A lack of European aerial refueling capability was one of several shortcomings afflicting the air arms participating in Operation Unified Protector in Libya in 2011.

The shortage meant that NATO was forced to call upon the U.S. Air Force's Boeing KC-135 and KC-10 tankers to ensure that the coalition operation was able to strike Gadaffi-loyalist forces across the vast desert state.

Now, more than two years after the engagement in Libya, work is underway to try to address at least part of the problem with a series of trials aimed at wresting the maximum performance from Europe's tanker platforms.

The first collective air-to-air refueling clearance trial, which took place this month, was a flight-test campaign with the goal of clearing potential receivers for the Continent's aerial refueling tankers. Organized by the European Defense Agency (EDA) and the Netherlands-based Movement Coordination Center Europe, countries have been invited to qualify their combat aircraft to refuel from the Italian air force's new Boeing KC-767 tanker. In the space of four sorties, flying in different areas of the flight envelope, air arms can clear their combat and support aircraft to refuel from the KC-767, leading to greater interoperability during coalition operations.

According to Laurent Donnet, project officer for the refueling trials, Europe's 42 tankers—comprising 12 different types of aircraft—lack up to 40% of the clearance required to refuel the many different types of European combat and support aircraft.

“For planning purposes alone, this means that during operations, more tankers are needed in the air because some aircraft are not cleared to refuel from certain tankers,” says Donnet.

Military officials suggest that Europe only has 50% of the tankers needed to meet refueling demands, but, Donnet says, “if all the tankers were cleared to refuel the different types, it would be possible to reduce the number of tankers needed in the air at one time, and we can make better use of the assets.”

During the trials—conducted in Sardinia Sept. 5-12—the KC-767 was able to refuel and qualify the French air force Dassault Mirage 2000 and Rafale fighters as well as the Swedish air force Saab JAS 39 Gripens. A French air force Boeing E-3F Sentry airborne early warning aircraft had been scheduled to participate in the trial, but was needed elsewhere. The clearance work conducted will also flow down to the other European operators of the Gripen, the Czech Republic and Hungary. France had already been granted wartime operational clearances for its Rafale and Mirage aircraft at the beginning of 2013, when the KC-767 supported French operations in Mali, but the new trials mean the aircraft can be refueled throughout the flight envelope. Italy has already cleared the Eurofighter Typhoon and Panavia Tornado aircraft to refuel from the KC-767.

Donnet is now working on another series of trials, expected to take place early in 2014 using the KC-767, and says the U.K. Royal Air Force is interested in providing one of its new Airbus A330-200 multirole tanker transport (MRTT) Voyager aircraft to build that type's refueling capability. The U.K. Defense Ministry is known to be exploring opportunities to share flight hours of the nine-aircraft core Voyager fleet.

“This is a more cost-effective approach. By doing the trials at the same time, we can maximize the number of test flights in one sortie, it is just dependant on the availability of the aircraft and the test pilots,” explains Donnet.

The EDA trials address one of the four key areas through which it hopes member countries will be able to boost capacity and capability of their tankers fleets. Other areas of study include improving access to commercially available refueling capability—such as that provided by Omega or even the U.K.'s AirTanker consortium—and encouraging European customers of the Airbus Military A400M to fit a refueling capability to that transport aircraft.

Another area of discussion is the possible creation of a European tanker operation similar in design to NATO's E-3 aerial warning and control system component and the Hungary-based Heavy Airlift Wing. Defense ministers from Belgium, France, Greece, Hungary, Luxembourg, the Netherlands, Norway, Poland, Portugal and Spain, signed a letter of intent to cooperate on such a program at the end of 2012 and EDA hopes to have a memorandum of understanding signed at the end of 2014 that allows for the possible procurement of tankers in conjunction with Occar, the European armament cooperation agency for initial operations, in 2020, and a full operational capability in 2021. No platform has been chosen, although the EDA is looking at both the A330 MRTT and the KC-46 or KC-767.

A major hurdle, however, will be overcoming the various certification demands set by different countries within Europe. The creation of a single European certification for refueling clearances would, Donnet says, be “challenging” because there is no starting place within European Aviation Safety Agency guidelines from which to draw up guidance.