Search Results

Many of the certification regulations in 14 CFR Part 25 are by design, broad and as such, can be subject to large differences in the interpretation of what constitutes adequate compliance. Advisory Circulars (AC's) were developed for many of the regulations to assist industry, as well as certification personnel, with what is considered an acceptable, but not the only means, of compliance. However, there are many regulations where no advisory material is available. In these cases, the “acceptable means” of compliance can vary to a greater degree among the various aircraft certification offices. This difficulty is aggravated as new applicants and regulatory personnel enter the certification field. Recent discussions and interpretations on the usage of an avionic unit's mean time between failure or MTBF for its detectable faults as the basic repair rate for undetected or latent faults, is a subject area where no significant advisory material exists.

The rapid growth in digital computer technology and display systems has impacted most aerospace disciplines. The designer manufacturer operator and even airplane passengers are all affected by this technology boom. The FAA in its role of certifying new aerospace products is no exception. This paper will emphasize the changing methodology of the FAA certification process with some specific examples of recent flight test programs.

The need to improve the efficiency and capacity of the Air Traffic Control and Navigation System has placed greater emphasis on the functional integration of subsystems which have been treated independently in the past. This paper presents results of limited test programs designed to explore the relationship of terminal area navigation and the air traffic control system, and to show the benefits of an optimum combination of both functions. The need for further analysis is indicated with respect to carrying out the third generation system design postulated by the DOT Air Traffic Control Advisory Committee. It is concluded that functional integration of ATC and navigation in the terminal area presents the greatest challenge. In other areas, such as enroute, the availability of new, integrated avionics systems provides an expanded operational capability.

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.

Recent changes in DoD procurement directives have encouraged the purchase of civilian products for use in certain military applications. One such application is the upgrade of avionics suites with the Global Positioning System (GPS) in military air transport aircraft to meet joint civil-military operational requirements. This paper reviews the Commercial Off-the-Shelf (COTS) concept and the proper use of TSOs, ACs, and FARs in both the design and integration process.

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.

This paper will discuss some considerations regarding man-machine interface during helicopter instrument flight. Several misconceptions have existed regarding FAA helicopter IFR certification. In response to some concerns pertaining to “excessive workload considerations,” designers have responded with several configurations. Some of these configurations have highlighted the need to educate the designer and the pilot population that the pilot must have the option to “actively participate” in the flight activity during helicopter IFR operations. “Active participation” includes the option of flying the vehicle through the normal flight controls. In addition, there has been some confusion regarding the terms “stability augmentation systems” and “autopilot.” Some individuals use the terms interchangeably. This paper will discuss the various lessons learned during FAA certification of helicopters for IFR flight from a certification test pilot's viewpoint.

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.