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The Lockheed C-5 Galaxy is an American military transport aircraft built by Lockheed. It was designed to provide strategic heavy airlift over intercontinental distances and to carry outsize and oversize cargo. The C-5 Galaxy has been operated by the United States Air Force since 1969 and is one of the largest military aircraft in the world.
Development
Background
In 1961, several aircraft companies began studying heavy jet transport designs that would replace the C-133 transport and complement C-141 Starlifters. The US Army wanted a larger transport than the C-141. In 1962, the proposed CX-4 six-engine transport was rejected, because it was not viewed as a significant advance over the C-141. By late 1963, the next conceptual design was named CX-X. It was equipped with four engines, instead of six engines in the earlier CX-4 concept. The CX-X had a gross weight of 550,000 pounds (249,000 kg), a maximum payload of 180,000 pounds (81,600 kg) and a speed of Mach 0.75 (500 mph/805 km/h). The cargo compartment was 17.2 feet (5.24 m) wide by 13.5 feet (4.11 m) high and 100 feet (30.5 m) long with front and rear access doors.[2]
Origin of C-5
The criteria were finalized and an official Request for Proposal was sent out in April 1964 for the "Heavy Logistics System" (CX-HLS) (previously CX-X). In May 1964, proposals for aircraft were received from Boeing, Douglas, General Dynamics, Lockheed, and Martin Marietta. Proposals for engines were received from General Electric, Curtiss-Wright Corporation, and Pratt & Whitney. After a downselect, Boeing, Douglas and Lockheed were given additional study contracts for the airframe, along with General Electric and Pratt and Whitney for the engines. In 1965 Lockheed's aircraft design and General Electric's engine design were selected for the new transport.[2]
The first C-5A Galaxy (number 66-8303) was rolled out of the manufacturing plant in Marietta, Georgia on March 2, 1968. On June 30, 1968 Lockheed-Georgia Co. began flight testing its new Galaxy C-5A heavy transport with the aircraft's first flight taking to the air under the call-sign "eight-three O three heavy".
Upon completion of testing the first C-5A was transferred to the Transitional Training Unit at Altus Air Force Base, OK, in December 1969. Lockheed then delivered the first operational Galaxy to the 437th Airlift Wing, Charleston Air Force Base, SC, in June 1970.
In the early 1970s, the C-5 was considered for the role of Shuttle Carrier Aircraft to transport the Space Shuttle to Kennedy Space Center by NASA, but rejected in favor of the Boeing 747 due in part to the 747's low-wing design. In contrast, the Soviet Union chose to transport its shuttles using the high-winged An-225, which is derived from the An-124, which is very similar to the C-5 in terms of design and function.
In the mid-1970s, wing cracks were found throughout the fleet. Consequently, all C-5A aircraft were restricted to a maximum of 50,000 pounds (22,700 kg) of cargo each. To increase their lifting capability and service life, 77 C-5As underwent a re-winging program from 1981 to 1987. The final re-winged C-5A was delivered in July 1986.
The first C-5B was delivered to Altus Air Force Base in January 1986. In April 1989, the last of 50 C-5B aircraft was added to the 77 C-5As in the Air Force's airlift force structure. The C-5B includes all C-5A improvements and numerous additional system modifications to improve reliability and maintainability.[3]
In 1998, the Avionics Modernization Program (AMP) began upgrading the C-5's avionics to include a glass cockpit, navigation equipment, and a new autopilot system.[4] Another part of the C-5 modernization effort is the Reliability Enhancement and Re-engining Program (RERP). The program will mainly replace the engines with newer, more powerful ones. Three C-5s are to undergo RERP as a test with full production planned to begin in May 2008.[5]
Design
The forward section of the C-5 Galaxy lifts open to allow loading of bulky items such as the Super Scorpio robotic rescue vehicles.
The C-5 is a large high-wing cargo aircraft. It has a distinctive high T-tail, 25 degree wing sweep, and four TF39 turbofan engines mounted on pylons beneath the wings. The C-5 is similar in appearance to its smaller predecessor, the C-141 Starlifter. The C-5 has 12 internal wing tanks and is equipped for aerial refueling. With aerial refueling, the Galaxy's range is limited only by crew endurance. It has both nose and aft doors for "drive-through" loading and unloading of cargo.[6]
Features of the C-5 include:[6]
- Its cargo compartment is 121 ft long, 13.5 ft high, and 19 ft wide (37 m by 4.1 m by 5.8 m), or just over 31,000 ft³ (880 m³). The compartment can accommodate up to 36 463L master pallets or a mix of palletized cargo and vehicles. - It is interesting to note the cargo hold of the C-5 is a foot longer than the distance of the first powered flight by the Wright Brothers' flyer at Kitty Hawk.
- It has an upper deck seating area for 73 passengers. The passengers face the rear of the aircraft, rather than forward.
- It can take off fully loaded within 8,300 ft (2,530 m) and land within 4,900 ft (1,490 m).
- Its Stall speed at maximum landing weight, zero bank, full flaps is approximately 114 knots (211 km/h).
- Its high flotation landing gear has 28 wheels to share the weight. The "kneeling" landing gear system that permits lowering of the parked aircraft so the cargo floor is at truck-bed height to facilitate vehicle loading and unloading.
- The nose and aft doors open the full width and height of the cargo compartment to permit faster and easier loading. Ramps are full width at each end for loading double rows of vehicles.
- The volume of unusable space in a C-5's tail assembly (aft of the ramp) is larger than the available cargo space of a C-130 Hercules.
