AD 76-13-10

76-13-10 GRUMMAN AMERICAN: Amendment 39-2657 as amended by Amendment 39-2777. Applies to Model G-164 and G-164A Ag-Cat Airplanes, S/N 1 through 1064, certificated in all categories.

Compliance required as indicated.

To prevent possible hazards associated with main landing gear strut failures, accomplish the following:

(a) For airplanes equipped with Grumman American main landing gear struts P/N A1515-11, -12, P/N A1530-11, -12, and Cessna struts P/N 0341109-1, -2:

(1) Within the next 100 landings after the effective date of this airworthiness directive, unless accomplished within the last 4400 landings, remove the gear struts and inspect the struts for cracks using dye penetrant or magnetic particle inspection procedures or with an FAA approved equivalent inspection procedure.

(2) Repeat the inspections of paragraph (a)(1) at intervals not to exceed 4500 landings.

(3) Inspect the struts for cracks and corrosion damage using dye penetrant inspection procedures,at each 1000 landings following the inspections specified in paragraph (a)(1) and (a)(2). This inspection can be conducted without removing the gear struts from the aircraft.

(b) Replace cracked or corroded parts prior to further flight with unused struts, Grumman American P/N A1530-33, -34 or with FAA approved equivalent parts.

(c) For the purpose of complying with this airworthiness directive, subject to the acceptance by the assigned FAA maintenance inspector, the number of landings may be determined by dividing each airplane's hours' time in service by the operator's fleet average time for takeoff to landing for the airplane type.

(d) Equivalent inspections and parts must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

(e) Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region, may adjust the compliance time in this AD. Grumman American Aviation Corporation Service Note No. 13 covers this same subjects.

Amendment 39-2657 was effective July 7, 1976.

This Amendment 39-2777 is effective November 30, 1976.