AD 66-01-02

66-01-02 GRUMMAN: Amdt. 39-174 Part 39 Federal Register December 28, 1965. Applies to Model G-164 Series Airplanes Equipped with J-5404/MA96K, SR-5404R/MA96K or SR-5404/MA96K Propellers on Continental W-670 (R-670) Series, Gulf Coast W-670-240, and Jacobs R-755 and L-4M Series Engines.

Compliance required within 25 hours' time in service after the effective date of this AD, unless already accomplished.

To prevent further instances of loose propeller hubs, accomplish the following:

(a) Remove propeller and check for matched sets of cone and spacer. The AN 5008- 20 rear cone (0.969 inch) must be used with the AN 5010-20 spacer (1.00 inch) and a No. 525-B rear cone (0.875 inch) must be mated with a No. 30091 spacer (1.105 inch). The overall average length of these sets must be 1.969 inch and l.980 inch respectively. An exception to these requirements is the Gulf Coast W-670-240 engine modified after 3/10/64 wherein the spacer has been omitted from the propeller installationdue to the 1-inch shorter propeller shaft.

(b) Determine that the propeller nut does not bottom on the crankshaft threads by comparing the number of total turns with propeller removed to the number of turns with propeller installed and properly torqued. To correctly seat the propeller hub on the crankshaft there should be at least one full turn less with the propeller installed. If a proper fit cannot be obtained, new matched sets must be installed. If this procedure indicates the need for a spacer on the Gulf Coast W-670-240 installation, install Grumman spacer P/N A1600-99 (1/8 inch long).

(Grumman Service Bulletin No. 32 dated September 9, 1965, and Service Bulletin No. 32A dated October 21, 1965, cover this same subject.)

This directive effective December 28, 1965.