- It has a MADAR (Malfunction Detection Analysis and Recording), a system that records and analyzes information and detects malfunctions in more than 800 test points. The C-5 is also known as "FRED" (Fucking Ridiculous Economic/Environmental Disaster) by its crews due to its reliability issues and large consumption of fuel. The C-5 requires an average of 16 hours of maintenance for each flight hour based on 1996 data.[7]
The Galaxy is capable of carrying nearly all of the Army's combat equipment, including bulky items such as the 74 ton armored vehicle launched bridge (AVLB), from the United States to any location on the globe.[6]
Operational history
C-5s were originally stationed at Altus AFB, OK; Charleston AFB, Dover AFB, DE; and Travis AFB, CA. AMC transferred some C-5s to the Air Force Reserve components starting with Kelly AFB, Texas, in 1985; followed by Stewart Air National Guard Base, NY; and Westover Air Reserve Base, Massachusetts. Beginning in October 2005 squadrons were formed at Wright-Patterson Air Force Base near Dayton, Ohio, the Tennessee Air National Guard at Memphis International Airport, TN and Martinsburg WV (WV ANG) in December 2006. The Wright-Patterson C-5s replace the squadron's C-141s, which were the last Starlifters to be retired. In December of 2006, the 167th Airlift Wing of the West Virginia Air National Guard in Martinsburg (WV) received the first of 10 C-5A aircraft slated for the base. 70-0459 was the first Aircraft to go to Martinsburg. Memphis received 70-0449 as their first aircraft in October 2004 from Travis AFB, while Wright Patterson received 70-0457 from Dover in October 05. Altus no longer has C-5s stationed at the base, and the C-5 school house has transferred to Lackland AFB, TX (Kelly Field). Westover switched all of their A models to B-models from Dover and Travis, while sending their A models to Memphis, Martinsburg and Wright-Patterson.
The C-5 is the largest aircraft to ever operate in the Antarctic. Williams Field near McMurdo Station is capable of handling C-5 aircraft and the first C-5 landed there in 1989.[8]
Fourteen C-5As have been retired as of 2005. Aircraft number 69-0004 was the first, sent to the Warner-Robins ALC for tear down and inspection. Data from inspection will be used to evaluate structural integrity and estimate remaining fleet lifespan. Thirteen C-5As were sent to the Air Force's Aerospace Maintenance and Regeneration Center (AMARC) for inspection. At AMARC, 66-8306 underwent tear down and inspection similar to 69-0004 at WR-ALC. The remaining 12 will eventually be reclaimed as destructive inspection is performed on the airframes to test for corrosion and fatigue.[9]
Sources have cited that the Air Force might be looking to replace some of these aircraft and have expressed interest in a military version of the new Airbus A380.[10]
Variants
C-5A
The C-5A is the original version of the C-5. From 1969 to 1973, 81 C-5As were delivered to US Air Forces bases. Due to cracks found in the wings in the mid-1970s, the cargo weight was restricted. To restore the plane's full capability, the wing structure was redesigned. A program to install new strengthened wings on 77 C-5As was conducted from 1981 to 1987. The redesigned wing made use of a new aluminum alloy that didn't exist during the original production.[11]
C-5B
The C-5B is an improved version of the C-5A. It incorporated all modifications and improvements made to the C-5A with improved wings, upgraded TF-39-GE-1C turbofan engines and updated avionics. From 1986 to 1989, 50 of the new variant were delivered to the US Air Force.[12]
C-5C
The C-5C is a specially modified variant for transporting large cargo. Two C-5s (68-0213 and 68-0216) were modified to have a larger internal cargo capacity, such as the removal of the troop compartment, to accommodate large payloads, such as satellites for use by NASA. A number of other modifications were made, including adding a second inlet for ground power which can then be used to feed any power-dependent equipment which may form part of the cargo. The two C-5Cs are operated by US Air Force crews on the behalf of NASA, and are stationed at Travis AFB, CA. 68-0216 completed the Avionics Modernization Program in January 2007.[13]
C-5M
Based on a recent study showing 80% of the C-5 airframe service life remaining, AMC began an aggressive program to modernize all remaining C-5Bs and C-5Cs and many of the C-5As. The C-5 Avionics Modernization Program (AMP) began in 1998 and includes upgrading avionics to Global Air Traffic Management compliance, improving communications, new flat panel displays, improving navigation and safety equipment, and installing a new autopilot system. First flight of the first modified C-5 with AMP(85-0004) occurred on December 21, 2002.[14]
Another part of the plan is a comprehensive Reliability Enhancement and Re-engining Program (RERP), which includes new General Electric CF6-80C2 engines, pylons and auxiliary power units, with upgrades to aircraft skin and frame, landing gear, cockpit and the pressurization system. The CF6 engine produces 22% more thrust (for a total of 54,000 lb (240 kN) from each engine) than existing C-5 engines which will result in a 30% shorter take-off roll, a 38% higher climb rate to initial altitude, a significantly increased cargo load, and a longer range between refueling.[5] The C-5s that complete these upgrades are designated C-5M Super Galaxy.[15]
The C-5 AMP and RERP modernization programs plan to raise mission-capable rate to a minimum goal of 75%.[5] Over the next 40 years, the U.S. Air Force estimates the C-5M will save over US$20 billion.[16] The first of 111 planned C-5M conversions was completed on May 16, 2006, and performed its first flight on June 19 2006.[16]
C-5Ms have been in flight testing out of Dobbins Air Reserve Base since June 2006. Two of the three (86-0013 and 86-0025) aircraft may be identified by the distinctive red nose boom used to acquire test data.[4] As of February 2008, the USAF will convert all remaining C-5Bs and C-5Cs into C-5M with avionics upgrades and re-engining.[17] The C-5As will only receive only the avionics upgrades.[18]
Operators
Unlike its Soviet (Ukrainian) counterpart, the civilian- and military-operated Antonov An-124 Ruslan or An-225 Mriya, use of the C-5 is confined entirely to the military and government use.
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