Official FlightLine RC 1600mm P-38 Lightning Thread

[Elbee]

I finished up my Lightening....

AT, Outstanding work on your P-38, great livery choice, and a nicely detailed report. Bravo Zulu, Sir. Best, LB

[GliderGuy]

AllThumbs - VERY nice! Sweet livery.

To help ensure its life, you may want to read post #4211 and #4212 and # 4218 for consideration.

Be sure the elevator horn is solidly glued in.

-GG

[Jpmcdo]

posted my issues with balancing but now have it so deleted text.

[GliderGuy]

This bird was newly delivered in 2018. After a huge number of flights (several thousand), she went in, yesterday. The design limit of something (receiver or control box) was finally reached.

It was dead calm, but after one uneventful flight...on flight #2 she began twitching as if hitting a wind sheer layer (which i knew was impossible). Aileron twitch...then aileron trim started needing to be added...not much, but a few clicks. Then more roll axis twitches. Time to get her down...and fast. On base leg, she stopped responding to aileron, so I moved to rudder for roll control...that worked.

Then on final, and still about 100 ft up, everything went bad. Bless her heart....she ate grass and dirt face first!

She's actually repairable, but after so many flights and looking pretty ragged after a hard life (had more than her fair share of bumps and bruises), it's time to retire her for spare parts. New one is on the way.

Hats off to the Flightline P-38 design team. One would have never guessed that so many, many flights could have been put on a foam airframe. Ya done great!

"Get something different", you say? My response...Ya gotta have a P-38 in your flying collection. They are soooo unique looking in the air, and they are so fun to fly!

-GG

[themudduck]

This bird was newly delivered in 2018. After a huge number of flights (several thousand), she went in, yesterday. The design limit of something (receiver or control box) was finally reached.

It was dead calm, but after one uneventful flight...on flight #2 she began twitching as if hitting a wind sheer layer (which i knew was impossible). Aileron twitch...then aileron trim started needing to be added...not much, but a few clicks. Then more roll axis twitches. Time to get her down...and fast. On base leg, she stopped responding to aileron, so I moved to rudder for roll control...that worked.

Then on final, and still about 100 ft up, everything went bad. Bless her heart....she ate grass and dirt face first!

She's actually repairable, but after so many flights and looking pretty ragged after a hard life (had more than her fair share of bumps and bruises), it's time to retire her for spare parts. New one is on the way.

Hats off to the Flightline P-38 design team. One would have never guessed that so many, many flights could have been put on a foam airframe. Ya done great!

"Get something different", you say? My response...Ya gotta have a P-38 in your flying collection. They are soooo unique looking in the air, and they are so fun to fly!

-GG

Nice post GG. Its quite refreshing to read that, as opposed to "I got hit by radio interference", "it was a Lemon receiver", "it was a gravity pocket", "it was sunspots", "foam planes are CRAP", "I'll never buy a foam plane again because FX was 1 day late" and so on. These models are fantastic products - they fly great and look great. I only wish I could fly mine as much as you do!

[Twowingtj]

GliderGuy Sad to hear that it went in. You just never know when the "expiration date" is going to arrive.

When that time comes for mine, I will replace it as well. It's my go to favorite Flightline bird.

[MikeT]

GliderGuy Sad to hear that it went in. You just never know when the "expiration date" is going to arrive.

When that time comes for mine, I will replace it as well. It's my go to favorite Flightline bird.

LOL. They all have one.

Mike

[GliderGuy]

Follow-up on post #4224….
It definitely was the P-38 electronics. I flew the MiG-29 and F-4 today with the same transmitter. No issues.

-GG

[GliderGuy]

Update…The new P-38 arrived in perfect shape. After putting a large number of flights on the previous bird, I knew where the minor weaknesses exist. So, I spent 3 days beefing up some weaker structural areas (example…the motor mount blocks do eventually begin to wiggle a bit, so I added some hot glue in strategic places to prevent this). Also added some beefing up to the elevator horn, since one has come loose on me). I also installed the upgrade landing gear. I discovered one minor issue with an intermittent outer wing plug connection. Seems like the factory new male/female “build” wasn’t quite right. Worked on correcting that issue….got ‘er done.

