The activities of the C-160G in the region have been far less publicized, if at all. The French Air Force has historically been very tight-lipped about the operations of Gabriels, only two of which exist. Escadron électronique aéroporté 1/54 "Dunkerque," or Airborne Electronic Squadron 1/54 “Dunkirk,” operates the pair of aircraft from Évreux-Fauville Air Base in northern France.

Since September 2014, France, which was among the first to join the multi-national coalition fighting ISIS, has publicly deployed land-based Rafale and Mirage 2000 and carrier-based Rafale and now-retired Super Etendard combat jets, Breguet Atlantic 2 patrol aircraft, and E-3F Sentry Airborne Warning and Control Systems (AWACS) planes, to support the operation. Its special operations forces and artillery units have contributed to the mission on the ground, as well.

The task force quickly took down the post. The replacement Tweet featured the same message, but only had the picture of the Rafales.

“Air support from France is a major part of coalition Defeat Daesh efforts through Operation Roundup,” the social media post said, using the Arabic acronym for ISIS and the nickname of the new cross-border mission. “CJTF-OIR works by, with and through partner forces to achieve a lasting defeat of the terrorist organization’s remnants in Iraq and Syria.”

On May 17, 2018, the official Twitter account of Combined Joint Task Force-Operation Inherent Resolve, the top command in charge of operations against ISIS in Iraq and Syria, made a post lauding France’s contributions to the air war against the terrorists. The Tweet included a picture of French Rafale multi-role fighter jets and the C-160G .

A rare, official image of a secretive French C-160G Gabriel intelligence, surveillance, and reconnaissance aircraft supporting the ongoing U.S.-led campaign against ISIS has emerged online. The plane’s appearance comes as coalition forces on both sides of the Iraqi-Syrian border are in the midst of a new offensive to take the steam out of the terrorist group's recent resurgence .

Based on the twin-engine C-160 Transall transport plane, the Gabriel, which first entered service in 1989, is primarily known as a signals intelligence collector. Festooned with various bits and bumps, it is recognizable from its cargo-hauling cousin. One of the most immediately noticeable changes is an array of very-high, ultra-high, and standard high-frequency radio antenna on top of the fuselage. It also features a prominent in-flight refueling probe to enable long-duration missions. Pods on the wingtips contain the main components of the Thompson-CSF Analyseur Superhétérodyne Tactique, or ASTAC. This system can locate, classify, and analyze hostile emitters, such as radars. The system can reportedly monitor up to 20 items of interest at once and send the information to operators back at base for further exploitation. Thompson-CSF also supplied the Epicéa, or Spruce, communications intelligence suite that can spot and monitor enemy transmissions. The C-160G carries this system inside a retractable dome that extends downward from the bottom of the fuselage in flight. Two sponsons on each side the rear of the fuselage each contain a single Omera 51 panoramic camera, giving the aircraft a secondary capability to collect wide-angle visual imagery. The equipment also allows the crew to perform this mission while remaining at high altitude where it is better protected from threats on the ground and in a better position to perform its main signals intelligence mission.

French Air Force A picture of one of the C-160Gs in flight with the Epicéa system deployed.

Though seeing one of the C-160G in an operational setting might be rare, that at least one of the Gabriels are flying over Iraq or Syria makes good sense. Aerial intelligence gathering has been an essential part of the campaign against ISIS from the very beginning and continues to be a key part of efforts to finally break up the group for good. In a similar vein, the U.S. Air Force has committed its own RC-135V/W Rivet Joint signals intelligence platforms, as well as EC-130H Compass Call electronic warfare planes, to both monitor the terrorists’ activities and jam their ability to communicate with each other. The United States and other coalition members have deployed a host of other dedicated manned and unmanned intelligence, surveillance, and reconnaissance aircraft to gather a variety of other intelligence information, as well as employed combat jets carrying podded sensors on tactical reconnaissance missions. From a specific capability standpoint, the C-160G sensors are nowhere near as robust as those on the much larger Rivet Joints and do not have any of jamming capabilities found on the Compass Calls. The Gabriels fill a niche that is more analogous to the U.S. Navy's EP-3E Aeries II or one of the various de Havilland Canada Dash-8-based platforms the U.S. Army and special operations forces operate.

USAF A US Air Force RC-135V/W takes off from Al Udeid Air Base in Qatar for a mission against ISIS in 2016.

And though the picture of the C-160G that CJTF-OIR posted online was undated, that the aircraft is in theater now wouldn’t be surprising either. In April 2018, the coalition kicked off Operation Roundup, which notably included a boost in French forces into the region. The month before, French President Emmanuel Macron had also vowed to continue supporting the predominantly Kurdish Syrian Democratic Forces, or SDF, in their continued efforts against ISIS. Earlier in April 2018, France had also joined the United States and the United Kingdom in series of missile strikes against sites linked to Syrian dictator Bashar Al Assad’s chemical weapons program. “You'll see increased operations on the Iraqi side of the border, and the French just reinforced us in Syria with special forces here in the last two weeks,” U.S. Secretary of Defense James Mattis told American legislators during a hearing on April 26, 2018. “This is an ongoing fight right now.”

US Army SDF personnel in machinegun-armed pickup trucks stage on the Syrian side of the border during Operation Roundup.

Aircraft such as the Gabriels will be critical in supporting Operation Roundup. Though ISIS’ immediate dreams of a physical Islamic caliphate spanning across the region are over, the organization continues to present a significant threat. At the same time, now that it is no longer focused on holding territory, its members have returned to their terrorist roots and have dispersed in remote areas, from which they have continued to launch sporadic attacks. Persistent surveillance across these wide regions will be essential to pinning down the militants and limiting their ability to operate freely.

DOD A map showing ISIS-linked terrorist attacks in Iraq between January and March 2018.