Search Results

The Lunar Electric Rover (LER), which was formerly called the Small Pressurized Rover (SPR), is currently being carried as an integral part of the lunar surface architectures that are under consideration in the Constellation Program. One element of the LER is the suit port, which is the means by which crew members perform Extravehicular Activities (EVAs). Two suit port deliverables were produced in fiscal year 2008: a 1-g suit port concept evaluator for functional integrated testing with the LER 1-g concept vehicle and a functional and pressurizable Engineering Unit (EU). This paper focuses on the 1-g suit port concept evaluator test results from the Desert Research and Technology Studies (D-RATS) October 2008 testing at Black Point Lava Flow (BPLF), Arizona. The 1-g suit port concept evaluator was integrated with the 1-g LER cabin and chassis concepts.

An integration study was performed coupling an SP-100 reactor with either a Brayton or Stirling power conversion subsystem. A power level of 100 kWe was selected for the study. The power system was to be compatible with both the lunar and Mars surface environment and require no site preparation. In addition, the reactor was to have integral shielding and be completely self-contained, including its own auxiliary power for start-up. Initial reliability studies were performed to determine power conversion redundancy and engine module size. Previous studies were used to select the power conversion optimum operating conditions (ratio of hot-side temperature to cold-side temperature). Results of the study indicated that either the Brayton or Stirling power conversion subsystems could be integrated with the SP-100 reactor for either a lunar or Mars surface power application.

This SAE Aerospace Information Report (AIR) describes procedures for use in the field to determine if 115/200 Volt, 400 Hz aircraft external electrical power connectors are excessively worn, which may result in the inability of the external power plug to be retained, intermittent electrical performance and arcing.

This SAE Aerospace Information Report (AIR) describes procedures for use in the field to determine if 115/200 Volt, 400 Hz aircraft external electrical power connectors are excessively worn, which may result in the inability of the external power plug to be retained, intermittent electrical performance and arcing.

Governmental assurance documentation bibliography updated; new tabulation effective as of April 1, 1967. Latest revision indicated in all instances, but no attempt was made to list supplements or amendments. Department of Defense Index of Specifications and Standards (DODISS) published annually in three parts (alphabetic, numerical, and listing of Federal Supply Classification following unclassified documents.

Error in suspension asymmetry or tire parameters may lead to vehicle drifting laterally from its intended straight-line path, which is called vehicle pull. Driver then needs to apply constant steering correction to maintain the vehicle in straight line which will lead to high driver fatigue and deteriorate driving experience. Manufacturing a perfectly symmetric suspension system is impractical, however an insight into the manufacturing tolerances of suspension system at the early design stage can be extremely useful. Also tire force and moment parameters at straight line operation and its maximum allowable variations will help in defining the tire parameter specifications and tolerances. The objective of this study was to develop a 1D model of suspension and tire system which can predict the torque experienced in steering and drift of the vehicle from straight line due to the tire force and moment and asymmetric suspension geometry.

Aircraft potable (drinking) water systems haven’t changed significantly in the last half-century. These systems consist of cylindrical water tanks pressurized by bleed air from the jet engines, with insulated stainless steel distribution lines. What has changed recently is the increase in the possibility of aircraft picking up contaminated drinking water at foreign and domestic stops. Customer awareness of these problems has also changed - to the point where having reliable drinking water is now a competitive issue among airlines. Old style potable water systems that are used on modern aircraft are high maintenance and exacerbate the growth of microbes because the water is static much of the time. The integrity of some pressurized water tanks are also a concern after years of use. Cost-effective mechanical and biological solutions exist that can significantly reduce the amount of chemicals added and provide good potable water.

In order to take full advantage of SiC, a high temperature package for power module using SiC devices was designed, developed, fabricated and tested. The details of the material selection and fabrication process are described. High temperature reliability test and power test shows that the package presented in this paper can perform well at the high junction temperature.