I chose the Pudgy (V) Maj McGuire option.

After an overall painting with UV protectant water base paint, 3-Days into it, she was ready to go.

Went out at sunrise this morning and got in 6 flights before the wind hit (cool front passing). Since I set her up just like the prior bird, 3 extra clicks of right aileron trim, and she was perfect.

Tons of fun to fly. Just don’t get too slow on final approach.

The prior P-38 was a true silver, and I have a spray can of silver leaf paint that matched. This bird came in a mica gray finish (or similar). I will eventually need to find a matching color.

The “power down” transmitter mode range check was EXCELLENT. Double checked that the controls all moved in the correct direction then pressed the throttle up. Away she went!

-GG

[Aros]

GliderGuy I love your input. Always so thorough and thoughtful in your take. Keep it up!

[GliderGuy]

Thanks Aros!

I neglected to mention that my “go to” elevator servo for my planes with only the single servo is the high-torque MKS HV-69.

While the stock servo is fine, the HV-69 adds a level of confidence albeit at an added cost. Moved to this MKS servo after the stock stab’s servo failed on my F-4….and also use it to drive the MiG-29 stabs.

This servo fits the P-38 elevator slot perfect.

-GG

[airotroy]

I finished up my Lightening, and all the stars and planets finally converged such that I could maiden it last weekend. Between bad winds, weather, family, COVID, and life, it has taken forever to get out to the field. A apologize in advance for the long writeup, but I figured it would all be useful info for anyone building or considering purchasing the Flightline kit. Bottom line is that it’s a terrific airplane, even at the increased price. It’s definitely not for beginners, but even so, it is a stable, predictable, beautiful model.

BUILD NOTES:

• Total Wt: 8 lbs 10.8 oz with two 4S2600 80C batteries
• The only substantive modification is that the undercarriage is upgraded to the shock-absorbing landing gear.
• After much consternation and confusion over CG location, I decided to go with the CG range suggested by Motion RC, which is between 65 and 75 mm. I can put my fat index fingers between the two marks I put on the bottom of the wings (see photo), and all three of the battery sets I use balance the aircraft okay around 70mm.
• All flight controls bypass the LBB and are plugged directly in to the receiver.
• The belly IFF lights are plugged into the LBB strobe light outlet. They really are cool and visible in flight when turning away from the runway.
• I soldered crossover + and – wires on the ESC side of the battery connectors to allow both batteries to feed both motors (Thanks, Evan D!). Both BECs are connected through the ESC servo Y-connector that plugs into the receiver. Since each battery can power the ESC/BECs independently, I don’t feel there is a need for a separate UBEC.
• The power system includes a dedicated voltage telemetry sensor for each battery. Telemetry programmed features (I actually stole this idea, but I can’t find the forum or link to it… I apologize for not being able to give proper credit.) include:
  • • Voltage of each cell on both batteries presented on transmitter, and recorded in telemetry log.
    • Difference between highest- and lowest-cell voltage reported for each battery
    • Two-position, spring-loaded toggle on transmitter announces flight time and voltage of lowest cell when pulled.
    • Haptic and audible warnings if any cell voltage is 3.5V or less for more than 3 seconds.
• The Loss Of Signal fail-safe is set to auto-level, power off, and gear up using the stabilizer receiver (Frsky S8R). Auto-level can also be engaged with toggle switch in case of loss of orientation.
• All control throws set at instruction manual recommendations, including 4mm up elevator “neutral” position, and recommended flap/elevator mixing.

PAINT SCHEME:

• The paint scheme is from the 459th Fighter Squadron “Twin Dragons” in Burma.
• The airplane represents Lt. Harry Sealey’s P38-F, “Haleakala” (named for the Hawaiian fire god).
• I made vacu-formed hub caps for the main wheels since they are a prominent part of the paint scheme.
• The nose cone and exposed servos were painted with matching Home Depot sample paint. The clear plastic around all of the lights were painted as well. I used a combination of Rustoleum rattle-cans, airbrushed Testor enamels, custom-cut vinyl sheets, custom-printed water-transfer decals, and cut-vinyl masking film to make markings (Yellow dashes were a B#&*%!). I made the vertical tail numbers with my cutting machine using the large, white squares in the kit-provided decal set.
• There is still some detailed painting and weathering to be done, but I wanted to get the bird flying before finishing that up.

