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100-524: In 2013, the five original BelugaSTs could not cope with production growth, and Airbus evaluated the Antonov An-124 and An-225 , Boeing C-17 or Dreamlifter , and A400M , before choosing to modify one of its own aircraft. The programme was launched in November 2014 to build five aircraft to replace the existing five BelugaSTs; the design freeze was announced on 16 September 2015. The program cost

200-458: A fly-by-wire control system. This is a hybrid control system, as it also implements conventional mechanical controls for some aspects; these have been arranged in a manner that provides redundancy against the failure of a single hydraulic circuit. A single An-124 is capable of carrying up to 150 tonnes (150 long tons; 170 short tons) of cargo internally in a standard military configuration; it can also carry 88 passengers in an upper deck behind

300-501: A ski-jump on take-off is subjected to loads of 0.5g which also last for much longer than a landing impact. Helicopters may have a deck-lock harpoon to anchor them to the deck. Some aircraft have a requirement to use the landing-gear as a speed brake. Flexible mounting of the stowed main landing-gear bogies on the Tupolev Tu-22 R raised the aircraft flutter speed to 550 kn (1,020 km/h). The bogies oscillated within

400-428: A tripod effect. Some unusual landing gear have been evaluated experimentally. These include: no landing gear (to save weight), made possible by operating from a catapult cradle and flexible landing deck: air cushion (to enable operation over a wide range of ground obstacles and water/snow/ice); tracked (to reduce runway loading). For launch vehicles and spacecraft landers , the landing gear usually only supports

500-414: A "boat" hull/floats and retractable wheels, which allow it to operate from land or water. Beaching gear is detachable wheeled landing gear that allows a non-amphibious floatplane or flying boat to be maneuvered on land. It is used for aircraft maintenance and storage and is either carried in the aircraft or kept at a slipway. Beaching gear may consist of individual detachable wheels or a cradle that supports

600-442: A 10 in (25 cm) thick flexible asphalt pavement . The 210,000 lb (95 t) Boeing 727 -200 with four tires on two legs main landing gears required a 20 in (51 cm) thick pavement. The thickness rose to 25 in (64 cm) for a McDonnell Douglas DC-10 -10 with 443,000 lb (201 t) supported on eight wheels on two legs. The heavier, 558,000 lb (253 t), DC-10-30/40 were able to operate from

700-530: A 214–222 t (472,000–489,000 lb) airframe would allow a 490–500 t (1,080,000–1,100,000 lb) gross weight . It should be powered by Russian PD-35s developed for the CR929 widebody, producing 35 tf (77,000 lbf) up from 23 tf (51,000 lbf). Two fuselages are planned, one for Volga-Dnepr with a width of 5.3 m (17.4 ft) from the An-124's 4.4 m (14.4 ft), and one for

800-474: A 90° angle during the rearwards-retraction sequence to allow the main wheel to rest "flat" above the lower end of the main gear strut, or flush within the wing or engine nacelles, when fully retracted. Examples are the Curtiss P-40 , Vought F4U Corsair , Grumman F6F Hellcat , Messerschmitt Me 210 and Junkers Ju 88 . The Aero Commander family of twin-engined business aircraft also shares this feature on

900-476: A forward and aft position. The forward position was used for take-off to give a longer lever-arm for pitch control and greater nose-up attitude. The aft position was used to reduce landing bounce and reduce risk of tip-back during ground handling. The tandem or bicycle layout is used on the Hawker Siddeley Harrier, which has two main-wheels behind a single nose-wheel under the fuselage and

1000-479: A further ten airlifters were on order. During 2008, it was announced that Russia and Ukraine were to jointly resume production of the type. At one point, it looked as if Russia would order 20 new-build airlifters. However, in August 2014, it was reported that the planned resumption of manufacturing had been shelved due to the ongoing political tensions between Russia and Ukraine . The sole remaining production facility

1100-585: A higher sink-rate requirement because the aircraft are flown onto the deck with no landing flare . Other features are related to catapult take-off requirements for specific aircraft. For example, the Blackburn Buccaneer was pulled down onto its tail-skid to set the required nose-up attitude. The naval McDonnell Douglas F-4 Phantom II in UK service needed an extending nosewheel leg to set the wing attitude at launch. The landing gear for an aircraft using

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1200-474: A higher sink-rate requirement if a carrier-type, no-flare landing technique has to be adopted to reduce touchdown scatter. For example, the Saab 37 Viggen , with landing gear designed for a 5m/sec impact, could use a carrier-type landing and HUD to reduce its scatter from 300 m to 100m. The de Havilland Canada DHC-4 Caribou used long-stroke legs to land from a steep approach with no float. A flying boat has

1300-489: A light aircraft, an emergency extension system is always available. This may be a manually operated crank or pump, or a mechanical free-fall mechanism which disengages the uplocks and allows the landing gear to fall under gravity. Aircraft landing gear includes wheels equipped with solid shock absorbers on light planes, and air/oil oleo struts on larger aircraft. As aircraft weights have increased more wheels have been added and runway thickness has increased to keep within

