JO 7110.65 3-1-14

When volcanic ash is present on the airport surface, and to the extent possible:

Avoid requiring aircraft to come to a full stop while taxiing.

Provide for a rolling takeoff for all departures. NOTE-

When aircraft begin a taxi or takeoff roll on ash contaminated surfaces, large amounts of volcanic ash will again become airborne. This newly airborne ash will significantly reduce visibility and will be ingested by the engines of following aircraft.

REFERENCE-

AIM, Para 7-5-9, Flight Operations in Volcanic Ash.