Royal Air Force commanders are facing what they call a cliff in terms of intelligence-gathering capability when operations in Afghanistan come to an end.

Of the five intelligence, surveillance and reconnaissance (ISR) aircraft types which will be in service by the end of the year, including the RC-135W Rivet Joint, three—Sentinel, MQ-9 Reaper and Shadow R1—are officially slated to be retired after 2015, leaving just the Boeing E-3D Sentry and Rivet Joint in operation. Commanders are keen to keep all three of the capabilities they are due to lose, each system more than proving its worth in the skies over Afghanistan, while the Raytheon Sentinel airborne stand-off radar (Astor) system is viewed as a useful capability in the eyes of the U.K.'s European partners, too.

Despite being heavily tasked in support of operations in Afghanistan, the RAF was able to send a single Sentinel to support the French Serval mission in Mali. By the time the aircraft had returned from its forward operating base in Dakar, Senegal, on May 25 at the end of what was called Operation Newcombe, aircraft and crews had racked up 697 flight hours during 66 sorties. The missions covered every corner of the vast Saharan nation, using the array of radar modes to deliver intelligence data to senior commanders on the ground and to cue-in other airborne ISR assets.

Within days of the Sentinel arriving in-theater in January, the aircraft was conducting sweeps of the country using its synthetic aperture radar (SAR) to produce swathes of map data on the areas around Mali's key urban areas including Timbuktu, Gao, Tessalit, Kidal and the Niger River delta region.

“In the early part of the operation, the focus was on using SAR to look at the airfields to see whether they could support C-130 [Hercules] or C-160 [Transalls] transports,” said Maj. Seymour Bailey, an army officer assigned to 5 Sqdn.”Some of these areas had not been mapped since 2010, and crews wanted to know who was in control of those airfields before they went in there.”

The detailed SAR imagery allowed image analysts to check out potential insurgent bases in the desert sands and, by combining SAR and ground-moving-target-indicator (GMTI) data, the analysts were able to examine “patterns of life” from these locations and identify any potential targets by cueing on aircraft equipped with full-motion video capability, such as French Air Force Harfang UAVs, Navy Dassault Atlantique IIs retrofitted for overland operations and one Cessna aircraft bought in on contract to support the operation. SAR and GMTI data were also being collected by a U.S. Air Force E-8 Joint Stars aircraft that was also aiding in the operation.

In the early part of the campaign, Sentinel crews found themselves slightly behind the curve; the aircraft would become airborne and proceed on a task, but would have to be retasked inflight because of the speed of the French advance across the country. Eventually, it was determined that coverage of some areas was no longer needed. “Initially, the French could not get their head around how long it takes to plan a mission,” said one officer, “but this was quickly resolved.”

Sentinel mission staff devote many hours to pre-flight planning. The GMTI data allowed the French to target the Al-Qaeda-backed Movement for Oneness and Jihad in West Africa (Mujao) insurgents who traversed the desert in small vehicles. When the insurgents realized that using these vehicles made them an obvious target, they began mingling with the local population and began attacking French and African forces using various insurgent tactics.

Sentinel GMTI was also used to track movements of the insurgents between the Algerian and Malian borders as well as at key crossing points along the Niger River delta. Foliage in the delta region proved to be a challenge, but crews were able to spot a number of crossing points being used by Mujao fighters who had shifted their movements to the center of the country, particularly as they were dispersed following major French pushes deep into the Sahel region.

The Sentinel is officially due to end its service career when operations wtih Afghanistan end, but that decision—made in the 2010 Strategic Defense and Security Review (SDSR—is being reexamined by defense ministry officials. At this point, the aircraft could well be offered to form part of NATO's Alliance Ground Surveillance system, according to Air Marshal Stephen Dalton, speaking in London last month.

In addition, RAF officers point out that since the wording in the SDSR says the Sentinel will be withdrawn “once it is no longer required to support operations in Afghanistan,” politicians should take into consideration that there may well be a need to support Afghan forces with ISR capability after U.K. combat troops have left.

There is no sign of training or operations tapering off in the near future. Raytheon U.K.'s Astor facility has trained 1,000 army, navy and air force students since 2005.