GarySS

My Feedback: (13)

Any ideas as to what these rod like extensions are on the trailing edges of the rudder and ailerons on this Cessna 182? I have also seen them on the TE of elevators, again on the Skylane. You can see them on this drawing:

Lightfoot

My Feedback: (1)

I would guess that hose are static eliminators.

rcu guest-delete

Lightfoot is right, They are Static-Electricity dischargers. This devices eliminate the static electricity that builds in the aircraft airframe when the plane flies.

LearjetMech

Yep, they are referred to as static wicks

GarySS

My Feedback: (13)

Thanks for the info, Guys! Are they hard? IS it dangerous walking around the airplane if you don't watch what you are doing? I have bumped my head on the trailing edge of a C-170A and that can hurt.

Chris 540

My Feedback: (3)

They are flexible and shouldn't hurt you. But yes the TE and everything else will hurt your head pretty good so watch out.

LearjetMech

Well Chris it actually depends on the model of aircraft. The ones on a small cessna like the one pictired are flexible. They are more whip like. But on a Learjet and other faster airplanes, they are rigid and made from carbon fiber. A while back I had posted a pic of where a pilot had turned into one and it went straight into his eye socket into his sinus cavity without breaking. Everytime an aircraft comes into our hangar we hang red ribbon streamers from them as to warn ourselves. Saved me many a times!

Chris 540

My Feedback: (3)

Yea...since he was asking about the 182 I answered since I have seen them personally. I'm sure they wouldn't do too well on the faster planes. Thats interesting that they are made of CF..never knew that.

I hope to get much more familiar with fast jets soon. Going to college for aeronautical engineer and will either..be an engineer..do the AF ROTC thing and hope to fly fighter/bombers.

FLYBOY

My Feedback: (11)

I lost a couple on our trip last week due to static. Fried them pretty good. Had one charge tap a little hole in the cowel. ON the Westwind and Falcon, they are CF and the wick itelf is very sharp. You don't want to touch it. It will poke you pretty easy. They are not usually flagged when we park. You always want to be carefull around planes and never touch something you don't know what it is. You can do damage to some things. There is a port on a turbo commander that if it gets plugged, it blows all the glass in the instruments in the pilots face. Happened one time and almost killed the pilots son in the right seat. A mud dobber got in and he didn't see it. The port gets checked very well by trained pilots. There are a lot of guys flying the plane that don't know about the severity of the problem though. Fun'

LearjetMech

Had a Lear 45 come in sometime ago that took a direct lightning strike on the the tip of the right horizontal. It melted the end cap. We began inspecting for other damage and what a mess. The tailcone stinger had screws in it that were melted. Control cables had to be replaced on the rudder due to weld spots in the cables. We even had arc marks all the way up to the lower belly fairing. Most aerodynamic panels on this AC are CF. The static wicks were non-existent in some areas. It must of been some strike cause it looked like the airplane just couldn't dissapate it enough. The Lear 45 is basically a flying computer, and I was really suprised to hear that they didn't lose one piece of avionics equipment. Now, with all this said I stand a firm believer that TWA 800 was NOT taken down by static in the fuel cell! Ain't no way in hell. Those planes have been flying around for years with empty center cells. I don't buy it. This definately would make for a interesting thread in this forum! Anyway FLYBOY, I used to work on Turbo Commanders and vaguely remember what you are talking about. Another thing about that aircraft is it will suck the gear up on start up if the handle is up if I remember correctly! Later!
Nik

smokingcrater

umm, isn't that one of those things that should get checked and fixed before the plane ever leaves prototype!

w8ye

My Feedback: (16)

I was always taught that the function of the static wick(s) was to offer a place for the static to leave a airplane. That it is unusual for a airplane to truly be struck by lightning from a cloud.

The situation is that the airplane builds up a static charge on itself as it moves through the air in certain atmospheric conditions and that the usual condition is that this electrical charge will jump from the plane (leave) to a cloud or other oppositly charged area in the atmosphere.

It almost always leaves the plane from the trailing edge of a control surface or a wing (or stabilizer) tip. On a plane without the static wicks, it will typically burn a hole or a burned place in the area where it leaves the plane.

