Transcription
Greetings folks. My name is Rob Madoo for the AOPA CFI to CFI newsletter. What if I could show you an easy way for your students to memorize the VFR cloud clearance and visibility requirements for every type of airspace in which they fly? I suspect a few of the CFIs out there might have just yelled, "Get out!" Well, it's true. Take a look at this graphic.
In an oxygen-rich environment with two brain lobes that work reasonably well, how long would it take your students to memorize this graphic artifact? Perhaps 10 minutes, maybe 15 minutes. The short investment of time involved in memorizing this illustration allows your students to immediately identify the VFR visibility and cloud clearance requirement for every airspace classification in which they'll fly.
Now, my friend Captain Altimer is going to help me show you how it works. The B pyramid represents the Earth's surface, and because pyramids were built by people with diminishing goals, they taper to a point on the top. The pyramid's vertical dimension from the surface to the apex represents the altitudes flown by VFR pilots, which is up to, but not including, 18,000 ft MSL, which is the upper limit of Class E controlled airspace. And since VFR flying is not allowed above this altitude, this memory aid does not apply up there, so we shall no longer speak of it.
The larger pyramid contains a smaller inverted pyramid within itself. The smaller pyramid allows the larger pyramid to be divided into four separate sections. Each of the four triangular sections is marked with a letter representing one or more types of airspace. We'll refer to each of the four smaller triangular sections as the top, bottom left, bottom right, and middle inverted pyramid.
The top pyramid and its contents represent the VFR minimums for Class E or G airspace at and above 10,000 ft MSL, extending up to, but not including, 18,000 ft MSL. And other classes of airspace such as Class B don't usually extend above 10,000 ft MSL. The cloud within this triangle identifies a cloud clearance requirement of 1,000 ft above, 1 statute mile to the side, and 1,000 ft below. The number five is the required flight visibility in statute miles.
The middle pyramid represents Class B, C, D, and E airspace with one exception. The cloud bisected by the middle and bottom right pyramid represents the cloud clearance requirements for these two sections of airspace below 10,000 ft MSL and extending to the surface. You are required to remain 1,000 ft above, 2,000 ft to the side, and 500 ft below any cloud formation in the above-mentioned classes of airspace. The one exception is in Class B airspace where you are only required to remain clear of clouds, and we'll remember this as "B clear."
A small line bisects the numbers three and one located in the cloud. The number three on the left side of the bisecting line is the required flight visibility in Class B, C, D, and E airspace below 10,000 ft MSL.
The bottom right pyramid represents Class G or uncontrolled airspace from the surface up to, but not including, 10,000 ft MSL. A horizontal line, one-third up this triangle, identifies the altitude from the surface up to 1,200 ft above ground level. Now, from the surface up to 1,200 ft above ground level, you are required to have 1 mile visibility and remain clear of all clouds. More than 1,200 ft above ground level but less than 10,000 ft MSL, you are required to maintain 1,000 ft above, 2,000 ft to the side, and 500 ft below any cloud formation, and this is the same cloud clearance requirement found in the middle inverted pyramid. The number one located on the right side of the bisected cloud is the required flight visibility in this area.
And this leaves us with the bottom left pyramid. It represents Class G airspace from the surface up to, but not including, 10,000 ft MSL. The moon in this section represents nighttime. The arrow points directly to the middle pyramid. Symbolically, this tells us that in this section of Class G airspace at night, the VFR requirements are the same as they are in the middle pyramid. And by default, the bottom right triangle represents the day VFR requirements for Class G airspace.
So, here are a few additional tips for interpreting this memory aid. First, the lowest visibility and cloud clearance in which pilots can fly under visual flight rules is one mile while remaining clear of clouds, and not surprisingly, this represents the minimums for special VFR flights. Second, if Class B, C, D, or E airspace touches the surface surrounding an airport, an additional cloud clearance requirement must be met. You must have a 1,000 ft ceiling in addition to the required 3-mile visibility for basic VFR flight underneath that ceiling. Thank you, Captain.
So there you have it. Your students can now draw this graphic from memory during the knowledge exam or use it to maintain the big picture perspective about VFR minimum requirements for different types of airspace and altitudes. Use of memory aids in general aviation, especially this graphic shaped like a pyramid, is not too uncommon, or too uncommon at all. I hope your students find it useful.