Official FlightLine RC 1600mm P-38 Lightning Thread

[BadBob]

Just want to share this: https://www.youtube.com/watch?v=9BaFIGntKCE. He drilled a pin hole in the Canopy to avoid the gatoring effect seen in glass.

[Oxotnik]

Awesome picts. Thanks for sharing them.

[downwindleg]

Hey Aros, you may very well have checked these potential problems already, but I seem to recall that you had a separate setup on the P-38 for when you had the camera mounted . I'm wondering if you might have the wrong setup. Also, when I first set my plane up, I had to put a small block of foam between the back of the batteries and the wing crossmember to avoid them sliding back an inch or so during flight and giving me the condition you described. Those are the only two things I can think of based on your description. Hope that helps, let me know what you figure out, Brad P.S. Out standing scale detail shots Fastdeddie !!

[BadBob]

Hey Aros, you may very well have checked these potential problems already, but I seem to recall that you had a separate setup on the P-38 for when you had the camera mounted . I'm wondering if you might have the wrong setup. Also, when I first set my plane up, I had to put a small block of foam between the back of the batteries and the wing crossmember to avoid them sliding back an inch or so during flight and giving me the condition you described. Those are the only two things I can think of based on your description. Hope that helps, let me know what you figure out, Brad P.S. Out standing scale detail shots Fastdeddie !!

Love the block of foam idea. Great! I'm in the balance process myself and will apply this. Thanks DW!

[BadBob]

I'm at the balance stage now and this bird is very nose heavy. Is the nose balanced with a slightly nose down attitude or level? I'm having to put a lot of weight in the aft section of the center pod and batteries are all the way back and the nose still wants to sink.

[OV10]

What size battery(s) are you using? I'm using a 6000mAh 4S(single) and no weight required. If you are adding weight, it should go as far aft as possible, the longer the moment(fulcrum) the less the weight required.

[Lon]

I'm at the balance stage now and this bird is very nose heavy. Is the nose balanced with a slightly nose down attitude or level? I'm having to put a lot of weight in the aft section of the center pod and batteries are all the way back and the nose still wants to sink.

Bob, Here's some pics of my battery placement with Admiral 2500s & 3600s. It's worked just fine for both my silver & green 38s.

[Tsmith]

Bob, Here's some pics of my battery placement with Admiral 2500s & 3600s. It's worked just fine for both my silver & green 38s.

I'm using two admiral 3000s and I find my sweet spot exposes just the first set of holes...slightly farther back from Lon's picture 1

[downwindleg]

Like Lon, I have the admiral 3600s and the sweet spot is about 5/8" back from the front , just a little more than Lon has but I'm sure it varies based on your set up . Like stock gear vs upgrade gear and what kind of wheels etc. It's been awhile since I set mine up Bob but if your still nose heavy, I have to ask if that is with the gear up or down? Since , when the gear come up, there is a significant shift in weight towards the tail. So you want to balance the plane with the gear up so that when the gear does come up in flight, your not instantly tail heavy. Forgive me if you already knew that- just checking, Brad

[Arycon]

Hey all, been awhile since Ive posted. Havent flown since then either. My flight buddy that is a snowbird is coming back to Florida so I gotta get my P-38 ready. Need help guys. Last time I flew (and everytime, actually) my bird is banking left. I know it may be misaligned rudder and I trimmed it slightly right on the clevices...question is - should I reset the aileron clevices to test if it is still banking? I put deflection on the ailerons at stick neutral to substitue tx trim. Only way I could get her to fly close to level. Also...I have a Eagle Tree Guardian to install in it. If for some reason I cant get the plane true level via neutral surfaces, will the gyro compensate automatically if something is still off and it banks? Not sure Im explaining this well. I dont want to plant my P-38. I gotta get this banking issue sorted. Has to either be rudder (which looked centered to me) or a wing warp issue.

[mr.frankenjet]

mine 2 required allot of ale trim to fly level, talk of wing alignment , maybe off a little. I have to measure it but she seems to fly ok anyway

[Arycon]

I will have to take a photo of my ailerons at neutral. They have roughly 4 to 5 mm deflection to keep the plane level. So left aileron pointed down that 4 to 5mm and the right aileron points up the same distance. This is how they are set with the transmitter trims to zero. I have had at least 10 planes and have set each one up flawlessly. I tried flying the P-38 with neutral aileron surfaces dead level with the wing and she banked left like a bird was sitting on the left wing. Rudder was as neutral by my eye as much as it could be preflight. Not sure how sensitive a twin is to rudder as this is my first one. Thats why I am here...should I recenter the ailerons and try adjusting the bank with rudder? Im just really nervous to fly it again with the ailerons neutral. The bank was bad. If rudder doesnt help level it out, getting her down will be very hard. Tx trim can only do so much. I want to install the gyro, but ideally I would like for the surfaces to be addressed first. Having so much deflection on the ailerons to stay level once in the air reduces the plane's response to banking right. She is much slower making a right turn because of it.

