Control Surface Bonding

danceskater · #1 02-26-2012, 02:46 PM

We have just finished an RV-10 empennage kit and I realized that there seems to be no provision to Bond those control surfaces to the tailcone. I am used to seeing a small braided copper cable from the control surface to the fuselage. I believe that this is to avoid the buildup of a small electrical potential across the rod end (hinge) which would lead to rapid corrosion. Is this something that is addressed in a subsequent kit?

Andrew M · #2 02-26-2012, 03:56 PM

Bonding can help with corrosion, it also serves to minimize radio interference and keep the hinges from welding tight in the event of a lightning strike.There really isn't anything I can think of to keep you from installing bonding straps if you want them.

aerhed · #3 02-26-2012, 04:13 PM

Most typically you don't see bonding wires unless you also have static dischargers to help dissipate the P-static buildup. Or the legendary clear air static buildup. I don't know a reason you can't use them. Faster you go, the more you need them.

Flying Scotsman · #4 02-26-2012, 10:02 PM

I've wondered about this a time or two...the Pipers I've been flying have generally had static wicks on them (don't recall any on the Cessnas, but it's been awhile since I flew those).

So how come none on RV's? Or are they unnecessary on Cherokees, too?

I have no plans to put any on the -7A, but I'm curious about their use/advantages/disadvantages/etc.

Mel · #5 02-27-2012, 06:43 AM

I have the static wicks on my -6. When I was building, I inquired at the Mooney Plant why some airplanes had the wicks and some didn't. I was told that the problem was the Loran. Precipitation static was particularly bad at 100 kHz. Since I was installing a Loran in my airplane, i added the wicks. Now that we are into GPS with a much higher frequency, the static wicks are no longer needed.

az_gila · #6 02-27-2012, 09:17 AM

Bonding is essentially required for all certified aircraft. The static discharge wicks are not required...

http://www.flightsimaviation.com/dat...rt_23-867.html

If you don't bond all parts together then you need to prove a lightning strike will have no effect.

az_gila · #7 02-27-2012, 09:18 AM

Quote:

Originally Posted by aerhed

Most typically you don't see bonding wires unless you also have static dischargers to help dissipate the P-static buildup. Or the legendary clear air static buildup. I don't know a reason you can't use them. Faster you go, the more you need them.

Not true - see previous post...

aerhed · #8 02-27-2012, 09:50 AM

Al, I guess I'll have to look this up. I know lots of old planes have no bonding but everything newer does. So, somewhere along the line this changed. You're maybe the best data sleuth on here, maybe you can find it.

az_gila · #9 02-27-2012, 10:15 AM

Quote:

Originally Posted by aerhed

Al, I guess I'll have to look this up. I know lots of old planes have no bonding but everything newer does. So, somewhere along the line this changed. You're maybe the best data sleuth on here, maybe you can find it.

Yep, it would depend on the year certified and the current rules at that time - the Grummans certified in the early-mid 70's are all bonded, as well as the 70's sailplanes I've seen.

My point was that it is not connected to the use of static wicks...

aerhed · #10 02-27-2012, 10:40 AM

Well, it is connected to the static wicks, in that it provides a path TO the wicks (if installed). That being said, I just flashed back on a 46 BC12D I recently recovered and I distinctly remember bonding straps on the ailerons with their own special screw holes in the aileron brackets. So, once again I guess I posted without thinking.