For decades, the FAA grouped big jets into three general wake turbulence categories: heavy, large, and small. That's all starting to change.

Why The Change?

We don't often view the FAA as a leader in efficiency, but they're actually doing some really great things with their new wake turbulence recategorization rules.

The previous horizontal separation rules for wake turbulence were overly broad, they were primarily based on max certified takeoff weight, and they kept some planes at greater-than-necessary separation distances.

Take this for example: the Boeing 767 and 747 are both 'heavy' aircraft, with a minimum separation of 4 miles. If a 767 is following a 747, that's just fine. But when a 747 is following a 767, there's more separation than what's really necessary.

NextGen Efficiency

It was well known that these rules were bogging down busy airports, so that FAA brought in wake turbulence and physics experts to find out where they could safely reduce separation minimums.

What they came up with were 6 aircraft categories, labeled A-F. But more than just a fancy lettering system, they were able to shave off some serious distance between aircraft. Remember that 767/747 scenario we just talked about? The previous separation of 4 NM is now just 2.5 NM.

That 1.5 NM can make a huge difference. If both aircraft are flying a Vref of 145 knots (yes, this a generalization), it creates a flight time savings of 37 seconds for the Boeing 747.

At first glance, that might not sound like a lot of time, but try this: open your phone timer or the clock on your computer. Then, time yourself for 37 seconds without doing anything else. It feels like an eternity, right?

Memphis Leads The Way

The first airport to implement these new wake Recat rules was Memphis, and they started in 2012. What they found was even better than expected: airport capacity got a 20% boost, and they could accept up to 22 more arrivals per hour.

FedEx was pretty happy about the new rules as well. They reported a fuel savings of $1.8 million per month after Recat took place.

More Airports Follow The Lead

Miami International, Louisville International, and most recently, Atlanta Hartsfield have also joined the Recat program.

UPS, based in Louisville, reported a 52,000 pound fuel savings each night from their arriving aircraft after the Recat rules took place.

And Atlanta Hartsfield, the busiest airport in the world, is able to shave off 60-90 seconds from many of their takeoffs with the new separation standards. When you run over 2,000 tower operations per day, that's a big deal.

Coming To An Airport Near You

The FAA plans to expand the Recat program to at least 15 more airports in the next few years, and one of them is most likely going to be near you.

So the next time you fly into a Recat airport, whether you're a pilot or passenger, enjoy those few less minutes you have to sit in a metal tube. And make sure you thank your Air Traffic Controller as well - their workload will be just a little bit higher, making sure they can fit you in at a reduced distance.