Landing Loads Facility

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Facility 1257
1964 Test Run

Center: Langley Research Center
Location: Hampton, Virginia
Year Built: 1956
Historic Eligibility: National Register Eligible
Important Tests: Landing Gear Systems. Runway Surfaces, Brake Systems


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Contents

[top] History

One of the most challenging design issues for modern aerospace vehicles is providing a high degree of safety and efficiency during critical takeoff and landing operations, especially during extreme environmental conditions. Studies of various concepts for facilities to conduct research on landing gear systems during simulated runway landings were conducted by the NACA in the late 1940s. Stimulated by the results of the studies, Langley proceeded to develop a landing track facility which immediately contributed to advancements in several key technology areas. The facility was subsequently upgraded in later years to serve NASA and the nation's needs in a wide variety of applications for aircraft and aerospace vehicles such as the Space Shuttle. This became a unique research facility which accommodated specific Shuttle tire and landing gear testing which provided braking and landing data required for the Space Shuttle development program.

There were several noteworthy research programs seeking solutions to aircraft landing problems. However, there were two which had the maximum impact and benefit to the aircraft industry, spacecraft operation, and the public.

• Pavement grooving to minimize hydroplaning

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Grooved Pavement on Display at Smithsonian Air and Space Museum

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• Design standard for aircraft tires based on the mechanical properties of bias and radial ply tires

The central focus for the research and technology studies of landing gear systems at Langley has been Building 1257, which is a unique track facility located in the NASA West Area. Other Langley buildings supporting operations at the track include 1258, 1259, 1260, 1261, and 1262. Since becoming operational in the mid-1950s, these facilities have resulted in world-wide recognition of Langley as a leader in research and technology for landing loads, landing gear systems, runway surfaces, and adverse weather effects.

The following topics are relevant to the history and operations of these facilities:

• Landing Loads Track (LLT)

• High-Speed Hydrodynamics Facility

• Aircraft Landing Dynamics Facility


[top] Landing Loads Track

Led by Langley's Upshur T. Joyner in the early 1950s, results of studies to develop a cost-effective catapult-type system for studies of landing loads concluded that a high-pressure water-jet-powered concept was the most promising approach. Accordingly, the concept was implemented in 1956 as the Langley Landing Loads Track (LLT). The LLT concept included an L-shaped water vessel, compressed air storage tanks, a quick-opening valve, and a reaction bucket on the rear of the test carriage. The test carriage was a tubular steel truss structure having a drop carriage which could be lowered at specified rates to simulate landing impact for a landing gear test article. Five arresting gear cables attached to 20 energy absorbers were used to dissipate the energy of the carriage at the end of the test run. The carriage rolled on steel rails spaced 30 feet apart.

After the catapult system propelled the carriage for about 400 feet with a maximum acceleration of 3.3 g's, the carriage coasted through a 1,200-ft test section where the test article was lowered for testing on runway surfaces of various textures and surface conditions. At a carriage speed of 100 knots, the test time was about 7 seconds. After the test, the arresting-cable system was engaged by the nose of the carriage and the carriage was stopped with a maximum deceleration of 1.1 g's over the last 600 feet of the 2,200-foot long track.

The original LLT operations included several buildings: Building 1257 (Track), Building 1257-A (Paved Test Strip), Building 1258 (Compressor Building and Control Room), Buildings 1259 and 1260 (Arresting Gear Housing Facilities), Building 1261 (Calibration and Shop Facility), and Building 1262 (Offices).

Research activities at the LLT covered a wide variety of critical technologies related to the landing gear characteristics of aerospace vehicles. Virtually every landing-gear component was studied in detail over the years including tires, skids, brakes, steering systems, air-cushion landing systems, cross-wind landing gear, and various runway conditions. In addition to providing high-priority data in support of civil and military programs and organizations, the facility has contributed critical information for beneficial applications within the general public such as tire performance, hydroplaning, and grooving for improved traction. Such applications have dramatically improved highway safety and benefited many other areas of public transportation and recreational areas.

Arguably, the LLT provided one of the most cost-effective products ever produced by the NASA technical program when it was used to understand and predict the fundamental factors that result in tire hydroplaning and to develop runway treatments such as grooving that minimize the hazard.

