Operation Deny Flight - Enforcement of No-fly Zone

Enforcement of No-fly Zone

After its adoption, Operation Deny Flight was relatively successful in preventing fixed-wing aircraft from flying over restricted air space in Bosnia. During the monitoring phase of Operation Sky Monitor, unauthorized fixed-wing flights averaged twenty per month, but during Deny Flight, the average was three. During the conflict, there were only an estimated 32 fixed-wing military aircraft in Bosnia, all of them former Yugoslav National Army planes under the control of the Bosnian Serbs. Thus, NATO primarily needed to prevent incursions into Bosnian airspace from Croatia and Serbia.

The first serious violation to the no-fly zone came on 28 February 1994, when six Serb J-21 Jastreb jets bombed a Bosnian factory. US Air Force F-16s shot down four of the six Serb jets over Banja Luka. This engagement was the first combat engagement of Operation Deny Flight, and its only significant air to air combat engagement. Perhaps more importantly, the Banja Luka incident was also the first combat engagement in the history of NATO. The Serbs acknowledged the loss of a fifth aircraft in the incident.

While Deny Flight was relatively successful in stopping flights of fixed-wing aircraft, NATO forces found it very difficult to stop helicopter flights, which presented a more complicated challenge. All sides in the conflict used helicopters extensively for non-military purposes, and some of these flights were authorized by the UN. Under the operation's rules of engagement, NATO fighters were only authorized to shoot down helicopters that committed a hostile act. Otherwise, NATO fighters issued orders to "land or exit", in other words, land the aircraft or leave the no-fly zone. Typically, helicopters in Bosnian airspace complied with these orders by landing, but then took off again after NATO forces departed. None of the parties in the conflict respected the ban on helicopter flights, as evidenced when Ratko Mladić responded to a BBC journalist's question about his violation of the ban with the statement, "The commander of the Bosnian Serb armed forces does not ride on a donkey."

Deceptive markings on helicopters further complicated matters for NATO pilots. Many of the combatants painted their helicopters to look like those of organizations that the UN's Zagreb Flight Coordination Center had authorized to fly in restricted space. For example, the army of the Republika Srpska often painted a Red Cross logo on their helicopters, and Croatian helicopters were given markings similar to those of UN humanitarian aid helicopters. The questionable identity of these helicopters became particularly problematic after the Black Hawk Incident in Iraq, because NATO pilots became more reluctant to engage potential belligerents without clear identification. As a result of the rules of engagement and difficulties in aircraft identification, NATO forces proved unable to stop most unauthorized helicopter flights, resulting in a documented total of 5711 unauthorized flights during the conflict.