Wake Turbulence Recategorization (ReCat) creates Wake Categories as replacements for Weight Classes for the purpose of establishing and applying wake turbulence separation minima used by air traffic controllers to separate aircraft. Wake categories are determined by aircraft weight, wingspan, approach and departure speed, and the ability of the aircraft to safely withstand a wake vortex encounter. Wake categories are used by air traffic control facilities that are authorized to provide wake turbulence separation under the Wake Turbulence Recategorization Program.
Currently, wake turbulence separation minima are greater than minimum radar separation minima in en route airspace, however there is an effort to allow 3 mile separation in certain en route airspace which would change that. The separation function does not change; however, the separation minima do. This does not necessitate changes in the procedures used by air traffic controllers to separate aircraft.
Integration of Wake Category in CARTS and STARS is complete. ATPA modification for single runway separation is complete but not required for implementation. ATPA modificationfor dependent staggerred approaches is ongoing. ATPA integrationin PRM is being considered for ATL.
JO 7110.65 Appendix A and paragraphs referring to wake turbulence considerations will need to be updated. The initial introduction of ReCat was accomplished throgh the publication of JO 7110.608, and may remain a separate order.
Regulatory oversight considerations: None, unless automated systems are used to determine whether an Airborne Loss Of Separation Mandatory Occurrence Report may be needed, or to monitor loss of separation due to compression on final approach which is monitored using quality assurance and quality control processes. Any automated systems will need to incorporate the separation minima associated with Wake Categories.
- Loss of separation severity, as a percentage of separation requirements may increase due to smaller demoninator and reduced space for recovery
- Wake encounter severity may increase due to reduced wake age at encounter due to reduced separation. Wake encounter frequency may increase due to consideration of encounter tolerance used in setting standards.
- Controller error may increase due to reduced separation standards providing less room for normal variability without error.
Corroborating sources and comments
FAA AVS Workplan for NextGen 2012, P. 66
Airbus Flight Operations Briefing Notes, Runway and Surface Operations, Preventing Runway Incursions; http://www.airbus.com/fileadmin/media_gallery/files/safety_library_items/AirbusSafetyLib_-FLT_OPS-RWY_OPS_SEQ01.pdf
RECAT of Wake Turbulence
The FAA Issues Notice To ATC Officials In Busiest Airports To Reduce Collision Hazards.
The Wall Street Journal (1/21, Pasztor, Subscription Publication) reports on an FAA initiative to reduce the risk of airborne collisions outside of some of the country’s busiest airports. Often the result of missed approaches and go-arounds, near-collisions are an issue previously highlighted by the NTSB after investigating previous incidents at the JFK, Las Vegas, and Charlotte airports. The altered landing and takeoff procedures, not spelled out in the article, are said to be taking effect at those airports as well as 13 others, including seven of the busiest 10 airports. The notice is said to apply to air traffic controllers at the affected sites and will apply to runways that are oriented in such a way that the extended center line of one runway intersects with another.