Flight Safety and Security
During FY 1995, engineers from the FAA worked to find acceptable fire extinguishing systems without halon, because the production of halon agents was outlawed in environmental regulations. FAA personnel also produced an interagency task force report for halon alternatives. In addition, FAA technicians completed testing of seat cushion fire blocking layers and developed a fire test method for airliner blankets. The tests showed that these materials, used by U.S. carriers, retain their fire resistance after service usage and remain compliant with FAA standards, but that some blankets have poor ignition resistance. In addition, FAA specialists conducted tests related to fire-hardening materials to delay fuselage burnthrough by a postcrash fuel fire. Finally, the FAA-sponsored International Materials Fire Test Working Group drafted an upgraded Aircraft Material Fire Test Handbook.
In FY 1995, FAA personnel continued to address the flight safety issues raised by incorporating advanced digital systems software into aircraft and avionics systems design. Together with their NASA colleagues, FAA researchers initiated projects to assess software requirements for flight-critical applications (such as fly-by-wire, fly-by-light, and power-by-wire) and integrated modular avionics systems that use software partitioning to protect separate applications from corrupting one another.
In the area of airport visual guidance, FAA specialists completed a study for improving taxiway holding position lights and developed new performance standards. The FAA also issued final reports on improved pavement marking materials and the use of retro-reflective beads in airport pavement marking.
During FY 1995, researchers from the FAA's Airport Pavement Research program worked on developing advanced pavement design methodologies. In a related matter, the FAA issued an RFP to design and build the first national airport pavement test facility. Using planes of various sizes and tire configurations, FAA specialists completed the calibration of a complex system of almost 500 sensors that are being used to collect data in a real-time mode, providing the first means of obtaining accurate information on pavement response and performance. FAA personnel established a data base to allow airport pavement researchers worldwide to have access to the data collected. FAA engineers introduced the layered elastic design method that provided alternate pavement design guidelines for the Boeing 777's impact on airport pavement, prior to the plane's first commercial flight in 1995. FAA researchers also conducted a study of airport runway roughness profiles at 10 airports.
In materials research, the FAA published a program plan for aircraft advanced materials research and development, which was coordinated with similar findings of the National Research Council (part of the National Academy of Sciences). FAA personnel continued to work with DoD personnel on regulatory issues related to the certification and standardization of composite components. FAA researchers completed a preliminary evaluation of probability-based approaches to composite structural design, developed a preliminary data base on service-related damage incidents in composite aircraft currently in service, and conducted a case study on the application of probabilistic approaches to an existing all-composite aircraft for risk-of-failure evaluation. FAA engineers continued to analyze aircraft structural safety through the use of the crash impact facility at NASA's LaRC. Internationally, FAA specialists participated in developing an air accident investigation tool with the Civil Aviation Authority in England.
In cooperation with NASA, the FAA sponsored an international Conference on Continued Airworthiness of Aircraft Structures in Atlantic City, NJ. The two agencies also conducted numerous technical workshops on structural integrity, corrosion, and inspection research. Engineers and scientists developed a computationally efficient and accurate numerical technique, called the finite element alternating method, to predict crack linkup and residual strength in the presence of widespread fatigue damage. During the fiscal year, technicians tested two full-scale wide-body panels to provide correlation data for predictive models. Software experts developed a phase I repair design and assessment software tool and sent it to selected users for prerelease field testing.
In response to structural failures caused by aging, researchers from the FAA's Aging Aircraft program built on NASA's extensive research base in nondestructive evaluation methods, metal fatigue, and modeling for structural life prediction. The program has been moving from the technology development stage into the demonstration, validation, and technology transfer stage. Researchers have developed a wide range of prototype nondestructive evaluation instrumentation to detect the presence of corrosion and small fatigue cracks in aircraft structures and components. NASA researchers developed a prototype eddy current instrument for detecting small fatigue cracks and turned it over to a private instrument manufacturer for commercial marketing.
During the fiscal year, researchers developed a laboratory prototype of a pulsed eddy current device for corrosion detection on a Gulfstream Aero Commander wing spar. Technicians reviewed a field prototype, based on the self-compensating ultrasonic device, for possible specification as an alternate inspection technique for the DC-9 wing box T-cap. Specialists also demonstrated a pulse-echo thermal wave inspection in the laboratory and during field trials at Northwest Airlines and as part of an Air Force corrosion detection program. Aviation technicians also developed an automated aircraft wheel inspection system to classify inspection signals during automated eddy current wheel inspections.
Personnel from the FAA Technical Center continued their development of an unleaded aviation gasoline for use in the existing fleet of general aviation aircraft with piston engines. During FY 1995, a Coordinating Research Council was formed to develop the data sets required to justify changes in aviation gasoline fuel specifications. While developing the basic procedure, FAA Technical Center personnel conducted testing on an engine that is considered the worst- case scenario for knock. Technical Center specialists also provided ongoing support for autogas supplemental-type certificates and turbine fuel specification changes to the various certification offices. Most of the effort in this area is in response to changes mandated by Congress or EPA. The construction of the Fuel Research Laboratory and Small Engine Test Facility expansion began in FY 1995.
FAA researchers continued to develop technologies and methodologies to mitigate and prevent the threat of catastrophic aircraft failure. They conducted studies and tests in flight-control technologies, lightweight material barriers for high-energy rotor fragment mitigation, and aircraft loads. Grant and small business innovation research awards further expanded research in aircraft control, load technology, and rotor fragment mitigation. In FY 1995, FAA specialists completed tests to aid in the design and evaluation of a high-temperature containment ring for application on small turbine rotors. Researchers continued their work on modern analytic methods that can predict horizontal stabilizer design antisymmetric buffet loads during the airplane design phase.
The Marine Corps continued to pursue the Integrated Maintenance Diagnostics system to monitor the health of helicopter dynamic flight components. This system continued its development and evaluation in the Marine Corps CH-53E for its application in all Marine rotorcraft. Military aviation specialists have designed that system to reduce avionics repairs and prevent structural fatigue, among other preventive maintenance measures.
In the area of aviation security technology, FAA specialists certified the first explosive detection system for finding bulk explosives in checked baggage. Experts at the FAA Technical Center used the certification standard, developed by the National Academy of Sciences, to do the testing. With support from industry and the national laboratories, Technical Center personnel developed a protocol for certification testing of trace explosive detection systems. Specialists from the FAA's aircraft-hardening program completed the development and testing of prototype hardened baggage containers. The FAA awarded a grant to the Great Lakes Composite Consortium to build a limited quantity of hardened composite containers in accordance with FAA specifications. In FY 1995, FAA specialists developed a computer-based training system for x-ray screeners to improve the detection of improvised explosive devices and weapons. FAA grantees at Embry Riddle Aeronautical University developed a screener selection test to determine whether trained security applicants are capable of reaching a required level of performance. Through cooperation with industry, FAA specialists simulated the development of an x-ray false-image projection system to increase screener vigilance. During the fiscal year, FAA technicians joined with industry specialists to conduct a study of domestic passenger baggage matching.
Curator: Lillian Gipson|
Last Updated: September 5, 1996
For more information contact Steve Garber, NASA History Office,