.

I really like this plane ! It looks great on the ground and flys remarkable well ... good job Freewing .....

You will also notice that if you are coasting at zero throttle and go to full it will drop a bit. I still like the way it flies though.

[seaviper]

Put 6 flights on mine today in formation with another L-39 (freshly maidened by one of our wingmen today) and an F-4. It was a good day. Next week we will have three L-39's in formation.

Congrats Hardway! She flies as good as she looks.

Currently 1 hour of flight time on the L-39 with no issues.

[T-CAT]

Now that I have 30 flights on the L-39, I figured I’d type up some observations about this great new addition to Freewing’s line of 80mm EDF jets. This aircraft has impressed me quite a bit as it tracks straight on taxi and takeoff, needed very little trim on its maiden flight, pierces through the wind nicely, has great overall performance and lands easily. That’s a jet worth owning. I believe it to be one of the nicest flying scale jets in Freewings line-up, and it is right up there for me with the Freewing 80mm A-10. I love that plane, so that’s great for me to feel that way with this jet.

Keep in mind, 20 of the first series of flights was with the Freewing 80mm 12-blade 1820kv inrunner 6S power system and the next 10 flights were with a Jetfan 80 6S power system (more on that and the Aux. air inlet testing in another post to follow).

Fit/Finish/Assembly
- The plane was packaged great with a low overall part count, everything was in order, had very little creasing or imperfections on any foam parts, and an impressive use of the foam packaging to fit all the parts in one box.
- Has a very nice paint job with very little paint bleed, and mine had the decals placed properly and aligned.
- It was easy to assemble and virtually impossible to get confused about which screw sizes to use, ha-ha. The glued surfaces mated well and allowed further joining pieces to bolt on straight and true. Just be sure to carefully look at how the tail piece is aligning when gluing to ensure the horizontal and vertical stabilizers fit properly as well.
- The wing tip light connector leads could have bit a tad longer for ease of assembly as well as fit tighter when connected to reduce the chance of disconnecting or intermittent illumination. I used tape to secure the connections after joining together, otherwise they could come undone during the install of the wing tip tanks, so a bit of care is needed to seat them well in the foam pocket of the tank.
- The landing gear is sturdy, and has been reliable. Using the F-4 main wheels was smart as they roll well, look good, and are rubber coated foam, but the nose wheel ruins the look a tad being non rubber coated foam and squared off at the edges.
- The new pressure-close nose gear door is great and appears to be trouble free. A small spring keeps it open, and upon gear retraction the door closes from the pressure of the strut, which is simple and reliable. The board deactivate the nose wheel steering when the nose gear is retracted, and that’s probably to more reliably keep the nose door shut. That was a great and thoughtful design.
- The landing gear deployment has a rather large delay, which I understand is for planes that have a nose gear door or main gear doors activating on a servo. However, this jet doesn't need the delay, so maybe in the future the multi-box could have an option to adjust for no delay.
- All servos except for one elevator had been centered from the factory, which was great to see. Also, servo arm access pockets are now molded into the foam :D. Thank you! Obviously, that made centering that one servo arm quick and easy with a screwdriver and no foam cutting or impression needed to access the screw.
- All screws were tight and all plastic glued pieces were secure with enough glue, and that was refreshing. I checked every screw from the servo arms, landing gear, battery tray, multi-box, etc., and all was well.
- The multi-box provides a somewhat all-in-one simplified wiring package with options for add-ons such as lighting (single flash, dual flash, etc.). The manual didn't quite represent the box connection positions well, so it was best for me to unscrew it from the wooden tray and simply look at the labels on the side of box while plugging in the servo leads.
- The battery bay is massive and should provide options for a wide array of battery sizes and weights. It also makes it easier to connect and disconnect components with less chance of messing up the foam or paint job.
- The lighting system looks great on the jet and can be seen while in flight.
- The mold details like rivets look phenomenal, and I'm very impressed with the work that went into the model.
- It was great to see a plastic covered cockpit to reduce the chance of foam damage from the sun. The pilots are okay, and have improved over the years, but are heavy and don't look realistic. I hope over time Freewing creates different molds to provide better realism even if they remain the same weight, although a reduction in weight would be welcomed too.

