The Chinook maintenance inspection process, or aircraft phasing, is about a 21-day process that includes the removal of aircraft blades, draining of all fluids, lubrication, brake disc assembly replacement, engine checks, aircraft part replacement and repair, and a good washing.
Soldiers work around the clock when an aircraft comes in for inspection to ensure it is ready to return to the fleet as soon as possible. At any given time, up to seven CH-47 may be in various stages of phasing throughout the brigade.
CH-47 Chinook, maintenance is done approximately every 25, 50, and 100 flight hours. Scheduled maintenance time and to keep her in order, certain things need to be replaced