SENIOR MASTER Sergeant Mark Sletten, a boom operator with the 906th Air Refueling Squadron, Grand Forks Air Force Base, North Dakota, maneuvers a halon bottle, or flightline fire extinguisher, into position on the Alpha ramp at the base. Sergeant Sletten and the crew from his aircraft performed crew servicing procedures under the watchful eyes of inspectors during an Operational Readiness Inspection on April 11, 2000