Official FlightLine RC 1600mm P-38 Lightning Thread

[Grossman56]

Great you found the problem, I'm just curious if the throttle trim was up too high. I know after I bind an airplane, hi find the trim position where one click will start the prop turning. You probably checked that, I'm thinking, but as you say, sometimes the answer is staring us right in the face.

Grossman56

[dkalwishky]

I did the initial bind a month ago so I don't remember if it was too high or not. I suspect when I did the bind I did not have the throttle in the lowest position.

[Chalredline1]

Thanks Ryan.

[xviper]

I really bad habit of mine used to be binding an electric plane with the throttle trim the way it is when you first select a new model. It is important to put the trim of the throttle to the lowest position before binding I was told that transmitters start of each new model memory with the throttle trim in the middle because that's where you want it to be when you are flying nitro planes. The trim needs to be in the middle so the engine can idle. On an electric motor, that is not necessary.

[Aros]

Well, at the field and irritated to report my P-38 suffered damage during an emergency landing. The wind is steady at 9-10mph but out of nowhere started gusting 15mph. I came down to land and noticed my front gear didnt deploy and was protruding from the bay so I waived off. I dont know if anyone else has had this problem, but my front gear has had an intermitent gremlin causing it to not cycle closed. It would lock up at roughly a 30° angle from the closed position. I cycled it about five times pre-flight after tweaking the steering linkage. All seemed fine. So I thought. The wind made landing hairy and I made multiple attempts to bring her down, cycling the gear multiple times to try and get the nose gear to drop. I knew the battery was getting dangerously low so I brought the gear up and made a belly landing with the nose gear locked at 30°. I landed in rough grass and dirt with clumps scattered thoughout.Two gear doors came off in the touchdown. One just pulled away from the bay with broken servo arm. The nose gear door, however, sheared at the pivot pin in addition to breaking the servo arm. The right bottom portion of the rudder was sheared in a straight line just below the horizontal stabilizer/elevator. Only the hinge pin is connecting it. Good news is nothing else on the body of the aircraft appears to be damaged, but the nose trunion is loose and likely needs replacing. Possibly the front gear strut if it is bent, but wont know until I get the nose retract to open fully. For the sake of safety I will replace both propellers entirely in case anything was stressed. Really frustrated over this nose gear. I really thought I had it sorted, but I was obviously wrong. Still, overall she is intact and will fly again after some shop TLC. Now to have a chat with the maintenance chief...

Ah bummer man, sorry to hear about the slight wreckage. I HATE when these things happen because it's beyond your control and you're helpless to do anything about it other than go through your check list and land the best you can given the situation.

Been there, done it, and will do it again I'm certain.

[Arycon]

Ah bummer man, sorry to hear about the slight wreckage. I HATE when these things happen because it's beyond your control and you're helpless to do anything about it other than go through your check list and land the best you can given the situation.

Been there, done it, and will do it again I'm certain.

Hah!

My friend, you are SO right. I cant even blame it on QC cause it is intermitent and worked just fine numerous times. It worked prior to the flight 4 checks in a row. I just got done cycling the gear a few minutes ago to take a damage assessment and the dang front gear dropped perfectly. Like you said, it just happens, and all you can do is keep calm and use your training as an RC pilot to bring the plane down as safely as possible.

So actual part casulties are nose gear door and bay piece. Two stripped 9g door sequence servos and both props (replacing them both for safety). I will replace the nose retract as well. Im not risking using the existing nose retract again, working now or not. New parts are already ordered and should be here hopefully by Friday. All in all, damage was minimal.

My Dad always said, if you dont want to pay for parts or make repairs then dont fly.

It happens to us all. Just part of the hobby.

[Aros]

My Dad always said, if you dont want to pay for parts or make repairs then dont fly.

Reminds me of the old saying, "If you ain't crashin' you ain't flyin'"! LOL, so true.

[xviper]

"If you're not crashing, you're not having enough fun."

[Arycon]

I also used to hear "Taking off is an option. Landing isnt."

[rtwatkins]

Hah!

My friend, you are SO right. I cant even blame it on QC cause it is intermitent and worked just fine numerous times. It worked prior to the flight 4 checks in a row. I just got done cycling the gear a few minutes ago to take a damage assessment and the dang front gear dropped perfectly. Like you said, it just happens, and all you can do is keep calm and use your training as an RC pilot to bring the plane down as safely as possible.

So actual part casulties are nose gear door and bay piece. Two stripped 9g door sequence servos and both props (replacing them both for safety). I will replace the nose retract as well. Im not risking using the existing nose retract again, working now or not. New parts are already ordered and should be here hopefully by Friday. All in all, damage was minimal.

My Dad always said, if you dont want to pay for parts or make repairs then dont fly.

