Wiktionary
droppable
a. Capable of being dropped (especially by an aircraft).
Usage examples of "droppable".
Hardpoints in the wings permitted the use of droppable auxiliary fuel tanks and could also be used to carry 1,000pound bombs.
And for the first time took a closer look at what he had assumed were droppable fuel tanks suspended beneath the wing.
In other words, when the craft touched shore, personnel aboard would have to exit over the bow and sides, rather than across a droppable ramp.
Both the thirty-six-foot LCP(R) and the forty-five-foot LCM had droppable ramps.
The opening there was the width of the corridor with droppable rail well marked with warning signs.