| Lockheed C-5 Galaxy | |
|---|---|
 A-C-5A "Galaxy" of the US Air Force | |
| Type | four-engined strategic transporter |
| draft country |
|
| Manufacturer | Lockheed Corporation |
| first flight June June | June 30, 1968 |
| commissioning | June 1970 |
| production time |
|
| quantity | 131 |
The Lockheed C-5 Galaxy is a mile wide-bodywide -body transport aircraft that was developed for the US Air Force in the early 1960s and is still in service with them today. Until the completion of the Soviet Antonov An-124 Ruslan, it was the largest aircraft in the world. At the end of 2012, 73 of the 131 units produced were still in service with the US Air Force.
History
Development
In the early 1960s, the US Air Force commissioned design studies for a new type of long-range strategic transport aircraft. The aim was to replace the aging Douglas C-133 Cargomaster and to supplement the existing, but too small, Lockheed C-141 Starlifter . The procurement of up to 200 machines was planned. The technical requirements of the project, now called Cargo Experimental-Heavy Logistics System (CX-HLS), were very high right from the start:
- a maximum payload of over 100 tons, more than twice as high as that of the C-141
- intercontinental-range
- a large cargo hold accessible from both ends of the fuselage for short turnaround times
- Takeoff fully loaded from 8,000 ft (2,438 m) runway length; Landing at 4,000 ft (1,219 m) semi-paved runway
Aircraft manufacturers Boeing, Douglas, General Dynamics Lockheed ,and Martin Marietta submitted designs for the aircraft, as well as General Electric, Curtiss-Wright and Pratt & Whitney for the engines. After a pre-selection, Boeing, Douglas , and Lockheed were allowed to continue their design studies for the aircraft and General Electric and Pratt & Whitney for the engines.
Procurement
In August 1965, General Electric was initially awarded the contract to develop the engines. With an estimated total weight of 350 t and the planned four engines, each engine had to be able to develop a thrust of around 180 kN which was enormous for the time. Finally, in October 1965, Lockheed - who had just built the C-141 - received an order for production of 115 of the aircraft, known in-house as the L-500 and by the Air Force as the C-5A Galaxy . Although Boeing's design was favored by the review board for technical reasons, the Department of Defense under Robert McNamara chose Lockheed– their offer was the cheapest. The final Boeing and Douglas designs, unlike the L-500 design, had a conventional tailplane and also differed in having side-opening bow doors from the winning Lockheed design, which had an upward-opening bow door.
One of Boeing's designs also had a shortened upper deck, giving the aircraft a hump. The idea of the hump flowed into the plans for the Boeing 747 a short time later.
Production
The first flight took place on June 30, 1968, at Dobbins Air Force Base in Georgia. The first C-5A was delivered in December 1969 and reported operational by the Military Airlift Command (MAC) in September 1970.
At the time, the Galaxy was the largest aircraft in the world, only in December 1982 was it overtaken by its Soviet counterpart, the Antonov An-124 Ruslan While this is 20 feet (6 m) shorter than the C-5, it has a longer wingspan, higher payload capacity, and higher takeoff weight. Since 1988, the Antonov An-225 has been the largest aircraft. On September 13, 2009, a C-5M set 41 world records (submitted to the FAI ) in the C-1.S class in one flight; e.g. B. 80 t payload in 24 min at 12 km altitude.
From the beginning, there were problems with the costs and the technology of the project. The American press considered the need for such an aircraft to be artificial, to provide the airline industry with tax-financed contracts worth billions, which in turn would benefit politicians and the military. The whole thing developed into the first major procurement scandal in the US defense industry.
The implementation of the overly ambitious requirements caused such high development costs that the price for a copy of the Galaxy continued to rise: from the estimated 16.5 to 60 million US dollars. In November 1969, the US Air Force pulled the emergency brake and reduced the order from 115 to 81 machines.
After all, tests and the first missions soon showed that the C-5 did not meet the requirements placed on it - in particular the range with a high payload. It turned out that parts of the wing structure had been designed too weakly and strengthening the wing would cost around 2 billion US dollars. The result was sometimes drastic flight restrictions for payload (no 100 t possible) or range and the resultant a lengthy and expensive conversion program, which culminated in the redesign and replacement of the wings all around-around 1987.