1400-403: A lower fuselage with the shape of a boat hull giving it buoyancy. Wing-mounted floats or stubby wing-like sponsons are added for stability. Sponsons are attached to the lower sides of the fuselage. A floatplane has two or three streamlined floats. Amphibious floats have retractable wheels for land operation. An amphibious aircraft or amphibian usually has two distinct landing gears, namely

1500-537: A nosewheel) chassis. Landing is done on skids or similar simple devices (fixed or retractable). The SNCASE Baroudeur used this arrangement. Historical examples include the "dolly"-using Messerschmitt Me 163 Komet rocket fighter, the Messerschmitt Me 321 Gigant troop glider, and the first eight "trolley"-using prototypes of the Arado Ar 234 jet reconnaissance bomber. The main disadvantage to using

1600-424: A range of 4,100 nmi (7,600 km) with five Sprut-SDM-1 light tanks, their 100 crew and 300 armed soldiers. The planned An-124-102 is larger at 82.3 m (270 ft) long from 69 m (227 ft), with an 87–88 m (286–290 ft) span versus 73.3 m (240.5 ft) and 24.0 m (78.7 ft) high compared with 21.0 m (68.9 ft). A new higher aspect ratio , composite wing and

1700-457: A similar arrangement, except that the fore and aft gears each have two twin-wheel units side by side. Quadricycle gear is similar to bicycle but with two sets of wheels displaced laterally in the fore and aft positions. Raymer classifies the B-52 gear as quadricycle. The experimental Fairchild XC-120 Packplane had quadricycle gear located in the engine nacelles to allow unrestricted access beneath

1800-520: A smaller wheel near the tip of each wing. On second generation Harriers, the wing is extended past the outrigger wheels to allow greater wing-mounted munition loads to be carried, or to permit wing-tip extensions to be bolted on for ferry flights. A tandem layout was evaluated by Martin using a specially-modified Martin B-26 Marauder (the XB-26H) to evaluate its use on Martin's first jet bomber,

1900-620: A stopgap until the Airbus A400M became 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

2000-564: A substantial increase in payload capacity was also desirable so that the same task could be completed with fewer trips. In 1971, design work on the project commenced at the Antonov Design Bureau ; the lead designer of the An-124 (and the enlarged An-225 derivative) was Viktor Tolmachev . During development, it was known as Izdeliye 400 ( Product #400 ) in house, and An-40 in the West . The design produced broadly resembled

2100-470: A total of 97 fatalities, including: Data from Jane's all the World's Aircraft 2006-07 , Volga-Dnepr General characteristics Performance Related development Aircraft of comparable role, configuration, and era [REDACTED] Media related to Antonov An-124 at Wikimedia Commons Landing gear Landing gear is the undercarriage of an aircraft or spacecraft that

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2200-557: A tricycle undercarriage to prevent damage to the underside of the fuselage if over-rotation occurs on take-off leading to a tail strike . Aircraft with tail-strike protection include the B-29 Superfortress , Boeing 727 trijet and Concorde . Some aircraft with retractable conventional landing gear have a fixed tailwheel. Hoerner estimated the drag of the Bf 109 fixed tailwheel and compared it with that of other protrusions such as

2300-671: Is € 1 billion for development and production. The original BelugaSTs were not to be withdrawn from service after introduction of the Beluga XL in 2019; a mixed fleet was to operate for at least five years, as the increased production rate of single-aisle aircraft requires the ability to move more parts. The BelugaST fleet flew more than 8,000 hours in 2017, doubled from 2014, but the five BelugaST aircraft were only halfway through their planned service life, and another operator could use them for civil or military logistic applications. The combined Beluga fleet rose to eight aircraft with

2400-560: Is Russia's Aviastar-SP in Ulyanovsk. The various operators of the An-124 are in discussions with respect to the continuing airworthiness certification of the individual An-124 planes. The original designer of the An-124 is responsible for managing the certification process for its own products, but the Russia-Ukraine conflicts are making this process difficult to manage. In 2019, there were 26 An-124s in commercial service. During

2500-645: Is a large, strategic airlift , four-engined aircraft that was designed in the 1980s by the Antonov design bureau in the Ukrainian SSR of the Soviet Union (USSR). The An-124 is the world's second heaviest gross weight production cargo airplane and heaviest operating cargo aircraft , behind the destroyed one-off Antonov An-225 Mriya (a greatly enlarged design based on the An-124). The An-124 remains

2600-412: Is also unique in that all four pairs of main wheels can be steered. This allows the landing gear to line up with the runway and thus makes crosswind landings easier (using a technique called crab landing ). Since tandem aircraft cannot rotate for takeoff, the forward gear must be long enough to give the wings the correct angle of attack during takeoff. During landing, the forward gear must not touch