FLIGHT NOTES:

• I made three flights, including the maiden. I was very conservative with these flights due to testing the complex radio programming and the testing of the landing gear retract/extend, flap retract/extend, and their impacts on flight characteristics. My key observations after only three flights:
  • Takeoffs were easy. I slowly accelerated the throttle, and by the time I reached 75%, the airplane was gently lifting off on its own, in a very scale-like manner, with no rotation required. The maiden takeoff was without flaps, and the two subsequent flights and touch-and-goes were with mid-flaps. The process and characteristics were the same for all takeoffs, with the only difference being that the takeoff run was about a third shorter when using flaps.
  • On the maiden, I only needed one click of down elevator for it to be trimmed up. That kinda makes me wonder about the utility of the 4mm up elevator “neutral” position. She flew beautifully. Very stable and predictable. A little rudder is needed to make coordinated turns. It will definitely lose altitude in a turn, so a slight increase in power and up-elevator are needed to maintain level flight. Steep turns at low altitude are probably a bad idea until one gets used to the airplane. It accelerates quickly, but also slows down quickly. The high-ish wing-loading is evident, so the airplane needs your attention throughout any maneuver. Loops and rolls were beautiful, and very scale-like, as were takeoffs and landings.
  • With gear down, glide slope on landing is easily managed with throttle. A complete power-off approach is probably not a good idea. Landings were made by leveling out just above the runway, and reducing throttle while holding it off until touchdown. Very little flare was needed.
  • Ground handling on takeoff was good, but the tail-end of the landing roll-out seems to be a little unstable. I suspect that giving the main gear wheels a little toe-in would help in that regard. That’s on my to-do list, so it will be interesting to see if provides improvement.
  • It’s a very docile airplane, and easy to fly, but does need to be flown while in the air and throughout the landing. All-in-all, a terrific airplane!
• Made three flights, using three different battery sets: 2x 3300mAh, 2x 3000mAH, and 2x 2600mAH. All flights were mostly at or below 75% throttle, with low approaches and touch-and-goes. The third flight was more aggressive with the throttle, with a few loops and rolls. I used my telemetry to tell me when my cell voltage was down to 3.8, and then landed, so I didn’t really pay that close attention to the time. All flights were easily 5 minutes.

NEXT TO-DO’s:

I need to get the airplane on my Watt Meter to get some power system data. I’m a little ashamed I didn’t do that before first flight, but I was so anxious to fly, I just outright forgot. I’m gonna play with the main gear wheel alignment, adding slight toe-in, to see if I can tame the landing ground-run. Also on the list is to add some weathering effects, but that will likely be a gradual add-on a bit at a time. The pilot and cockpit could use a makeover, for sure. I’ll play with the Taranis programming as well. The programming I have done still needs some tweaking, and I need to spend some time working on the stabilize receiver's gain settings. Really, there is nothing critical. The airplane is really a winner, as-is!

Great paint and write up. Using 3000 4s and CG perfect. Have flown 3 times now and at 1/2 to 2/3rds power on take off, turns, and landings, she holds true and has no stall tendencies. Probably my favorite plane. Only complaint was the wiring came too short and resulted in a birds nest of wiring. 1/2 flaps on take off and landing resulted in no lift and helped with both. Overall I'd suggest this plane even at the high point price its sitting at now. $100 more than I paid for it in March.

[GliderGuy]

An additional few tips from experienced gained after years of flying this bird and tons of flights…..

