53-13-01 De HAVILLAND GYPSY QUEEN: Applies to All Model 70-4 Engines and to Those 70, 70-2, and 70-3 Engines Incorporating Modification G.1493.
Compliance required not later than September 1, 1953.
In order to prevent the loss of propeller control because of failure of the oil transfer mechanism, Modification G.1920, as described in de Havilland Engine Service Modification News Sheet GQ. 70 dated May 8, 1953, must be accomplished. Should Modification G.1728 not be incorporated, it is strongly recommended that it be embodied concurrently with Modification G.1920.
The FAA concurs in this mandatory action.
(de Havilland Modification News Sheet GQ. 70 dated May 8, 1953, available from de Havilland Aircraft Co., representative at Linden Airport, Linden, N.J., covers the same subject and describes method of repair.)