Photo: PlaneView cockpit Class B screen with aircraft position displayed, from Eddie's cockpit.

Eddie Sez:

You can get violated for exceeding 200 knots below the lateral limits of Class B airspace and the worst part of that is you can be encouraged to do that by the guy on the other side of the microphone right up until the time that guy violates you. It isn't that the SOB on that side of the radio is out to get you, as much as it may seem. Air traffic control is trying to cram a lot of airplanes in that airspace you are using and they may actually want you flying faster than you should. The problem arises when your speed gets in someone else's way and a computerized program at the FAA flags you. You need to know where that airspace is.

What follows comes from the references shown below. Where I think it helpful, I've added my own comments in blue.

You Aren't Being Paranoid, (they really are out to get you)

What follows comes from The FAA / Absolute Authority, which also appeared in an article I wrote for Business & Commercial Aviation Magazine, September 2015, "Absolute Discretion."

Figure: TECKY ONE Paranoid Trap, from Eddie's notes, taking KSJC TECKY ONE Departure (FAA SW-2, 28 May 2015 to 25 Jun 2015) ground track and altitude restrictions and using KSFO Class B Airspace Restriction overlay.

You may have heard of 14 CFR 91.117(c) and you may even know what it says:

[14 CFR 91, §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).

But how often do you consciously plan for it? The controller also knows the rule but may not care until the day the sky is crowded with smaller aircraft that are having trouble spotting you in time to avoid a collision. You can be sure that on a day that it does matter the controller’s opinion will carry more weight than yours. Consider the San Jose TECKY ONE departure published on January 8, 2015.

If you simply pull up the departure procedure, read the narrative, and mentally fly the solid black line, you can be forgiven for thinking you can accelerate to 230 knots right after takeoff. The first waypoints departing Runway 30 left or right have two restrictions: you must be at least 900 feet in altitude and you cannot be faster than 230 knots. Since we are normally keyed to remaining below 250 knots when below 10,000 feet, we tell ourselves our new target speed is 230 knots until passing STCLR or MLPTS.

Figure: TECKY ONE displayed on G450 FMS, from Eddie's aircraft.

The flight management systems on many airplanes will dutifully accelerate to that speed, Class B overhead or not.

NORCAL Departure Control would be fully within their rights to point out that you are flying below the San Francisco Class B airspace and your speed cannot exceed 200 knots under 14 CFR 91.117(c). The fact the Class B is not mentioned or depicted on the departure procedure is no excuse. There have been violations issued and NORCAL has been called several times on the discrepancy:

[NBAA Airmail, February 3, 2015] Pilots are reminded that the aircraft is below the Class B airspace in the turn and then just prior to SPTNS. Several pilots have had Pilot Deviations filed against them for exceeding the 200 KIAS limit below the Class B.

An even more insidious source of Class B high-speed trouble happens on arrival, when approach control is trying to sequence aircraft for approaches. “Fly 210 till the marker,” is a clearance to fly a specific speed but it is not clearance to violate an FAR.

So how do you protect yourself from the unknown Class B area that may be lurking over your head? If your departure or destination lies underneath a Class B area you should print the chart or have it readily accessible in the cockpit. If you can overlay the chart on your avionics you should. You should also add Class B considerations to departure procedure and approach briefings.

List of Class B Airspace, United States

What follows is a list that is current as of this writing, but be advised the list is growing. There is an incomplete list in the Aeronautical Information Manual. The real list is in FAA JO 7400.9X Airspace Designation, which you can download below. You can also look on current sectional charts.

PlaneView Trick

Note to PlaneView users: you can pull up the Class B chart for an airport and have your aircraft position displayed if the chart is compliant and you are within its dimensions. The secret is you need to pull up the chart from the Class B airport's file. For example, in the screen shot shown at the top of this page, the airplane was headed to KBED but the Class B in question is for Boston, so the Charts page was selected from KBOS under the "Airspace" tab. Here is a description of the steps, first the conventional method, then the new and improved way to do this.

Figure: Looking for Class B on the PlaneView DU, from Eddie's aircraft.

We are in the chocks here, not yet started. But the point is we are looking at an approach plate on DU 3 and we can see our aircraft symbol placed in relation to the chart. Any chart with the airplane symbol on the top right (just below the word "chart") is drawn to scale and lets us view our airplane in its real time position.

This is Bedford (KBED) which is just outside of Boston, Massachusetts. We know KBOS is in Class B airspace. But what does that mean to us when flying to KBED?

Figure: Looking for Class B on the PlaneView DU, from Eddie's aircraft.

The "Book Answer" is to go to the map display . . .

Figure: Looking for Class B on the PlaneView DU, from Eddie's aircraft.

Under "Map Data" we select "Term Airspace" . . .

Figure: Looking for Class B on the PlaneView DU, from Eddie's aircraft.

And viola! There are the lateral rings of the Boston Class B, as well as the Class D of various airports in the area. This is the way we are taught to use this display but there is a problem. Which of those rings are the Class B? What are the altitudes associated with each ring? This is better than nothing, but we can do better.

Figure: Looking for Class B on the PlaneView DU, from Eddie's aircraft.

Go back to the chart display and under the top-left menu select "Search Arpt" . . .

Figure: Looking for Class B on the PlaneView DU, from Eddie's aircraft.

Type in KBOS and select it.

Figure: Looking for Class B on the PlaneView DU, from Eddie's aircraft.

Select the "Airspace" tab and there you have it: the airplane symbol relative to the Class B Airspace chart you are used to seeing. The altitudes are there too. I usually have this page up while being vectored for the approach.

Don't kick yourself for not knowing this. (It took me several years to discover.)


FAA JO 7400.9X Airspace Designation, U.S. Department of Transportation, August 7, 2013