1) The wing’s outer panel fore or aft drag fittings may <hard landing> break/snap from their central panel root rib. So before each flight, grab the tip and wiggle back and forth. If it moves, you’ve got a problem. To delay this breakage, during the build I invert the bird, score the finish inside the channel of the fittings, and fill the channel of the 4 fittings with a STRONG epoxy. Be careful and don’t get any spill-over, but smear some epoxy onto the root rib right at the end of the channel. Note: You can make this mod after the build, too. Just remove the outer panels.
2) Prop strike damage can be minimized by setting the motor brake to ON. The springy upgrade gear will compress enough to get a prop strike. Stopping the prop rotation just prior to touch down works well to minimize prop strike damage.
3) Have some servo wire extensions handy for the build. Some of the wires are a bit too short. Extensions will make the task much easier.
4) If you don’t have the newly designed prop hubs, get some! The old design hubs do crack. If you sling a prop, the roll rate and shaking is incredible.
5) Use Foam-Tac to help secure the prop nuts and spinner bolts. Otherwise, the prop nuts will work loose. This is exacerbated by setting the prop brake to on.
6) Keep a few landing gear servos on hand. They sometimes fail.
7) Land gear down if the nose gear servo fails. Minimal damage will result…just the way she sits.
8) Land gear up if a main fails to come down.
9) Consider upgrading the elevator servo. It’s a critical function. I use the MKS HV-69 high torque servo….fits perfect, and it adds peace of mind!
10) Take care during inverted low flights. Using just a little too much down elevator can cause entry into an inverted snap roll. She can bite you!
11) Maintain speed on final approach. If the wing lift lets go, she will drop hard and fast.
12) Periodically check the main’s retraction alignment…esp. after a hard landing. Misalignment may cause a gear jam.
13) Yes….Definitely do the wiring mod discussed in prior posts to ensure either battery alone will keep both mills spinning. The roll rate when one mill stops pulling is instantaneous and AGGRESSIVE.
14) The book suggested 4 mm of up elevator trim is necessary. Book throws, mix, and CG are fine to start with.

-GG

[airotroy]

An additional few tips from experienced gained after years of flying this bird and tons of flights…..

1) The wing’s outer panel fore or aft drag fittings may <hard landing> break/snap from their central panel root rib. So before each flight, grab the tip and wiggle back and forth. If it moves, you’ve got a problem. To delay this breakage, during the build I invert the bird, score the finish inside the channel of the fittings, and fill the channel of the 4 fittings with a STRONG epoxy. Be careful and don’t get any spill-over, but smear some epoxy onto the root rib right at the end of the channel. Note: You can make this mod after the build, too. Just remove the outer panels.
2) Prop strike damage can be minimized by setting the motor brake to ON. The springy upgrade gear will compress enough to get a prop strike. Stopping the prop rotation just prior to touch down works well to minimize prop strike damage.
3) Have some servo wire extensions handy for the build. Some of the wires are a bit too short. Extensions will make the task much easier.
4) If you don’t have the newly designed prop hubs, get some! The old design hubs do crack. If you sling a prop, the roll rate and shaking is incredible.
5) Use Foam-Tac to help secure the prop nuts and spinner bolts. Otherwise, the prop nuts will work loose. This is exacerbated by setting the prop brake to on.
6) Keep a few landing gear servos on hand. They sometimes fail.
7) Land gear down if the nose gear servo fails. Minimal damage will result…just the way she sits.
8) Land gear up if a main fails to come down.
9) Consider upgrading the elevator servo. It’s a critical function. I use the MKS HV-69 high torque servo….fits perfect, and it adds peace of mind!
10) Take care during inverted low flights. Using just a little too much down elevator can cause entry into an inverted snap roll. She can bite you!
11) Maintain speed on final approach. If the wing lift lets go, she will drop hard and fast.
12) Periodically check the main’s retraction alignment…esp. after a hard landing. Misalignment may cause a gear jam.
13) Yes….Definitely do the wiring mod discussed in prior posts to ensure either battery alone will keep both mills spinning. The roll rate when one mill stops pulling is instantaneous and AGGRESSIVE.
14) The book suggested 4 mm of up elevator trim is necessary. Book throws, mix, and CG are fine to start with.

-GG

Good stuff - thanks

[Oxotnik]

About two years ago, I had a battery die on me during the takeoff climbout ( I was running a single 4S-5AH batt, which was fully charged and the IR looked fine before takeoff… it was the first flight of a battery that had been given to me… live and learn), and my P-38 crashed hard. I’d been debating gluing her back together, but recently bought a replacement P-38 instead. I’m definitely going to a parallel-dual-batt setup on this one. I haven’t yet opened the box. I’m hoping that the spinner backplates have been upgraded, as I had to make a couple emergency landings when a backplate broke. Will definitely put the upgraded struts on this one (as I did on my first one). Will paint on some invasion stripes and use a Callie-graphic livery.