[top] Aircraft Landing Dynamics Facility

When the LLT was designed and put into operation in 1956, its maximum speed capability of 110 knots was sufficient to cover the landing speeds of propeller-driven civil aircraft of the time. However, the rapid advances in size and weight of jet commercial aircraft and military aircraft in the 1960s resulted in landing speeds beyond the capabilities of the facility-for example, the Shuttle Orbiter lands at speeds between 190 and 220 knots. In response to the lack of facility research capability for the higher speeds, Langley upgraded and refurbished the LLT concept and components beginning in 1982 to provide a new facility capable of testing at speeds of up to 220 knots. (Note: Just prior to awarding the contract for upgrades, the carriage crashed through the storage building at the end of the runway. The replacement carriage still at the facility is the one used for Shuttle testing. See more on the crash)

In order to provide increased performance, a larger L-vessel system was installed along with a new test carriage to withstand the loads of the increased catapult thrust. The maximum carriage acceleration was increased to about 20-g's. The overall track was extended to 2,800 feet and the test section was lengthened to 1,800 feet to permit additional test time at the higher speeds. A new arresting gear system was installed to stop the carriage within 500 feet (with a maximum carriage deceleration of about 6-g's). The updated facility, known as the Langley Aircraft Landing Dynamics Facility (ALDF) permits a test time of about 5 seconds at maximum speeds. Test articles can be subjected to vertical loads of up to 65,000 pounds or sink rates of up to 20 ft/sec.

Data acquisition is accomplished with onboard battery-powered instrumentation within the carriage. Measurements of critical data made by strain-gauge load beams are sent via telemetry to a ground station in the instrumentation room of the Command Center (Building 1258), and high-speed motion picture records are made during the test run.

After a 3-year project to upgrade the LLT, the ALDF became operational during the summer of 1985.

One of the many unique applications of the ALDF occurred in the 1980s when Langley and the NASA Wallops Flight Facility joined in a research program to evaluate the effects of heavy rainfall on the aerodynamic performance of airfoils. The effort had been stimulated by concern over potential causal factors for several fatal commercial transport accidents experienced during low-altitude operations in severe wind shears accompanied by heavy rainfall. Without prior documentation, the potential impact of severe rain on the ability of wings to produce lift was questioned within the scientific community. In addressing the potential impact of heavy rain encounters on aircraft lift characteristics, Langley conducted exploratory small-scale model tests in its 14- by 22-Ft Tunnel and other NASA and university tunnels using spray bars to simulate rain, but it was recognized that a large-scale test was required for valid extrapolation to full-scale conditions.

In 1987 NASA and the FAA modified the ALDF to accommodate testing of a large-scale representative transport wing section having a 10-foot chord and a 13.1-foot span. A 525-foot overhead rain simulation system was installed at the site, capable of producing simulated rain fields of up to 40 in./hr with rain droplets of realistic size. The rain simulation system consisted of several overhead irrigation pipes positioned along the track from which over 1500 spray nozzle arrangements were positioned to simulate the heavy-rain encounter.

[top] High-Speed Hydrodynamics Facility

The Langley High-Speed Hydrodynamics Facility consisted of an open tank of water 2,200 feet long located beside the landing-loads track. The tank, which became operational in 1956, was 8-feet wide and was filled with fresh water to a depth of 5 feet. The arrangement next to the LLT permitted the cost-effective use of the existing rails, propulsion equipment, and arresting-gear system of the LTT for high-speed tow-tank type investigations. Hydrodynamic tests were carried out with a boom extension on the carriage that extended over the tank to provide a support for the model towing structure and mode1. Integral sloping beaches were provided along the entire length of the tank for the suppression of waves. In addition, plastic-screen wind deflectors were installed along the side of the tank to minimize the effect of wind on the water surface.

Forces and moments acting on the model subject were measured by an electrical strain-gage balance attached to a hydraulically operated towing staff on the end of the boom. Raising and lowering the model mounting staff provided changes in draft and nominal wetted length. To eliminate air drag on the model, the model was run behind a windscreen.

In addition to the measurement of hydrodynamic loads, underwater photographs could be taken at five locations along the length of the tank. Three of the stations consisted of tunnels with glass windows in the bottom of the tank for taking photographs and one of the stations also included a window for taking photographs from the side.

