Checkride

Given the complexity of our national airspace system, sometimes referred to as “alphabet airspace” because of the letter designations assigned to each type, it isn’t surprising that many pilot applicants struggle with this challenging topic during their practical test.

Perhaps the difficulty lies not so much with the complexity of the subject matter as much as how we attempt to learn the material. Faced with a seemingly endless list of numbers, details, and facts, it might be tempting to just rote-memorize them to get past the checkride. Bad idea! A better plan would be to understand why each of the various airspace rules applies, enabling better understanding and longer retention.

The national airspace system is mainly designed to separate aircraft, but it also protects pilots from themselves. Take Class G, for example. Air traffic control does not take place in Class G operations, so it protects VFR pilots from themselves by including more restrictive rules for night operations. For VFR, adequate outside visual references must be maintained to safely operate. During daylight hours, it’s just one mile of visibility and clear of clouds—much tougher to do safely at night, hence the higher night minimums.

Understanding that the boundary between Class G and the overlying “controlled” Class E airspace is lower at airports with instrument approach procedures explains why higher visibility and cloud clearance for VFR pilots above 700 feet, day or night, helps protect transitioning IFR pilots from local VFR traffic.

As an airport’s traffic volume increases, other airspace options are added to ensure safe separation. The first one lowers the Class E airspace to the surface. This requires better visibility and cloud clearance down to the runway, protecting IFR operations while still providing VFR pilots the option to operate in less-than-required Class E weather by obtaining a Special VFR clearance. The night restriction for Special VFR requiring the pilot and aircraft to be IFR qualified and equipped is another way these rules protect pilots.

At busier airports, the next step adds a control tower, creating Class D airspace. With a control tower, the new requirement becomes communication, without which there is no direct ATC control. But even without two-way radio communications, the tower still has access to light-gun signals to enable limited communications. Since this airspace is “controlled,” the same VFR visibility and cloud clearance requirements of Class E apply. And since the controlled airspace drops all the way to the runway, as with all airports having surface-controlled airspace (except many of the busiest Class B airports—NO SVFR), the rules associated with Special VFR operations also apply whenever the airport becomes IFR: ceilings below 1,000 feet and/or visibility below three statute miles.

Adding a Terminal Radar Service Area (TRSA) brings radar service to the safety equation. These are almost identical, operationally, to Class C airports, but without the requirement to participate. Communication is again the primary requirement with the addition of a Mode C (altitude-reporting) transponder within and above Class C airspace. Even with the added protections of radar service, ATC does not guarantee separation between VFR and other traffic. It’s still see and avoid.

At the nation’s busiest airports, Class B services provide separation between all aircraft. This is the only controlled airspace in which basic VFR rules permit “clear of clouds” operations for VFR aircraft, since ATC provides sequencing and separation between all aircraft in Class B airspace. Communications, Mode C transponders (within the Mode C veil), and real-time ATC clearances are required.

At 10,000 feet above sea level and higher—because the 250-knot speed limit is no longer applicable—Mode C transponder, even better visibility, and greater cloud clearance are essential to adequately see and avoid fast-moving jet traffic while VFR. Upon reaching 18,000 feet mean sea level (FL180), forget about VFR: Everybody must be IFR-controlled by ATC in Class A. See? Easy as A-B-C.