French Air Force enters the AESA Era

The evaluation team at the CEAM test centre has been developing the concept of operations for Rafale’s new AESA radar. The team leader gives us an update.

On 24th October 2012, a new type of Rafale took to the skies from the runway at Mont-de-Marsan (BA 118) Air Base, home of the French Air Force’s CEAM test centre. From the outside, there was virtually nothing to distinguish it from the dozens of Rafales that had already visited the base. However, hidden inside the radome was the promise of an air combat revolution: the RBE2-AESA, the first European active electronically scanned array radar to be installed on a combat aircraft.

“Altogether, we have already performed about 60 flights with the new radar,” Lieutenant-Colonel Laurent Royer, Head of the Rafale evaluation team at the CEAM, explained last summer. A total of 90 flights are planned under the experimentation programme with a view to handing over an initial batch of four aircraft to 1/7 fighter squadron “Provence” in Saint-Dizier early in 2014, along with an initial concept of operations to take best advantage of this new capacity, particularly in air-to-air combat.

“The trap we must avoid is that of simply transposing our current tactics without taking account of the vast potential of this new antenna,” explains Royer. That potential has several dimensions. First, radar coverage: with range increased by 50% and an ability to scan up to 70° on either side of the aircraft axis, the volume scanned by the RBE2-AESA is much larger than that of the RBE2-PESA (see below). According to Royer, the number of tracks that can be detected simultaneously is increased almost by a factor of three.

For the pilot, this extra information could have reached saturation level, but apparently this is not the case: “We wondered whether we would need to rethink how the information is processed for the crew, but the existing interface easily aborbs the extra load.” This is also the case for the computer and its capacity to integrate the new data. “Evidently, there is no problem; the system remains fluid,” Royer declares.

The antenna of the RBE2-AESA (left) comprises around 1,000 transmit/receive modules. The exact number is classified.

The jump in the radar’s scanning capability opens up new perspectives for Rafale pilots in the air defence mission. The details of these tactical changes remain classified, but Royer gives us a few hints: “Two AESA Rafales flying at standoff distance behind a wave of fighters offer a capacity that is comparable to a mini-Awacs.” Though the exact range of the new radar is classified, it is estimated at 150 km or more against a non-stealthy fighter-type target.

In Beyond Visual Range combat, this crucial advantage can be used to make the Rafale even harder to detect. While AESA-equipped aircraft hang back, out of range of enemy aircraft weapons and sensors, other, non-AESA Rafales can approach the targets with their radar switched off, maximising the element of surprise to launch their Mica missiles using target designations transmitted by Link 16 from the AESA Rafales. An concept of operations similar to that of the US Air Force, which has already announced its intention to use its AESA-equipped F-15Cs for long-range target detection, allowing the stealthier F-22 to fire its missiles without being detected.

Clearly, the arrival of the Meteor at the end of the decade will be another game changer. The new ramjet-powered air-to-air missile will offer a maximum range similar to that of the RBE2-AESA. Further tactical changes will be required at that time.

The other advantage of the AESA is its ability to detect targets with much smaller radar cross sections (RCS) than the existing PESA, at the same range. “We have already peformed trials with low-RCS aircraft like the Grob 120, TBM, Epsilon and, of course, the Rafale, but the ultimate test will be the Neuron UCAV,” Royer explains. The demonstrator (more readily available than an F-22 or B-2!) will be used to accurately characterise the performance of the AESA against stealth aircraft. The CEAM will also be testing the radar’s resistance to countermeasures — a complex process since it will involve exposing the radar to French jamming systems (Spectra, etc.) whose implementation requires relative discretion. A great deal of work was required in preparation for a small number of test flights to evaluate performance in this domain.

Initially, the CEAM had a single aircraft available for the test campaign: Rafale C137, delivered in autumn 2012. This was a pre-production aircraft, without spares for maintenance of the new sensors. The evaluation team had to wait for delivery of the first production AESA aircraft (B339, a two-seater) in September 2013 to be able to validate the new air-to-air tactics with two aircraft. In the air-to-ground mode, the task of the CEAM was essentially to check for degraded performance compared with the RBE2-PESA, since no improvement was expected. That is why the AESA radar was installed on a two-seater, Rafale B305, for terrain-following tests. According to Royer, the operation takes around two hours.

France has only ordered 60 AESA radars, but it should be possible to install them on any aircraft in the Air Force or Navy fleets. Once they have been upgraded to software standard F3.3 — which is now the case for all French Rafales — any aircraft can be fitted with an RBE2-AESA radar. Accordingly it was important to verify on a real aircraft that the radar complied with this “plug and play” requirement. The one change that is needed is a new radome to accommodate the new antenna, which comprises around 1,000 transmit/receive modules. The new antenna, which is around 20 kg heavier than that of the RBE2-PESA, simply requires the installation of an extra hinge to attach the radome to the airframe. Royer explains that, as soon as the aircraft is powered up, it recognises the new antenna and immediately reacts like an aircraft equipped with an AESA radar.

