New T-Routes in the PNW

FAA added several new T-Routes in the Pacific Northwest on January 30, 2020, and other routes there and throughout the U.S. were expanded.

T-routes are described in AIM 5−3−4. Airways and Route Systems and elsewhere in the AIM, ACs, and other documents. They are low-altitude RNAV routes (shown in blue on enroute charts) similar to the victor airways based on VORs, but T-routes require GNSS and are available to aircraft with a suitable RNAV system–viz., an IFR-approved GPS. T-Routes originally were intended to provide efficient paths for IFR traffic through busy Class B airspace (see this briefing from AOPA), but as FAA shifts from VOR-based navigation to PBN, T-routes are becoming more common throughout the national airspace system.

For example, here’s a segment of T268 (click the preceding link to see the route at SkyVector.com), a new route from the Seattle area across the Cascades to Spokane, WA and beyond.

T268 from Seattle to Spokane

This new route closely parallels the V2 airway, but because it can zig and zag a bit around high terrain, it offers lower MEAs, which can be helpful when avoiding ice. Compare the GNSS-based MEAs (in blue) below with the MEAs for the VOR-based V2 airway.

Another section of T268 provides an efficient route from the area around Paine Field (KPAE) north of Seattle east across the Cascades while remaining clear of the increasingly busy airspace that surrounds Seattle.

Another excellent example of how a T-route can offer advantages over VOR-based airways is the stretch between the Redmond-Bend area in Oregon south toward Reno and Las Vegas.

A segment of T274

The new T274 closely follows V165, but well-placed bends allow the MEA to drop, for example, from 14000 ft to 10100 ft. That’s potentially a big help, both for avoiding icing and for reducing the need for oxygen.

Compare the MEAs for the T-route and victor airway

If you fly IFR and haven’t closely reviewed the low-altitude enroute charts recently, take another look. You may find new T-routes that give you new options in the areas where you fly.

FAA publishes T-routes and other changes to airspace in the Federal Register. You can find the complete list of the January 2020 changes here.