56-16-04: Landing Gear Torque Knees

56-16-04 UNIVERSAL (Globe): Applies to Models GC-1A and GC-1B Aircraft. To be accomplished as soon as possible but not later than September 15, 1956. It has been reported that the landing gear was replaced with an E.L.I. type gear (air-oil) on a Globe Model GC-1B airplane with a serial number higher than 196. A subsequent failure of one of the aluminum alloy torque knees resulted in the loss of the left landing gear and damage to the airplane. It is probable that the Adel aluminum alloy knee was substituted for the regular P/N 64A40 forged steel knee. The Adel aluminum alloy knee is not a suitable replacement on the E.L.I. gear assembly, since it does not provide for the extension stop, P/N 64A31. To preclude similar occurrences, all aircraft not equipped with Adel main landing gear struts must replace the aluminum alloy torque knees with forged steel knees. 1. On aircraft equipped with Adel struts, the Adel forged aluminum torque knee assembly is satisfactory and may be retained. 2. Forged steel knees, E.L.I. P/N 64A40 are suitable as replacements on all types of landing gear units. This supersedes AD 46-33-01.