Research activities in the high-speed tank included fundamental studies as well as contributions to high priority Navy seaplane programs such as the Martin YP6M-1 kit-propelled flying boat and the Convair XF2Y-1 Sea Dart water-based jet fighter. When Navy interest in seaplanes diminished in the 1950s, support for hydrodynamic research at Langley was markedly reduced and NASA management terminated hydrodynamic work in 1959.

Follow-on studies using the high-speed tank components and structure continued after the cessation of hydrodynamic research. For example, in 1972 the tank was evacuated and filled with clay to permit an investigation of aircraft tire behavior and operating problems in various types of soil. This research was stimulated by interest in aircraft capable of conducting operations from unpaved airfields.

[top] Paved Test Area

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In 1965, Floyd L. Thompson approved the construction of a test strip to the north of the track. The area is 2000-feet long of which 500-feet is of reinforced concrete. It was built to off-load research work from the track itself which did not require the full capabilities of that portion of the facility. The test strip was built to include removable sections so that small stretches of experimental road surface could easily be installed and removed. The test vehicle was assembled at the track and was a truck with a tire mounted on the front.

[top] Off-Site Test Equipment

The Diagonal-Braked Vehicle (DBV) System was used between 1969 and 1995. After several prototypes, the vehicle most used was a 1969 Ford XL. In support of the Shuttle program, the DBV was used to conduct runway friction evaluation tests at the Shuttle Landing Facility at Kennedy, gypsum runways at White Sands Test Facility, and lakebed runways at Dryden. Additionally, the DBV was tested on 50 different runways across the U.S., England, Germant, Italy, and Spain.

The Instrumented Tire Test Vehicle (ITTV) was designed to evaluate tire performance. The test truck was a 1976 Ford CT 900. Over 800 test runs were conducted as part of the NASA/USAF/Industry Improved Tire Life Program. The ITTV was replaced by the Mobile Tire Test Facility in 2007.

The Mobile Tire Test Facility (MTTF) improved data acquisition and operator controls over the older ITTV. It was immediately committed to support C-17 aircraft operations at Fort McCoy, WI. The vehicle is available for investigations in tire/pavement friction performance.


The Grip Test Trailer included a manual tester as well as trailer attached to a vehicle. This apparatus was used to measure the friction by braked wheels.

[top] Significant Contributions

The landing dynamics research programs were to develop an understanding of systems to ensure safe and efficient landings and takeoffs of high-speed aircraft and spacecraft. Significant contributions included:

X-15 nose-gear shimmy research

• Skid material research for reentry-type vehicles

• Tire-to-landing-surface friction and strength tests for new types of runway surfacing materials

• Impact loads on colliding with or running over various types of runway lights

• Research on tire tread patterns and braking effectiveness

• Radial tires and prototype brake systems

• Aircraft safety in landing: runway flooding, hydroplaning, identification of slippery runways, friction and stopping performance, rubber deposits and removal, development of the International Runway Friction Index


[top] Areas of Testing

Research and the Landing Loads Facility covered several broad areas, with overlap between the research topics. The landing impact research increased significantly during WWII. Testing shifted from full-scale landing tests to using models in the Impact Basin. The methodology established was used to determine landing loads under controlled conditions, and the principles were found to be equally applicable to ground landings. Landing gear tests at LaRC focused on insuring that the system met design specifications and functional requirements. The programs also included the air cushion landing system (ACLS) and the active control landing gear (ACLG). These two programs concentrated on braking and steering systems, and development of a design to minimize landing impact loads on aircraft fuselage. Most facilities are limited to testing only a portion of the parameters affected a system. LaRC's facility was the only exception with the capability to test full-size landing gear in takeoff and landing conditions.

As early as 1958 and continuing through the end of the 1970s, research was conducted in braking system performance to provide information on tire friction to aircraft braking and define tire behavior on wet surfaces. The objective was to identify sources of degraded braking performance and collect data for the development of more advanced braking systems. A majority of the current knowledge about hydroplaning was obtained from these tests. A treadmill was constructed to serve as a tire test vehicle, allowing control of various parameters. Since these tests were limited to low speeds, a C-123B aircraft was used to test braking on various runway surfaces. With the introduction of jet aircraft, additional attention was given to takeoff and landing on water or slush covered runways.

