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This paper explains the need for and use of operational field failure data to eliminate modes of equipment failure from existing designs and to prevent their recurrence in future designs. At The Boeing Company these processes are called “corrective action” and “experience retention.” Experience retention goes farther than the “field fix” or hardware corrective action because the process is considered complete only when needed changes have been made to basic resources such as methods and data manuals. The paper explains how field failure reporting principles are applied by specialists whose only job is to report factual qualitative data. It shows how specialists use this information to assure that modes of failure are eliminated from like follow-on hardware as well as retained in basic company resources.

THIS article, written shortly after the signing of the armistice, deals with the Naval aviation situation at the outbreak of war and its development during the war, ending with a brief discussion of the probable future lines of development. Figures are given showing the expansion occurring during the nineteen months of warfare, and the different ways in which the various types of aircraft were used. Future development is treated briefly, but that logical assumptions were made is indicated by the fact that the year which has elapsed since the article was written has shown a very decided trend along the lines indicated.

The precise, instantaneous attitude control of a rocket in flight requires absolute alignment of both the true axis of thrust and the gimbal center relative to each other and to the vehicle axis. This necessitates checkout procedures on the completed rocket engine which accurately define and adjust the true axis of thrust in relation to the pivot center of the supporting gimbal. Optical metrological and alignment methods currently in use at Rocketdyne make possible fast, as well as accurate, thrust chamber alignment checkouts.

The role of the aircraft manufacturer in the design, integration, and optimization of commercial transport airplane stopping systems is discussed. Specific emphasis is placed on: system design considerations, configurations, and features; laboratory and flight testing; typical problems encountered; and future basic data requirements. Advancements in stopping system simulation techniques and antiskid control systems in recent years have allowed large improvements in stopping system efficiency. Future improvements are dependent on obtaining basic data on tire and brake dynamic characteristics for use in simulation studies to control and improve the combined brake and tire frequency response phase lag. It is anticipated that new rational landing rules being developed by the FAA must account for and include the effect of the engine thrust reversing system on stopping distances.

The ORZS flight experiment is designed to measure gas diffusion through plant growth substrates at varying water content levels in microgravity. This information is critical for proper water management and the prevention of root zone hypoxia during plant growth and advanced life support (ALS) biomass production experiments. Microgravity data that suggest enhanced hysteresis in water retention may alter the gas diffusion process, changing the optimum root zone moisture control set point in μg plant growth systems. Small gas diffusion cells are being evaluated as measurement systems for coarse-textured plant growth media at 1g and 0g. Design guidelines aim to minimize gravitational force while maintaining a representative porous medium. Substrate physical properties (e.g., water retention) pose additional complications for diffusion coefficient determination.

It’s a common practice to use different kinds tools to aid in the development and verification of modern safety critical avionics systems. These tools play a key role in avionics engineering and used in all project phases: requirements development, software design, source code development, integration, configuration management, and verification. Tools assist to analyze and improve system safety by automation of some of the activities which if performed manually and are therefore prone to human error. However, incorrect functioning of a tool can have negative impact on the safety and performance of the Safety Critical system. Hence, tools are proposed to be qualified whenever any of the design assurance process(es) described in RTCA/DO-178C or RTCA/DO-254 are eliminated, reduced, or automated using the tool unless the output of the tool is verified manually. Qualification of the tool gives confidence in the tool functionality.

An inventory was made of the quantities and types of wastes to be produced by typical missions proposed by NASA's Office of Space Science and Applications (OSSA) for the initial operational phase (IOC) of the Space Station. Of the 35 missions inventoried, 21 missions involve “payloads” (instrument packages) attached externally to the Space Station, 12 involve payloads that are located on “free-flying” platforms remote from the Station and 2 missions, (Life Sciences and Materials Sciences laboratories) comprise a complex series of experiments to be carried out inside the Station's pressurized volume. The study objective was to acquire the information needed to define preliminary OSSA waste management requirements for the Space Station and the National Space Transportation System. The study revealed that all missions combined will generate approximately 5350 kg (11800 lbs) of waste (solid, liquid and gas) every 90 days.

OV-10A LANDING GEARS - The landing gears of the OV-10A have been designed to meet extremely severe landing and operating conditions. The articulated main gear and semi-articulated nose gear assemblies have proven to be well suited to meeting the requirements for high sink rate landings onto bumps, steps and holes in addition to taxiing and making take-offs over undulating contours. Development data on the landing gear shock struts in laboratory airframe drops and actual flight test landings show good agreement with predicted performance.

Life Cycle Cost (LCC) analysis forms a vital input to the design of cost effective aerospace propulsion systems. By necessity, LCC analysis requires extensive communication between a large range of participants in a given program: customer, aircraft manufacturer, engine producer, equipment suppliers, and across professional disciplines within each of these organisations. This paper presents an overview of ARP 4294, “Data Formats and Practices for Life Cycle Cost Information”, which provides a range of specific data formats and recommended practices to support these communications. ARP4294 is primarily directed at the LCC of military propulsion systems. Consistency and understanding of information exchanged are promoted as are the role and responsibilities of participants at each phase of the program. ARP 4294 supplements the general guidelines of AIR 1939 and complements ARP 4293.

This paper summarizes results from the first NASA Life Support Systems Analysis Workshop sponsored by the Office of Aeronautics and Space Technology on June 24-27, 1991, in Milwaukee, Wisconsin, and provides a brief overview of the second workshop held May 12-14, 1992. The objectives of the workshops were to: 1) encourage communication in life support systems analysis among NASA, the aerospace industry, universities, and the chemical processing industry; 2) provide access and exposure to current NASA life support systems analysis efforts; 3) establish and provide results of the workshop sessions to NASA and the participants regarding future activities and directions for the development of life support systems analysis capabilities. The participants included representatives from NASA Headquarters and field centers, major aerospace companies, aerospace R&D and manufacturing companies, chemical processing companies, and universities.

LIQUID-OXYGEN injection, especially in combination with water injection, has proved to be a practicable means of improving power output of aircraft engines at altitude. Its use for limited periods in nonservice installations has increased speed, rate of climb, and operational ceiling without increasing the tendency toward knocking. The injection system can be readily applied to existing aircraft. It is remarkably light in weight - a system weighing 180 lb, including about 100 lb of oxygen, will increase the power of an R-2800 by 300 hp for 16 min. Maximum permissible boost is limited by engine cooling.