During development it was known as Izdeliye 400 (Product #400) in house, and An-40 in the West. First flown in 1982, civil certification was issued on 30 December 1992. In July 2013, 26 An-124s were in commercial service with 10 on order.
During the 1970s, the VTA (Military Transport Aviation) arm of the Soviet Air Force had a shortfall in strategic heavy airlift capacity. Its largest planes consisted of about 50 Antonov An-22 turboprops, which were used heavily for tactical roles. A classified 1975 CIA analysis concluded that the USSR did "...not match the US in ability to provide long-range heavy lift support."
The An-124 was manufactured in parallel by two plants: the Russian company Aviastar-SP (ex. Ulyanovsk Aviation Industrial Complex) and by the Kyiv Aviation Plant AVIANT, in Ukraine. Design work started in 1971 and construction of facilities began in 1973. Manufacturing on the first airframe began in 1979. Ultimately this project brought together over 100 factories contracted to produce systems and parts.
The first flight took place in December 1982 and the first exposure to the West followed in 1985 at the Paris Air Show.
Russia and Ukraine agreed to resume the production in the third quarter of 2008. In May 2008, a new variant—the An-124-150—was announced; it featured several improvements, including a maximum lift capacity of 150 tonnes. However, in May 2009, Antonov's partner, United Aircraft Corporation announced it did not plan production of An-124s in the period 2009–2012. In late 2009, Russian President Dmitry Medvedev ordered production of the aircraft resumed. It is expected that Russia will purchase 20 new aircraft.
An-124-100 kneeling with front ramp down (note tilt of aircraft fuselage and retraction of front wheels)
not kneeling - nose gear up
Externally, the An-124 is similar to the American Lockheed C-5 Galaxy, having a double fuselage to allow for a rear cargo door (on the lower fuselage) that can open in flight without affecting structural integrity. It is slightly shorter, with a slightly greater wingspan, and a 25% larger payload. Instead of the Galaxy's T-tail, the An-124 uses a conventional empennage, similar in design to that of the Boeing 747.
The aircraft uses Oleo strut suspension for its 24 wheels. The suspension has been calibrated to allow landing on rough terrain. and is able to kneel to allow easier front loading. The plane has an onboard overhead crane capable of lifting up to 30 tonnes of cargo, and items up to 120 tonnes can be winched on board.
Up to 150 tonnes (150 long tons; 170 short tons) of cargo can be carried in a military An-124; it can also carry 88 passengers in an upper deck behind the wing centre section. The cargo compartment of An-124 is 36×6.4×4.4 m (118×21×14 ft), ca. 20% larger than the main cargo compartment of C-5 Galaxy, which is 36.91×5.79×4.09 m (121.1×19.0×13.4 ft). Due to limited pressurisation in the main cargo compartment (24.6 kPa, 3.57 psi), it seldom carries paratroopers.
Pilots have stated that the An-124 is light on the controls and easy to handle for an aircraft of its size.
Germany led the recent effort to lease An-124s for NATOstrategic airlift requirements. Two aircraft are leased from SALIS GmbH as a stopgap until the Airbus A400M is available. Under NATO SALIS programme NAMSA is chartering six An-124-100 transport aircraft. According to the contract An-124-100s of Antonov Airlines and Volga-Dnepr are used within the limits of NATO SALIS programme to transport cargo by requests of 18 countries: Belgium, Hungary, Greece, Denmark, Canada, Luxembourg, Netherlands, Norway, United Kingdom, Poland, Portugal, Slovakia, Slovenia, Finland, France, Germany, Czech Republic and Sweden. Two An-124-100s are constantly based on full-time charter in the Leipzig/Halle airport, but the contract specifies that if necessary, two more aircraft will be provided on six days notice and another two on nine days notice. The aircraft proved extremely useful for NATO especially with ongoing operations in Iraq and Afghanistan.
United Launch Alliance (ULA) contracts the An-124 to transport the Atlas V launch vehicle from its facilities in Decatur, Alabama to Cape Canaveral. ULA also uses the An-124 to transport the Atlas V launch vehicle and Centaur upper stage from their manufacturing facility in Denver, Colorado to Cape Canaveral and Vandenberg Air Force Base. Two flights are required to transfer each launch vehicle (one for the Atlas V main booster stage and another for the Centaur upper stage). It is also contracted by Space Systems Loral to transport satellites from Palo Alto, CA to the Arianespace spaceport in Kourou, French Guiana.
Airbus Transport International, a subsidiary of Airbus, has selected another Russian cargo company, Polet Airlines as "designated carrier" to the company. Polet expects its three An-124-100s will transport astronautic equipment manufactured by EADS, which is Airbus' parent company, and components of the Airbus A380 superjumbo. The Rolls-Royce Trent 900 is the only A380 engine that can be transported whole in a Boeing 747F.
As of 2013 the An-124 has visited 768 airports in over 100 countries.
On May 1987, an An-124 set a world record, covering the distance of 20,151 km (10,881 nmi) without refuelling. The flight took 25 hours and 30 minutes; the takeoff weight was 455,000 kg.
In July 1985, an An-124 carried 171,219 kg (377,473 lb) of cargo to an altitude of 2,000 m (6,600 ft) and 170,000 kg to an altitude of 10,750 m (35,270 ft).
An An-124 was used to transport the Obelisk of Axum back to its native homeland of Ethiopia from Rome in April 2005.
Joint proposal with Air Foyle to meet UK's Short Term Strategic Airlifter (STSA) requirement, with Rolls-Royce RB211-524H-T engines, each rated 60,600 lbf (264 kN) and Honeywell avionics—STSA competition abandoned in August 1999, reinstated, and won by the Boeing C-17A.
variant ordered by the Russian Air Force with new avionics, a new improved braking system and a payload of 150 tons.
Russian Air Force (14 + more in reserve. By 2020 it is planned total to upgrade 20 aircraft in the version of An-124-100M, including aircraft in storage. As of December 2014 the Russian Armed Forces Air Force received a total of 9 aircraft, which JSC " Aviastar-SP" in Ulyanovsk has upgraded.)
^Antonov An-124 Performance @ Antonov.com Retrieved 10 August 2013.
^Though the as planned An-124-100M-150 enlarged version has a 7% higher payload than the operational Boeing 747-8F. The 747-8F has over two times the range (5,050 mi or 8,130 km) with a payload of 295,800 lb (134,000 kg) than the An-124-100M-150 with the same payload. The An-124-100M-150 is to carry less than half the payload at the same range.
^E. Gordon, Antonov's Heavy Transports, Midland Publishing.