An important area of braking research was the work done with support from the FAA in the study of aircraft anti-skid braking systems. Begun in the early 1970s, this work used the wheels, brakes, tires, and hydraulic components from a DC-9. Besides the conclusions and recommendations from the study, the data was used to validate computer mathematical models, showing reasonable agreement. The research formed the basis to develop physical and computer models to calculate braking friction on a variety of runway surfaces.

A third area of research was tire testing. The Landing Loads Facility was one of two in the country capable of testing tires at realistic speeds and conditions (the other was at Wright Patterson Air Force Base.). The facility at LaRC had the advantage of simulated dynamic landing conditions. Different aircraft tires were tested in the decade beginning in 1965. Beginning in the 1980s, various types and sizes of tires and pavement types were tested. Part of this resulted in the National Tire Modeling Program which was developed in-house and through industry tests. Later testing in the 1990s focused on recommendations to improve tire life. The tire testing program included cornering characteristics, including the Navy T-45 Goshawk and the Space Shuttle.

A number of accidents involving aircraft skidding in the 1950s led to research in pavement surface characteristics. Braking and directional control were considered extremely poor during and after heavy rains. The treadmill tests mentioned earlier were used to study tire behavior on wet pavement. A companion study to the tire itself was methods to clear water ahead of the wheel. Modifications to the wheel eliminated tire planing. In the 1960s, measurements were taken on different runway materials. By 1965, researchers developed a grooved pattern in concrete to facilitate the channeling of standing water. The results led to the grooving of military and civil airport runways as well as public highways.

Research in an area related to the above areas was hydroplaning. Tire hydroplaning, particularly with pneumatic tires, was first demonstrated in 1957 during a treadmill study. In the 1960s, the Landing Loads Facility was used almost exclusively in hydroplaning research. This research led to establishing the critical speed for hydroplaning, and the definition of three types of the phenomena.

One of the significant contributions LaRC made to the Shuttle Program was research to understand the excessive tire wear experienced in the first five landings made at Kennedy Space Center. This gained attention in 1985 with the landing of Mission 51-D's tread damage and shoulder wear. A single tire mounted on the carriage dynamometer on a simulated KSC runway surface, resulting in a modification to create a longitudinal corduroy texture. Other testing conducted at the Landing Loads Facility included cornering characteristic of the main and nose gear tires, and post-tire failure drag.

Several smaller projects have contributed to aircraft safety. Crashes of commercial airliners in 1977 and 1980 led to feasibility studies on rain-on-radome disrupting multipath signals. Other relevant research investigated the effect of heavy rain on airfoils.

[top] Facility Closure and Demolition

From 1996 to 2004, through a partnership with LaRC, the Federal Aviation Administration (FAA) and other aviation organizations, the ALDF Complex was utilized to conduct over 18,000 tests as part of the Joint Winter Runway Friction Program.

Following completion of the program, testing and research activities at the facility began to steadily decline. In 2008, LaRC made the decision to close the ALDF Complex because there were no projects, programs or direct funding sources interested in its continued maintenance and upkeep. Prior to making the decision to close the facility, LaRC solicited feedback from other government agencies, industry, and academia regarding possible use of the facility for their own research endeavors. No parties were interested in establishing a lease agreement with NASA to keep ALDF operational for research activities. In order to reduce unneeded and unused infrastructure at the Center, LaRC started the process to demolish the ALDF Complex.

In 2012, LaRC prepared an Environmental Assessment to determine potential environmental impacts from the demolition. The assessment determined that the demolition would adversely impact the Center's cultural resources since the ALDF Complex is eligible for listing in the National Register of Historic Places. In order to mitigate the adverse impacts LaRC has documented the rich history of the facility through this website, as well as through preparing Historic American Engineering Record documentation on the facility. Part of this includes a photo documentation. The facility was demolished in 2015.

