If you ever share an airport with large aircraft, including airliners and cargo aircraft, you're sure to hear controllers warning pilots about
heavy aircraft. The word is typically used in conjunction with a wake turbulence advisory. When a controller warns you, for instance, that you will be landing behind a heavy aircraft, he or she is referring to an aircraft that is capable of takeoff weights that are greater than 255,000 pounds, regardless of the aircraft's current actual weight. Some lighter aircraft that are known to create severe wake turbulence, such as the Boeing 757, may also be designated heavy.
When your light aircraft is following a heavy aircraft at the same altitude or within 1,000 feet below the larger aircraft's altitude, air traffic controllers are required to provide separation of at least five miles - six miles when the heavy aircraft is over the runway threshold. Takeoff separation may be measured by distance or time intervals. For example, when a small aircraft will take off behind a heavy aircraft, controllers must provide a three-minute interval between the departures of the two aircraft. Pilots may request additional separation. If you wish to make such a request, contact ground control as soon as possible and before taxiing onto the runway.
Heavy is just one of three aircraft classes identified by air traffic controllers for the purposes of wake turbulence separation. Aircraft are classed as small if they are certificated for takeoff weights of less than 41,000 pounds. Aircraft are considered large if they are certificated for a takeoff weight of between 41,000 pounds and 255,00 pounds. How much separation controllers must leave between aircraft depends on their classification.
Call Up
While any radio call might be considered a call up, the Aeronautical Information Manual takes a narrower view of the term. Technically, call up refers only to the first voice contact between a facility and an aircraft. Because it is the first voice communication, the person calling must use his unit's full identification and the identification of the unit he is calling. That means that a pilot making a call up to the approach control facility at Baltimore Washington International Airport would say, "Baltimore Approach, Cessna One-Two-Three-Alpha-Bravo," rather than using the abbreviated form acceptable on a later call, "Approach, Cessna-Alpha-Bravo."
