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Boom or bust! – RAAF KC-30 loses boom | Australian Aviation Magazine
Sources say preliminary reports suggest the boom's probe snapped off near the F-16's receptacle, causing the boom to spring up and strike the underside of the KC-30, possibly snapping off one of its two guiding fins and causing it to oscillate wildly until it snapped off at the pivot point.
The boom departed the aircraft and fell to the ocean below.
Fortunately both aircraft recovered safely and no-one was injured.