The Danish "mountainous terrain" shouldn`t pose a problem regarding single engine missed approach climb gradient
.
From my interpretation of the "facts presented", the gear was not locked. Cockpit indication would be 2 green, and 1 either orange or red, or maybe even flickering green
. An uncertainty in any case, but you know something is not right. Well done by the crew for giving ATC an early notice and deciding to burn fuel to reduce landing weight (not as much pressure on the gear upon touchdown) and as we know; lower landing weight means lower Vref
. Even better was the decision of the crew/cabin crew to move passengers away from the props
. Also, a good landing as seen on the clip. Too bad about the collapse though