It happens to us all. Just part of the hobby.

do you think it's the sequencer that caused your issues Arycon? reason I ask is that the sequencer on mine failed.... the retracts still work, but all my gear doors no longer do. I did notice, before the complete failure, that they were intermittent in working... I was thinking that maybe I was getting out of range (which now that I think on it, I had full control over the rest of the plane functions) but ya.... Sorry to hear you have issues :/ hope your repairs go smoothly

since I've got an open channel available on the receiver still, I've thought about taking the gear doors to the receiver directly & having the radio sequence them.

[downwindleg]

Sorry to hear about your nose wheel issue. I too experienced this problem on flight nine of my bird but I didn't notice that the nose gear did not deploy until too late. When I landed, as you say, the gear door was torn off as well as the bay piece with some minor foam damage just aft of

[downwindleg]

Apparently, I got timed out on the previous post and then you have to log out to log back in to be authorized to post and you lose some or all of your original post!!! Very annoying. Anyway, as I was saying, I had some minor foam damage aft of the nose gear bay. Thay was sunday but saturday I maidened the plane!!! Woohoo!!!I set every thing up per instructions. Using two admiral 3600 mah packs set 5/8" back from front of battery bay it balanced at 70 mm. I had to do some minor foam carving on the underside of the battery hatch/ cockpit cover on the two outside front corners so that the cover would seat properly. Probably wouldn't have had to do that with the 3000 packs but I was going for max flight time. When everything felt right, I went for it. She came off the ground nicely but was climbing uncommanded. I immediately started adding down trim but ran out before I had it leveled out. I landed after a 2min. 15 second white knuckle ride for flight #1. After unclinching my keyster, I returned the trim to neutral and took the elevator down a bit. Flight # 2 went much better, got her trimmed out and did a few easy maneuvers to get the feel for it. As promised, she is a dream to fly. Good solid feel- like shes' on rails! Did five more successive flights with each one getting better adding more aileron throw and dialing in some down to offset the ballooning with the flaps deployed on approach. Thanks Motion RC , Brad

[Arycon]

do you think it's the sequencer that caused your issues Arycon? reason I ask is that the sequencer on mine failed.... the retracts still work, but all my gear doors no longer do. I did notice, before the complete failure, that they were intermittent in working... I was thinking that maybe I was getting out of range (which now that I think on it, I had full control over the rest of the plane functions) but ya.... Sorry to hear you have issues :/ hope your repairs go smoothly

since I've got an open channel available on the receiver still, I've thought about taking the gear doors to the receiver directly & having the radio sequence them.

It is not the sequencer. My doors have always worked fine. At this point I cannot confirm if it is a bad servoless retract or a binding of the steering linkage. Based on experience, I believe it is the retract unit. I used to experience this problem on a Dynam T-28 and it only ever stopped once I used non Dynam retract replacements. I think I dropped a set of E-flite retracts in it. I m hoping to tinker with the plane more tonight. I plan to get the rudder repaired and then I am simply waiting on the retract and nose gear bay items to arrive. I have 9g nylon servos to replace the door servos. They arent MG like the rest of the plane so they stripped out on landing when the doors pulled off.

I am hoping the replacement retract doesnt have the same issue. If it does, then the problem lies elsewhere. This is something we should all keep an eye on in case it pops up again. Hopefully it is an isolated issue. I think I likely have a bad unit, but since the problem is intermitent it got past QC and understandbly so. When I fired up the gear late last night (long post crash) they came down multiple times in a row. Another potential culprit is the Y harness. Now that I think about it, it could easily be that. Maybe a contact on the leads isnt connecting properly. Since I have to disassemble the plane for some of the repairs I will chuck the Y and use another I have.

Will keep you guys posted as to what I find. I dont think this is going to be something that keeps happening to various owners. I think I just got unlucky. Should be able to sort the problem with some minor mechanic work. Im confident replacing the Y harness and retract will correct the problem.

[downwindleg]

Hey, not only did I finally maiden the Joltin' Josie, but also figured out how to post pictures. No video but I did get some pics post maiden. Wanted to show off Callie's Graphics and well. maybe my invasion stripes just a little bit. LOL

[Arycon]

Hey, not only did I finally maiden the Joltin' Josie, but also figured out how to post pictures. No video but I did get some pics post maiden. Wanted to show off Callie's Graphics and well. maybe my invasion stripes just a little it. LOL

Looking good! Graphics are fantastic.

[Aros]

Congrats Brad! I love the Joltin' Josie! She looks fantastic. I can't wait to fly at your gorgeous field in July!

[FLTRI]

Arycon,

Do you fly off of a runway that has lots of small rocks, gravel, or just generally kinda dusty/dirty? If you do, open that retract up and see if there is a small stone or other debris on the inside of it. The jackshaft screw drive inside of is not sealed from the elements, and comes from the factory with light grease on it. It's a dirt magnet, and will collect stuff pretty fast. The retract motor has an overload circuit built into it so it doesn't burn the motor up if it jams. That will cause the exact symptoms you are describing. The debris jams it, you cycle it back, and the debris may or may not come loose. Few more cycles, and it jams the jackshaft screw again. I've had my Avios Sea Fury retracts apart a couple of times for just this issue. Clean up the jackshaft screw, the other gears, put a tiny dab of white lithium grease on the shaft and reassemble. While you are in there, look at the jackshaft screw itself. It can get bent in a hard landing, and cause the same intermittent issues...