2700-465: Is required to reduce the impact with the surface of the water. A vee bottom parts the water and chines deflect the spray to prevent it damaging vulnerable parts of the aircraft. Additional spray control may be needed using spray strips or inverted gutters. A step is added to the hull, just behind the center of gravity, to stop water clinging to the afterbody so the aircraft can accelerate to flying speed. The step allows air, known as ventilation air, to break

2800-405: Is the most common, with skis or floats needed to operate from snow/ice/water and skids for vertical operation on land. Retractable undercarriages fold away during flight, which reduces drag , allowing for faster airspeeds . Landing gear must be strong enough to support the aircraft and its design affects the weight, balance and performance. It often comprises three wheels, or wheel-sets, giving

2900-578: Is used for taxiing , takeoff or landing . For aircraft, it is generally needed for all three of these. It was also formerly called alighting gear by some manufacturers, such as the Glenn L. Martin Company . For aircraft, Stinton makes the terminology distinction undercarriage (British) = landing gear (US) . For aircraft, the landing gear supports the craft when it is not flying, allowing it to take off, land, and taxi without damage. Wheeled landing gear

3000-705: The Beriev A-40 Hydro flaps were used on the Martin Marlin and Martin SeaMaster . Hydroflaps, submerged at the rear of the afterbody, act as a speed brake or differentially as a rudder. A fixed fin, known as a skeg , has been used for directional stability. A skeg, was added to the second step on the Kawanishi H8K flying boat hull. High speed impacts in rough water between the hull and wave flanks may be reduced using hydro-skis which hold

3100-658: The Leipzig/Halle airport , but the contract specifies that if necessary, two more aircraft will be provided at six days' notice and another two at nine days' notice. The aircraft proved extremely useful for NATO especially with 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

Airbus BelugaXL - Misplaced Pages Continue

3200-509: The Lockheed C-5 Galaxy , an American strategic airlifter, but also incorporated numerous improvements, the greater use of carbon-fibre composites in its construction (comprising around 5% of the aircraft's total weight) and the more extensive use of titanium being amongst these benefits. Aluminium alloys make up the primary material used in its construction, limited use of steel and titanium alloys were also made. Unlike

3300-561: The Martin Marlin , the Martin M-270, was tested with a new hull with a greater length/beam ratio of 15 obtained by adding 6 feet to both the nose and tail. Rough-sea capability can be improved with lower take-off and landing speeds because impacts with waves are reduced. The Shin Meiwa US-1A is a STOL amphibian with blown flaps and all control surfaces. The ability to land and take-off at relatively low speeds of about 45 knots and

3400-702: The Martin XB-48 . This configuration proved so manoeuvrable that it was also selected for the B-47 Stratojet . It was also used on the U-2, Myasishchev M-4 , Yakovlev Yak-25 , Yak-28 and Sud Aviation Vautour . A variation of the multi tandem layout is also used on the B-52 Stratofortress which has four main wheel bogies (two forward and two aft) underneath the fuselage and a small outrigger wheel supporting each wing-tip. The B-52's landing gear

3500-532: The P3 group provide the upper fuselage, while Aciturri produces the horizontal tail plane extension, auxiliary and ventral fins. Data from Airbus. General characteristics Performance Related development Aircraft of comparable role, configuration, and era Antonov An-124 The Antonov An-124 Ruslan ( Russian : Антонов Ан-124 Руслан ; Ukrainian : Ан-124 Руслан , lit.   ' Ruslan '; NATO reporting name : Condor )

3600-756: The 1970s, the Military Transport Aviation Command ( Komandovaniye voyenno-transportnoy aviatsii or VTA) arm of the Soviet Air Forces had a shortfall in strategic heavy airlift capacity. Its largest aircraft consisted of about 50 Antonov An-22 turboprops, which were used heavily for tactical roles. A declassified 1975 CIA analysis concluded that the USSR did "...not match the US in ability to provide long-range heavy lift support." Soviet officials sought not only additional airlifters,

3700-577: 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 Space 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

3800-832: The An-124 without support from Russia. At MAKS Air Show in 2017, the Central Aerohydrodynamic Institute (TsAGI) announced its An-124-102 Slon (Elephant) design to replace the similar An-124-100. The design was detailed in January 2019 before wind tunnel testing scheduled for August–September. It is intended to be produced at the Aviastar-SP factory in Ulyanovsk. It should transport 150 t (330,000 lb) over 3,800 nmi (7,000 km) (up from 1,675 nmi, 3,102 km), or 180 t (400,000 lb) over 2,650 nmi (4,910 km) at 460 kn (850 km/h). The Russian MoD wants

3900-634: The Arianespace spaceport in Kourou, French Guiana and by SpaceX to transport payload fairings between their factory in Hawthorne, California and Cape Canaveral. By 2013, the An-124 had reportedly visited 768 airports in over 100 countries. By late 2020, three civil operators of the An-124 remained. Antonov Airlines with seven aircraft, Volga-Dnepr Airlines with 12, and Maximus Air Cargo with one. In November 2020, Volga-Dnepr reported that it

