Even without a "descend via" clearance from ATC, speed restrictions still apply along STAR arrival routes. Here's why...

Review: Flying A STAR

Standard Terminal Arrival Routes (STAR) are predefined flight paths used to transition aircraft from the en-route structure into the terminal area.

While STARs are very common for jets, piston aircraft can also be assigned STAR arrivals, and it's something any instrument-rated pilot should understand.

STAR arrival procedures streamline inbound IFR traffic into defined routes. They often start with a transition route, and eventually, all of these transition routes merge, and the aircraft join the same route.

ATC organizes arriving traffic in three dimensions. They're managing altitude, lateral path, and airspeed to keep traffic separated, and arrivals help with all three.

Flight Crew Report: Failed To Meet A Speed Restriction

STARs can be complex, resulting in the potential for missed altitude and speed restrictions. The key to flying a STAR is early planning, a thorough briefing, and closely monitoring speed and altitude throughout the procedure.

The following NASA ASRS report details a crew that failed to comply with a speed restriction, resulting in a vector from ATC followed by a radio confrontation. Here's what happened...

What Does The AIM Say About Speed?

When you're flying a STAR, speeds are part of the lateral portion of a STAR. That means if the STAR is a part of your filed routing, or ATC instructs you to "join the ZZZ arrival", you need to comply with the speeds published on the arrival, even if you aren't given a "descend via" clearance.

The FAA's AIM 5-4-1 says, "published speed restrictions are independent of altitude restrictions and are mandatory unless modified by ATC. Pilots should plan to cross waypoints with a published speed restriction, at the published speed, and should not exceed this speed past the associated waypoint unless authorized by ATC or a published note to do so."

If you see an "expect" altitude or speed restriction, that is not mandatory until issued by ATC. However, "When otherwise cleared along a route or procedure that contains published speed restrictions, the pilot must comply with those speed restrictions independent of any descend via clearance" (AIM 5-4-1).

So, when you're cleared for an arrival, and you're following a lateral path, you must comply with the speed restrictions. Additionally, if you're cleared to "descend via" the arrival, you must comply with both the speeds and altitudes along the STAR.

When Should You Slow Down?

If the speed restriction is at a specific waypoint, when exactly can you slow down? The answer is a little ambiguous. The FAA says that, "ATC anticipates pilots will begin adjusting speed the minimum distance necessary prior to a published speed restriction so as to cross the waypoint/fix at the published speed."

From that point on, controllers will expect you to adjust your speed as necessary to meet any further crossing restrictions. Because every airplane performs differently, there's not a specific point when you can or cannot begin to slow down.

You just have to meet the speed restriction at the designated waypoint.

ATC Can Modify Or Cancel Speed Restriction

For changes to published speed restrictions along a STAR, ATC can issue you new instructions. They may cancel the speed restrictions altogether, issue you a new speed restriction at a waypoint, or tell you to "maintain" a certain airspeed.

What's The Most Challenging STAR You've Flown?

Where have you encountered challenging STARs? Tell us in the comments below.

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