Falling (p. 183 PHB)
A fall from a great height is one of the most common hazards facing an adventurer.
At the end of a fall, a creature takes 1d6 bludgeoning damage for every 10 feet it fell, to a maximum of 20d6. The creature lands prone, unless it avoids taking damage from the fall.
What you need: Winged Boots
Each round up equals 60 feet using the Dash Action (assuming 30 ft. of normal movement).
For every 10 feet up you travel you deal +1d6 bludgeoning damage when you fall, to a maximum of 20d6 if jumping 200 ft. or more. On a hit the target is knocked prone, unless they take no bludgeoning damage from you falling on them.
Note: It is assumed you begin flying again to halt your movement once you hit your opponent with the attack action (using your movement action for the round you fall).
Minimum Jump: 1 round up + 1 round down (assuming opponent is within 5 ft.) +6d6 damage and the target is knocked prone, unless they take no bludgeoning damage from you falling on them.
Full Jump: 4 rounds up + 1 round down = 5 rounds +20d6 damage and the target is knocked prone, unless they take no bludgeoning damage from you falling on them.
Wondrous item, uncommon (requires attunement)
While you wear these boots, you have a flying speed equal to your walking speed. You can use the boots to fly for up to 4 hours, all at once or in several shorter flights, each one using a minimum of 1 minute from the duration. If you are flying when the duration expires, you descend at a rate of 30 feet per round until you land. The boots regain 2 hours of flying capability for every 12 hours they aren't in use.