One Day / One Night

Day

  At about twenty minutes before the hour, aviation in the US was starting like it had done for many years. The tail end of the day’s first inbound rush was close to landing at several airline hubs. Passengers onboard many airliners were hopeful that there was enough time to make early morning business meetings, or catch connecting flights. Others waiting in passenger lounges were busy making telephone calls, checking e-mail, or enjoying their first cup of morning coffee.

  At many of the general aviation airports across the United States, pre-flight inspections and flight plans for numerous business and personal aircraft were being completed by pilots, as their aircraft were fueled and readied for departure, as their day of flying was just beginning. Conversely, pilots flying in many overnight cargo aircraft had, or were close to landing as their day was coming to the end.

  Beautiful flying weather in many parts of the country gave student pilots one less thing to be concerned about.

  Air traffic controllers settled in for another normal day at their jobs.     

  Suddenly, an uneasy feeling spread across airport terminals, airport FBO’s, and air traffic facilities, as word of an aircraft crashing into the World Trade Center in New York City started filtering across the country. People stopped what they were doing and huddled around the closest television set, wondering how such a thing could happen on such a beautiful fall day in New York.

  Many unbelievingly stared at the sight when they were able to see it on TV. 

  Then, as millions watched in utter disbelief, a second aircraft flew into World Trade Center Tower number 2.

  As the world watched events unfold in New York and then in Washington DC, word spread across the aviation community that large passenger airliners had been hijacked and used as tools of terrorism to murder and destroy thousands of human lives here in the United States. Minutes after an aircraft had impacted the Pentagon, an unprecedented order came from the Air Traffic Control Command Center. A directive that contained tremendous insight in regards to what was happening, the command to clear the skies of all civilian aircraft was immediately issued to all air traffic control facilities and flight service stations:

  “SPECIAL NOTICE: DUE TO EXTRAORDINARY CIRCUMSTANCES AND FOR REASONS OF SAFETY…ATTENTION ALL AIRCRAFT OPERATORS…BY ORDER OF THE FEDERAL AVIATION COMMAND CENTER: TAKE-OFFS AT ALL AIRPORTS ARE NOT AUTHORIZED...ALL AIRBORNE AIRCRAFT ARE DIRECTED TO LAND…EFFECTIVE IMMEDIATELY.”

  Shortly thereafter, another notice was issued:

  “UNTIL FURTHER NOTICE: ALL FLIGHT OPERATIONS IN THE NATIONAL AIRSPACE OF THE UNITED STATES BY UNITED STATES CIVIL, BY FOREIGN CIVIL, AND BY FOREIGN MILITARY AIRCRAFT ARE PROHIBITED…”

  At first, many air traffic controllers and pilots could not believe what they were hearing.

  Immediately clear the skies of ALL aircraft?

  But, with the stark realization of what had happened still fresh in everyone’s minds, pilots were quickly informed that there was a national emergency and that they needed to land as soon as possible. Minutes that followed had aviation radio frequencies filled with reroutes, radar vectors to airports, landing clearances for those on final, and cancellation of take-off clearances for those on runways. Pilots who were airborne questioned if they could continue on to their destinations. While some controllers were too busy to be questioned, others simply restated that they needed to land as soon as possible. Specialists in Flight Service Stations across the country broadcasted over their frequencies and over navaids that the airspace over the United States was closed.

  Across the United States, close to seven hundred aircraft were directed to safe landings in the first four minutes after the order was given.

  Then, word reached all air traffic facilities that another aircraft had crashed in western Pennsylvania and that there could be several more aircraft unaccounted for.

  Tensions rose as aircraft were vectored to the closest available airport. Human emotions were sometimes hard to put aside as terse instructions and radio calls were made while controllers intently gazed at their radarscopes or at aircraft in the pattern, looking for any sign of deviation from their flight paths.

  Another two thousand eight hundred aircraft were landed in the next fifty minutes.

  During this time, numerous aircraft from foreign countries were flying over America and needed to be rerouted to the closest International airports that could accommodate both their size, and the hundreds of passengers that needed to clear customs. As controllers struggled to clear the skies, valuable time was spent as controllers had to explain to the pilots of these aircraft why they were suddenly being diverted and forced to land. While this was happening, word was spread that many airports were quickly reaching saturation levels where they could no longer safely accept any more aircraft.

