AD 62-24-02

62-24-02 BOEING: Amdt. 506 Part 507 Federal Register November 10, 1962. Applies to 707/720 Airplanes, Serial Nos. 18385-18397, 18400-18404, 18374, 18414-18419, 18411, 18372, 18373, 18335-18339, 18079-18082, 18423-18425, 18376, 18377, 18451-18453 Inclusive; Also Applies to Airplanes Which Have Been Modified By Operators to Incorporate Motor Operated Valves Per Boeing Service Bulletins 1414, 1483, 1484, 1489, 1490, 1491, 1492 and 1493. Compliance required within 350 hours of airplane time in service after the effective date of this directive, unless already accomplished. Hydraulic system motor operated valves, Whittaker P/N 146505-1, incorporated in both the utility and auxiliary hydraulic systems, have failed in service due to stress corrosion in the end cover retaining nut. All failures have occurred in parts with the original heat treatment. To prevent such failures: (1) Modify all valves by installing new end covers and nuts of the same Whittaker part number but identified by a blue anodized color; and (2) Replace the valve shear seals and the bearing with new longer seals and a new bearing. (Whittaker Service Bulletin SBC 2021 covers this same subject.) This directive effective November 10, 1962.