4000-777: The Beluga XL fleet was expanded with a sixth aircraft in June 2019. The BelugaSTs could still have 10–20 years' flying life left, and may be offered for sale, or used to serve external customers. The aircraft's lower fuselage is assembled on the Airbus A330 final assembly line, and then moved to another facility for the year-long process of assembling the upper fuselage and the lowered nose fuselage. The first section arrived in Toulouse in November 2016. Final assembly started on 8 December 2016. The first large sections: one central and two lateral rear section panels, arrived on 12 April 2017 at

4100-668: The C-5, it lacks a fully-pressurised cargo bay or the ability to receive fuel in-flight . In 1973, the construction of the necessary facilities to produce the new airlifter began. Two separate final assembly lines plants were established to produce the airlifter: the company Aviastar-SP (ex. Ulyanovsk Aviation Industrial Complex) in Ulyanovsk , Russia and by the Kyiv Aviation Plant AVIANT , in Ukraine. Furthermore,

Airbus BelugaXL - Misplaced Pages Continue

4200-600: The Russian MoD of 6.4 m (21 ft) wide to carry vehicles in two lines. On 5 November 2019, the TsAGI released pictures of a 1.63 m (5 ft 4 in) long and 1.75 m (5 ft 9 in) wide model, ahead of windtunnel testing. On 26 March 2020, TsAGI released new pictures of a wind tunnel model, announcing that the researchers of the Institute had completed the first cycle of aerodynamic testing;

4300-662: The Toulouse Final Assembly facility (L34) from Aernnova's factory in Berantevilla , Spain. Constructed by Airbus subsidiary Stelia Aerospace in Meaulte , its 12 m × 4 m (39 ft × 13 ft), 8.2 t (18,000 lb) nose section was delivered in May 2017. The 9 m (30 ft) wide, 8 m (26 ft) long and high, 2.1 t (4,600 lb) upper front fuselage part, framing

4400-531: The XL's autoland capacity. Airbus started operating the first BelugaXL on 9 January 2020, with all six freighters scheduled to be operating by the end of 2023, and the previous A300-600STs phased out from 2021. With 30% more capacity than the original BelugaST, the BelugaXL can carry two A350 XWB wings instead of one. Its new fuselage is 6.9 m (23 ft) longer and 1.7 m (5 ft 7 in) wider than

4500-503: The aft upper fuselage, while the upper central fuselage is cut off, facilitated by the metal construction. The enlarged freight hold is mounted in three months with 8,000 new parts on the junction line. The unpressurised hold begins with the tail adapted by Spain's Aernnova , and continues by building the upper fuselage with two side panels and a crown for each section, for a maximum diameter of 8.8 m (29 ft). Produced by Stelia Aerospace , its main freight door has 24 latches, and

4600-416: The aircraft can be landed in a satisfactory manner in a range of failure scenarios. The Boeing 747 was given four separate and independent hydraulic systems (when previous airliners had two) and four main landing gear posts (when previous airliners had two). Safe landing would be possible if two main gear legs were torn off provided they were on opposite sides of the fuselage. In the case of power failure in

4700-414: The aircraft cost, but 20% of the airframe direct maintenance cost. A suitably-designed wheel can support 30 t (66,000 lb), tolerate a ground speed of 300 km/h and roll a distance of 500,000 km (310,000 mi) ; it has a 20,000 hours time between overhaul and a 60,000 hours or 20 year life time. Wheeled undercarriages normally come in two types: The taildragger arrangement

4800-494: The aircraft resumed; at this point, Russia was expected to procure 20 new-build An-124s. In August 2014, Jane's reported that, Russian Deputy Minister of Industry and Trade Yuri Slusar announced that production of the An-124 had been stopped as a consequence of the ongoing political tensions between Russia and Ukraine . In late 2017, multiple An-124s were upgraded by the Aviastar-SP plant in Ulyanovsk , Russia, three of which were reportedly scheduled to return to flight during

4900-547: The aircraft, one at Aviastar-SP (ex. Ulyanovsk Aviation Industrial Complex) in Ulyanovsk , Russia and the other was the Kyiv Aviation Plant AVIANT , in Ukraine. Assembly of the first aircraft begun in 1979; the An-124 (which was sometimes referred to as the An-40 in the West ) performed its maiden flight on 24 December 1982. The type made its first appearance in the Western world at the 1985 Paris Air Show . Viktor Tolmachev

5000-470: The airstream, it is called a semi-retractable gear. Most retractable gear is hydraulically operated, though some is electrically operated or even manually operated on very light aircraft. The landing gear is stowed in a compartment called a wheel well. Pilots confirming that their landing gear is down and locked refer to "three greens" or "three in the green.", a reference to the electrical indicator lights (or painted panels of mechanical indicator units) from

