Partners in Freedom

		Lockheed Martin C-130 Hercules


Specifications Manufacturer Lockheed Martin Date in service C-130A . . . . . . . . . . . . .1956 C-130E . . . . . . . . . . . . .1962 C-130J . . . . . . . . . . . . . 1996 Type Transport Crew Three Engine Allison T56-A-15 turboprops Users U.S. Air Force (Active, Air National Guard, and Reserve), U.S. Navy, U.S. Marine Corps, U.S. Coast Guard, and over 65 countries Dimensions Wingspan . . . . . . . . . . .132.6 ft Length . . . . . . . . . . . . . . 97.8 ft Height . . . . . . . . . . . . . . 38.4 ft Wing area . . . . . . . . .1,745 sq ft Weight Empty . . . . . . . . . . . .75,743 lb Gross . . . . . . . . . . . .175,000 lb Performance Cruise speed . . . . . . . .360 mph Range . . . . . . . . . . . .2,700 n mi

		Highlights of Research by Langley for the C-130 Lockheed used aerodynamic computational codes developed by Langley in the configuration development of models of the C-130. Under a Langley contract in the early 1970’s, Lockheed produced an advanced boron reinforced metal center wing box for the C-130 that was flight tested on three C-130E aircraft. In the 1980’s, Lockheed tested a composite center wing box for the C-130, which was not implemented but provided expertise for applications of advanced composites to other Lockheed Martin products, including the F-22. Lockheed, under contract to Langley, developed piloted simulators and interacted with Langley researchers to develop advanced cockpit liquid crystal flat-panel displays for the C-130J. The Lockheed (now Lockheed Martin) C-130 Hercules is arguably the most versatile military transport aircraft ever built. The aircraft is capable of operating from rough, dirt strips and is the prime transport for air dropping troops and equipment into hostile areas. C-130’s fulfill a wide range of operational missions in both peace and war, with specialized versions of the aircraft that perform an enormous number of roles. The C-130J incorporates state-of-the-art technology to reduce manpower requirements, lower operating and support costs, and provide life cycle cost savings over earlier C-130 models. Langley’s contributions to the C-130 program include composite structures and materials, noise reduction, cockpit displays, and aerodynamic technologies. Lockheed has extensively used basic and applied research studies conducted by Langley in the continuous evolution of the C-130. For example, aerodynamic analyses of wing performance, stall characteristics, and loads have been accomplished with computational methods developed by Langley. Also, Langley methodology has been used to predict C-130 exterior noise and to reduce interior noise. Lockheed’s participation in the design and development of advanced simulators at Langley and Langley’s research on advanced cockpit displays led to the adoption of liquid crystal flat-panel displays for the C-130J. The most interactive Langley and Lockheed studies of the C-130 have occurred in applications of composite structures and materials. Under Langley sponsored contracts in the 1970’s, Lockheed fabricated and tested a boron reinforced metal center wing box to improve the fatigue life by a factor of three and reduce the weight by 300 lb. The modified wing box was subsequently flight tested on three C-130 aircraft, which are still in routine fleet service. In the 1980’s, a subscale all-composite C-130 center wing box was designed, fabricated, and structurally tested as part of the Langley Advanced Composites Technology (ACT) Program to validate the potential for increased load levels with reduced weight. On November 6, 1998, Lockheed Martin arranged for a C-130J to visit Langley for a special ceremony in honor of NASA’s continuous contributions to the C-130 Hercules.