  Quick assessments made by controllers and traffic management officials allowed some aircraft to continue on to airports that were, or close to their intended destination.

  The closure of the airspace over the United States not only affected US air traffic controllers; many foreign air traffic facilities were also impacted. At that time of day, hundreds of aircraft flying to the US were forced to divert to many Canadian airports, or forced to turn around and return to airports in Europe, Alaska, or to countries and islands in the Pacific. With most of these aircraft flying over open water and well beyond any radar coverage, the work required to contact, inform, and reroute these aircraft required a tremendous team effort by US and International air traffic controllers.

  Approximately one hundred aircraft were in the skies over the Pacific Ocean when the recall order was issued. Controllers in Tokyo and Oakland Air Traffic Control Centers needed to issue immediate instructions to aircraft, many of them hours away from land or suitable airports.

  Over the Atlantic, another one hundred and twenty aircraft were diverted to Canadian airports at Halifax and Gander. Within a few short hours, thousands of passengers and aircraft crews were suddenly stranded in the two Canadian cities.

  At twenty minutes before the hour that one day, there had been approximately five thousand civilian aircraft flying under Instrument Flight Rules and in direct contact with air traffic control. An additional three to five thousand other aircraft were flying under Visual Flight Rules. In the course of two and a half hours after the order was given, almost all aircraft contacted through air traffic control towers, flight service stations, and air route traffic control centers had been rerouted and safely landed at the nearest available airport. Within three hours, only a handful of civilian aircraft, mostly Lifeguard flights, were still flying at a time when normally, close to ten thousand aircraft would be in the skies over the United States.

  Air traffic controllers across the country, and indeed, around the world that one day were tasked with an unprecedented situation that called for many immediate and difficult decisions. All the while keeping in the back of their minds, the fear and concern that further hijacking attempts could still be made, maybe even to aircraft that were currently under their control.

  As more facts came to light, it had become evident that the decision to clear the skies and land all aircraft had possibly stopped additional terrorists from taking over other aircraft. Hundreds, maybe thousands of lives were saved by this quick decision.

  The skies over the United States suddenly became very silent that one day. Except for military, law enforcement and medical evacuation flights, the skies over America would remain that way for many days.

  Silent too were America’s air traffic control facilities. What normally would have been busy hours of the day with the skies filled with aircraft receiving instructions from controllers in en-route centers, weather briefings being given by flight service specialists, and controllers in towers issuing landing and take-off clearances, these hours were filled with an uneasy silence as controllers monitored military and law enforcement aircraft as they orbited overhead.

  Faith in America’s aviation system, one of the safest modes of transportation in the world, was shaken to its very core that one day. Comforting to many, was the fact that without incident, thousands of aviation professionals around the world known as air traffic controllers safely directed and landed hundreds of aircraft when the order was given to clear the skies.    

Night

  It was near the end of a long, busy day that had thunderstorms affecting air traffic operations throughout the country. A persistent line of thunderstorm with it's associated turbulence located over the center and southeastern portion of the United States had caused all of the airlines and most other users of the air traffic system to reroute many of their aircraft north, while another line of thunderstorms extending along a cold front was causing problems and delays on the east coast.

  Air traffic controllers in all six areas of specialization in the air route traffic control center were not only contending with the usual amount of air traffic that operated daily in the center’s several hundred thousand square miles of airspace, but also with a considerable increase in over-flight traffic, extra miles-in-trail restrictions to adjacent facilities, and convective weather problems of their own. 

  There was a broad mix of aircraft flying at 10:30 PM that evening. Each area was feeling the effects of having the extra air traffic. Many of the westbound aircraft consisted mainly of airliners filled with passengers that had caught the “last flight out,” while most of the aircraft headed eastbound were either passenger aircraft trying to catch up with being delayed by the weather, or overnight package delivery and mail carrying aircraft speeding to their hubs so that their cargo could be sorted and sent on their way by early morning.

