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AD 71-10-02 ACTIVE

Overvoltage Relay Ground
Key Information
AD Number 71-10-02 Status Active
Effective Date May 14, 1971 Issue Date Not specified
Docket Number Unknown Amendment 39-1206
Product Type ["Aircraft"] Product Subtype ["Small Airplane"]
CFR Part --- - Part 39 CFR Section N/A
Citation This information is not available.
Applicability
Manufacturer(s) Aerostar Aircraft Corporation
Model(s) PA-60-600 (Aerostar 600) PA-60-601 (Aerostar 601)
Regulatory Text

71-10-02 AEROSTAR: Amdt. 39-1206. Applies to all Model 600 and 601 airplanes certificated in all categories.

Compliance required within the next 10 hours' time in service after the effective date of this AD, unless already accomplished.

To assure all over-voltage relays are properly grounded, accomplish the following:

A. On S/N 61-0001 and 60-0001 through 60-0005:

(1) Inspect each overvoltage relay installation and assure that the overvoltage relay base and the aircraft structure are in direct contact.

(2) If the installation appears satisfactory from the inspection, use an ohmmeter to determine that low resistance continuity of less than one (1) ohm exists between the base of each overvoltage relay and the airplane structure.

(3) If a satisfactory ohmmeter indication is not achieved, ground the overvoltage relay base to the aircraft structure using good aircraft grounding practice.

B. On all others;

(1) Inspect each installation of thecrimp wire terminal which connects to the overvoltage relay base and assure that the crimp terminal and relay base are in contact.

(2) If the results of the inspection are not satisfactory, rearrange the components as follows:

(a) Install the nylon bearing from the bottom side of the overvoltage relay base so that it isolates the overvoltage relay base from the aircraft structure.

(b) Install the crimp wire terminal over the nylon bearing so that it is in electrical contact with the overvoltage relay base.

(c) Install the AN960 washer over the nylon bearing so it is in contact with the crimp wire terminal.

(d) Install the two nylon washers on top of the AN960 washer and insert the NAS221 screw through the two nylon washers and the nylon bearing, and tighten the screw into the nut-plate provided.

(e) Assure that the nylon bearing is seated properly to prevent electrical contact of the crimp wire terminal, the AN960 washer, and the overvoltage relay base with the NAS221 screw and the aircraft structure.

(f) Repeat the above procedure for the opposite side of each overvoltage relay except for elimination of the crimp wire terminal.

(3) Using an ohmmeter, determine that low resistance continuity of one (1) ohm or less exists between the base of each overvoltage relay and the airplane structure with the respective alternator switch in the "on" position. Low resistance continuity should not exist with the respective alternator switch in the "off" position.

(4) If the existing installation of either overvoltage relay will not give a satisfactory check and cannot be changed as described above, accomplish an equivalent FAA approved modification.

If Aerostar Aircraft Corporation Service Bulletin No. S.B. 600-24 dated November 23, 1970, or later FAA approved revision, has been compiled with and an appropriate entry made in the airplanes' permanent maintenance record, the requirements of this AD will be considered satisfied.

This amendment becomes effective on May 14, 1971.