Special Use Airspaces In The USA

There’s a saying, or at least there should be, in American aviation, and it goes something like this: “Just one F-16 streaking at Mach speed 500 feet over your head can ruin your day.” It was for this very reason that my buddy Kees and I were somewhat alarmed last autumn when we were informed by ATC that the MOA we were about to enter was active down to 10,000 feet. At the time, we were level at 9,500.

Heck, even if I didn’t know what an MOA was, I’d have requested a lower altitude – say, 5000 feet lower. Given the American penchant for acronyms, for all one knows MOA could stand for “Mushed on Arrival”. But of course, MOA stands for Military Operations Area, and as one would suspect, the United States is particularly chock full of active MOAs, apparently allowing US armed forces to practice dropping large bombs into small pickle barrels from unusual attitudes and at high speed.

One must also take special note of the differences between all the so called Special Use Airspaces, or SUAs: MOAs, Warning Areas, Restricted Areas, Prohibited Areas, and the ever-so homey-sounding Controlled Firing Area. All of these SUAs are covered under Part 73 of the Federal Aviation Regulations (FAR).


According to the latest Aeronautical Information Manual (AIM), an MOA is “…airspace established outside of Class A Airspace area to separate or segregate certain nonhazardous military activities from IFR traffic and to identify for VFR traffic where these activities are conducted.”

Remember that activities that are “nonhazardous” from the military’s point of view (they refer to planes not dropping bombs or firing missiles, but rather merely performing aerobatic or abrupt maneuvers at alarmingly high rates of speed) are rather more hazardous than the conditions to which your typical VFR pilot is accustomed.

But this does not mean that you cannot fly in an MOA – you can, but you’d be a fool not to check on the latest information about activity within it. Fortunately, MOAs are indicated on Sectional, VFR Terminal Area, and Enroute Low Altitude Charts (see Box), and when you’re within 100 miles of one, any pilot can get the skinny on activity by contacting the local Flight Service Station (tune your radio to 122.0).

FSS will give you information about activities, or scheduled activities in the MOA in question. Even if the MOA is active, you still may be perfectly capable of flying through – FSS will have information on the “operations floor” of the activity, and let you know, for example, that it’s safe to enter at the time you call as long as you stay below a certain altitude. Heed this advice.

Even if you have contacted FSS, you are also expected to contact the MOA’s controlling authority before you enter an active MOA.

Warning Areas
Warning Areas, denoted by a dark blue hatched line, and noted with the letter ‘W”, denote areas along the three nautical mile limit around the US coastline – areas in which US armed forces or NASA may be conducting operations that could have infelicitous effects on one’s GA aircraft.

For the Mother Lode of Warning Areas, take a gander at the Jacksonville, VFR Florida sectional, whose entire coastline is one long blue hatched area from north to south, with individual Warning Areas within the larger, Warning Mother Ship. This is because Florida’s coast is particularly important the US, for air force, naval and NASA activities (see the box).

You may fly into a Warning Area that is not active; see the box for information.

Restricted Areas
These are essentially Warning Areas on the ground as opposed to in international waters, and similarly marked with a number referencing the SUA legend (see box). The threats within a Restricted Area include gunfire, aerial gunfire or missile and (ahem) guided missile launches, any of which could crimp your style. As with Warning Areas, you may fly through Restricted Areas when they are not active. Be certain!

Prohibited Areas
The USA only has a few “No Fly Zones”, currently established in Washington, D.C.; Kennebunkport, Maine; Waco, TX, Thurmont, Maryland; Amarillo, Texas; and Mount Vernon, Virginia. These too are marked by dark blue hatched lines, and the word Prohibited, with a number beginning with P. (See box) According to the FAR, “No person may operate an aircraft within a prohibited area unless authorization has been granted by the using agency.” FAR Section 73.85 defines the “Using agency” as “…the agency, organization or military command that established the requirements for the prohibited area.” FAR Sections 73.87 through 73.99 define designated prohibited areas.

Note too, that Prohibited Areas change from time to time.

Controlled Firing Areas
The best part of Controlled Firing Areas isn’t what they are – areas in which military types are firing all sorts of cool stuff all over the place – but rather what they are not: a threat to you. Under the terms of this SUA, and what makes it different from all other SUAs, any aircraft spotted – either by a plane spotter or radar – means that all activities within the CFA is immediately halted. So insignificant to pilots is the CFA that they are not even listed on charts – we just thought you’d like to know about them!

Having all this information in the recesses of your mind is fine and good, but put it to use to avoid inadvertently violating an SUA. Before getting your standard Weather Briefing (see related article), study the sectional chart of your intended route, and ask the briefer specifically about any SUAs you might approach to see if they are active. Check the NOTAM’s (Notices to Airmen) – your briefer should do it as part of the standard briefing, but if he or she doesn’t, make sure you ask.

One other phenomenon in the states are TFRs – Temporary Flight Restrictions. These are temporary designations of an area as restricted or, more likely, prohibited, sue to any number of reasons. It could be because of flooding or other natural disaster. A TFR is put in place when a plane crash – such as EgyptAir or the John F Kennedy accident – results in heavy recovery activity. They’re slapped on any area in which heavy small plane and helicopter activity is occurring, such as the American football Super Bowl. And TFRs are put in place whenever the President of the United States pops down to the corner store – wherever the convoy is, there’s a TFR. TFRs are covered in FAR part 91.137.