helicopters are more expensive than fixed-wing aircraft, which limits their application to viticulture. Their manœuvrability is a bonus, however. They are particularly useful for crop spraying
, and the turbulence created by the rotors helps the spray to penetrate (although there are the usual problems where individual landholdings are small). They are commonly used as airborne wind machines in New Zealand and very occasionally in Europe to stir up cold, dense air just above the vineyard surface with warmer air above to prevent spring frost damage. It is not uncommon, for instance, to have helicopters on standby when the risk of frost is high. On occasion they have been used in an attempt to dry excess moisture off vine leaves and bunches immediately after heavy rainfall at harvest.
