Airspace questions continue to be a sticky point on checkrides. Here are some lesser-known airspace areas you should be familiar with. And when you're done reviewing these 5 areas, sign up for our National Airspace online course to make sure you're checkride-ready when it comes to airspace.

1) TRSAs

Terminal Radar Service Areas, or TRSAs, are busy class D airports, that aren't busy enough to receive class C or B status.

TRSAs provide pilots the option to receive radar services not normally found at Class D airports. However, pilots aren't required to use radar services. TRSAs don't change the airspace you are flying in, only the availability of certain ATC radar services.

Class D tower operators will encourage you to utilize TRSA radar services, though, because it increases communication and safety.

2) Military Training Routes

Military training routes (MTRs) consist of two types: instrument routes (IR), and visual routes (VR). Military training routes are pre-published, low-level tactical flight plans utilized by military aircraft. But why does this matter to you?

Being able to correctly identify MTRs allows you to stay clear of fast-moving military aircraft, reducing your chance of a mid-air collision.

On VFR charts, MTRs are thin grey lines (they are NOT depicted on IFR charts). The altitude where MTR operations occur is found in the numbers that come after the VR or IR acronym. Four digits indicate that planes will be at or below 1,500 feet AGL, while three digits indicate that there are portions of the route that are flown higher than 1,500 feet AGL.

3) Class E Floors

Unless you've flown in Alaska or a remote part of the western US recently, it's unlikely you've encountered class G airspace that extends above the standard 700' or 1200' AGL. In some remote regions, class G airspace extends up several thousand feet.

Class E airspace with a floor that start at a designated (non-standard) altitude is identified with a blue scalloped line with large bold altitudes written alongside it. These numbers indicate the altitude where the floor of class E airspace begins.

4) Special Air Traffic Rules Areas

Sometimes airport airspace rules go beyond the standard Class G, E, D, C, and B.

Part 93 breaks down these sections of complex airspace. For example, FAR 93.161, 93.162, and 93.163 explain Pearson Field's airspace rules. Pearson field (KVUO) sits just northwest of Portland International (KPDX), underneath the shelf of the KPDX Class C airspace, and less than 3 miles from the departure end of runway 28R. The FAR describes the airspace area, as well as the procedure for getting into and out of KVUO.

5) NOAA Regulated National Marine Sanctuary Designated Areas

Located near the United States' major bodies of water, these areas are regulated in order to preserve wildlife populations in sensitive regions. Outlined under 15 CFR 922, you should remain clear of these wildlife preserves. How high do you need to be to stay clear? It's marked on the chart, as well as described in the FARs.

On the chart, you'll see a text box with instructions and altitudes to stay clear of. The sanctuary area is marked with a solid red line and red polka dots. For more information about specific NOAA Preserves click here.

Want to learn more about special use airspace before your checkride? Sign up for our National Airspace System online course and become an airspace pro today.