In general, the airspace over a particular country is controlled by that country. It is that country’s aviation regulatory body, such as the FAA in the United States or the CAA in Britain, and the air-traffic control organizations that determine where, when and how aircraft are allowed to fly. On top of the local regulations, pilots and airlines are required to follow the directives of the country in which they are registered. For instance, a British Airways flight flying over the United States would be bound by the rules of both the FAA and the CAA. Plus, each airline may set more restrictive rules on their own operations.
Because of this, a lot of confusion has arisen as to whether specific airlines from specific countries were prohibited from flying over the disputed areas of eastern Ukraine.
Airspace restrictions are generally set up for two reasons: to ensure the safety of aircraft and their occupants and to ensure the safety of people on the ground. In the case of some restricted military airspace, this may be because of training flights or weapons testing.
Restrictions may also exist because the country is trying to protect an asset inside the restricted airspace. A good example of this is the prohibited flight zones in and around Washington, where flights below 18,000 feet are generally prohibited without prior authorization. These were created to reduce the risk that someone would use aircraft to damage or destroy portions of the U.S. government. While the restrictions existed before the Sept. 11, 2001 attacks, they were revised in response. The same is true of the airspace restrictions over Disneyland in California and Walt Disney World in Florida.
Other restrictions will arise from disruptions to normal aviation services. For instance, if the air-traffic control radar at an airport fails, certain types of flights may be prohibited.
The specific details of each flight restriction are published as a Notice to Airmen.
These documents tell pilots the location, applicable times and specific limits for each area of restricted airspace. Many of them will also give the reason for the restriction and the consequences that may arise from a violation. For instance, violating the restrictions around airspace over Washington may carry civil and criminal sanctions. If the U.S. government perceives that the aircraft is an “imminent security threat,” deadly force may be used. Plus, permanent restrictions will be indicated on air navigation charts:
Much has been written about the fact the FAA, the CAA and Eurocontrol had issued a series of NOTAMS to their respective pilots, airlines and air traffic control organizations about the risks of operating over Eastern Ukraine. Some articles have even insinuated that the region through which MH17 was flying was off limits to U.S. airlines because of the risk of being shot down amid the ongoing conflict between the Ukraine government and separatist militias.
But a careful read of the NOTAMs issued by Ukraine, Eurocontrol, the CAA and the FAA tell a different story — and this is what Malaysia Airlines is pointing to in its defense of its actions.
In all cases, flights on the air-traffic routes were permitted so long as the aircraft was operating above 32,000ft. MH17 was flying at 33,000 feet when it was shot down.
The reasons for closing the routes below this are not stated in the NOTAMs. But it is reasonable to believe that the restrictions were in place because of military operations in the area and the consequent risk to commercial traffic. Plus, the neighboring airspace roughly above Crimea is totally restricted. This is because both Ukraine and Russia are attempting to provide air-traffic control services in the region, greatly increasing the risk of a mid-air collision — not because of the risk of missiles.
While it is difficult to determine whether Malaysia Airlines improperly assessed the risk associated with flying over the disputed areas of eastern Ukraine, there was certainly no consensus that commercial flights on established air-traffic routes, flying above 32,000ft in the region, were at risk.
Yes, several authorities recommended caution in planning flights in this region and for frequent checks of new and revised airspace restrictions. But, at the time of the crash, there were no restrictions in place for any commercial flights above 32,000ft in the area where MH17 crashed.
Only now, after this terrible incident, has a NOTAM been issued, closing off all altitudes to U.S.-based carriers. And, many airlines are being more cautious than is currently required of them, with most circumventing Ukraine entirely.