Yardbird mentioned in his Phantom thread that the F-4E was fitted with static dischargers. I hope I’m not insulting anyone by explaining it this way, but those are the springy little “curb feelers” on aircraft wings and tails that channel away static electricity, which caused a number of mid-air explosions in earlier years. You can also see another type of SD as parallel lines that are set into the length of the F-16’s radome, and they are usually molded into the larger scale kits.
But my question is, these static dischargers, if you’ve ever just walked around, say, an F-16, are many and prominent on real a/c. Prominent, but small. But we never see them on models. They are probably no more than 3/16’s of an inch, maybe a quarter inch, in diameter and less than a foot long, so they’d be smaller than a 1/4-inch-long section of human hair in 1/48. But, hey, we represent other, smaller things like the pins for RBF flags and ejection seat rings, why ignore the dozen or so static dischargers all over the F-16?
And Darwin, I’m pretty sure I recall seeing them fitted to old ANG and Reserve C and D models in the 80’s. Heck, I’ve flown Piper Saratogas that had them. And Yardbird or Bernie would certainly know this: Are they connected to anything other than the airframe itself, like a flying ground wire or lightning rod? I’m really dumb about the fundamentals of electronics.
A trivial detail, but I wonder why static dischargers have always been overlooked by us detail fiends. I’m going to put them on the next modern jet I do and see if anyone a) notices and b) wonders what those little hairs are trailing from my flying surfaces.
TOM
TOM
Tom,
I know what static dischargers are and yes, they are on a lot of airplanes. You have me stumped on whether or not they are connected to anything besides the basic airframe. I wouldn’t think it necessary, because it would be like a chasis or frame ground on an automobile. The entire frame is electrically the same point. You can hook the ground wire to any point on it and electically, it is all grounded to the same point. The basic frame of most airplanes is metal of some sort which is probably electrically conductive. All lights, electronics, SDs, etc are connected to this common ground. Any static electricity build up would be conducted to the dischargers, where it would be released into the atmosphere as tiny bolts of lightning, probably so small that you couldn’t even see them. Darwin [alien]
Wow ,Tom you have a point there… I am one of those people that try to replicate every knob and switch in the cockpit and, quite honestly, never gave the static discharge wicks much of a thought. I think ,to me, the hardest part would be to find good reference material showing where ALL of the wicks are.I don’t recall seeing specific pics of them or diagrams of where they are on a particular A/C.This is where being able to work on the real deal would really come in handy.I do secretly wish I was one of those people who got up every morning to go to work to see my modeling project sitting in a 1:1 scale hanger.You have access to unprecedented detail.Like WHICH panel leaks WHAT,exposed avionics,the color matching alone would make it worth while.But you certaninly raise a valid point,why don’t we see more of them at contests?
I put them on my 1/48th Monogram Skyraider over 25 years ago when I built it. And they are very prominent on the real one. I didn’t have one sitting in the backyard to look at either! They were on the ailerons, elevators and rudder.
The only model I can remember with static dischargers was the Hasagawa 1/32 scale F-16A. No other model had them included on the kits. I installed SD’s on my 1/48 F-4G from Hasagawa.
hey all,
they are not forgot about all of us, I put them on the 1/72 P2v neptune I built fur my dad. I figured I had to, he spent a few years flying in em, and working on them. I usually dont put em on, but I dont usually superdetail like that either.
jim
Most people wouldn’t bother putting the static diachargers on their models…how far do you really want to go? How easily would they be damaged after they’re installed on a model? Yes, they’re fairly promonent on full sized aircraft.
Through the pages of FSM and the pics of models posted here on this forum, I’ve seen sone simply outstanding work - and very seldom have I ever seen a static discharger.
These models really don’t need them - there’s enough great detail and weathering work to look at - so I’d never think less of a model just because it lacks this detail.
That’s my story and I’m sticking to it.
What size wire would you use on something that`s 1/72?
The EF111 hasegawa that I`m working on has the "nubs"on the stabilators and I was thinking of adding them,but not sure the gauge of wire to use.
Maybe one of the aftermarket Photoetch manufacturers could be given suggestions for some sets.
thanks
Rt4957
The Academy 1:32 scale MiG-21 I built a while ago had SD’s on the trailing edges of all the wings. I didn’t realize it until I read this thread, but that must be what they are. Actually, the kit pieces were way oversize, so I scratchbuilt replacements from .3 mm wire. To replicate the conical shapes on the ends of the rods, I dipped the ends of the wires in epoxy, turned them in my Dremel tool and sanded the hardened epoxy until I got the correct (or, at least, desired) shape.