[top] Photos

[top] Building

1958 TrackLocation of Associated Buildings1963-06-20 Landing Loads Track1963-10 Loads Track1964 AerialSpraying SlushSlush LevelingSlush Bed After Run1972 West End of Track (bldg 1258)1972 Sled Storage (bldg 1261)1972 Office Area (bldg 1262)1972 Landing Loads Track1972 Landing Loads Track1973 Sled1975 Aerial (Bldg 1261)1975 Aerial (Bldg 1262)1975Outdoor Anechoic Test Apparatus (See more drawings)1978 Office Area Looking West198519851985 Building Identified1986 F-4 Static Test19871987 Bldg 12581987 Bldg 12581987 Track1987 Bldg 12591987 Bldg 1259A1987 Bldg 12601987 Bldg 12611987 Bldg 1261A198819891989199119891994 Bldg 12621991 East End of Building IdentifiedEnhanced Capabilities1989 Test in Simulated Rain1989 Aviation Week Cover1990 Aerial1993 Aerial South View1993 Aerial North View101.JPG2000 Recessed Test Surface with Tom YagerRain Apparatus1998Fire, Construction, AerialsShuttle Related TestsOther Tire Tests

[top] Test Carriage

1972 Carriage at Landing Loads Track1972 Carriage at Landing Loads Track1982 (See Carriage Crash)SledL-051.jpg1964 Test Run1985198519851985 Sled Parts Identified19851988198819881988198920122001-L-02103.jpg2001-L-02100.jpg2001-L-02108.jpg

[top] People

L-83-3,103.jpgL-80-8100.jpgL-77-3254.jpgL-75-2254.jpgL-69-2989.jpgL-00-357.jpgL-00-00354.jpgL-90-13341.jpgL-90-05947.jpgL-90-03827.jpgL-89-08201.jpgL-89-08197.jpgL-83-3,105.jpgL-83-3,104.jpg


[top] Demolition

In order to mitigate the adverse impacts LaRC has documented the rich history of the facility through this website, as well as through preparing Historic American Engineering Record documentation on the facility. Part of this includes a photo documentation.

6602.JPG6603.JPG6604.JPG6605.JPGMore Photos1260 with 1259 in background May 20131259 May 20131259 June 20131260 June 20131260 June 2013


[top] Awards

Group Achievement Award

This prestigious NASA certificate is awarded to any combination of Government and/or non-Government individuals for an outstanding group accomplishment that has contributed substantially to NASA's mission.

The criteria should include:

  • The quality of results and the Agency or multi-Center level of impact on programs or operations;
  • Effective management of cost and schedule;
  • Customer satisfaction;
  • Team growth and capacity for future contribution (Government personnel only); and
  • Additional credit for development of innovative approaches, use of and contributions to lessons-learned data banks, and/or
  • Success in responding to unforeseen crises.


1985 Center Award: Design Team1986 Agency Award: Development and Construction Team1985 Center Group Achievement (Citation)

[top] Films

[top] General Facility

1957: Landing Loads Track

1995 NASA Astronaut Visit

2005:NASA Test Carriage

Landing Loads Track Propulsion Model Tests

ALDF Launch Runs 59-63

Wing Rain Tests 1988 - great views of the carriage in action

Wing Rain Tests 1989

Lecture Film Showing Various Test Runs

Landing Loads Track

The Aircraft Landing Dynamics Facility

Aerial Coverage of ALDF Carriage Runs

News Reports About the Lunar Landing Research Facility

[top] Pavement Surfaces and Friction

1959: Tests of Several Types of Landing Skid Materials Made at NASA Langley Landing Loads Track

Hydroplaning

1963 Hazards of Tire Hydroplaning to Aircraft Operations (see File Handout)

Automobile Tire Hydroplaning

Inorganic Paint

US Space Foundation Safety Grooving

1994 Shuttle Landing Facility Runway Modification Project

1995 2nd Annual NASA Tire Runway Friction Workshop - Skidabrader Equipment and Surface Panels

1996 3rd Annual NASA Runway Friction Workshop

1997 4th Annual NASA Runway Friction Workshop

2004 11th Annual NASA Runway Friction Workshop

Brain Stew with Tom Yager

Slippin' and Slidin'

