If you were told to “maintain 250 knots” below Class B airspace, what would you do?
Report: Flying Under New York Class B Airspace
When it comes to flying around busy airspace, there are a plethora of rules and restrictions. This experienced, ATP-rated, corporate jet captain filed a NASA ASRS report for mistakenly breaking a regulation and questioning ATC’s rationale. So, what would you do?
New York (N90) TRACON often requests aircraft to maintain above 200 knots below the shelf of the New York Class B. In this particular case, we were asked to maintain 250 knots. I’ve also been instructed to maintain 210 knots or greater below the Class B. This creates a dilemma between violating 14 CFR 91.117(c) or telling ATC that we are unable, which is likely to upset the controller, jam up the frequency, and cause even more issues.
Speed Restrictions in/Around Class B Airspace
There isn’t a specific speed limit for operating within Class B airspace. If you’re below 10,000 feet, you need to adhere to the standard speed restriction of 250 knots. However, if you’re in Class B at 10,000′ MSL or higher, you can fly at a speed higher than 250 knots (although ATC usually restricts aircraft speed for traffic flow and separation purposes).
Most Class B airspace ends at 10,000′ MSL, so this isn’t a major factor most of the time. Nevertheless, some Class B airspaces extend higher, such as Denver’s Class B, which extends up to 12,000′ MSL.
But what happens if you’re beneath a Class B shelf and not actually within Class B airspace itself?
According to 91.117(c), “no person may operate an aircraft in the airspace underlying a Class B airspace area designated for an airport or in a VFR corridor designated through such a Class B airspace area, at an indicated airspeed of more than 200 knots (230 mph).“
This is done to help distinguish aircraft operating within Class B from those outside of it. Some aircraft flying below Class B may not be in contact with ATC, and the speed restriction of 200 knots gives ATC an additional buffer to clear the way in case of an airspace deviation.
Does an ATC Instruction Change the Regulation?
In the example given above, ATC issued speed instructions that exceeded the regulatory requirement of 91.117(c). As a result, many pilots have debated whether a cleared instruction makes the excess speed legal.
In 91.117(b), the speed restriction around Class C and D is prefaced with “unless otherwise authorized or required by ATC.” This phrase is not used in relation to speeds beneath the shelf of Class B airspace.
Based on this, the answer is “no”. You cannot fly at a speed higher than 200 knots beneath a Class B airspace shelf. Just like pilots, controllers can make mistakes, and this controller likely overlooked the regulation.
What Can You Do?
If this situation occurs to you, the most conservative course of action is to say “unable”. If asked why, remind ATC that you’re below Class B airspace and the speed limit is 200 knots.
Controllers aren’t out to catch you; they make mistakes too.
That being said, know the regulations well and always back yourself up by filing a NASA ASRS report if you make a mistake. And if you have questions about speed restrictions, you can always enhance your knowledge with our National Airspace online course.
Has anything similar ever happened to you? Share in the comments below.