		Langley Contributions to the C-130

Composite Structures and Materials		Lockheed Martin has had an interest in Langley research on the development of advanced composite structures for the past 30 years. Working under a long series of Langley contracts, Lockheed has developed composite flaps, wing trailing edges, and propellers for the C-130J. As a result of extensive experience from these efforts, Lockheed has also developed composite process improvements for reduced costs. In 1968, thorough inspections of the Air Force C-130 fleet revealed that almost half of the 619 aircraft in operational service had fatigue cracks in the center wing section. The technical community offered numerous recommendations to update and repair this vital aircraft. In the 1970’s, Lockheed conducted a five-phase program under a Langley contract to develop and demonstrate the selective reinforcement of conventional metallic structures with boron composites. This program, under the direction of Langley researcher H. Benson Dexter, was designed to demonstrate that advanced filamentary boron composites could improve static strength and fatigue endurance with less weight than would be possible with metal reinforcement. Contract activities included the development of a basis for structural design, selection, and verification of materials and processes; manufacturing and tooling development; and fabrication and test of full-scale portions of the center wing box. The baseline C-130E aluminum center wing box design was modified by removing aluminum and adding unidirectional boron reinforcing laminates bonded to the crown of the hat stiffeners in the wing structure. The center wing sections on three C-130E fleet aircraft with fatigue cracks were replaced with the new stronger aluminum wing box. This hybrid design improved the fatigue life by a factor of three while reducing the weight by 300 lb over the conventional metallic wing. Flight tests of the modified center wing structure were later conducted on three C-130E fleet aircraft. These aircraft were entered into routine fleet service in 1974 and are still operational. Unfortunately, the Air Force was not ready to commit to the new technology. In the 1980’s, Lockheed actively participated in several contracts for the development of composite wing and fuselage structures that led to the Langley Advanced Composites Technology (ACT) Program. Working under a Langley contract managed by Randall C. Davis, Lockheed designed and fabricated a full height, half-chord, all-composite center wing box for the C-130. This wing box was designed, fabricated, and successfully tested at the higher load requirements of the special operations aircraft. The resulting wing box weight was lower than the conventional metal wing box. Funding reductions for the ACT Program terminated the potential C-130 applications, and the remaining advanced composite program elements were applied to other aircraft such as the F-22.
Advanced Cockpit Displays		Under NASA contract, Lockheed built three individual simulators that are located at Langley, NASA Ames Research Center, and Lockheed. Interactions with the Langley staff regarding NASA research on advanced cockpit displays led to the development of head up display (HUD) technology and liquid crystal flat-panel displays, which provide integrated instrument information and significantly reduce pilot workload and increase maneuver precision for the C-130J.
Acoustics		As a result of certain mission specific requirements, the external and interior noise characteristics of the C-130 have received considerable attention from Lockheed. The utilization of the aircraft for special missions requires that the exterior noise be minimized. Likewise, the interior noise for missions that transport combat troops or sensitive instrumentation must be controlled through accurate acoustic analysis. In accomplishing these tasks, Lockheed used noise prediction and control methods developed by Langley.
Aerodynamic Technologies		The aerodynamic development of the C-130 by Lockheed included the utilization of advanced databases of Langley experimental and computational studies. Although no wind-tunnel tests of the C-130 configuration have been conducted in Langley facilities, discussions of the interpretation and application of Langley aerodynamic concepts and data to the C-130 were common during the development of the aircraft. For example, Lockheed’s interest in providing short takeoff and landing capabilities to the C-130 stimulated discussions on all facets of Langley research on high-lift systems, including trailing-edge flaps, propeller-induced effects, and powered-lift concepts. Lockheed remained particularly informed and interested in potential applications of the externally blown flap (EBF) and the upper-surface blowing (USB) powered-lift concepts conceived and developed at Langley. Numerous discussions with Langley researchers took place, especially with John P. Campbell and Joseph L. Johnson, Jr. for the EBF concept, and with Johnson for the USB concept. Lockheed has applied computational codes developed by Langley to assess and improve aircraft characteristics, including the stall characteristics of the C-130J. Aerodynamic loads and several other significant aerodynamic topics have been investigated with the computational code USM3D, which was developed by Neal T. Frink of Langley. Another Langley aerodynamic code, FUN2DI, was used by Lockheed to simulate the effects of leading-edge ice shapes on the C-130J wing and empennage lifting characteristics. In this particular application, the code significantly reduced the number of tests required to support Federal Aviation Administration (FAA) certification.
Recognition Visit		As a gesture of goodwill and recognition of the contributions of all the NASA research centers (Langley, Ames, Glenn, and Dryden) to the development of the C-130 Hercules, Lockheed Martin arranged for a visit of a C-130J to the Langley Research Center on November 6, 1998. The C-130 flew to Langley from the Lockheed Martin facility in Marietta, Georgia. Langley Director Dr. Jeremiah Creedon welcomed representatives from Lockheed Martin, Congress, NASA Headquarters, and the Air Force Air Combat Command, as well as Langley employees in a formal ceremony at the Langley flight hangar. Mr. James A. (Micky) Blackwell, Jr., President of Lockheed Martin’s Aeronautics Sector, recognized the contributions of NASA employees to the C-130 and the fruitful partnership between NASA and industry that it represented. Mr. Blackwell’s compliments were especially meaningful to the Langley staff because he began his aerospace career as a NASA employee at Langley in 1962 and worked with Dr. Richard Whitcomb at the Langley 8-Foot Transonic Pressure Tunnel. Langley researcher Mary Beth Wusk and her daughter complete their tour of the C-130J at Langley in 1998.