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Performance Success Stories

Closing the Gap: Saving Time by Safely Flying Closer

Highlights:
  • Wake Recat allows aircraft to safely take-off and land closer to each other.
  • The new standards can increase effective capacity and flight efficiency at many airports, including less fuel burn.
  • Joint Analysis Team research found aircraft flying through Indianapolis and Philadelphia save an estimated $2.4 million and $765,000, respectively, in airborne and taxi-out time per year which includes time and fuel-cost savings.
  • Analysis shows the impact of Wake Recat is driven by the mix of aircraft typically flown at an airport, and the duration and characteristics of peak-hour traffic.

NextGen Implementation Plan (PDF)

Separation Management
Provides controllers with tools to manage aircraft in a mixed environment of varying navigation equipment and wake performance capabilities.

NextGen Priorities Focus Area

Planes are taking off and landing faster at Indianapolis International Airport and Philadelphia International Airport thanks to an FAA modernization program that safely reduces the required distance between certain types of aircraft during landing and take-off.

Most people who fly have experienced turbulence, the rough air you sometimes feel during your flight. Often, it's a result of weather. Other times it's caused by nearby aircraft. Similar to the way a boat creates a wake, or ripples in the water as it passes through, wake turbulence forms behind an aircraft as it passes through the air. The bigger the aircraft, the bigger the wake of air behind it.

Wake turbulence isn't just a minor nuisance. It can be hazardous for other aircraft passing through it. Air traffic controllers must space out aircraft so the wake from one plane does not impact others behind it. For decades, the FAA separated aircraft by weight. Over the years, the types and sizes of commercial aircraft have changed dramatically — ranging from jumbo jets to small regional aircraft.

Realizing that not all aircraft produce the same amount of wake turbulence, the FAA worked with other government agencies, airlines and air carriers to study the issue. Following a decade of extensive research, experts determined the required separation between certain aircraft can be safely decreased leading to the recategorization of wake turbulence separation standards, or Wake Recat.

Allowing aircraft to safely take-off and land closer to each other can increase effective capacity and flight efficiency at many airports, including less fuel burn. That is the case for aircraft traveling through Indianapolis and Philadelphia using the new separation standards. The NextGen Advisory Committee's Joint Analysis Team (JAT) — operational and analytical experts from the FAA and aviation industry — measured the impact of Wake Recat at the two airports.

The team found aircraft flying through Indianapolis and Philadelphia save an estimated $2.4 million and $765,000, respectively, in airborne and taxi-out time per year. This includes time and fuel-cost savings.

As expected, the JAT found the mix of aircraft typically flown at an airport — and duration and characteristics of peak-hour traffic — are critical drivers of Wake Recat impact. At Indianapolis, peak hours are dominated by aircraft types that are positively impacted by Wake Recat, as well as by the same type of operation — either arrivals or departures. Consequently, about 23 percent of eligible aircraft pairs experience a decrease in separation, and only 4 percent of aircraft pairs experience an increase in separations at take-off and landing. The JAT determined Wake Recat is particularly effective during peak demand.

Due to a significant difference in fleet mix and more mixed operations (take-offs and landings) during peak-hours, the opportunity for Wake Recat benefits is lower at Philadelphia. About eight percent of eligible aircraft pairs experience decreased separations. Less than a half percent of eligible pairs saw an increase in separations at take-off and landing.

Eligible pairs of flights are defined as consecutive flights on the same runway performing the same type of operation, (e.g., both arrival and both departure), are within five minutes of each other, and operate during the study's reporting hours.

Indianapolis and Philadelphia are not the only locations where Wake Recat is being used with strong results. The new standards are having a profound impact on FedEx operations in Memphis according to Dan Allen, the managing director of flight, technical, and regulatory compliance at FedEx. "It's almost like creating a new runway," he said. "It's created 17 percent more capacity. We've saved three-and-a-half minutes on taxi and two-and-a-half minutes en route."

Allen explained the FedEx Express network could operate 14 days with the amount of fuel the company has saved since the FAA deployed Wake Recat in November of 2012. Memphis is the busiest cargo airport in North America and the home of the FedEx Express Global "SuperHub," which processes a major portion of the freight carrier's packages.

Wake Recat is in place at 18 airports nationwide.

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This page was originally published at: https://www.faa.gov/nextgen/snapshots/stories/?slide=63