The move came a day after American Airlines began wiring inspections on all 309 of its MD-80s. AA's inspections continued yesterday, leading to more than 130 flight cancellations in addition to the 325 it cancelled Wednesday (ATWOnline, March 27). Inspections stem from US FAA's audit of domestic airlines' compliance with agency airworthiness directives. "Delta is working in full partnership with the FAA and is proactively and voluntarily revalidating the full compliance of a prior airworthiness directive completed earlier this year," it said. It added that an "aggressive and proactive re-inspection schedule" would allow it to return to a full schedule "early" today. According to AA, the inspections are to ensure that bundles of wires on auxiliary hydraulic systems are installed and spaced in accordance with an AD. AA said inspections would be completed late yesterday, allowing a return to a normal schedule today. DL said it added extra staff yesterday at its Atlanta hub to help deal with the crowds of passengers the cancellations were expected to cause. Southwest Airlines and United Airlines also have grounded aircraft temporarily this month for inspections.