HTH

[Arycon]

Arycon,

Do you fly off of a runway that has lots of small rocks, gravel, or just generally kinda dusty/dirty? If you do, open that retract up and see if there is a small stone or other debris on the inside of it. The jackshaft screw drive inside of is not sealed from the elements, and comes from the factory with light grease on it. It's a dirt magnet, and will collect stuff pretty fast. The retract motor has an overload circuit built into it so it doesn't burn the motor up if it jams. That will cause the exact symptoms you are describing. The debris jams it, you cycle it back, and the debris may or may not come loose. Few more cycles, and it jams the jackshaft screw again. I've had my Avios Sea Fury retracts apart a couple of times for just this issue. Clean up the jackshaft screw, the other gears, put a tiny dab of white lithium grease on the shaft and reassemble. While you are in there, look at the jackshaft screw itself. It can get bent in a hard landing, and cause the same intermittent issues...

HTH

Jamming was present out of the box before the plane ever went outside. I will still crack the retract open to check for obstruction. Thanks for the suggestion. I dont think this is widespread. I think it just an isolated problem. Just wanted to let everyone know just in case. Good habit to drop your gear and verify they are fully deployed. A bird this beautiful, you dont want to mistake them for being down if they arent. On the allied green, it can be difficult to confirm they are down if you deploy gear on the downward leg or final turn. I plan on doing a pass now with the gear dropped on the final turn but waiving off and going around for the actual touchdown. This way I can see close up if they are up or down. My heart was in my throat on the belly landing.

Oh, btw...stock stability aside...has anyone contemplated adding a gyro? Im thinking about doing it. It would have helped immensely with the crosswind gusts I experienced on final. When this big bird lurches your heart stops. I thi nk it is worthwhile to look into. A gyro will be piece of mind considering the investment of the plane.

Anyone recommend a brand or unit from experience?

[FLTRI]

Jamming was present out of the box before the plane ever went outside. I will still crack the retract open to check for obstruction. Thanks for the suggestion. I dont think this is widespread. I think it just an isolated problem. Just wanted to let everyone know just in case. Good habit to drop your gear and verify they are fully deployed. A bird this beautiful, you dont want to mistake them for being down if they arent. On the allied green, it can be difficult to confirm they are down if you deploy gear on the downward leg or final turn. I plan on doing a pass now with the gear dropped on the final turn but waiving off and going around for the actual touchdown. This way I can see close up if they are up or down. My heart was in my throat on the belly landing.

Oh, btw...stock stability aside...has anyone contemplated adding a gyro? Im thinking about doing it. It would have helped immensely with the crosswind gusts I experienced on final. When this big bird lurches your heart stops. I thi nk it is worthwhile to look into. A gyro will be piece of mind considering the investment of the plane.

Anyone recommend a brand or unit from experience?

Ah, okay. It's more prevalent on tail draggers to get grit in the gear housing, as the prop kicks up stuff and it gets sucked in there. I consider it a regular maintenance item to pull the retracts and clean them up about every 20th flight...

Yes, to the gyro. I use a Lemon seven channel receiver with 3-axis gyro, in every plane I own. It's a very nice unit, and economical as well. You don't need a laptop to program it. It has potentiometers for aileron, rudder and elevator that you can set individually with a small screwdriver. It has the ability to be switched on or off in flight via a switch on your Tx. If you have an 8 channel Tx with a rotary knob or slider, you can infinitely adjust master gain while in flight. A satellite is also available for it. I have at least 15 of them, and have never, ever had any issue at all...

This is the one I use. There is a long thread on RCG that cover it, and a couple of members there work with Lemon to make improvements, and provide clear English instructions.

[downwindleg]

I noticed there was some recent discussion about using a sound system on this plane. Here's something helpful I discovered on the Mr. RC Sound system I installed on my fms 1700 P-51, both from Motion RC of course. As you know, you have to hold some power on with flaps down to avoid stalling on approach for landing. My problem was that with that great sound system on, I couldn't tell what my approach power setting was because I could no longer hear the actual motor over the sound system rolls royce merlin! This made for some very inconsistant landings including an actual stall, luckily close enough to the ground to avoid soiling myself. So what I discovered was in the timer settings. This feature may not be available on all radios, but on my Spectrum dx9 you can set the level of rpm in which your timer is activated so the timer is only running when the throttle is above a preset percentage. When you go above or below that percentage there is an audible tone that goes off to let you know when you have gone above or below that preset. Soooo if approach throttle speed is say 20% with flaps deployed for a good touchdown speed, just set your timer at that percentage and you will hear that tone as you throttle down for landing and know your at the right throttle setting even though you can't hear the motor. This technique has worked out very well for me, with or without the sound system on for much more consistent landings. I now use this technique on all my larger planes. Just remember to pull back further on the throttle after touchdown! Cheers, Your Six is Clear