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 flown by aircraft descending out of the flight levels into the busiest airports in the country. If you haven't flown a jet or turboprop, chances are you haven't flown a STAR. However, even piston aircraft can be assigned STAR arrivals, and it's something any instrument-rated pilot needs to 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. Arrivals help with all three.

Flight Crew Report: Failed To Meet A Speed Restriction

STARs can be complex procedures and they sometimes leave crews confused, resulting in missed altitude and speed restrictions. The key to flying a successful 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?

Long story short, 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).

When you're cleared for an arrival, you're following a lateral path and you must comply with the speed restrictions. And, if you're cleared to descend via the arrival, you're managing your altitude to hit each crossing restriction as well.

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 Just Cancelled Your 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 The Most Challenging STAR You've Flown?

There are some pretty challenging STARs around the country. Charlotte (KCLT) has some of the most notorious. Where have you encountered challenging STARs and how did you manage your descent? Tell us in the comments below.