  The last bank of aircraft had already left the major airline hub, and the varied array of DC-9’s, DC-10’s; B727’s, B757’s, Airbuses, commuter jets and turboprops were all flying out on their preferred departure routings. Since there was quite a difference in aircraft climb performance and speeds, air traffic controllers intently monitored the sector, ready to make quick decisions to amend altitudes or adjust climb and cruising speeds so that all aircraft could safely reach their cruising altitudes. At the same time, routing adjustments were being entered into the computer as pilots requested short cuts and direct routes, taking advantage of jet stream winds or sophisticated navigational equipment onboard their aircraft.  

  Controllers working in low altitude sectors were providing air traffic services to the many general aviation aircraft, commuter airliners, smaller freight, and business aircraft that were also flying. These aircraft also needed ATC clearances, routes around active military airspace, and weather and flight information to and from the numerous airports in the area that were not served by air traffic control towers or radar approach controls.

  In one area, the usual evening rush of international departures from major airline hubs in the Midwest were conflicting with the westbound aircraft that had departed from several Canadian airports. Controllers in the area were not only busy with these aircraft, but needed to handle much of the coordination necessary via the older telephone communications system that tied the US and Canadian air traffic facilities together.

  Just shy of 10:30 P.M., technicians who monitored the various computers, radio frequencies, internal systems, and navigation aids that kept the air traffic control center operating, activated a routine preventative changeover to another electrical circuit to handle the radarscopes, flight strip processors, and printers for the evening. A procedure that had taken place monthly without problems for the last seven years.

  For some unexplained reason, an electrical surge arced through the equipment causing main and backup systems to fail. After these had failed, another set of backup switches also failed.

  At that moment, all flight strip printers tripped off line. A few seconds later, every air traffic controller noticed that their radarscope display had frozen.

  Accustomed to seeing occasional power interruptions or computer failures, controllers waited patiently for the computer to automatically reset and normal operations to continue.

  In any air traffic sector with aircraft moving along at speeds of up to six hundred miles per hour, a loss of data for ten seconds is a long annoyance.

  For thirty seconds, loss of radar data is close to an eternity.

  In the past, if the main radar data processor didn’t come back on line in a few seconds, most controllers would simply switch over to the back up radar system and continue.

  The power surge that had gone through the air traffic control center knocked the main computer that handled flight plan and radar data processing, the back-up computer; all voice radio and landline communications equipment, and every radarscope completely off line.

  Less than a minute later, only the radio and landline communications equipment returned to normal.

  At that time, there were over one hundred and eighty aircraft, and more than two hundred and fifty flight plans in the center’s airspace and computer system.

  For the next fifty eight minutes, the thirty eight controllers who were plugged in and working their sectors at the time of the equipment failures, would have to separate and insure the safety of the aircraft in their sectors by using only their radios, pens, and non-radar procedures learned during “basic controller training” that for some, was close to twenty years ago.

  Every air traffic controller, whether they work in Towers, TRACON’s, or Air Route Traffic Control Centers, has had to go through a period of training where they have had to prove that they could work a control area without the use of radar. For Center training, conducted for most at the FAA Mike Monroney Aeronautical Training Center in Oklahoma City, Oklahoma, the dreaded “Phase Three” training was where trainees passed the Academy, or failed. Before reaching Phase Three, air traffic controller trainees intensely studied the Air Traffic Rulebook, the 7110.65, learning non-radar rules and procedures, and basic air traffic control. In Phase Three, simulated sector problems ranging from forty to one hundred and ten percent traffic levels would test controller trainees to their limits. Other controller trainees would sit across the room acting as pilots and controllers in adjacent facilities, radioing for various air traffic clearances in a scripted training scenario. Instructors hovered over each trainee, watching and listening to each clearance. For those who passed their training at the Academy, another round of non-radar training, “Phase Eight,” was conducted at most En-Route facilities. Again, controller trainees sat at a simulated sector, sans radar, taking non-radar problems unique to their area of specialization, all under the watchful eye of a Full Performance Level Controller (FPL) who was rated as an instructor for the sector.

  With only the use of pencils, overhead maps, and reports from the “pilots,” controller trainees had to form a mental picture of where all of the aircraft were in the sector and safely move them through, or into and out of the various airports within the sector.