Preliminary results from testing of 26 X 6.6 radial-belted and bias-ply aircraft tires at NASA Langley's Aircraft Landing Dynamics Facility (ALDF) are reviewed. These tire tests are part of a larger, on going joint NASA/FAA/Industry Surface Traction and Radial Tire (START) Program involving three different tire sizes. The 26 X 6.6 tire size evaluation includes cornering performance tests throughout the aircraft ground operational speed range for both dry and wet runway surfaces. Static test results to define 26 X 6.6 tire vertical stiffness properties are also presented and discussed.

This SAE Aerospace Information Report (AIR) describes field-level procedures to determine if 400 Hz electrical connections for external power may have been subjected to excessive wear, which may result in inadequate disengagement forces.

The objective of this project was to replace electromechanical power line contactors with a Static Transfer Switch (STS) to improve the transfer of electrical power between aircraft generators and decrease required maintenance. The switch requirements include high reliability, lightweight, and high speed (less than 15mS) power transfer. An STS can shorten the bus transfer time to less than the “ride-through” of aircraft electronic loads and therefore have the ability to control and transfer electrical power while maintaining critical mission requirements. The content of this paper and presentation will discuss the initial problem, the research and development approach, design, and initial testing of the STS.

Flight control technology for 8000 psi has emerged almost simultaneously with new fire-resistant hydraulic fluids, such as MIL-H-83282 and CTFE. A proliferation of industry recommendations has resulted in a wide variety of mechanisms for solving associated actuator design problems, including tighter clearances, special seals, finishes, materials, and many others. As there are few common agreements on the issues, an extensive three-phase test program was undertaken to attempt to corroborate some of these approaches or suggest others that may be better or more cost effective.

An 8000 psi test program was conducted to resolve conflicts and issues surrounding the use of CTFE and MIL-H-83282 fluid with vented and unvented actuator rod seals. Each of the four possible combinations had unique problems and each responded to appropriate corrections including new backup rings designed to operate with standard clearances. It was concluded that all combinations were viable within certain limits. Advantages and disadvantages of each configuration were identified and specific recommendations made for both dynamic and static seals within the context of existing military specifications.

Shortly after World War II, as aircraft became more sophisticated and power-assist, flight-control functions became a requirement, hydraulic system operating pressures rose from the 1000 psi level to the 3000 psi level found on most aircraft today. Since then, 4000 psi systems have been developed for the U.S. Air Force XB-70 and B-1 bombers and a number of European aircraft including the tornado multirole combat aircraft and the Concorde supersonic transport. The V-22 Osprey incorporates a 5000 psi hydraulic system. The power levels of military aircraft hydraulic systems have continued to rise. This is primarily due to higher aerodynamic loading, combined with the increased hydraulic functions and operations of each new aircraft. At the same time, aircraft structures and wings have been getting smaller and thinner as mission requirements expand. Thus, internal physical space available for plumbing and components continues to decrease.

Shortly after World War II, as aircraft became more sophisticated and power-assist, flight-control functions became a requirement, hydraulic system operating pressures rose from the 1000 psi level to the 3000 psi level found on most aircraft today. Since then, 4000 psi systems have been developed for the U.S. Air Force XB-70 and B-1 bombers and a number of European aircraft including the tornado multirole combat aircraft and the Concorde supersonic transport. The V-22 Osprey incorporates a 5000 psi hydraulic system. The power levels of military aircraft hydraulic systems have continued to rise. This is primarily due to higher aerodynamic loading, combined with the increased hydraulic functions and operations of each new aircraft. At the same time, aircraft structures and wings have been getting smaller and thinner as mission requirements expand. Thus, internal physical space available for plumbing and components continues to decrease.

