Paired approach flight demonstration: Planning and development activities

Simultaneous arrivals to closely spaced parallel runways (CSPR) are permissible when visual approaches can be conducted, and visual separation from the lead aircraft and its wake can be provided by the trail aircraft flight crew. During instrument meteorological conditions (IMC), CSPR visual approaches cannot be conducted, and instrument approach procedures are used. These procedures reduce the airport capacity because of increased separation to compensate for surveillance uncertainty and larger collision avoidance response times associated with having a controller in the loop. To increase capacity during IMC, the Paired Approach procedure has been developed. The Paired Approach procedure is a part of Interval Management (IM), which leverages automatic dependent surveillance-broadcast (ADS-B) Out for the lead aircraft (referred to as the Target aircraft) and ADS-B In for the trail aircraft (referred to as the IM aircraft). During the Paired Approach procedure, the IM aircraft uses speed commands from the flight-deck IM (FIM) equipment to maintain precise spacing between itself and the Target aircraft. The IM flight crew is given a time-based spacing parameter referred to as the assigned spacing goal, which is the desired spacing behind the Target aircraft. The desired spacing between the IM and Target aircraft in a Paired Approach operation is the spacing that will keep the IM aircraft far enough behind the Target aircraft to avoid the risk of a collision while still being close enough to the Target aircraft to avoid an encounter with its wake. The FAA is conducting a Paired Approach Flight Demonstration at San Francisco International Airport in early 2019. Honeywell is developing the prototype avionics that will be used and Alaska Airlines, United Airlines, and Honeywell are providing aircraft. The FAA is choosing to scope the demonstration based on a limited part of the Paired Approach operational concept due to technology and concept maturity.