2030. The draw-down of the Hercules C5 fleet began in 2016, with two left in service by December 2020. The fourteen C4 extended variants were scheduled to retire on 31 March 2035. However, due to the crash of Hercules C4 ZH873 in August 2017, one Hercules C5 was retained to keep the fleet at 14 aircraft. The 2021 Defence Command Paper brought forward the retirement of the Hercules fleet to 2023. The Airbus Atlas C1 (A400M) replaced the RAF's fleet of Hercules C1/C3 (C-130K) which were withdrawn from use on 28 October 2013, having originally entered service in 1967. Based at RAF Brize Norton, the Atlas fleet is operated by No. 30 Squadron and No. LXX Squadron. The first Atlas C1 (ZM400) was delivered to the RAF in November 2014. The A400M is also expected to replace the C4/C5 variants. Originally, twenty-five A400Ms were ordered; the total purchase has now dropped to twenty-two. No. XXIV Squadron acts as the Air Mobility OCU (AMOCU) for the Globemaster, Hercules and Atlas, while No. 206 Squadron is the OEU. Air transport tasks are also carried out by the Airbus Voyager KC2/3, flown by No. 10 Squadron and No. 101 Squadron. The first Voyager (ZZ330) arrived in the UK for testing at MOD Boscombe Down in April 2011, and entered service in April 2012. The Voyager received approval from the MOD on 16 May 2013 to begin air-to-air refuelling flights and made its first operational tanker flight on 20 May 2013 as part of a training sortie with Tornado GR4s. By 21 May 2013, the Voyager fleet had carried over 50,000 passengers and carried over 3,000 tons of cargo. A total of fourteen Voyagers form the fleet, with nine allocated to sole RAF use (three KC2s and six KC3s). As the Voyagers lack a refuelling boom, the RAF has requested a memorandum of understanding (MoU) with the USAF allowing the UK access to tankers equipped with refuelling booms for its RC-135W Rivet Joint . Helicopters RAF helicopters support the British Army by moving troops and equipment to and around the battlefield. Helicopters are also used in a variety of other roles, including in support of RAF ground units and heavy-lift support for the Royal Marines. The support helicopters are organised into the tri-service Joint Helicopter Command (JHC), along with helicopters from the British Army and Royal Navy. No. 22 Squadron, based at RAF Benson,