61-16-01 AERONCA: Amdt. 320 Part 507 Federal Register August 8, 1961. Applies to All Model 15 Series Aircraft.
Compliance required as indicated.
As a result of cracks found on the wing lift strut fittings, P/N 5-463-2, the following inspection shall be accomplished. For those aircraft with 1,000 or more hours' time in service, the inspection shall be accomplished within 25 hours' time in service after the effective date of this AD, unless accomplished within the last 25 hours' time in service, and at each periodic inspection thereafter. For those aircraft with less than 1,000 hours' time in service, the inspection shall be accomplished at the next periodic inspection after the effective date of this AD, and at each periodic inspection thereafter.
(a) Detach the wing lift strut assembly and remove the upper and lower 1 1/2-inch diameter, 2024 tubular fittings, P/N 5-463-2. Clean, remove the paint and polish lightly with crocus cloth so as to increase the contrastfor inspection. Using the dye penetrant method and a 10-power glass, or equivalent, inspect for cracks on the inside and outside of the fitting surfaces, particularly in the area of the bolt holes and 90 degrees to the centerline of the bolt holes. All cracked tubes and all tubes with an outside diameter exceeding 1.515 inches at any point must be replaced prior to further flight.
(b) Fittings being reinstalled shall be finished with the following or equivalent: Two coats of zinc chromate primer on the inside and outside of the fitting and finish enamel on the outside of the fitting. The 1/4-inch bolts attaching the fitting to the strut and the 1/2-inch bolt attaching the strut assembly to the airplane shall be torqued only enough to bring the respective parts into contact. The fitting must not be forced out of round.
(c) When it is necessary to install new fittings, Aeronca P/N 5-463-2, Champion Aircraft Corporation P/N 1-9280, Prentice Aircraft, Inc. P/N 61-16-1, orFAA approved equivalent may be used. Existing AN 4 bolts, if not damaged, may be reinstalled in holes that match. No elongation of old holes in struts is permissible.
(d) The following rework may be used if the holes in new fittings and old struts do not match to allow proper installation. AN5 bolts may be installed in all holes or in any combination.
(1) If holes do not match, line-drill the assembled strut and fitting (19/64 inch) and ream to accept an AN 5 bolt. (.3125 inch minimum, .3135 inch maximum diameter.) In the event that portable equipment must be used, drill the hole 19/64 inch and accomplish the final sizing with a tapered hand reamer to assure alignment.
(2) Install AN 5-22A bolts each with two AN 960-516 washers, and AN 365-524 nuts in holes that require rework.
(e) When Prentice Aircraft, Inc., P/N 61-16-1 or FAA approved equivalent is installed, the repetitive inspections required by this directive may be discontinued.
(Aeronca Service Helps and Hints No. 59 and Champion Aircraft Corporation Service Helps and Hints No. 59 cover the same subject.)
This directive effective August 18, 1961.
Revised November 28, 1961.
Revised April 10, 1962.