5100-467: The arrangement of flight control surfaces, such as the slats , flaps , and spoilers , resembling the layout of the C-5. The An-124 has a slightly shorter fuselage, has a slightly greater wingspan, and is capable of carrying a 17 percent larger payload. In place of the C-5's T-tail , the An-124 is furnished with a conventional empennage , similar in design to that of the Boeing 747 . The An-124 features

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5200-521: The cargo door, was delivered from Stelia Rochefort on 7 July 2017. The 3.1 t (3.1 long tons; 3.4 short tons), 10 m (33 ft) long and 8 m (26 ft) high door was delivered by Stelia Rochefort in September 2017. In October 2017, 75% of the first BelugaXL structural assembly was done; with systems, mechanical, and electrical integration underway before integration of the tail elements, which had already been received. Its maiden flight

5300-513: The change would imply purchasing between 50 and 60 engines with spares . The Russian engine specialist Aviadvigatel also indicated that a further development of its PD-14, which was intended for use on an upgraded model of the Russian-manufactured An-124, designated PD-35, generated 50% more power than the present Ukrainian Progress D-18T engines. During January 2019, Antonov revealed its plans to restart production of

5400-562: The deliveries of the first three XLs, as the five originals stayed in service until being withdrawn from 2021. The BelugaST fleet was reaching its limits, flying five times daily, and six days per week, for 10,000 hours in 2017, while some parts are moved over land. The time required for a BelugaST to move the parts of an A320 is three times as long as for the BelugaXL, and nine times longer for A350 parts. After an Airbus A350 production increase, Airbus aimed to deliver 880 aircraft in 2019, and raise A320neo output to 63 per month by 2021;

5500-455: The early 2000s, the cargo operator Volga-Dnepr opted to upgrade its An-124 freighter fleet, these works included engine modifications to conform with chapter four noise regulations, various structural improvements that increased service life, and numerous avionics and systems changes to facilitate four person operations, reducing the crew needed from six or seven. During April 2008, it was announced that Russia and Ukraine had agreed to resume

5600-608: The end of 2017. The flight test campaign used a single, instrumented aircraft. The front cargo door was attached in December 2017. In January 2018, the second arrived in Toulouse for its transformation, in two months less after lessons learned from the first. The first BelugaXL rolled off the assembly line on 4 January 2018, unpainted and without engines. Fewer than 1,000 flight test hours were planned for its certification campaign. After fitting its Rolls-Royce Trent 700 engines, it

5700-410: The entire aircraft. In the former case, the beaching gear is manually attached or detached with the aircraft in the water; in the latter case, the aircraft is maneuvered onto the cradle. Helicopters are able to land on water using floats or a hull and floats. For take-off a step and planing bottom are required to lift from the floating position to planing on the surface. For landing a cleaving action

5800-529: The fall of the Soviet Union , commercial operations of the An-124 became an increasingly important area of activity; to this end, civil certification was sought for the type by Antonov; this was issued on 30 December 1992. Sales of the An-124 to various commercial operators proceeded throughout the 1990s and into the mid 2000s; many of these were former military aircraft that were refurbished by Antonov prior to delivery, or unfinished fuselages that had been preserved, rather than producing new-build aircraft. During

5900-753: The first (MSN1824) had completed more than 140 test flights over 500 hours, the final stage before certification. A third airframe was undergoing conversion, expected to last until the fourth quarter of 2019, for delivery in 2020. Operations were expected to start with two XLs in the second half of 2019. After more than 200 flight tests over 700 hours, the BelugaXL received its European Aviation Safety Agency (EASA) type certification on 13 November 2019. The last two BelugaXLs to be produced are expected to have 180-minute ETOPS approval, allowing them to be used for transatlantic flights, typically to transport satellites to North American launch sites. As of February 2021, tests were being conducted to gain approval for

6000-469: The following year. As Russia–Ukraine relations continued to sour, Antonov begun to source new suppliers while also pushing to westernize the An-124. During 2018, the American engine manufacturer GE Aviation was studying reengining it with CF6s for CargoLogicAir , a Volga-Dnepr subsidiary. It was believed that this would likely provide a range increase; as Volga-Dnepr Group operated 12 aircraft,

6100-514: The front cargo door. Other features intended to ease loading including an onboard overhead crane in the cargo deck, capable of lifting up to 30 tonnes, while items up to 120 tonnes can be winched on board. Two separate radar units are typically present, one is intended for ground mapping and navigation purposes, while the other is for weather . During the 2000s, Germany headed an initiative to lease An-124s for NATO strategic airlift requirements. Two aircraft were leased from SALIS GmbH as

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6200-418: The fuselage for attaching a large freight container. Helicopters use skids, pontoons or wheels depending on their size and role. To decrease drag in flight, undercarriages retract into the wings and/or fuselage with wheels flush with the surrounding surface, or concealed behind flush-mounted doors; this is called retractable gear. If the wheels do not retract completely but protrude partially exposed to

