An airline that operates an extensive domestic and international network has used RFID in its maintenance operation for more than two years, tagging emergency equipment in the cabin that must be on every plane and must not be expired-oxygen generators, life vests, portable oxygen bottles, first-aid kits, medical kits, defibrillators, fire suppression squibs, and so forth. RFID replaces repeated date inspections, allowing the firm to get the maximum life out of an asset before removing it from service. Additional projects are planned to use RFID for internal distribution, identifying and tracking tire inventory, and other projects.