Scope and Sequence of Groundings Revisited
As the National Airspace System (NAS) has reopened in phases, so have the Department of Transportation (DOT) and FAA clarified in increments the sequence o

As the National Airspace System (NAS) has reopened in phases, so have the Department of Transportation (DOT) and FAA clarified in increments the sequence of grounding actions made in the earliest minutes. FAA reports have narrowed but not eliminated the gap between its official timeline of decisions on September 11, versus third-party reports and observed actions directly from the field.

The FAA recently modified comments partially due to an article in AIN’s October issue (“Shutdown of National Airspace System Was ‘Organized Mayhem,’” page 4). In that report AIN described the historic precedents for grounding of civil aircraft and cited the plan for Security Control of Air Traffic and Air Navigation Aids (SCATANA), the 1971 FAA-Norad guide to diverting nonmilitary aircraft in times of defense emergency.

FAA public affairs spokesmen now state that the recent actions were simply “the first unplanned grounding.” The FAA has also since retrieved SCATANA from its own archives for review. In practice, the grounding actions on September 11 mirrored its exhaustive procedures developed decades earlier, but current FAA officials were likely unaware that this blueprint existed. Actions taken at the Air Traffic Control System Command Center (ATCSCC) were instead described as ad hoc–cobbled from common sense and best available information.

AIN also reported DOT statements in the October edition that all airborne traffic in the NAS was ordered grounded at 9:25 a.m. on September 11 by Secretary Norman Mineta. In fact, by that hour the process was well under way on a regional basis, having been initiated at the FAA New York Center at 9:06 a.m. as a verbal ground-stop for all traffic in its airspace. A ground-stop is a halt in place or recall of flight-ready or taxiing aircraft. No national orders were issued, but ATCSCC alerted all centers of the suspected terrorist activity.

At 9:08 a.m., a written order, also originating from and limited to New York Center, “sterilized” New York airspace with a directive for airborne traffic to fly out of the control area. The written ground-stop and sterilization expanded the order to aircraft departing Washington and Cleveland Centers for New York airspace. The FAA has not identified the individual(s) first issuing the orders. At 9:26 a.m., following New York’s lead and Mineta’s verbal order, FAA Administrator Jane Garvey issued a verbal ground-stop order for all aircraft in the NAS regardless of destination. At 9:29 a.m., Garvey signed Advisory 031 to all en route centers nationwide to implement in writing the earlier verbal order.

Early estimates of the number of airborne targets in the NAS as of this grounding order had been 4,300. In testimony to the House Subcommittee on Transportation on September 21, Garvey said there were 4,873 aircraft operating under IFR but did not assess VFR activity. The most recent FAA statement reported 4,546 total airborne targets as of the time of the national order. Garvey told Congress that at 9:45 a.m. “all airborne aircraft were told to land at the nearest airport–the first time in our history that all civil aircraft in the United States were grounded.” The FAA has since acknowledged at least three prior groundings due to defense exercises.

At 10:39 a.m., Notam FDC1/9731 was issued to close operations at all U.S. civil airports. The FAA also reported that at 11:06 a.m. the ATCSCC issued an advisory stating that no airports were authorized for takeoffs and landings, though it is not clear how this advisory differs from earlier orders. The agency officially reported that all civil nonemergency flights in the NAS had landed by 2:16 p.m., but field reports and observations indicate that the timing was as late as 2:07 p.m. in the continental U.S., and later still for Hawaii.