  In the Phase Eight graded problems, one loss of separation between aircraft was cause for failure. Controller trainees, who passed Phase Eight, would then be sent down to the control room to begin two to four years of on-the-job training in the live air traffic environment.

  For the first few minutes that one night, air traffic controllers spent their time attempting to inform pilots flying in the now non-radar sectors, of what had happened. Truthfully, most did not actually know what had happened, only the fact that they had “lost their radar.” Many of the first radio transmissions consisted of such phrases as: “radar contact lost,” or “say your position from…”

  Controllers had to quickly find where the aircraft were in relation to others, and find a way to get the aircraft safely onto a non-radar route, such as on a jet airway or over a known navigational fix. Technically, each aircraft had to be given a new, entire route clearance to their destination in case radio contact was lost. Many controllers alternated between sitting in their chairs writing down information on their flight progress strips that came from aircraft or from other controllers, and jumping up from their chairs to look at overhead Jet and Victor (low altitude) airway maps.

  In the radar environment, five miles is the minimum lateral separation between aircraft flying at the same altitude. With the loss of radar, minimum lateral separation increases to twenty miles.

  One of the problems that controllers suddenly faced that one night, was that as they found out where aircraft were from their radio reports, by the time the radio transmission was finished, the aircraft, some moving close to six hundred miles per hour, had already moved, having flown another few miles. For the intense minutes that followed, most controllers attempted to piece together where each aircraft was, and project ahead to where it would be in the minutes ahead.

  In what would normally be a rather mundane flight across the United States, pilots soon found themselves busier than normal. It soon became apparent to most that the situation in the air traffic control center was far from normal as controllers asked constant questions regarding each aircraft’s position, speed and altitude. As their flights progressed, many pilots soon found themselves pulling out airway maps or going though their inertial navigational equipment as new routes were issued. Pilots needed to recalculate their fuel situation as the direct routes that they were on were taken away, replaced with new clearances via Jet airways or direct to new navigational fixes.

  Traffic Collision and Avoidance indicators (T/CAS) became even more important as each flight crew heard that “radar contact was lost.”         

  Each air traffic facility in the United States has in place, procedures to implement when such a situation occurs. These contingency plans have step-by-step instructions that delegate airspace to adjacent en-route facilities, or to underlying facilities such as TRACON’s (Terminal Radar Approach Control), and procedures for air traffic to be rerouted away from the affected facility.

  If a smaller airspace such as a TRACON had lost its radar, the en-route center would take over the airspace and a somewhat normal, albeit much less in volume, operation would continue.

  The only time it had been done in reverse was in simulated training.

  In each area of specialization, at each radar sector that was in operation that one night, each individual air traffic controller reacted differently to the complete loss of their main means of safely separating large volumes of aircraft. Some found it to be a challenge, while tension gripped others as it soon became very obvious that the radar and flight data processing systems were not coming back on line soon.

  Regardless of how much training one receives, there is no way to expect what someone would do, or how he or she would react until coming face to face with the situation.

  For most controllers on duty, a full-scale loss of primary and secondary radar and radar data processing had never happened in their entire careers.

  Voices rose as controllers made numerous radio and coordination calls. Shouts across the room between controllers were made as controllers attempted to find out where aircraft were, what altitude certain aircraft were at, or what radio frequency a particular aircraft was on. With over two hundred and fifty flight plans in the system at the moment of failure, flight progress strips were being searched and double checked as controllers tried to remember if a particular aircraft was still coming, had already flown through, or was flying right in the middle of their sector.

  For close to one full hour, aircraft ranging from single engine aircraft with one pilot, cargo aircraft with crew sizes ranging from two to four, business jets and turboprops with anywhere from two to twenty passengers, and large airliners and jumbo jets carrying as many as five hundred people, were methodically identified, located, and issued air traffic clearances and routes that would guarantee their safe passage through the center’s airspace.

  As time progressed, one back-up radar system returned which allowed the use of one radarscope in each area. Slowly, all systems returned and normal air traffic operations were restored two hours and ten minutes after the situation began.

  A few airlines have audio channels on board their aircraft that allow passengers to listen to air traffic control communications. It’s a good chance that several passengers were looking closely out their windows during their flight that one night.