The static wick(s) offer a way for the static to bleed off the airframe before building up to a trumatic level and that if it does build up to such a level, then when it leaves the plane, it will jump from the static wick and perhaps burn it rather than some part of the actual airframe?

I have never experienced such a phenomina personally in my flying of full size aircraft so I may not be a expert on the matter? I have, replaced static wicks on aircraft that were damaged, I suppose, from static discharge?

I also have, however, experienced this with control line model airplanes when flying in snow flurries that the flying wires will build up enough static charge to knock the daylights out of you periodically. It jumps from the wires onto your hand and feels like getting shocked by a spark plug.

Enjoy,

Jim

LearjetMech

Well no! Look at the Sioux City, Iowa DC-10 crash. The only place on the entire airplane where all three hydraulic systems ran together was under the #2 engine. The #2 Fan let go due to metal failure and cut all of them. Total Hyd. loss. We learn things from crashes. While it is a bad thing to say, it has to happen. It is really the only transportation sector I can think of that makes mistakes and keeps learning from those mistakes to build a better safer product. You dont see the automotive industry retrofitting older cars with airbags. You dont see the auto industry fessing up and saying we had a bad design that causes crashes and we are going to fix it. Take for instance the Crown Vic that cops are dying in when hit from behind due to the design of the truck around the tank. Ford fought tooth and nail against the Dallas Poice Dept. on this issue. I do not know where it stands, but I know they (Ford) are re-thinking their original thinking. While an airplane crash is horrific and my eyes tear everytime I hear of one, flying is still safer then driving. I have a neighbor that is an Aviation Safety Inspector for the FAA here in Dallas. We got to talking one day and he said that we need to be on the lookout for our first 777 crash. He said Boeing has a 10 year average on new design crashes due to design, not pilot error! Another thing to watch for is a plane that is all computer flown with a pilot there as a monitor only. Another guy I work with, his daughter is an engineer with Lockheed on the JSF program. The JSF is going to be the last "manned" fighter they build. So watch for job openings in the War department that many of us on this site qualify for hands down better than anyone else! "Gee honey, how was your day at work", "Well dear, I bombed two nuclear factories, one tank platoon, and took out fourteen bridges all by my lunch hour, but I ran out of gas and had to ditch in the Indian Ocean. O'well they'll have a new plane for me in the morning, that had a bad camera lense anyway." "Wow, you must be tired, but can I get you to run up to Walmart to get some diapers and dinner on your way home!" That is what the next war is going to be like!

LearjetMech

w8ye,
I can almost guarantee that most high time full scale jet IFR rated pilots have been in an airplane and been struck by lightning. Static wicks do not decay in a short amount of time from normal flying. If you have replaced one most likely it was due to a strike of some kind. They pilots of that Lear 45 had no idea they had been hit. They said everything felt normal, but just heard the crackle! They were very nervous about the ferry flight they had to make once they saw the damage. A little 500 mile and hour tape and he got to us no problem. You are correct in that a function of the wick is to give the electricity a path to leave, but it can also accept it too. If the aircraft enters a storm of certain severity, the aircraft may not be able to dissapate it fast enough. I'll see if I cant get some of those pics from work!

FLYBOY

My Feedback: (11)

Only in a perfect world. It is an inlet about as big as a dime on the right side of the fuse. If it plugs, the glass in the instruments gets blown out. You would think they would fix that. Yes, the gear will go up on start, it has no squat switches. Dumb, but thats the way they build them.

Yes, lightning strikes do wierd things. Blew a hole in the back of our West Wind one time you wouldn't believe. Had intermittent relay failures over the next 5 years that they always blamed on that one strike. Strange what happens to planes in the air.

As for flight 800, They had to have something other than the truth to blame that on. Anyone that believes those tanks just exploded to static is a fool. No different than the crash report I got on Payne Stewarts Lear. No freekin way! There is only one explanation for everyone in the plane to be incapacited in an instant and that is explosive decompression. Anything else, someone would have keyed a mic, tripped the auto pilot and dropped the nose, or made an attempt to handle the situation. Explosive decompression from a bulkhead letting go or something like that would have put them all out instantly and it would have done just what it did. Strange how they come up with some of their stuff. No way it could have been a slow leak. Too many things in the plane to prevent that from stopping the pilots from corrective action.