이 문서는 공급자가 9100의 조항을 준수하고자 할 때 AQAP-2110을 적용하는 것에 관한 정보와 지침을 제공하기 위해 작성 및 발행된 것이다. 이 문서는 AQAP-2110-SRD.2 및 IA9137로 간행된다. 이는 NATO와 산업계에서 AQAP-2110과 9100 간의 관계에 대한 이해와 활용을 촉진하기 위해 NATO와 산업계 대표들이 공동으로 작성한 것이다. 획득 국가가 자국의 조달 방법으로 대외군사판매(FMS)를 이용할 때는 AQAP가 필요할 수 있다. 이 문서는 획득 국가와 9100을 준수하고자 하는 공급 국가의 AQAP-2110 요구사항 해석에 있어 공통성을 제공하는 데에 목적을 두고 있다. 이 문서의 내용은 법적 또는 계약상의 지위를 갖지 않으며, 일체의 AQAP-2110 또는 9100 요구사항을 대체하거나 그 요구사항에 추가되는 것도 아니다. 있을 수 있는 조건의 다양성(작업 또는 공정의 유형, 사용 기기 및 관련 인원의 역량에 따르는) 때문에, 이 지침이 모든 것에 적용되는 것으로 간주하거나, 계약 요구사항 충족에 필요한 특정 수단 또는 방법을 강요하는 것으로 간주해서는 안 된다. 이해당사자들은 이러한 요구사항을 충족하기 위해 다른 수단 또는 방법을 사용할 수도 있다는 점을 알고 있어야 한다. 이 지침 사용자는 계약서에 명시되는 바와 같이 AQAP 2110 요구사항이 공급자와 하청업체가 지켜야 하는 의무사항임을 명심해야 한다.

この文書は、供給者が9100の規定を遵守する場合の、AQAP-2110の適用に関する情報及びガイダンスを提供するために作成され、発行された。この文書は、AQAP-2110-SRD.2及びIA9137として発行されている。この文書は、NATO及び業界によるAQAP-2110及び9100の関係の理解及び利用を容易にするために、NATO及び業界の代表者が協同で策定した。AQAPは、調達国が対外有償軍事援助（FMS）を調達手段として利用する場合に、必要となる場合がある。 この文書の目的は、調達者及びその9100供給者によるAQAP-2110要求事項の解釈の共通化に寄与することである。 この文書の内容は法的位置づけも契約上の位置づけも有せず、AQAP-2110の要求事項又は9100の要求事項のいずれに対しても取って代わるものでも、追加するものでも、削除するものでもない。 様々な状況が、作業、工程の種類、又は使用される機器、及び関わる要員のスキルのような要因に左右されて存在し得るため、このガイダンスは網羅的なものと見なされることも、また、契約書の要求事項を満たすための特定の手段や方法を義務付けるものと見なされることも望ましくない。ステークホルダーは、これらの要求事項を満たすために、他の手段や方法が使用され得ることを認識すべきである。 このガイダンスの利用者は、AQAP 2110要求事項が、契約書に引用されているとおり、供給者や二次供給者に義務付けられていることに留意することが望ましい。

This paper presents an application of Bayesian Belief Networks for modeling the uncertainty in aircraft safety diagnostics. Belief networks or influence diagrams represent possible means to efficiently model uncertain causal relationships among components of a system. HUGIN is a software for the construction of knowledge based systems based on Bayesian networks. A HUGIN prototype is dicussed to illustrate how a Bayesian approach could be used to support the decision search routine of aircraft safety inspectors when diagnosing equipment of subsystem malfunctions. The example focuses on diagnostic procedures for assessing aircraft tire condition.

Certain standard parts in the aerospace industry require qualification as a prerequisite to manufacturing, signifying that the manufacturer’s capacity to produce parts consistent with the performance specifications has been audited by a neutral third-party auditor, key customer, and/or group of customers. In at least some cases, a certifying authority provides manufacturers with certificates of qualification which they can then present to prospective customers, and/or lists qualified suppliers in a Qualified Parts List or Qualified Supplier List available from that qualification authority. If this list is in an infrequently updated and/or inconsistently styled format as might be found in a print or PDF document, potential customers wishing to integrate qualification information into their supplier tracking systems must use a potentially error-prone manual process that could lead to later reliance on out-of-date or even forged data.