I don’t know many flights I had on my first P-38, but they numbered well over a hundred, probably pushing two. It was my favorite warbird (and I have a bunch of warbirds, probably around 80), and due to its piggish wing loading, it was my go-to plane on windy days.

I’m anxious to get my new P-38 detailed and up and flying. I will be setting her up for parallel dual batts and her brain will be a FrSky X8R, with a 4-channel XBus expansion (I can go to a second X8R, if I end up needing more than 12 channels), and a voltage sensor. I will bypass the Blue Box for ailerons, elevator, and rudders, and will give each aerosurface its on own channel (with maybe a few exceptions, if it doesn’t make sense to not-wye one with another servo). I am a bit worried about real estate in the bay for having two X8Rs and a Blue Box for the gear sequencing and LEDs. Some foam alterations may be required.

I fly quite a few twins (I have a real weakness for sexy twins… <grin>) and have been setting them up with differential thrust. My original was not setup with differential thrust though. Has anyone flown the P-38 with differential thrust? I’m actually a bit worried that the P-38 may not like differential thrust, due to its heavy wing loading. Thoughts?

Also, you guys that are running dual batteries greater than 5AH total, have you needed to add additional up-Ele for neutral? Do you have any trouble getting the nose to flair for landing?

[GliderGuy]

Flying with 2 Admiral 4S 3000, I don’t have any issues with CG and/or the flare to touchdown, but the 4 mm of up trim at neutral stick is necessary.

As fast as she departs control when one prop stops pulling, you may want to reconsider adding differential thrust control.

While the elevator servo is fine, a bit more peace of mind is added by replacing it with an MKS HV-69.

-GG

[airotroy]

I too run 2-3000 4 Admirals with some up elev programmed. No problems on take off or landing as long as she comes in with some speed. I'v yet to add diff thrust and as good as she handles in the turns doubt if I do. I take it the elev servo's have been an issue ? I dont have near the 80 war birds you do but this one has become my favorite plane of all.

[Twowingtj]

Oxotnik I'm running two Admiral 4S 4000s in mine. I removed the little bit of foam ahead of the aluminum brace and have the batteries right up against that. It CGs fine. Flys great and has no issue flaring on landings. I can fly hard for around 7.5+ minutes too.

I'm running 8 channels. Not a lot of room in that aft cockpit area.

Have you got the silver or green?

I had Callie do this livery for me in honor of the Mrs, who got the bird for me. It's one of my favorite twins as well.

[Oxotnik]

Oxotnik I'm running two Admiral 4S 4000s in mine. I removed the little bit of foam ahead of the aluminum brace and have the batteries right up against that. It CGs fine. Flys great and has no issue flaring on landings. I can fly hard for around 7.5+ minutes too.

I'm running 8 channels. Not a lot of room in that aft cockpit area.

Have you got the silver or green?

I had Callie do this livery for me in honor of the Mrs, who got the bird for me. It's one of my favorite twins as well.

Thanks for the input! You don’t have a problem putting two 4AH batts in the bay? I remember a single 6AH batt being pretty tight.

I went with the OD Green P-38, like my first one.

When I got my first one, I was running a DX6 and even when I upgraded to a DX9, I never changed the channelization. So, I was controlling it in a 6-channel config. I’m looking forward to having more flexibility with my up-to-16-channel OTX radio and battery-voltage telemetry. If it wasn’t needing the Blue Box to control the LEDs, I may even not use the blue box. The back bay was definite crowded on my first P-38.

Chuck

[GliderGuy]

I take it the elev servo's have been an issue ?

The stock elevator servo is fine, but after an elevator servo fail / F-4 crash…I have decided to upgrade ALL my single servo elevator birds TO BE ON THE COMFORT SIDE OF CAUTION…albeit at a $cost$.

My good experience with the high torque MKS HV-69 on my MiG-29 set me on that path. The HV-69 also has a lower operating voltage spec…nice if you run long wires.

Cutting off one mounting tab is all that’s needed for a perfect P-38 fit and more peace of mind.

For the F-4, some “fill” work is needed as the HV-69 is smaller than the stock servo. No biggie.

I sleep better.

-GG