A couple of years ago I went to Kefalonia and as we boarded the aircraft (Boeing 757) for the return flight, the Captain said something like
"Ladies and Gentleman, as some of you have already noticed, one of the fairings on the left wing is missing. There is no need to be alarmed, it just got slightly damaged a couple of days ago so has been removed for repair.
The aircraft will still fly perfectly well and is absolutely safe."