Everything written about Istres starts with the runway, and most of it is written slightly wrong. The published chart for LFMI is unambiguous: one runway, 15/33, true bearings 151 and 331, 3,750 metres long and 53 metres wide, aerodrome elevation 82 feet — about 25 metres. Threshold 15 sits at 77 feet and threshold 33 at 62 feet. That is the runway a crew declares and calculates against.

The five-kilometre figure comes from what is beyond it. Off the 33 end there is a stopway of 1,208 metres by 59 metres, built to the same construction standard as the runway itself and marked out over 600 metres of its length; the 15 end has a shorter one of 114 metres. Add the paved lengths together and the strip runs to just under 5,000 metres without a break, which is why France calls this the longest runway in the country and Europe struggles to beat it. The nuance matters: this is not five kilometres of declared landing distance, it is 3,750 metres of it with an enormous amount of concrete to spare.

The 1,200-metre extension went in during 1992, paid for by Airbus Industrie. Toulouse needed somewhere to mistreat very large aeroplanes a long way from a suburb, and Istres, sitting on the empty steppe of the Crau with the mistral blowing down it, was the obvious answer. The Airbus A380 certification campaign came here for, among other things, the “tests piscines” — landings on a runway artificially flooded to measure aquaplaning and braking performance on standing water.

The second consequence is emergency traffic. Because of the length and the fire and rescue equipment that goes with it, Istres has taken civil aircraft that could not go anywhere else. The most famous case was on 31 March 1992, when a Boeing 707 freighter lost both right engines in turbulence at 35,000 feet and put down here flapless and downwind at close to 200 knots with the right wing burning. The third consequence was the Space Shuttle, which needed exactly this: a very long, very wide, very well-instrumented runway on the far side of an ocean.

France signed for twelve Boeing C-135 tankers on 20 September 1962, specifically so that the Mirage IV could reach targets it otherwise could not. The first aircraft, number 471, arrived on 3 February 1964 and the last of the batch, number 740, on 7 October 1964; the first nuclear alert was taken the following day. Re-engined between 1984 and 1989 with CFM56s and redesignated C-135FR, given wing refuelling pods in 1993, and joined in 1997 by three second-hand ex-USAF KC-135R aircraft known in French service as KC-135RG, they lasted just short of sixty years. Across the whole fleet the type flew 391,000 hours and was present in every operation France took part in: Épervier, Daguet, Enduring Freedom, Harmattan, Serval and Barkhane, Chammal, Hamilton.

The tanker squadrons were gathered at Istres by stages. ERV 4/93 Aunis stood up on the base with C-135Fs on 13 July 1965 and became ERV 1/93 in 1976; the instruction squadron Landes moved in from Mont-de-Marsan on 5 September 1991; and on 1 August 1996 both were folded into a single unit, ERV 93 Bretagne, which from then on was the only French squadron operating C-135s at all. The 31e escadre aérienne de ravitaillement et de transport stratégiques was activated over the top of them on 27 August 2014.

The Airbus A330 MRTT Phénix replaced all of it. The first aircraft, MRTT 41, was handed over at Istres on 27 September 2018 and flew its first French service sortie on 12 October. Arrival of the type forced new infrastructure — maintenance hangar 31 was built in the north of the base in 2017 simply because the aeroplane would not fit in the old ones, along with a fuel depot able to service two Phénix at once.

What a strategic tanker actually buys is reach without permission. A Phénix carries around 110 tonnes of fuel in its wings, of which some 60 tonnes can be given away, and it can refuel two fighters at once or an E-3F Sentry from the boom. That is what turns a fighter with a few hours of fuel into one that can cross an ocean, and it does so without a diversion airfield, an overflight clearance or a host nation’s consent.

The Armée de l’air et de l’espace classes three of its bases as strategic: Saint-Dizier, Avord and Istres. Saint-Dizier is where the Rafale B of the Forces aériennes stratégiques (strategic air forces) sit alert with the ASMPA-R stand-off missile. Istres is different. It carries the deterrent’s legs rather than its warhead, and it has also carried the warhead itself for most of its modern life.

The nuclear strike history here is long and is usually forgotten. On 1 April 1980 escadron de chasse 4/7 Limousin formed at Istres with fifteen SEPECAT Jaguar and the pre-strategic mission, armed with the 25-kilotonne AN-52 free-fall bomb. It disbanded on 31 July 1989 and was reborn the next day as escadron de chasse 3/4 Limousin, converting to the Dassault Mirage 2000N; it passed under the command of the Forces aériennes stratégiques on 1 September 1991 and in 1996 took over the full strategic mission as the Mirage IVP bowed out. On 1 September 2011 escadron de chasse 2/4 La Fayette moved down from Luxeuil and replaced it, flying the Mirage 2000N from Istres until the type was withdrawn in September 2018, when both remaining nuclear squadrons were concentrated at Saint-Dizier and converted to the Rafale.

The infrastructure stayed. When the special munitions depots were reorganised between the end of 2008 and 2012 for the arrival of the ASMP-A, five dépôts ateliers munitions spéciales became three dépôts vecteurs ASMPA — at Istres, Saint-Dizier and Avord — and two were closed. Under the new arrangement the missile body is held in the depot and issued to the squadron; the warhead is kept separately in its own protected zone. France does not publish where its warheads are, and neither will we.

The current contribution is the tanker. A nuclear raid without air refuelling is a one-way trip with a much shorter reach, and the exercises say so plainly: Poker, the full simulated nuclear raid, runs four times a year and can mobilise up to fifty aircraft, Rafale and Phénix and E-3F together. The stated ambition of the re-equipped force is to move twenty Rafale and ten MRTT 20,000 kilometres in 48 hours.

