Electrical Bonding - Piper Malibu Meridian PA-46-500TP Airplane Maintenance Manual

1. General (See also 23-60-00.)
All electrical and electronic equipment and specified components shall be installed in such a manner as
to provide a continuous low resistance path (bonds) from the equipment enclosure/component to the
airplane structure. Bonds must be installed to ensure that the structure and equipment are electrically
stable and free from the hazards of lightning, static discharge, electrical shock, etc.
A. All parts shall be bonded with as short a lead as possible.
B. All bonding surfaces shall be cleaned prior to the installation of the bonded joint.
C. All nuts used in bonding shall be of the self-locking type. (Do Not use fiber-locking type).
D. All electrical bonding shall be accomplished without affecting the structural integrity of the airframe.
2. 100 Hour Inspection
Each 100 hours, visually inspect shield and shield terminations of each electrical harness for integrity,
condition, and security. If electrical arcing is evident, check for intermittant contact between conducting
surfaces. Arcing can be prevented by bonding or insulation, as appropriate.
Inspect the components listed in Chart 1 as follows:
A. Bond connections shall be secure and free from corrosion.
B. Bonding jumpers installed so as not to interfere in any way with the operation of moveable
components of the aircraft.
C. No self-tapping screws used for bonding purposes.
D. Exposed conducting frames or parts of electrical or electronic equipment should have a low
resistance bond of less than 2.5 millohms to structure. If the equipment design includes a ground
terminal or pin, which is internally connected to such exposed parts, a ground wire connection to
such terminal will satisfy this requirement.
E. Parts shall be bonded directly to the primary structure rather than to other bonded parts.
F. Where aluminum or copper is bonded to dissimilar metallic structures, ensure installed hardware
(typically washers) is as called out in the parts catalog to minimize electrolytic corrosion and ensure
the hardware should corrode first.
3. On Condition Inspection
Whenever any electrically bonded component (see Chart 1) is removed and reinstalled, or visual
inspection reveals the electrical bonding to be suspect, measure resistance between component and
aircraft structure.
To ensure proper operation and suppression of radio interference from hazards, electrical bonding of
equipment must not exceed the maximum allowable resistance values specified in Chart 1.
A. Measurements should be performed after the grounding and bonding mechanical connections are
complete to determine if the measured resistance values meet the basic requirements.
B. A high quality test instrument (AN AN/USM-21A or equivalent) will accurately measure the very low
resistance values specified.
C. Another method of measurement is the millivolt drop test as shown in Figure 1.
6G7
PIPER AIRCRAFT, INC.
PA-46-500TP, MALIBU MERIDIAN
MAINTENANCE MANUAL

ELECTRICAL BONDING

(PIR-PPS55006, Rev. T.)
(PIR-AC 43.13-1, Rev. B.)
51-80-00
Apr 15/07
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