Electrostatic Problem Identification

Before solving an electrostatic problem, you must first obtain as much information as possible. 

1)      An electrostatic problem most likely will have been squawked by the pilot. If so, ask in detail what was identified.

2)      If there was not enough information given by the pilot, ask if you can contact him to further detail his squawk.

3)      It is necessary to qualify that the problem is due to P-static; ask the following question:

a.      Does it only occur when the aircraft is flying in a precipitation environment or in close proximity to charged clouds, an “electrical storm”? (if the interface or degredation to the Comm/Nav systems takes place in clear air or on the ground, it is not a P-static induced problem)

4)      Having obtained the information indication that the problem is due to P-static, you must then find out which systems are affected. Ask the following questions:

a.      Which manufacturer’s VLF/Nav/Comm/UBF systems does the aircraft have?

b.      Which are these are affected?

c.      If only one system is affected according to the squawk, are the others unaffected?

                                                               i.      If the reply is not a clear yes or no, ask the person to find out. Tell him it is very important that you know all of the affected systems.

5)      Ask for a drawing of the aircraft showing:

a.      Antenna installation (type, position)

b.      Composite parts with the type of composite clearly marked

c.      The areas protected by anti-static paint (if any)

d.      The emplacement of dischargers (if any)

e.      The position/construction of access panels.

 

All of this information is obtainable through the manufacturer.

 

If there is no recording of the noise, ask if it is continuous (like the wind), or if it is like a fast clicking. To explain, say that a wind-like noise corresponds to a streamering corona discharge and that a clicking noise corresponds to an ARC/surface discharge. This information (with all of the other facts you have gathered) will allow an expedient determination of the nose source.

 

This information is just to give an indication of potential problem areas: however, the above examples are those whcih are most frequently encountered. It is now recommended to carry out a verification using the Electrostatic Diagnostic Testing Capability, which will pinpoint the cause enabling corrective measures to be initiated.

Noise System Possible Source Potential Areas
Wind VLF/ADF/VHF/VOR Corona

-Defective Antenna
-No antistatic primer  on   fiberglass areas-radome,   fairings etc...
-Paint to thick
-Windshields
Clicking VHF/VOR Bad Bonding -Unprotected Composite Panels
-Defective Retainers Discharge
-Lightening Diverter Strips