How will the AESA radar subsequently be deployed in the forces? As the specialists in the air-to-air combat domain 1/7 fighter squadron “Provence” in Saint-Dizier will be the first to bring this new capacity into service with an initial batch of four AESA Rafales. Beyond that, decisions have still to be made. In Royer’s opinion, the 60 antennas should be deployed in all squadrons to make the most of the multi-mission concept. Until then, the specialists at the CEAM will continue to refine concepts of operation in order to provide operational units with an initial turnkey capacity, which will subsequently be honed through day-to-day experience within the squadron.

radar_Général J.RodeInterview with General Joël Rode, former Commander of the French Air Force’s CEAM test centre

What I understand today, based on my experience as an air defence pilot and my discussions with the evaluation teams, is that this new radar will give the Rafale capacities that are not only largely superior to what it can do today, but also to those of the Mirage 2000-5F, which is the French reference in air-to-air combat. In addition, the arrival of the Meteor made the integration of the new radar imperative.

Experimentation is still in progress, and many areas of the operating envelope have still to be validated. An example is electronic warfare, which will be significantly impacted by the arrival of the RBE2-AESA. We also have a lot of work to perform concerning the use of the radar on a day-to-day basis, in order to determine new tactics in line with its performance. We also have to prepare our technicians for the arrival of the new system, to ensure that it can be easily transferred from one Rafale to another.

The arrival of the “active” RBE2-AESA in no way signals the end of the road for the “passive” RBE2-PESA. Only 60 AESA radars have been ordered by the French Air Force and Navy, who will therefore have to learn to live for many years ahead with their “older-generation” sensors. This is why work is still ongoing to upgrade the PESA radar. The Rafale evaluation team at Mont-de-Marsan will soon start testing new enhancements designed to boost electronic warfare performance. This software upgrade aims to improve performance in electronic counter-countermeasures (ECCM) to enable the radar to continue to function properly even in the presence of advanced jamming systems. Such potential threats — absent in Libya and Mali — must be taken into consideration to ensure that the Rafale has a credible capacity in a scenario of forcible entry into more heavily defended territories. Altogether, around 60 flights will be needed to complete this experimentation, which will subsequently be applied, via a simple software retrofit, to all French Rafales.

Work has also focused on the enhanced terrain-following capability of the new radar. Until now, during high-speed flight at very low altitude in poor visibility, the aircraft relied preferentially on a digital terrain model. Using the radar for terrain-following will increase autonomy, since the RBE2-PESA will now allow the Rafale to “see” the terrain beneath the aircraft, in order to determine the best flight profile to remain below the enemy’s radar horizon. The CEAM has performed several missions in support of this effort, including flights over the Emirati desert to test this capacity in real-world conditions.

The Rafale has successfully completed its first test flights in a new heavily-armed configuration, comprising six air-to-ground precision AASM Hammer missiles, four medium and long range air-to-air missiles from the MICA family, two very long range METEOR missiles, as well as three 2,000 liter fuel tanks. Photo: Dassault Aviation

The Soviets had ESA, albeit passive ones, in the MiG-31, back in the late 70s or early 80s. We have them, passive ones, in the B1B, and B-2, although those are being, or may have already been, replaced now with AESAs, (active elements)

You get most of the operational benefits with the passive ones, but not as long of detection range, for a couple of technical reason. More total power and lower effective noise figure. The downside is more cost, and maybe more weight. Cooling the beasts is a challenge too.

I have a big heart for the French AF. The French guys, as we called them. They were just great. The special ops guys were... Well you wanted them on your side

What is wrong with you? Don't you know it is required practice on FR to act the fool and claim the French are useless! Rather than try and make sense you should have posted something to do with 'white flags,' or even better, 'reverse gears.' /sarcasm.

Seriously though, I saw some French activity in Bamako during an investment trip I'd taken there a couple years ago, and those guys are formidable.

The most beautiful countryside, wine with lunch, the best beef in the world, shrines, Sacre Couer, cigarettes, the architecture, the art, devotion to Ella Fitzgerald and Louis, Normandy preserved as in 1944, fashion

St Vincent du Paul, st Catherine, John vianney, Therese, Miss Arc, the resistance. Le Beaux

Most Americans i know hate France. If we’re driving around and end up on the wrong highway and we pass a Buenaventura, they scream, get the map. Get me out of France! And when they’re there they scream for the
want of Burger King

I believe the Vikings that were ancestors stayed in Normandy for a bit before moving on to Ireland. So that could be why I like it. It could be that filet of sole I had on the beach at Le Havre

Once we were in St Mere Eglise and we stopped in the church in the square. I looked around. The stained glass windows had been blown out, on one side, in the war. These had been replaced by town artisans, freehand artwork. The images taking up the entire windows were paratroopers descending. Our guys. 82 and 101 airborne.

Ah the French. If you go there and smile and say s’il vous plait, oui, et merci, and get off the Eiffel Tower/louvre path, its really great

No one believes me. Watch the flames. Well, its late. But it is independent thinking and highly discouraged

I believe you because I have experienced France firsthand. From the Belgian border to the Med. From Mt. St. Michel to the Alps. The people are very engaging and friendly. The country is beautiful. Even the cicadas in Provence in the summer, with the very loud noise they make was cool. The French enjoy life differently than we do. America owes a lot of its culture and history to the French.

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