46-23-02 ERCO: (Was Mandatory Note 5 of AD-718-6.) Applies Only to 415-C, -CD and -D Aircraft Serial Numbers 113 to 263, Inclusive.
The flexible hose in the engine breather line should be inspected immediately. If the inner liner of this hose is an amber color, it is susceptible to contraction and possible clogging. Hose which shows evidence of clogging should be replaced at once by hose supplied by Erco or by equivalent hose such as AN 884 or AN 878. If hose has an amber lining but is still in satisfactory condition, it may be continued in service for a maximum of 25 hours, whereupon it must be replaced by satisfactory hose as described above.
(Erco Service Department Memorandum No. 11 dated February 1, 1946, covers this same subject.)