Typically, the first indication to a pilot that the flight’s going to be held on the ground is a radio call from local ground control at the departure airport advising them of a “Ground Stop” with an update time. Often this call arrives after the aircraft has pushed back from the gate and is actively taxiing towards the departure runway. This radio call initiates a flurry of activity in the cockpit between the pilots, the dispatcher, local company operations, air traffic control, flight attendants and the passengers. Before going any further in the disection of this fictitious delay, however, a little background information will be very beneficial.
Definition: Flight Crew. A flight crew consists of a captain, first officer and flight attendants. The flight crew is tasked by their company with safely flying the aircraft from departure airport A to destination airport B and ensuring the safety of their passengers throughout the flight. Depending on the size of the aircraft operated, this crew may include three, four or more flight attendants. Both the captain and first officer, during this delay situation work directly with their dispatcher, who’s usually located at a company’s operations control center.
Definition: “Dispatcher”. A dispatcher is jointly tasked with the safe operation of this flight from point A to point B. A dispatcher however, has unique duties for example which include, but are not limited to, planning the route the flight takes to its destination, the fuel planning for that flight, the altitude they will climb to, careful analysis of any maintenance items on the aircraft which could affect the safe conduct of the flight, Notices to Airmen at the departure airport and arrival airport, etc…
Definition: “Ground Stop”. The FAA uses the term “Ground Stop” to indicate to all pilots that some condition either en-route (i.e. – weather) or at the destination airport has reduced the capacity of the air traffic system to handle the normal volume of aircraft into that airport and necessitated that a delay program be implemented – thereby limiting the number of arrival aircraft into that destination. A quick analogy may clear up any questions.
Visualize this: road construction on a two lane interstate, one lane closed to traffic. Result – two lanes of traffic must merge into one. Speeds are reduced or slowed to a crawl, cars are forced to stop and go and the backup starts to extend many miles back – especially during rush hour. Now imagine this traffic jam in three dimensions at speeds in excess of 7 miles a minute (420 miles per hour).
Pilots call these lanes we fly into an airport “Arrival Procedures” and they are used to descend airplanes from high altitude down to a destination airport. When Air Traffic Control closes an arrival procedure (i.e. weather precludes its use), airborne aircraft planning to use the recently closed procedure have to go somewhere. Air Traffic Control reroutes these aircraft onto an alternate arrival procedure. This has the same effect, however, as a lane closure on an interstate highway. Planes could quickly saturate the open arrival procedure and without intervention, a traffic jam could develop violating in-trail spacing requirements.
Definition: “In-trail spacing”. This number refers to how close an airplane can safely get to the airplane in front of it. So, without quickly limiting the number of aircraft on the “open” arrival procedure, safety could be compromised and a traffic jam could stretch over hundreds of miles. Air Traffic Controllers always take immediate action to prevent this and considering that at any one time there are over 5,000 aircraft airborne in the continental United States, this brings home the need for their timely intervention. Holding patterns initially manage flow on the open arrival procedure but in parallel with holding aircraft, the FAA command center initiates a ground delay program to keep aircraft on the ground thus preventing any further saturation of the system – which brings usfull circle back to the initial radio call from ground control and the “Update Time” for the ground stop.
Definition: “Update Time”. This is a time that senior managers in the FAA’s national command center, after thoroughly reviewing all factors affecting the air traffic system (i.e. weather, runway closures, equipment outages, etc…) determine if the ground stop will remain in effect or be lifted. Typically, FAA reevaluates every hour or when conditions change dramatically and then send out messages nationwide to advise aircraft affected by the delay program on the status of the delay. If the situation has improved, they lift the stop and begin sequencing aircraft into the airspace system and get them off the ground. If not, they issue another update time. So armed with these definitions and a brief explanation of Air Traffic Control’s role in the ground delay, what’s going on in the cockpit? Stand by for more.