Static Wick

[wantobe]

I noticed during AirVenture that a lot of (maybe most) LSAs did NOT have static wicks. Cirrus SR22 also did not have them. How can they get away with it?

[martymayes]

1000's of airplanes don't have static dischargers. Not sure what they are getting away with?

[Bob Dingley]

I noticed during AirVenture that a lot of (maybe most) LSAs did NOT have static wicks. Cirrus SR22 also did not have them. How can they get away with it?
My guess is because LSAs are restricted from flying in clouds there is no need to spend money on wicks. As for the Cirrus, you can't waste time or $ attaching them to non conducting structure. Don't have any idea what limitations are in the Cirrus POH. My experience with composite AC is VFR only don't have the fine copper mesh imbedded in the gel coat, but the IFR certified ones do. Cirrus ...?
Bob

[Richard Warner]

My 1953 Cessna 180 doesn't have them and it does a good job of flying in the clouds as well as out of them.

[wantobe]

I think the use or absence of static wick should depend on the rate of the static electrical charge generation (which should depend on the rate the air rubs the airframe skin, namely, true airspeed.) and the discharge of this electrical charge. I do not see how the cloud plays a role in this aspect.

[Bill Greenwood]

My 1988 Beech B 36 has 3 static wicks on each aileron, and 3 on each side of the elevator. I guess the radios work fine in the little actual IMC flying that I have done.
The disadvantage is that in the winter the snow melts and forms ice on the wicks and then it only takes a small bump to break the whole wick off. Mine are the skinny, stiff ones, not the larger rubber ones that seem more flexible.

[martymayes]

I think the use or absence of static wick should depend on the rate of the static electrical charge generation (which should depend on the rate the air rubs the airframe skin, namely, true airspeed.) and the discharge of this electrical charge. I do not see how the cloud plays a role in this aspect.

I've never had P-static while flying in clear air. Flying in clouds, snow, rain, dust particulate, yes. Once that is present, then yes, at all speeds.

[Bob Dingley]

P-static has not been much of a problem since I stopped using LORAN-C. GPS and VHF nav is pretty much immune. Also, most ADF gear is heading for the museums. In the LORAN-C days, it was common for the CDI to have a steady "off" flag until out of the rain. When it was real bad I wrote it up and they usualy fixed it by removing the old raggedy static wicks and put new ones on. ( can't believe ACS gets almost fifty bucks each for these)

Sorry about the confusion about clouds. I wasn't thinking those little puffy ones. Many times clouds contain rain, thunder and lightning. Those are the clouds that produce P-static. I know of one event where an aircraft picked up so much of a charge in clear air that just touching it was like grabbing an electic fence. To long for this thread, PM me if interested.

Bob

[martymayes]

P-static has not been much of a problem since I stopped using LORAN-C. GPS and VHF nav is pretty much immune. Also, most ADF gear is heading for the museums. In the LORAN-C days, it was common for the CDI to have a steady "off" flag until out of the rain. When it was real bad I wrote it up and they usualy fixed it by removing the old raggedy static wicks and put new ones on.

VHF communication can become impossible due to P-static. You can bet when you hear P-static breaking squelch on the com, there is St. Elmo's fire on the airframe, somewhere.

BTW, you can test static dischargers before removing them from service. All you need is a megger (megohmeter). The usual fault point is where the discharger attaches to the airframe, corrosion interferes with the bond.