Two very different institutions are often confused. The CEAM at Mont-de-Marsan is the air force’s own operational evaluation centre: it takes an aircraft that already works and decides how the Armée de l’air et de l’espace will fight with it, writing the tactics, the manuals and the training syllabus. DGA Essais en vol at Istres belongs to the Direction générale de l’armement, the state armament directorate, and does the job before that one. It flies the aeroplane to find out whether it does what the contract says, qualifies the weapons on it, and signs for it on the state’s behalf. One is the customer’s tactician; the other is the state’s engineer.

The centre was created in 1944, immediately after the Liberation, as the Centre d’essais en vol, and kept that name until the end of 2009. It has shed sites steadily — Brétigny-sur-Orge until 31 December 2000, Colomb-Béchar and Hammaguir in the Sahara until 1967, Melun-Villaroche until 1998, Toulouse until 2009 — and now works from two: Istres and Cazaux. Between them they employ close to 900 people. In 2023 they flew more than 4,000 test sorties for about 6,500 flight hours and formally accepted some eighty aircraft. The centre marked its eightieth anniversary at Istres on 4 July 2024.

EPNER, the École du personnel navigant d’essais et de réception, was founded in 1946 at Brétigny by François Hussenot, Maurice Cambois and Charles Cabaret and moved to Istres in 1962. It trains test pilots, flight test engineers, test flight engineers and observers, test parachutists and even the air traffic controllers who handle trials traffic — one of only a handful of such schools in the world, and it takes allied students.

The civil work is real too. The most celebrated single day was 2 May 2001, when Concorde F-BTSD flew two landing cycles at Istres on Michelin NZG tyres, the decisive trial in the certification that allowed the type back into service after the Gonesse accident. Dassault, Safran and Thales all run trials from the same ramp, and Istres controls its own test and acceptance air traffic as one of seven national centres de contrôle d’essais et réception.

The decree of 14 January 1964 created the Forces aériennes stratégiques, and Istres was in from the start. Escadron de ravitaillement en vol 4/93 Aunis stood up on the base on 13 July 1965 with C-135F tankers, and escadron de bombardement 1/93 Guyenne on 15 October 1965 with the Dassault Mirage IVA. For eleven years Istres was both a bomber base and a tanker base; the Guyenne was renumbered EB 1/94 on 30 June 1976 and moved to Avord, leaving the tankers behind.

At the peak in 1968 the force held 62 Mirage IV across nine bombing squadrons on three wings, with twelve C-135F tankers behind them. Nine bombers stood permanent operational alert, able to be launched inside five minutes with the remainder following within the hour, and three tankers stood alert alongside them. The reaction time was later relaxed to fifteen minutes. The aircraft had the range to reach their targets and not the range to come home; crews expected to abandon the aeroplane after release, at best over neutral or allied territory.

The base was also a launch point for the sharper end of French Africa policy. After the kidnapping of Françoise Claustre in 1974, Mirage IVs flew photographic reconnaissance over Chad from Istres; each sortie lasted around eight hours and needed five C-135F tankers to support it. Further African missions followed in May 1978 and at the end of 1984, and the same pairing was used in earnest as late as 21 February 2003, when two Mirage IV in grey-green paint with UN markings and two C-135FR left Istres for Prince Sultan Air Base in Saudi Arabia to fly reconnaissance for the United Nations over Iraq under Opération Tarpan. They flew home on 19 March, the day before the invasion.

Istres itself had already featured in a darker Cold War episode. During the generals’ putsch in Algiers between 21 and 24 April 1961, several officers involved in the plot flew from the base to Algiers in military aircraft with the agreement of the base command. The base commander was on leave; his deputy, Commandant Marcel Fischer — Resistance, the 1944–45 campaign, Indochina, Morocco, Algeria — took responsibility, and was given 85 days of close arrest and early retirement.

The tanker transition is finished and the fleet build-out is not. Twelve A330 MRTT Phénix had been delivered by 20 September 2023, completing the first order; a thirteenth, MSN 1608 and the first of the third tranche, was accepted in June 2025 in the same month that the last KC-135RG left the fleet. It is a converted A330-200: three such airliners were bought in 2020 and 2022 under the post-Covid aerospace support plan and flown white in transport configuration, and the remaining two are being turned into tankers to take the force to fifteen by 2028. That already makes France the largest A330 MRTT operator in the world.

It is also, by the air force’s own account, not quite enough. Général Jérôme Bellanger, chief of staff of the Armée de l’air et de l’espace, said in October 2025 that the size of the A330 MRTT fleet was being watched closely, “d’autant plus que sa polyvalence créé une superposition des attentes et des contrats opérationnels” — the aeroplane is so useful that everyone wants it at once, while it remains under the command of the strategic air forces and can be recalled to France at any moment.

The other change is logistical. On 16 May 2024 the Hub des armées passenger terminal was inaugurated at Istres by Général Stéphane Mille, then chief of the air staff. It is built for 100,000 passengers and 9,000 tonnes of freight a year, can process 540 people at once — two A330 loads — and covers about a hectare. It has largely taken over from Roissy as the door through which French forces leave for operations, and it is a long way from the 10,000 passengers a year the base handled before the Phénix arrived.

What that adds up to was visible on 8 September 2026, when Mission Pégase 26 left Istres: four Rafale F4, three Phénix and two A400M Atlas, around 300 personnel, more than 40,000 kilometres and five and a half weeks by way of Greenland, Canada, Alaska, Japan, South Korea, Indonesia, India, Qatar, Réunion and Egypt. The Rafale reached Alaska in roughly eleven hours without landing, on six air-to-air refuellings. Général de brigade aérienne Yann Malard had taken command of the base twelve days earlier, on 27 August 2026.