6300-424: The fuselage lower sides as retractable main gear units on modern designs—were first seen during World War II, on the experimental German Arado Ar 232 cargo aircraft, which used a row of eleven "twinned" fixed wheel sets directly under the fuselage centerline to handle heavier loads while on the ground. Many of today's large cargo aircraft use this arrangement for their retractable main gear setups, usually mounted on

6400-438: The fuselage. The 640 t (1,410,000 lb) Antonov An-225 , the largest cargo aircraft, had 4 wheels on the twin-strut nose gear units like the smaller Antonov An-124 , and 28 main gear wheels. The 97 t (214,000 lb) A321neo has a twin-wheel main gear inflated to 15.7 bar (228 psi), while the 280 t (620,000 lb) A350 -900 has a four-wheel main gear inflated to 17.1 bar (248 psi). STOL aircraft have

6500-512: The ground vibration test in early June 2018, with Office National d'Etudes et de Recherches Aérospatiales (ONERA) and Deutsches Zentrum für Luft- und Raumfahrt (DLR) measuring its dynamic behaviour compared to flight envelope theoretical models. The flight-test programme was expected to last 600 hours. The second aircraft had its lower fuselage completed by mid-June, before upper shell structural work and freight door fitting after summer, for completion by September or October. The first flight

6600-603: The hull out of the water at higher speeds. Hydro skis replace the need for a boat hull and only require a plain fuselage which planes at the rear. Alternatively skis with wheels can be used for land-based aircraft which start and end their flight from a beach or floating barge. Hydro-skis with wheels were demonstrated as an all-purpose landing gear conversion of the Fairchild C-123 , known as the Panto-base Stroukoff YC-134 . A seaplane designed from

6700-471: The hydrodynamic features of the hull, long length/beam ratio and inverted spray gutter for example, allow operation in wave heights of 15 feet. The inverted gutters channel spray to the rear of the propeller discs. Low speed maneuvring is necessary between slipways and buoys and take-off and landing areas. Water rudders are used on seaplanes ranging in size from the Republic RC-3 Seabee to

6800-402: The landing gear usually consists of skis or a combination of wheels and skis. Some aircraft use wheels for takeoff and jettison them when airborne for improved streamlining without the complexity, weight and space requirements of a retraction mechanism. The wheels are sometimes mounted onto axles that are part of a separate "dolly" (for main wheels only) or "trolley" (for a three-wheel set with

6900-441: The largest military transport aircraft in service. In 1971, design work commenced on the project, which was initially referred to as Izdeliye 400 ( Product #400 ), at the Antonov Design Bureau in response to a shortage in heavy airlift capability within the Military Transport Aviation Command ( Komandovaniye voyenno-transportnoy aviatsii or VTA) arm of the Soviet Air Forces . Two separate final assembly lines plants setup for

7000-413: The limited pressurisation of its main cargo compartment (24.6 kPa, 3.57 psi), the airlifter has seldom been used to deploy paratroopers or to carry passengers, as they would typically require oxygen masks and cold-weather clothing in such conditions. In comparison, the upper deck is fully pressurised. The floor of the cargo deck is entirely composed of titanium , a measure that is usually prohibited by

7100-417: The lower corners of the central fuselage structure. The prototype Convair XB-36 had most of its weight on two main wheels, which needed runways at least 22 in (56 cm) thick. Production aircraft used two four-wheel bogies, allowing the aircraft to use any airfield suitable for a B-29. A relatively light Lockheed JetStar business jet, with four wheels supporting 44,000 lb (20 t), needed

7200-504: The main gear struts lengthened as they were extended to give sufficient ground clearance for their large four-bladed propellers. One exception to the need for this complexity in many WW II fighter aircraft was Japan's famous Zero fighter, whose main gear stayed at a perpendicular angle to the centerline of the aircraft when extended, as seen from the side. The main wheels on the Vought F7U Cutlass could move 20 inches between

7300-489: The main gears, which retract aft into the ends of the engine nacelles . The rearward-retracting nosewheel strut on the Heinkel He 219 and the forward-retracting nose gear strut on the later Cessna Skymaster similarly rotated 90 degrees as they retracted. On most World War II single-engined fighter aircraft (and even one German heavy bomber design ) with sideways retracting main gear, the main gear that retracted into

7400-412: The main landing gear fairings. As a consequence of the heat and blast effects produced by these APUs, some airports require pavement protection to be deployed. The landing gear of the An-124 is outfitted with an oleo strut suspension system for its 24 wheels. This suspension has been calibrated to allow for landing on rough terrain and is able to kneel, which allows for easier loading and unloading via

7500-519: The material cost. It is suitable for carrying almost any heavy vehicle, including multiple main battle tanks . The An-124 is powered by four Lotarev D-18 turbofan engines, each capable of generating up to 238–250 kN of thrust. To reduce the landing distance required, thrust reversers are present. Pilots have stated that the airlifter is relatively light on the controls and is easy to handle for an aircraft of its size. A pair of TA18-200-124 auxiliary power units (APUs) are accommodated within

