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Weather is a major cause of aircraft accidents and incidents and the single largest contributor to air traffic system delays. Through improvements in the knowledge of current weather conditions and reliable forecasts, the Federal Aviation Administration (FAA) can improve aviation safety, increase system capacity, and enhance flight planning and fuel efficiency. The FAA has established an Aviation Weather Research (AWR) program to address specific requirements for weather support to aviation by providing the capability to generate more accurate and accessible weather observations, warnings, and forecasts and also by increasing the scientific understanding of atmospheric processes that spawn aviation weather hazards. The goal of AWR is to provide meteorological research that leads to the satisfaction of specific aviation weather requirements.

Hazardous atmospheric icing conditions occur at sub-zero temperatures when droplets come into contact with aircraft and freeze, degrading aircraft performance and handling, introducing bias into some of the vital measurements needed for aircraft operation (e.g., air speed). Nonetheless, government regulations allow certified aircraft to fly in limited icing environments. The capability of aircraft sensors to identify all hazardous icing environments is limited. To address the current challenges in aircraft icing detection and protection, we present herein a platform designed for in-flight testing of ice protection solutions and icing detection technologies. The recently developed Platform for Ice-accretion and Coatings Tests with Ultrasonic Readings (PICTUR) was evaluated using CFD simulations and installed on the National Research Council Canada (NRC) Convair-580 aircraft that has flown in icing conditions over North East USA, during February 2022.

“As we handle more operations and passengers in the air, we must make certain we have the capacity to handle increased traffic on the ground.” - Jane Garvey, FAA Administrator (4/20/98) The FAA Technical Center (Aviation System Analysis and Modeling Branch, ACT-520) has been responsive to the FAA Airport Capacity Program customers for the past 22 years, developing, testing, and applying airfield and airspace simulation models. More than 90 capacity studies have been completed with ACT-520 personnel contributing their technical expertise to the Airport Design Teams. The teams are comprised of FAA personnel, airport operators, air carriers, other airport users and aviation industry representatives at major airports throughout the US. Initial studies focused on modeling airport operations from final approach, taxi, gate operations and departure processing. Later in the program, local airspace studies were included in some airport study efforts.

Average continuous flow rates for each type of aircraft exit were examined in 89 full-scale evacuation demonstrations. Passengers tend to form continuous lines at available exits when evacuating an airplane. The study concludes that, with rare exception, the passenger rates of egress from the same type exit on different make and model airplanes are not significantly different. Passenger cabin configuration, seat pitch, and aisle width have no significant bearing on the egress rates provided the aircraft certification requirements for minimum aisle width and exit accessibility are met. Injuries resulting from actual emergency evacuations and evacuation demonstrations are also examined.

Area navigation offers a means of establishing an air route system without the constraints entailed in flying toward or away from the signal source. In terminal areas, an area navigation system of routes, combined with ATC computer-aided sequencing and airborne collision-avoidance technology, offers possibilities for establishing future methods of moving high volumes of traffic on and off a complex of multiple parallel runways. Such a system would reduce air-ground communications and controller workloads which are serious limiting factors in today's system. In the en route system, the use of area navigation will result in more efficient utilization of airspace, although regimentation of traffic will continue to be necessary in areas of high traffic density. An area navigation system, based on VOR/DME inputs is possible in the near future.

Since the first airplane was certified in 1927, the standard configuration has been with the main lifting surface or surfaces forward of the stabilizing surface. Although some of the advantages of the canard configuration were recognized quite early - by the Wright Brothers, for example - canard surfaces have been used to date only as additional control surfaces on some military airplanes, and on some amateur built airplanes. As a result, the Airworthiness Regulations of Reference 1 address only tail aft configurations. When FAA was first approached regarding certification of a canard configured small airplane, an FAA/Industry Empennage Loads Working Group was formed to develop technical proposals for the necessary rule changes and policy. The concerns addressed by this working group are discussed in the following sections.

Microprocessor technology is allowing functions in aircraft to be implemented to a greater degree by digital process control than by conventional mechanical or electromechanical means. A review of this technology indicates a need for updated certification criteria. A high level of commitment to the technology such as fly-by-wire is completely beyond the scope of existing certification criteria. This paper emphasizes the areas of software validation levels, increased concern with basic power system qualification, and increased environmental concerns for electromagnetic interference and lightning.

Powered-lift aircraft, such as the V-22 tilt-rotor, are likely to spin-off a civil version. The present FAA airworthiness certification standards are not considered to be adequate for these unique aircraft. The FAA has drafted certification criteria and held a public conference to review the draft and identify significant technical certification issues that require further effort to establish correct standards for powered-lift aircraft. Some of those issues are discussed.

The issues involved in certifying head-up displays for civil aircraft are reviewed and proposed guidelines for the certification of head-up displays are presented. These guidelines are based on experience with civil and military head-up displays and follow the intent of the existing rules.

