51-19-02 PIPER: Applies to Models PA-18 Serial Numbers 18-487 to 18-730 Inclusive; PA-20 Serial Numbers 20-554 to 20-690 Inclusive; and PA-22 Serial Numbers 22-1 to 22-90 Inclusive.
Compliance required by August 31, 1951.
Overage oil radiator hose was installed in an undetermined number of Piper airplanes. Inspect immediately to determine that the proper hose marked with a solid white line and a broken red line and AN H-35 or MIL H-6000 are installed. Defective hose are marked "Aromatic Resistant Gates Vulco" followed by a date with the opposite side marked by a solid white line and broken red line. All defective hose should be replaced as soon as possible but not later than August 31, 1951.
(This information supersedes that in Piper Service Letter No. 165 dated March 23, 1951.)