AD/CESSNA 336/4 - Open Wire Aerial Installation - Modification - CANCELLED

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

The backstory: In 1966, aviation authorities required owners of Cessna 336 aeroplanes to modify how the aerial (antenna) wires were rigged to the mast. The goal was to remove dangerous sideways forces ('side loads') that could damage the structure. Owners had to complete this work within 300 hours of flying time after August 1969.

Why it matters: By 2008, every affected aircraft had already made this modification, so the unsafe condition no longer exists. This document officially removes the legal requirement, tidying up the rulebook.