One of the benefits (and excitements) of learning to fly is that you have the ability to GO REALLY FAST. “There are no speed limit signs in the sky,” you might say.
You’re absolutely right that there are no speed limit signs in the sky. But that doesn’t mean that there are no aircraft speed limits. Because, in fact, there are.
The main thing to remember is that, in general, “if you go high, you can fly!” – Above 10,000 feet MSL (mean sea level – this means “above sea level”) there are no aircraft speed limits. You can fly as fast as your little heart (and the planes little – or not so little – motor) desires.
But below 10,000′ MSL, you have to maintain an indicated airspeed at or below 250 knots (KIAS). And that’s not all.
If an airplane is within class B airspace, regardless of altitude, it is limited to 250 knots indicated airspeed. If it is flying “under the shelf” of class B airspace, it is limited to 200 knots indicated airspeed. There are also areas called “class B corridors” where aircraft can fly without clearance into class B airspace, and in these corridors, they are limited to 200 knots indicated airspeed as well.
Regulations also state that at or below 2500 AGL (above ground level – over the ground), when within 4 nautical miles from a class C or class D airport, you cannot fly any faster than 200 knots indicated airspeed. Air Traffic Control (ATC) may ask an aircraft to deviate from the 200 KIAS limit, but cannot ask an aircraft to go faster than the 250 KIAS limit (though they can always ask you to go slower).
Generally, these rules are in place so that aircraft with wildly different performance aren’t flying at all different speeds when they are likely to be near one another. Additionally, the lower you go, the more likely you are to be flying with birds, and if you are flying more slowly, if you happen to hit a bird (known as a bird strike), you are less likely to do significant damage to your airplane, such that you would not be able to control and land it.
For those of you who want to see the actual regulation, see 14 CFR 91.117. The above information applies to aircraft speed limits in the United States, under Federal Aviation Administration (FAA) regulations. Other countries may have different rules.
Have any more questions or comments about aircraft speed limits? Hurry up and tell us below!
Andrew Hartley is a Certificated Flight Instructor in Columbus, Ohio.