Tom
As Yardbird said, “The entire airfarame is electrically the same point”. On the P-3
Orion the static discharge wicks were the AN/ASR-3. They were attached with 2 screws.
Their description is as follows: The attachment end was bare metal…A dull aluminum color. The wick portion was about 3/16in. in diameter and was some kind of cord covered with a black rubber insulation. They were about 12 inches long.
That description will cover virtually all U.S. Propellor driven aircraft. I can’t speak for
any jet aircraft.
Ray
Ray
The static dischargers on the Herk are the same, there’s a trio on each elevator, rudder, and aileron. The airframe is electrically grounded to each control surface through an internal ‘bonding wire’ that basically connects the control surface through a wire attached with terminals at both ends. It’s easier to illustrate than to describe.
I’ve replicated these dischargers on 1/72 Herks with short lenghts of fishing wire. Depending on the manufacturer, they can either have the rubber cover (need to trim constantly on real aircraft) or they have a metal braid cover. Depending on how old the discharger is, it can either be black, silver (for the braid), or the same color as the surface it is attached to.
I attached SDs on a model of a T-28 Trojan back in 1977 when I was working at NAS Whiting Field. I made them out of whiskers I cut off from my dog. Didn’t even have to paint them. They looked too much like foreign material that got stuck on the model by mistake so I never repeated the process. (Besides, I couldn’t get the dog to sit still after his first little trim)
You can create static dischare wire out of stretched sprue or take a small diameter stranded wire and untwist the strands. Then use one of the strands. I do not think I would bother with a model any smaller than 1/48th scale.
In the right atmospheric conditions you should see the lightning storm generated by helo blades. Watch an aircraft being refueled sometime. You should see a ground wire attached to the aircraft to prevent a static electricity spark from igniting the fuel. rangerj
Were I to add them to a model, I wouldn’t put the wicks on 1/72 at all. In 1/48, I would use my own hair, painted with MM steel or better, a dark metal like the old Gunmetal shade. For 1/32 small segments of fine wire would do, with a tiny drip of CA on the tip to represent the rubber “eye-jabbing protector” on the end.
A fighter pilot friend just recently was trying to make me understand the difference between St. Elmo’s Fire and static electricity. I just couldn’t get it and still don’t. We were talking about several cases where F-101B’s just blew up in midair for no reason (including, on one night intercept exercise, my friend’s wingman, who with his WSO, were never found in the Gulf of Mexico, over which this occurred). It turned out fuel was pooling in the lower fuselage under the wings and being set off by static electricity. The PBM or its successor, I think it was, was prone to the same thing, and I’ve been told by a former MAC pilot friend that several accidents caused by static electricity-triggered explosions was the main reason why the huge C-133 stayed in the USAF inventory for such a short period of time, being withdrawn after only about seven or eight years of service during the Vietnam period.
TOM
I am using toothbrush bristles cut down on my S-3. The S-3 has several rather obvious SD’s along the vert. stab. and outer wing edges.
Though they are small, they do add to some airframes such as the Viking.
RAy
Hey Rt4957 !
In answer to your question…
1/4" diam divided by 72 is about 3.5 thousandths of an inch.
1 foot long in that scale is less than 3/16".
Wire is available in that diam (we use it where I work), and you can probably stretch sprue down even smaller, but I haven’t the foggiest idea how you could get a 3/16" long 3.5 thou diameter whisker to be attached to a perpendicular surface. The closest pin drill size I’ve ever seen is about 10 thou. That’s a gaping hole compared to a 3.5 thou “wire”.
Chris
Thanks Bossman
I myself was thinking that either the hole or the attaching BLOB of whatever glue would detract from what i was trying to do
The demensions help, will print and save the formula for future reference
Again Thank You
P/S to the S-3 builder,nice choice,one of my favorite type planes,and next on the build list[:D]
Rt4957
Static dischargers are common to many planes. I’ve seen them on a few warbirds and as to the question about being connected to anything other than the airframe, as I remember it when I sold aircraft parts [many moons ago in another life with piper a/c] , they were separate items attached by screws onto the surface.
I’d say the SDs are closer to 6-8 inches than a foot, and I’ve seen several different styles. Some have bands of bright colors, I suspect for higher visibility, so the unwary will realize they’re about to poke their eye out. I recently saw yellow and hot pink bands on the SDs on the same F-16CJ, so it’s clear the maintainers don’t try to color coordinate. I have a couple photos I’d be glad to share, if anyone needs them or can post them to the Web and link them here.
Tally Ho
-Larry
If any of you are interested go to the tools-n-tips section on this very topic www.aircraftresourcecenter.com…no offense to the folks at FSM…