As a pilot, having a clear understanding of Special Use Airspace (SUA) is critical to safety, no matter what area of the country you fly. Add in the booming commercial space market, and you have yet another reason to ensure you’re not in the wrong place at the wrong time, especially when flying in unfamiliar territory. To help, here’s a quick review of SUA in the USA.
The first and most restrictive form of SUA is the prohibited area. As the name suggests, this is the airspace where all flight is prohibited within its boundaries, from the surface to the prescribed altitude. Prohibited areas are usually associated with national security, do not have an effective time, and can be surrounded by temporary flight restrictions (TFRs). Luckily, these most restrictive airspace areas are relatively rare. That said, the serious nature of any encounter with their boundaries provides a strong incentive to note and avoid them by a safe margin. You’ll find prohibited areas indicated on charts with a “P” and a two or three-digit number. For example, P-40 — the designated area surrounding the presidential retreat at Camp David, Md. — is marked as a cyan box, circle, or another shape.
Unlike prohibited areas, restricted areas constrain, but do not completely outlaw, operations within the boundaries. A restricted area may not go all the way down to the surface, while prohibited areas protect something on the surface.
A key difference is that restricted areas, in many cases, are more about airspace. Also, restricted areas are only restricted when they are “active,” meaning that a pilot may pass through this airspace outside of that “active” window.
Restricted areas are more common than their prohibited cousins. They are labeled on the charts with an “R” and a number, usually three or four digits, and possibly a letter. An example would include R-2517 around Vandenberg Space Force Base, home to extensive space flight operations with eight launch complexes (both vertical and horizontal).
The best way to ensure that you are transiting during the inactive time is to contact the controlling ATC facility or operate on an IFR flight plan.
The twin to a restricted area is a warning area. While the two are nearly identical in depiction and description, a warning area differs because it extends beyond three nautical miles off the coast, where the U.S. does not have sole jurisdiction. Since the FAA can’t technically restrict airspace outside the country, the agency has established warning areas to identify airspace that pilots should avoid without contacting the controlling ATC facility.
Warning areas also differ from restricted areas in that pilots are not banned from the airspace under threat of enforcement action but rather warned that the activities within could be hazardous to non-participating aircraft. Both warning and restricted areas are depicted on the charts as cyan boxes.
Military Operations Areas
Next are Military Operations Areas (MOA). These are areas where the military can practice activities that may require more space than the restricted area will allow. However, MOAs differ from restricted areas because IFR pilots may be cleared through an active MOA if ATC can provide separation. Also, a MOA is not technically restricted, meaning that VFR pilots may enter a MOA even if it is active. Similar to how a Flight Service briefer will tell you VFR is “not recommended” during bad weather, entering an active MOA is likewise “not recommended.” MOAs usually have a name (e.g., Bull Dog or Avon Park) and are depicted on charts as magenta boxes.
Another type of area that should concern pilots is the alert area. These are areas of increased flight training or other unusual aeronautical activity. Alert areas are designed to keep transient traffic away from pilots doing air work or other operations that might not fit neatly with through traffic.
Alert areas don’t have a controlling ATC facility, so you don’t have to ask permission to enter or transit the alert area. It’s only charted so that you can be aware of it and not be surprised by the airplane that could be maneuvering unpredictably. Florida has several alert areas due to the close proximity of many flight schools. Alert areas are depicted on charts with magenta hash marks and an “A” followed by numbers and possibly a letter.
Controlled Firing Areas
As defined by the Aeronautical Information Manual, controlled firing areas (CFA) contain activities that, if not conducted in a controlled environment, could be hazardous to non-participating aircraft. CFAs are usually set up for ordnance disposal or static testing of large rocket motors.
The difference between CFAs and other special-use airspace is that activities must be suspended when a spotter aircraft, radar, or ground lookout position indicates an aircraft might be approaching the area. Another interesting fact is that CFAs are not charted since they do not cause a non-participating aircraft to change its flight path.
National Security Areas
Unlike the mandatory nature of prohibited or restricted areas, a National Security Area shows airspace that pilots are requested to avoid. National Security Areas could include military installations or a nuclear plant. In other words, it would not require designation as a prohibited area, but it’s an area that the FAA or other agencies would prefer pilots avoid. They are depicted by dashed heavy magenta lines and a text box with an explanation. A word of caution: these areas may be subject to a TFR issued by a Notice to Air Mission (NOTAM).
Other Airspace Areas
There are still other airspace areas that are of importance to pilots. These include parachute jump operations, a special flight rules area (SFRA), and a TFR, to name a few. See the airspace chapter in the FAA’s Pilot’s Handbook of Aeronautical Knowledge for more details.
Aircraft Hazard Areas
We want to highlight one relatively new term you may want to learn more about — the aircraft hazard area (AHA). An AHA is a term used by ATC to segregate air traffic from a space launch or reentry vehicle and any debris this activity might generate.
AHAs are designated via NOTAMs and may include a combination of different special-use airspaces to protect any transiting aircraft — TFRs, restricted areas, warning areas, and what’s known as an altitude reservation (ALTRV) to protect airspace users from any operational anomalies and falling debris.
For GA pilots, the accompanying TFRs and restricted areas are what you’ll most likely see graphically depicted on a flight planning chart before a launch. You can find out more about AHAs and the FAA’s efforts toward minimizing their impact on the aviation community in this issue’s feature article, “Let’s Give ’Em Some Space.”
A Few Final Tips
Please be aware that some of these special-use airspace types can overlap. For instance, you could encounter a restricted area sitting on top of a prohibited area. Just because you flew over the prohibited area doesn’t mean you’re free and clear. You may also see restricted areas and MOAs that overlap or abut.
The bottom line — there are three basic strategies you can use to avoid an unpleasant run-in with a SUA:
- Learn what types of SUA you may encounter in your route of flight and the requirements of each one.
- Get a good briefing to know what’s active and what’s not.
- Stay in contact with ATC when possible. That could mean filing IFR or requesting flight following to help you avoid any last-minute SUA and TFR issues.
Source: By Tom Hoffman and James Williams, FAA Safety Briefing Magazine