Answer:

descents

Answer	Crossword Clue
DESCENTS	They lead to landings
DESCENTS	Starts of many spelunking explorations
DESCENTS	They may start at the top

DESCENTS	Slopes
DESCENTS	Flight finishes
DESCENTS	Sudden attacks.
DESCENTS	Thrill-givers on roller coasters
DESCENTS	Assaults; forays
DESCENTS	Thrills for sky divers
DESCENTS	Parts of mountaineering trips
DESCENTS	Last parts of flights

DESCENTS	Submarine actions
DESCENTS	Downturns