View Full Version : Wing aerial things?

12th Jun 2008, 13:09
First post - be kind.

Sat over the wing of an A320 from Santorini this week and noticed some short black aerials (?) extending from the winglet and conical flap fairings. What are they for? Thanks in advance.

12th Jun 2008, 13:25
Static Wicks - See below (See 737 example at bottom link.)


12th Jun 2008, 20:30
Very concise. Thanks :ok:

12th Jun 2008, 20:45
Concise but wrong, static wicks or dischargers afford no protection against lighning strikes.

Static dischargers are installed on the airplane to reduce radio receiver interference. This interference is caused by a corona discharge emitted from the airplane surfaces as a result of precipitation static and engine charging. Precipitation static results from an electric charge accumulated by the airplane striking charged air and moisture particles.
Static usually discharges at the wing and tail extremities and is coupled into the radio receiver antennas. The static dischargers are designed to discharge the static at points which are a critical length away from the wing and tail extremities where there is little or no coupling of the static into the radio receiver antennas.

The dischargers that are installed along the trailing edges of the wing and tail surfaces consist of a carbon block mounted near the end of a slender rod. The rod has controlled resistive characteristics and is attached to a metal base. The base is fastened and bonded to the trailing edge surfaces. The wingtip dischargers are smaller but have the same general construction and are attached in the same manner.

Frequently, a lightning strike is referred to as a static discharge. This is incorrect and may cause you to think that the static dischargers found on the external surfaces of the airplane prevent lightning strikes.
These static dischargers are for bleeding off static charge only; they provide no lightning protection function. As the airplane flies through the air, it can pick up a static electrical charge from the air (or dust/water particles in the air). This static charge can become large enough to bleed off the airplane on its own. If the charge does not bleed off on its own, it will usually result in noise on the VHF or HF radios. The static dischargers help to bleed the static charge off in a way that prevents radio noise.

The static dischargers are frequently hit by lightning. The dischargers have the capacity to carry only a few micro-Amps of current from the collected static energy. The approximate 200,000 Amps from a lightning strike will cause damage to the discharger or make it fully unserviceable.

12th Jun 2008, 21:10
static wicks or dischargers afford no protection against lightning strikes.

Oh yes they do! spanners, did you copy that direct from a Boeing Manual.:)

Without wicks, an airframe will build up a static charge to the point where a lightning strike is more likely to occur. QED - They afford protection against lightning strikes. :ok:

PS 1. Welcome to Prune tgon.
PS 2. spannersatcx is nearly always right. ;)

13th Jun 2008, 07:12
Loving it here already! ;)

13th Jun 2008, 07:37
yes from the manual, won't argue with Mr Boeings definition of static wicks.

ps1 welcome

ps2 can't argue with that, will always admit when wrong (not often):ok:

ps3 wish I had one:sad:

14th Jun 2008, 13:03
Come on, spanners, keep up! :ok:

14th Jun 2008, 20:37
trying too, too old and tired now:{