Interview with Jim Batterson

Ground Vehicle Testing at Wallops

[top] Tires and Landing Gear

Landing and Taxiing of an F-94C Nose Landing Gear

X-15 Nose Gear Shimmy Test

1959 Landing Loads Track Test of Titanium Landing Gear Skid

1959 Test of All Metal High Temperature Landing Gear Wheel at Landing Loads Track

1959 Tests of Landing Gear Skids and Wheels with Metal Tires

1960 W 2F-A 2F Node Wheel Shimmy Tests at the NASA Landing Loads Track

Heavy Rain Radial Tire Tests

F-8U Main Landing Gear Tests

Automobile Dual Braking

Tire Tread Development

Space Shuttle Series #1

Space Shuttle Series #2

[top] Documents

[top] Facility Information

1964 Field Inspection Talk given at the track during the 1964 Field Inspection of Advanced Research and Technology.

Arresting Gear System Schematic

Master Drawing List for Carriage Arrest System, 1984

Construction Drawing of Track

Variety of Annotated Photos

Tire Dynamometer Diagram

Landing Loads Track: A Unique Facility

NASA Langley's Unique Aircraft Landing Dynamics Facility

1966 Description of Landing Load Tracks

1966 Technical Facilities Resume

1968 Effects of Pavement Texture on Wet-Runway Braking Performance

1971 Effect of Runway Grooving on Tire Spin-Up Behavior

1972 Aircraft Tire Behavior During High-Speed Operations in Soil

1974 Landing Loads Track Quick Facts

1980 Space Shuttle Response to Verification Certification Committee

1982 Objectives of Aircraft Landing Dynamics Facility Program

1982 Carriage Isometric

1983 NASA Selects Contractor to Build New Test Carriage

1984 Aircraft Landing Dynamics Facility Fact Sheet

1984 Master Drawing List for Carriage Arrestment System

1985 Aircraft Landing Dynamics Facility, A Unique Facility with New Capabilities

1985 ALDF Has Successful First Run

1985 ALDF Completion to Extend Landing Dynamics Research

1985 Aircraft Landing Dynamics Facility Dedication Program

1986 Aerospace Engineering Article on Landing Dynamics Research

1987 Langley Aircraft Landing Dynamics Facility


1993 Development of Large-Scale, Outdoor, Ground-Based Test Capability for Evaluating the Effect of Rain on Airfoil Lift

1999: Research Aims to Prevent Accidents on Hazardous Runways

2002 Paving the Way

2004 Research Aims to Prevent Accidents on Hazardous Runways

2005: NASA Vision - Aircraft Landing Dynamics Facility (includes video)

2012 Historic and Architectural Documentation

[top] Further Reading

Batterson, Sidney A.. 1957. Recent Data in Tire Friction During Landing

Batterson, Sidney A.. 1965. A Study of the Dynamics of Airplane Braking Systems as Affected by Tire Elasticity and Brake Response

Davis, Pamela A., Sandy M.Stubbs, and John A.Tanner. 1987 Langley Aircraft Landing Dynamics Facility

Daugherty, Robert H. and Thomas J. Yager. 1997. Texture Modification of the Shuttle Landing Facility Runway at Kennedy Space Center

Horne, Walter B., and Trafford J.W. Leland. 1962. Influence of Tire Tread Pattern and Runway Surface Condition on Braking Friction and Rolling Resistance of a Modern Aircraft Tire

Joyner, Upshur T. and Walter B. Horne. 1954. Considerations on a Large Hydraulic Jet Catapult

NACA. 1957. Investigation of The Planing Lift of a Flat Plate at the Langley High-Speed Hydrodynamics Tank

NASA Researcher News 2005. ALDF Celebrates 50 YEars.

NASA Researcher News. 2006. Tom Yager: ALDF Researcher

[top] Memories

Andy Goddin: Mary, I guess you hear a lot of “my father worked here back in......” My father worked at the track back in the mid fifties. I remember one time they drained the tank that ran alongside the track. It was on a Saturday and I got to come out to the track with my father. He and another man checked the entire tank. That afternoon, my father turned on the water to refill the tank. We came back out on Sunday afternoon and he turned the water off as the tank was full.

I remember seeing the small Carriage in the building and he explained how it worked. When I started work for Klate Holt back in 1981, my very first job was in one of the arresting gear houses.

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