7600-611: The nacelle under the control of dampers and springs as an anti-flutter device. Some experimental aircraft have used gear from existing aircraft to reduce program costs. The Martin-Marietta X-24 lifting body used the nose/main gear from the North American T-39 / Northrop T-38 and the Grumman X-29 from the Northrop F-5 / General Dynamics F-16 . When an airplane needs to land on surfaces covered by snow,

7700-451: The nose includes the cockpit, while a four-seat courier section is supplied by Airbus. Its vertical stabiliser is 50% larger; it has auxiliary fins on the horizontal stabiliser, and two ventral fins beneath the empennage. The BelugaXL operates at Mach 0.69 up to 35,000 ft (11,000 m) over 2,300 nmi (4,300 km; 2,600 mi) instead of the original Beluga's 900 nmi (1,700 km; 1,000 mi). Deharde Aerospace and

7800-444: The nosewheel/tailwheel and the two main gears. Blinking green lights or red lights indicate the gear is in transit and neither up and locked or down and locked. When the gear is fully stowed up with the up-locks secure, the lights often extinguish to follow the dark cockpit philosophy; some airplanes have gear up indicator lights. Redundant systems are used to operate the landing gear and redundant main gear legs may also be provided so

7900-594: The original BelugaST, and it can lift a payload 6 t (5.9 long tons; 6.6 short tons) heavier. Its aft section is based on the A330-300 , while its forward is based on the A330-200 for centre of gravity reasons, and the reinforced floor and structure is derived from the A330-200 Freighter . The A330 wings, main landing-gear, central and aft fuselage form a semi-built platform with few systems, without

8000-722: The outset with hydro-skis was the Convair F2Y Sea Dart prototype fighter. The skis incorporated small wheels, with a third wheel on the fuselage, for ground handling. In the 1950s hydro-skis were envisaged as a ditching aid for large piston-engined aircraft. Water-tank tests done using models of the Lockheed Constellation , Douglas DC-4 and Lockheed Neptune concluded that chances of survival and rescue would be greatly enhanced by preventing critical damage associated with ditching. The landing gear on fixed-wing aircraft that land on aircraft carriers have

8100-556: The pilot's canopy. A third arrangement (known as tandem or bicycle) has the main and nose gear located fore and aft of the center of gravity (CG) under the fuselage with outriggers on the wings. This is used when there is no convenient location on either side of the fuselage to attach the main undercarriage or to store it when retracted. Examples include the Lockheed U-2 spy plane and the Harrier jump jet . The Boeing B-52 uses

8200-595: The production of the An-124 in the third quarter of 2008. One month later, 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, the Russian United Aircraft Corporation announced it did not plan to produce any An-124s in the period 2009–2012. During late 2009, Russian President Dmitry Medvedev ordered production of

8300-458: The programme used components, systems, and various other elements drawn from in excess of 100 factories across the Eastern world. In 1979, manufacturing activity on the first airframe began. On 24 December 1982, the type performed its maiden flight . Three years later, the An-124 made its first appearance in the Western world when an example was displayed at the 1985 Paris Air Show . Following

8400-520: The results confirmed the characteristics laid down during preliminary studies. The Antonov An-124 Ruslan is a large, strategic airlift , four-engined aircraft . An aircraft with a similar role, it externally bears numerous similarities 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 , as well as

8500-513: The runway loading limit . The Zeppelin-Staaken R.VI , a large German World War I long-range bomber of 1916, used eighteen wheels for its undercarriage, split between two wheels on its nose gear struts, and sixteen wheels on its main gear units—split into four side-by-side quartets each, two quartets of wheels per side—under each tandem engine nacelle, to support its loaded weight of almost 12 t (26,000 lb). Multiple "tandem wheels" on an aircraft—particularly for cargo aircraft , mounted to

8600-538: The same thickness pavements with a third main leg for ten wheels, like the first Boeing 747 -100, weighing 700,000 lb (320 t) on four legs and 16 wheels. The similar-weight Lockheed C-5 , with 24 wheels, needs an 18 in (46 cm) pavement. The twin-wheel unit on the fuselage centerline of the McDonnell Douglas DC-10 -30/40 was retained on the MD-11 airliner and the same configuration

8700-525: The second (MSN1853) was 30% converted. After successful landing gear and flight-control system checks, MSN1824 was to be fuelled and ground tested. The third was expected to begin its conversion before the end of 2018. MSN1853 was to be first operational in 2019, after proving work in 11 European stations, while MSN1824 flight instrumentation was to be disassembled. It was rolled out with its Rolls-Royce Trent 700 engines but no winglets in April 2018. It passed

8800-508: The takeoff dolly/trolley and landing skid(s) system on German World War II aircraft—intended for a sizable number of late-war German jet and rocket-powered military aircraft designs—was that aircraft would likely be scattered all over a military airfield after they had landed from a mission, and would be unable to taxi on their own to an appropriately hidden "dispersal" location, which could easily leave them vulnerable to being shot up by attacking Allied fighters. A related contemporary example are

