AD/CESSNA 310/3 - Oxygen Line - Modification - CANCELLED

What this document does: It officially cancels an old aircraft safety rule that is no longer needed.

The original rule (from 1956): Owners of Cessna 310 aeroplanes had to install a rubber protective sleeve around the oxygen supply line. This prevented the metal line from rubbing (chafing) against the aircraft frame and potentially causing a leak or fire. The work had to be done immediately ("forthwith").

Why it is being cancelled: The rule was issued in 1956. By 2008—more than 50 years later—all affected aircraft would have been modified long ago. The unsafe condition no longer exists, so keeping the rule on the books serves no purpose.

Who this affects: Owners, operators, and maintenance engineers of Cessna 310 series aircraft. For them, this cancellation removes an obsolete compliance obligation.

Key takeaway: This is housekeeping—removing a half-century-old safety requirement that everyone has already followed.