Flight
- The instruction manual's suggested CG and throws are great in my opinion. Sometimes a suggested control throw in a manual are overly responsive for my personal liking.
- Very little trim was needed on the initial flight, and it was immediately apparent that the plane was easy to fly, predictable, tracked well, and cut through the wind nicely (even more so than the Avanti) without much oscillation from turbulence. Point the jet where you want it to go and it’s there.
- Inverted flight required the smallest input of elevator to remain in level flight, so small that it took me by surprise. It may take the least amount of input of any scale jet I've owned.
- Aerobatics are spirited and can handle a wide range of maneuvers. With the same battery as I use in the Freewing Avanti, it didn’t knife edge quite as well as the Avanti (I'm only using that jet as reference since the L-39 is often being compared it) and tends to want to roll towards the top side. The knife edge maneuver required more rudder throw for me than the Avanti and the coupling was a tad more prominent, but easily managed since it was rather small.
- The speed and thrust are comparable between this and the Avanti with the same power system, and is hard to tell much of a difference. It has great power. The L-39 and it’s smaller wingspan makes it seem faster than the Avanti, but it’s not clear. Maybe someone will get some well-calibrated radar passes to see.
- The jet does have a slight tendency to climb with power off, but not horribly. I’m not sure if many others experience the same thing, but a few pilots at the field experience the same thing.
- The L-39 feels like it flies heavier than the Avanti. Its glide ratio seems to be less, but it still does great for a scale jet. The L-39 is sporty and amazing. It’s obviously not a sport jet and not quite in the same class as the Avanti, yet it is one of the sportiest scale jets I’ve flown. It is versatile and easy to fly.
- The stalls are predictable and easy to recover, and in no way did I feel it would not recover easily.
- In landing configuration, a pitch change does occur with flaps and gear deployment and the manual points out a transmitter mix to use if wanted, but I chose not to use the flap to elevator mix since it wasn't significant enough for me to do so. The airplane can hold a nice stable attitude for landing and settles in great for touchdown with proper use of throttle and attitude. The landing speed is impressive as it landed even slower than I thought it would. The main wheels roll well, so adjusting the landing speed properly to touchdown helps tremendously with ground roll distance.
-The jet tracked well on the ground, whether that be taxing or on takeoff and landing. My nose strut does have a very small bit of vertical “play” that seems to be the cause of a chattering sound during taxi. The grub screws are all tight, so I’ll look into reducing the sound soon. It’s possible the screw just needs to move to a more advantageous position on the strut pin groove to ensure no gap is present, or it could be something else.

I think this jet is great performer at a great value, and has scale features and great flight characteristics that makes me proud to own it. It’s one of the best flying scale jets I’ve owned from Freewing. It’s easy to tell the hard work that went into this model and it was well worth it. I really look forward to flying it more. I think they hit another home run with this one.

With that said, I do not think this L-39 is all that comparable to the Freewing 80mm EDF Avanti S, other than they both mostly fly predictably. I would not personally look into the purchase of the L-39 thinking “it’s like an Avanti”, but it is a sporty scale jet and a great one at that.

[T-CAT]

Mentioned earlier, I installed a 6S Jetfan 80 power system in the L-39, which is the same one I’ve used in the Avanti (as well as other power systems). In addition, after the new paint job I gave the plane, I wanted to test the outcome of closing the Aux./cheater air inlet. I haven’t flown the Jetfan set-up in this jet until today or flown with the cheater closed. My first 20 flights on this jet were using the Freewing 80mm 12-blade 1820kv inrunner power system and with the cheater inlet open. Today’s first flight with the Jetfan power system was with the cheater intake closed and the following flight were performed after taking the cheater cover off. The cover was made of thin styrene and painted over to make it look seamless and smooth. Well, I DO NOT recommend closing it, ha-ha. It was a night and day difference in performance, purely negative. I don’t care too much about the longer rollout or less low end thrust if it’s relatively small because our runway is massive, but I do care that I had to fly at significantly higher throttle settings to get it to fly even remotely decent. It was very underpowered and laggy, not just a little. Even the top speed was worse. After I took the cover off to reopen the Aux. air inlet for the following flights, the plane functioned as expected, the lag was gone, and the speed was back to normal levels. The Jetfan is faster than the stock outrunner setup, and MAYBE a tad faster than the Freewing inrunner system, but that’s debatable. So, was it worth it, no, not in my opinion. I happen to like the Freewing 80mm 12-blade inrunner power system for a tad better performance than this stock 12-blade outrunner power system, at a good price, but the stock outrunner system performs good too. I already had both the FW inrunner and Jetfan to try, so I did. Personally, I’ will take the Jetfan out and reinstall the FW inrunner I had in there previously. I’ will keep the Jetfan for a more suitable airframe. In the Avanti, this same Jetfan power system flies better, but in the L-39 it just doesn’t seem to take to it quite as well.

[T-CAT]

After the first 20 flights over the week, I decided to repaint the L-39, so today I got a chance to fly with it. It shows up extremely well in the sky with those colors, as well as at dusk. Some of the pictures are at the beginning of the day with the jet unplugged and another picture of it at dusk with the lights on. I’ll tell you, those lights showed up SO incredibly well on those later flights, even the sunny afternoon flights they could be seen at times.

[seaviper]

Nice writeup T-Cat. I concur on the aux inlet cover. My testing showed a dramatic reduction in performance with the inlet covered.
https://www.hobbysquawk.com/forum/rc...190#post156190

As far as the battery tray goes, my wingman flew the Admiral 5000, Admiral 4500, and Predator 4000 in his L-39 yesterday. The 4000 was almost all the way up at the fwd bulkhead. But she flew fine.

Our jet group is waiting on the third member to get his L-39 this week. Then we will make a decision as to whether we re-paint them. I imagine an airbrush is in my future.
We have made the decision to not install or, in my case, remove the pylons. The drop tanks do look nice. But they slow her just a little.

Yesterday we got in 6 flights on the L-39. I'm around 20 flights now. The fan appears clean. I guess the bird sits high enough off the ground that it doesn't "hoover up" as much stuff as some others.

[urrl]

This flight went about 4 minutes with 6000mAh battery but I really was not using much throttle management. The battery weight did not seem to hamper maneuverability.