8900-422: The vehicle on landing and during subsequent surface movement, and is not used for takeoff. Given their varied designs and applications, there exist dozens of specialized landing gear manufacturers. The three largest are Safran Landing Systems , Collins Aerospace (part of Raytheon Technologies ) and Héroux-Devtek . The landing gear represents 2.5 to 5% of the maximum takeoff weight (MTOW) and 1.5 to 1.75% of

9000-685: The water suction on the afterbody. Two steps were used on the Kawanishi H8K . A step increases the drag in flight. The drag contribution from the step can be reduced with a fairing. A faired step was introduced on the Short Sunderland III. One goal of seaplane designers was the development of an open ocean seaplane capable of routine operation from very rough water. This led to changes in seaplane hull configuration. High length/beam ratio hulls and extended afterbodies improved rough water capabilities. A hull much longer than its width also reduced drag in flight. An experimental development of

9100-482: The wing centre section. The forward area of this upper deck is where the flight deck and the crew area accommodated; movement between the upper and lower decks is via a pair of foldable internal ladders. The cargo compartment of the An-124 is 36×6.4×4.4 m (118×21×14 ft), ca. 20% larger than the main cargo compartment of the C-5 Galaxy, which is 36.91×5.79×4.09 m (121.1×19.0×13.4 ft). Largely due to

9200-499: The wings was raked forward in the "down" position for better ground handling, with a retracted position that placed the main wheels at some distance aft of their position when downairframe—this led to a complex angular geometry for setting up the "pintle" angles at the top ends of the struts for the retraction mechanism's axis of rotation. with some aircraft, like the P-47 Thunderbolt and Grumman Bearcat , even mandating that

9300-424: The wingtip support wheels ("pogos") on the Lockheed U-2 reconnaissance aircraft, which fall away after take-off and drop to earth; the aircraft then relies on titanium skids on the wingtips for landing. Some main landing gear struts on World War II aircraft, in order to allow a single-leg main gear to more efficiently store the wheel within either the wing or an engine nacelle, rotated the single gear strut through

9400-445: Was common during the early propeller era, as it allows more room for propeller clearance. Most modern aircraft have tricycle undercarriages. Taildraggers are considered harder to land and take off (because the arrangement is usually unstable , that is, a small deviation from straight-line travel will tend to increase rather than correct itself), and usually require special pilot training. A small tail wheel or skid/bumper may be added to

9500-404: Was ground tested for months to assess its systems operation, while bench tests in Toulouse and Hamburg, on flight simulators and in laboratories, simulated flight loads on full-scale copies of specific joints between the upper bubble and the lower fuselage, clearing the aircraft for flight, then type certification. In March 2018, the first BelugaXL (MSN1824) was having its engines fitted, while

9600-409: Was indefinitely grounding its fleet of An-124 aircraft to inspect the 60 engines (including spares) following the 13 November 2020 unconfined engine failure at Novosibirsk . As of 29 December 2020, the first Volga-Dnepr An-124-100 was back in service. As of late 2020, 20 An-124s were in commercial service. As of June 2019 , five accidents with An-124 hull losses have been recorded involving

9700-500: Was on 19 July 2018, from Blagnac , Toulouse, France. In February 2019, the first aircraft flew to various destinations, including Airbus's wing plants in Bremen , Germany and Broughton , Wales. The first BelugaXL to enter service was the second aircraft built, which rolled out on 19 March 2019; the first test aircraft will be retro-fitted after certification. The second aircraft (MSN1853) commenced flight-testing on 15 April, and by then,

9800-440: Was scheduled for summer 2018 before 10 months of flight tests necessary for its certification campaign, and a 2019 service entry. The second aircraft was to enter final assembly line in December 2018, and the three remaining each following year. After mating the vertical fin, tail cone and horizontal stabiliser including the outboard vertical surfaces, the main freight door was to be attached from mid-November, before power-on at

9900-510: Was the Chief engineer of An-124 and An-225. After the dissolution of the Soviet Union , commercial operations were quickly pursued for the An-124, leading to civil certification being obtained by Antonov on 30 December 1992. Various commercial operators opted to purchase the type, often acquiring refurbished ex-military airlifters or stored fuselages rather than new-build aircraft. By July 2013, 26 An-124s were reportedly in commercial service while

10000-467: Was used on the initial 275 t (606,000 lb) Airbus A340 -200/300, which evolved in a complete four-wheel undercarriage bogie for the heavier 380 t (840,000 lb) Airbus A340-500/-600. The up to 775,000 lb (352 t) Boeing 777 has twelve main wheels on two three-axles bogies, like the later Airbus A350 . The 575 t (1,268,000 lb) Airbus A380 has a four-wheel bogie under each wing with two sets of six-wheel bogies under

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