[Oxotnik]

My P-38 wants to roll right. On close inspection my h stab is not perfectly in plane with the wings. To further compound it, the left h stab tip is canted up at a slightly higher angle. It took me a couple flights to get my ailerons trimmed, but once I got them trimmed, my P-38 flies like a dream.

[BadBob]

What size battery(s) are you using? I'm using a 6000mAh 4S(single) and no weight required. If you are adding weight, it should go as far aft as possible, the longer the moment(fulcrum) the less the weight required.

2-4s Turnigy 3300's.

[BadBob]

My P-38 wants to roll right. On close inspection my h stab is not perfectly in plane with the wings. To further compound it, the left h stab tip is canted up at a slightly higher angle. It took me a couple flights to get my ailerons trimmed, but once I got them trimmed, my P-38 flies like a dream.

There's an apparent factory defect in the elevator. See FLTRI's post #1666, P.84 and other responses to this there as well.

[Arycon]

There's an apparent factory defect in the elevator. See FLTRI's post #1666, P.84 and other responses to this there as well.

That is regarding incidence and the plane needing 4mm up elevator. Mine is banking to the left strongly with all surfaces set neutral at the clevice side. Never had a plane do that before.

[downwindleg]

Hey Arycon, is it fair to assume that it is rolling left beyond your ability to trim it out with the slide trims on the transmitter?

[T-CAT]

My P38 has a relatively drastic left bank tendency, but it was easy to determine why. I had a feeling it would do so before the maiden flight, but didn't adjust for it ahead of time to ensure that really was the cause. The right side flap surfaces are warped and cause a downward deflection, so they act a bit ailerons with left bank functionality since it's pushing the right wing upwards. I did my best to massage the surfaces and gradually bend them to as close to neutral as possible without sacrificing the integrity of the foam and wooden flap structure. It will never be flawless in terms of banking tendency, but it was less. So, after a few flights, I gradually manually adjusted the left and right aileron clevises to position the left aileron slightly down, and right aileron deflection slightly upward. I used an additional flight to see if the clevices needed to be adjusted further, and if it needed a little extra trim, I was okay using the trim on the Transmitter for the remainder needed. It's no big deal, but it's something for you to look into.

[OV10]

There's an apparent factory defect in the elevator. See FLTRI's post #1666, P.84 and other responses to this there as well.

Bob,
There is NO factory defect in the elevator.
You need to read ALL the relevant aspects regarding that topic. I was one of the original inquirers of the reasoning for the factory required 4mm up elevator.
It was first thought that there was an incidence issue and there IS NONE. What the real issue is this, the inability to be able to move the battery(s) far enough aft enough to be able to meet the appropriated CofG(CG). The design of the forward cross member in the wing center section where the fuselage meets the wing prevents the battery from going any further back. If the battery were able to do this, then the weight shift would have been accomplished enough to meet the CG without having to use 4mm of up elevator as the neutral. Flight Line had to go this route because from a design aspect they would have had to redesign that cross member piece/location and most likely it was a conscious engineering/marketing decision to let it be as it is and just do the abnormal trim versus the cost of a design modification. So it is a tad nose heavy because of the inability to shift the weight which requires the 4mm of up elevator as the neutral level flight. This does present a slight disadvantage for inverted flight because the amount of down elevator required for level flight is more than normal but capable of doing so and in my own personal opinion was an acceptable range to risk in the engineering eyes of the manufacturer.
This plane is a phenomenal flier and has been received by the RC community with an almost rabid passion. You first started posting on this thread back in June and actually showed some pics(post #2117) of your assembly in late July. It is now the second week of Nov and you still haven't flown yours. As mentioned to you in my post#2394, "your getting wrapped around the nits of nothing before having flown it, just go fly this bird and have a ball. I believe "xviper" gave you very similar advice around that same too.(a month ago) This bird flies so easy for being a twin." Set it up like every other 'Joe Pilot' has done per the manual and let her rip.
Best regards,

[Arycon]

My P38 has a relatively drastic left bank tendency, but it was easy to determine why. I had a feeling it would do so before the maiden flight, but didn't adjust for it ahead of time to ensure that really was the cause. The right side flap surfaces are warped and cause a downward deflection, so they act a bit ailerons with left bank functionality since it's pushing the right wing upwards. I did my best to massage the surfaces and gradually bend them to as close to neutral as possible without sacrificing the integrity of the foam and wooden flap structure. It will never be flawless in terms of banking tendency, but it was less. So, after a few flights, I gradually manually adjusted the left and right aileron clevises to position the left aileron slightly down, and right aileron deflection slightly upward. I used an additional flight to see if the clevices needed to be adjusted further, and if it needed a little extra trim, I was okay using the trim on the Transmitter for the remainder needed. It's no big deal, but it's something for you to look into.

I know for a fact that there is droopage on my flaps at the edges. The flap is not reinforced very well out of the box and that may be part of it. Ive been trying to think of a way to stiffen them and still allow them to close flush with the wing. downwindleg - it wasnt full TX trim but way too much. But the amount of deflection I needed on the ailerons is also a bit excessive. I need to give it a good once over.