In the early 1980s, as part of the armaments program under President Ronald Reagan, the US government decided to procure another 50 units of the series. The positive experiences during Operation Nickel Grass also contributed to this decision. So Lockheed resumed production for the improved C-5B model. Your first flight took place on September 10, 1985, and the machines were delivered from January 1986 to April 1989.
From the outset, Lockheed tried to win other customers for their transporter in addition to the military but was unsuccessful. These circumstances earned the Galaxy the nickname FRED, which stands for Fantastic Ridiculous Economic Disaster.
Modernization
Since 2004, 52 C-5 Galaxys have undergone extensive upgrades to increase their reliability and durability, allowing for service into 2040. Modernization is divided into two programs. First, the machines go through the "Avionics Modernization Program" (C-5 AMP), the planning of which began in 1998. AMP included a complete avionics replacement , installation of a Global Air Traffic Management System, improvements to communications and navigation systems, new cockpit displays and safety equipment, and installation of a new autopilot.
After the AMP, the machines go through the Reliability Enhancement and Re-engineering Program (C-5 RERP). The focus here is on replacing the engines: they were replaced by the F138-GE-100 type with up to 222.41 kN thrust , which corresponds to a thrust increase of 22% and leads to significantly improved flight performance (among other things, the required runway could be 30%, the time to reach cruising altitude is reduced by 38%). The F138-GE-100 is a variant of the civilian General Electric CF6-80C2, which also includes the Boeing 747-400drives. Furthermore, Lockheed Martin carries out work on the pylons, auxiliary engines, wings, flaps, cockpit and hydraulic system. The so revised machines are referred to as C-5M Super Galaxy. On June 19, 2006, the first completely rebuilt aircraft completed its maiden flight at Dobbins Air Reserve Base, Georgia .
A total of one C-5A, 49 C-5Bs and both C-5Cs will be converted to C-5M Super Galaxys. Originally, all C-5A were to be rebuilt, but since the costs rose from 11.1 billion US dollars estimated in November 2001 to 17.5 billion US dollars by the end of 2007, this project was abandoned (with the exception of a C-5A, which had already been remodeled at that time). As a replacement, the fleet was expanded to include the Boeing C-17 Globemaster III . The complete modernization of all remaining C-5 Galaxys was completed in the summer of 2018, with a total cost of 7.7 billion US dollars.Lockheed was able to deliver the last C-5M Super Galaxy on August 2, 2018.
Deployment
A total of 131 C-5s were built, six of which have been lost in accidents so far. The aircraft in service are in service with the Air Mobility Command (AMC), the Air National Guard (ANG) and the Air Force Reserve Command (AFRC). Since entering service in 1970, the C-5 has participated in virtually every major US Air Force airlift operation. Despite all the technical problems, the C-5 Galaxy quickly proved indispensable to the USAF because it can be used to transport even bulky military equipment or troops quickly and - with air refueling - to every corner of the world.
Since the early 1990s, it has been increasingly relieved by the Boeing C-17 Globemaster III, which in many cases can operate more efficiently than the C-5. From the older A-series, 42 machines were decommissioned from November 2003 to November 2011 and February 2014 to December 2015 at the 309th Aerospace Maintenance and Regeneration Group (AMARG). [7] [8] By September 2017, the remaining 33 copies of the A version were also retired. [6] Since a successor model has not yet been developed, the remaining machines, converted to C-5M Super Galaxy by 2018, are to remain in service until 2040.
Engineering/Design
shoulder wing
In order to be able to meet the requirements, only a high-wing or shoulder -wing construction was possible from the outset . This has the following advantages:
- The cargo space is not affected by the continuous wing spar, as this runs above the cabin;
- The engines can be suspended under the wings and still have sufficient clearance from the ground. This prevents too much dust being sucked up when using semi-paved slopes.
This ground clearance is also important for another feature of the Galaxy : To make loading and unloading easier, the entire aircraft can be lowered using the landing gear hydraulics . In order to keep the ground pressure low on unpaved ground, the weight is distributed over 28 wheels, four of them at the bow. The main landing gear consists of four supports with six wheels each in a 2+4 arrangement.