Materials are available for preventing or retarding aircraft cabin fires involving urethane foam seat cushions. Realistic fire tests performed in a wide-body test article demonstrate that some in-flight and ramp fires can be prevented, and that the allowable time for safe evacuation can be significantly extended during a survivable postcrash fuel fire, when the urethane foam seat cushion is covered by a “blocking layer” material.

Numerical simulations indicate that blast loading on aircraft structural joints can impart loading rates in excess of 10 Mlb/sec (ten million pounds per second, Reference 1). Experimental evidence, on the other hand, suggests that mechanical joint failure loads are highly loading rate dependent; for example, the failure load for a dynamically loaded tension joint can double from its static value. This paper discusses the progress and to-date findings of research on the assessment of strength failure of aircraft structural joints subjected to loading rates expected from an internal explosive detonation, and several associated experimental procedures to generate such dynamic loading. This work is conducted at MDC and at the University of Dayton Research Institute (UDRI) in support of the FAA Aircraft Hardening Program.

This paper compares the flammability of plastic automotive components to that of commodity, engineering, and specialty plastics as well as those used in commercial aircraft cabins with regard to performance in microscale combustion calorimetry tests. Not surprisingly, automotive components used in engine and passenger compartments are as flammable and ignitable as the commodity and engineering plastics of which they are made and much more flammable than those used in the interiors of aircraft.

In 2021 the Federal Aviation Administration in collaboration with the National Research Council of Canada performed research on altitude ice crystal icing of aircraft engines using the modular compressor rig, ICE-MACR, in an altitude wind tunnel. The aim of the research campaign was to address research needs related to ice crystal icing of aircraft engines outlined in FAA publication Engine Ice Crystal Icing Technology Plan with Research Needs. This paper reports the findings on ice accretion from a configuration of ICE-MACR with two compression stages. Inherent in two-stage operation is not just additional fracturing and heating by the second stage but also higher axial velocity and potentially greater centrifuging of particles. These factors influence the accretion behavior in the test article compared to single stage accretion.

The Ice Crystal Environment Modular Axial Compressor Rig (ICE-MACR) was developed by the National Research Council of Canada (NRC) with support from the Federal Aviation Administration (FAA) in response to the need to understand ice crystal icing of aircraft engines at high altitudes. Icing wind tunnel tests on static hardware lack some of the real physics of turbofan compressor such as centrifuging and fracturing of particles, and melting of particles due to compression heating, heat transfer through a casing wall, as well as annular geometry effects. Since the commissioning of ICE-MACR in 2019 new insights have been gained on the physics behind ice crystal icing of turbofan engines. Additionally, the results of various test campaigns have been used to validate engine ice accretion numerical codes. This paper summarizes the key insights into ICI of turbofans gained from the ICE-MACR to date.

High Ice Water Content (HIWC) has been identified as a primary causal factor in numerous engine events over the past two decades. Previous attempts to develop a remote detection process utilizing modern commercial radars have failed to produce reliable results. This paper discusses the reasons for previous failures and describes a new technique that has shown very encouraging accuracy and range performance without the need for any modifications to industry’s current radar design(s). The performance of this new process was evaluated during the joint NASA/FAA HIWC RADAR II Flight Campaign in August of 2018. Results from that evaluation are discussed, along with the potential for commercial application, and development of minimum operational performance standards for future radar products.

In the early design stages of the advanced technology high-bypass-ratio engines, it became evident that maintainability considerations and more effective maintenance concepts would be necessary to achieve higher reliability and more economically successful powerplants. This paper reviews the major design considerations from a maintainability standpoint. It describes the concepts developed specifically to provide more effective maintenance for the wide-body jets. It discusses the effectiveness of these programs, and provides an insight into new philosophies and trends envisioned by the Federal Aviation Administration for future maintenance management programs.

In view of the fact that future generations of derivative or new aircraft will be faced with problems of increasing operating efficiency, new and more advanced technology will have to be introduced. To this end, the Federal Aviation Administration has been examining the certification question and has concluded that simulation may be increasingly important in the future certification activities. Through a contract with Lockheed Aircraft Company, the FAA will be able to review past use of industrial simulation in connection with certification.

The Federal Aviation Administration has placed increasing emphasis on modern information systems to achieve safety improvements. The ASAS (Aviation Safety Analysis System) is a comprehensive new system to upgrade significantly the agency's ability to collect process and disseminate safety-related information.

This paper describes the recently established Commercial Aviation Alternative Fuel Initiative (CAAFI), including its goals and objectives, as well as presents an alternate fuel roadmap that was originally generated by industry and refined by the CAAFI stakeholders. CAAFI is designed to coordinate the development and commercialization of “drop-in” alternate fuels (i.e. fuels that can directly supplement or replace crude oil derived jet fuels), as well as exploring the long-term potential of other fuel options. The ultimate goal is to ensure an affordable and stable supply of environmentally progressive aviation fuels that will enable continued growth of commercial aviation. This initiative is organized into four sub-groups: Research and Development (R&D), certification, environment, and economics & business. The R&D group seeks to identify promising new drop-in alternate fuels, and to foster coordination of development efforts.