Can I fly a STAR (standard terminal arrival route) if I can't maintain the minimum speed for it?

Question

I fly a single-engine airplane not capable of more than 120 KIAS. I'd love to fly a STAR (standard terminal arrival route) into my local airport (US), but want to make sure I fully understand the STAR procedure.

Most of these STARS I'm looking at flying are RNAV stars with "expect" altitudes, which I understand fully, but have published speed segments of around 250 to 210kts. It's my understanding that if I'm cleared for the arrival "cleared the Tops 5" I'm to follow published speeds and lateral guidance and the altitudes I'm given.

Is there ever a case I could fly a STAR and not have to follow published speeds or is it implied when flying the STAR? If my understanding is correct, I wouldn't be able to fly a STAR with published speeds if I can't meet them?

Could I file for a STAR in my flight plan and not get whacked with a pilot deviation if I'm cleared for the arrival and can't meet the speeds. I would think I couldn't fly them if I can't meet the speeds, but want to make sure I'm not missing something.

Answer 1

According to the FAA's Instrument Procedures Handbook, chapter 3 (p. 3-16):

Pilots may have noticed that minimum crossing altitudes and airspeed restrictions appear on some STARs. These expected altitudes and airspeeds are not part of the clearance until ATC includes them verbally. A STAR is simply a published routing; it does not have the force of a clearance until issued specifically by ATC. For example, minimum en route altitude (MEAs) printed on STARs are not valid unless stated within an ATC clearance or in cases of lost communication.

So unless ATC explicitly, verbally assigns you a minimum airspeed, you don't have to maintain it. If they do assign one and you can't maintain it, you can simply say "unable" and request to fly it at a lower airspeed. If ATC can't allow that for some reason (like spacing) then they'll likely vector you instead.

That means that if you are simply cleared for the STAR with no specific airspeed it's not a pilot deviation to fly it more slowly than the airspeed on the procedure.

I have no idea how likely or not it is that ATC would allow you to fly the STAR you have in mind. That would depend heavily on traffic, and things could change at any time.

Answer 2

If you’re flying low and slow, in practice you’re not going to spend much time on a SID or STAR unless you lose comms. ATC would rather vector one plane (you) off the procedure so the dozen jets and turboprops behind you going twice as fast can stay on it.

Traffic is light enough now (late 2020) that if you specifically tell them you want it for the practice, you may actually get to stay on the routing—but with lower speeds and altitudes that you can actually achieve.

The key to avoiding a pilot deviation here is to not accept any instruction or restriction you aren’t capable of obeying. Just tell them “unable” if that happens and offer what you can do, and they’ll find a way to make it work. Don’t parrot what they say and then think about whether you can actually do it!