Two decks
The two openings at the bow (the nose is folded up) and stern are equipped with ramps and winches, which enables short turnaround times. The cargo area is 37 m long, 5.8 m wide and 4.1 m high. For example, the C-5 can accommodate several main battle tanks , helicopters , missiles or complete trucks in its cargo hold. For passenger transport, up to 270 seats can be palletized on the main deck, which is pressurized and air-conditioned for this purpose. Above this is the upper deck with the pilot 's cockpit , quarters for a second crew and couriers, and behind the central wing a fully equipped compartment for 75 passengers. Thus, the C-5 Galaxyas a troop carrier, it can accommodate 345 passengers in addition to the crew.
Variants
- L-500 : Lockheed's internal model number and designation for unrealized civilian versions of the Galaxy.
- C-5A : First production series; 81 machines were built until 1973.
- 66-8303 to 66-8307 c/n 500-0001 to 500-0005 (5 pieces)
- 67-0167 to 67-0174 c/n 500-0006 to 500-0013 (8 pieces)
- 68-0211 to 68-0228 c/n 500-0014 to 500-0031 (18 pieces)
- 69-0001 to 69-0027 c/n 500-0032 to 500-0058 (27 pieces)
- 70-0445 to 70-0467 c/n 500-0059 to 500-0081 (23 pieces)
- 70-0468 Order withdrawn
- 71-0180 to 71-0212 Order withdrawn
- 72-0099 to 71-0112 Order withdrawn
- C-5B : Second production series of 50 machines, delivered from 1986 to 1989. The structural reinforcements that were subsequently required for the C-5A were taken into account here from the outset. In addition, improved avionics and adaptation to the state of the art.
- 83-1285 c/n 500-0082 (1 piece)
- 84-0059 to 85-0062 c/n 500-0083 to 500-0086 (4 pieces)
- 85-0001 to 85-0010 c/n 500-0087 to 500-0096 (10 pieces)
- 86-0011 to 86-0026 c/n 500-0097 to 500-0112 (16 pieces)
- 87-0027 to 86-0045 c/n 500-0113 to 500-0131 (19 pieces)
- C-5C : Two C-5As were converted to carry space cargo, such as satellites and parts of the International Space Station (ISS) . The upper deck troop compartment has been removed and the tailgate has been modified to accommodate special containers for space parts that are too large for the C-5A/B.
- 68-0213 c/n 500-0016 (1 piece)
- 68-0216 c/n 500-0019 (1 piece)
- C-5D : Lockheed's design proposal for new Galaxy construction in the early 1990s, but was never implemented.
- C-5M : From 2004 to 2018, a total of 52 C-5 machines were converted to the C-5M "Super Galaxy" standard at a cost of US$7.7 billion. The modernization included new F138-GE-100 engines , new avionics and a heavily revised glass cockpit.
Specifications
| parameter | Data of the C-5B Galaxy | Data of the C-5M Super Galaxy |
|---|---|---|
| crew | 5 + max. 15 in the front part of the cabin | |
| length | 75.53m | |
| span | 67.88m | |
| wing area | 575.98 sqm | |
| wing stretch | 7.99 | |
| wing loading | 295 to 659 kg/m² | 299 to 661 kg/m² |
| Height | 19.34m | |
| hold dimension | Length: 43.80 m, width: 5.79 m, height: 4.11 m | |
| empty mass | 169,643 kg | 172,370kg |
| maximum take-off mass | 379,657kg | 381,018kg |
| maximum payload | 118,387 kg or up to 345 soldiers | 129,274 kg or up to 345 soldiers |
| fuel capacity | 193,620 liters | |
| top speed | 919 km/h (at 7,620 m altitude) | 932 km/h (at optimal flight altitude) |
| march speed | 880 km/h (at 7,620 m altitude) | k. A |
| service ceiling | 10,900m | k. A |
| max rate of climb | 8.75m/s | 9.14m/s |
| Range | 4,440 km (at maximum payload) |
|
| transfer range | 10,411km | 12,936km |
| takeoff distance | 2,600m | k. A |
| landing track | 1,100m | k. A |
| landing speed | 225km/h | k. A |
| engine | four turbofan engines TF39-GE-1C with 191.34 kN thrust each | four turbofan engines F138-GE-100 with 222.41 kN thrust each |
| thrust to weight ratio | 0.21 to 0.46 | 0.24 to 0.53 |
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