Vehicle health management research for legacy and futureoperational environments

The Air Force will require the ability to diagnose and predict component failures in order to more effectively meet the requirements of the fast and agile Aerospace Expeditionary Force (AEF) and future space vehicles. This paper will cover topics relevant to vehicle health management for current and anticipated support environments. It reflects current projects underway at the Air Force Research Laboratory in the air vehicles and human effectiveness directorates. Specifically, the predictive failures and advanced diagnostics (PFAD) for legacy aircraft, passive aircraft status system (PASS), and the space operations vehicle integrated system (SOVIS) projects will be discussed     

Power management and distribution system for a more-electricaircraft (MADMEL)

A five-phase Power Management and Distribution System for a More-Electric Aircraft (MADMEL) program was awarded by the Air Force to Northrop/Grumman Military Aircraft Division in September 1991. The objective of the program is to design, develop, and demonstrate an advanced electrical power generation and distribution system for a More-Electric Aircraft (MEA). The MEA emphasizes the use of electrical power in place of hydraulics, pneumatic, and mechanical power to optimize the performance and life cycle cost of the aircraft. This paper presents an overview of the MADMEL program and a top-level summary of the program results, development and test of major components to date. In Phase I and Phase II studies, the electrical load requirements were established and the electrical power system architecture was defined for both near-term (NT-year 1996) and far-term (FT-year 2003) MEA application. The detailed design and specification for the Electrical Power System (EPS), its interface with the Vehicle Management System, and the test set-up were developed under Phase III. Phase IV, fabrication and testing of the subsystem level hardware, has been completed. Overall system level integration and testing, Phase V, is scheduled to be completed by September 1999     

High Voltage/High Power for Airborne Applications

The Air Force has requirements for large amounts of electrical power at high voltage (up to hundreds of kilovolts) for certain airborne applications. Because of the severe weight and volume constraints, these systems cannot be realized using conventional technology. The Air Force, therefore, has been heavily involved in the development of lightweight power generation and conditioning equipment. Programs have been undertaken to reduce the weight of rotating machines, transformers, switches, inverters, and capacitors. The advances made in these areas are described, and some aspects of the use of these components in the design of lightweight systems are discussed.     

减少飞机全寿命费用的研究

本文在调查大量实际费用数据的基础上,分析计算了 30 0架歼击飞机安装不同发动机后全寿命费用变化情况。结果表明,投入适量经费,提高发动机可靠性,减少燃料消耗费,提高发动机寿命,延长或取消发动机翻修寿命,实行视情维修,将大大减少飞机的全寿命费用。      

作战飞机空空对抗的优化配置研究

为了给空军作战飞机的最优规划提供科学的依据,对空空对抗环境下的作战飞机进行了优化配置研究。介绍了四级空中优势的概念,建立了作战飞机的经费优化模型和数量优化模型。应用该模型对某战役想定下的作战飞机进行了经费优化和数量优化,验证了模型的有效性。     

A maintenance-free lead acid battery for inertial navigationsystems aircraft

Historically, aircraft inertial navigation system (INS) batteries have utilized vented nickel-cadmium batteries for emergency DC power. The United States Navy and Air Force developed separate systems during their respective INS developments. The Navy contracted with Litton industries to produce the LTN-72 and Air Force contracted with Delco to produce the Carousel IV INS for the large cargo and specialty aircraft applications, over the years, a total of eight different battery national stock numbers (NSNs) have entered the stock system along with 75 battery spare part NSNs. The standard hardware acquisition and reliability program is working with the Aircraft Battery Group at Naval Surface Warfare Center Crane Division, Naval Air Systems Command (AIR 536), Wright Laboratory, Battelle Memorial Institute, and Concorde Battery Corporation to produce a standard INS battery. This paper discusses the approach taken to determine whether the battery should be replaced and to select the replacement chemistry. The paper also discusses the battery requirements, aircraft that the battery is compatible with, and status of Navy flight evaluation. Projected savings in avoided maintenance in Navy and Air Force INS systems is projected to be $14.7 million per year with a manpower reduction of 153 maintenance personnel. The new INS battery is compatible with commercially sold INS systems which represents 66% of the systems sold     

C-17 successful application of existing automatic test equipment

The C-17 Program utilizes existing B-1B Automatic Test Equipment (ATE). The C-17 decision is in harmony with the Air Force emphasis on reducing proliferation of unique ATE. The ATE selection was made after consideration of cost, performance and supportability tradeoffs. Minimal augmentation of the government inventoried equipment was required which did not affect the existing hardware and software configuration, This approach significantly reduced C-17 program ATE development costs and afforded the program the use of established logistics elements and support structure. The C-17 program demanded concurrency of support structure and aircraft development-the ATE solution met that demand by reducing risks to a manageable level for both test program set development, and Air Force operation and training requirements     

Passive millimeter wave imaging considerations for tactical aircraft

Air Force, Army, Navy, and NASA Research Laboratories, in addition to major aerospace companies, are considering millimeter wave (MMW) imaging technology as an enhancement to sensor suits on both occupied and unoccupied vehicles. This is a review of the basic technology involved in MMW imaging and some of the programs and products that might benefit from passive day or night imaging through mist, haze, fog, clouds, smoke and/or dust. Potential applications include UAV surveillance of ground vehicles, airborne approach to airfields, tankers, flight leaders, and detection of airborne targets, including stealth aircraft.     

A hybrid deep neural network based on multi-time window convolutional bidirectional LSTM for civil aircraft APU hazard identification

Safety is one of the important topics in the field of civil aviation. Auxiliary Power Unit(APU) is one of important components in aircraft, which provides electrical power and compressed air for aircraft. The hazards in APU are prone to cause economic losses and even casualties. So,actively identifying the hazards in APU before an accident occurs is necessary. In this paper, a Hybrid Deep Neural Network(HDNN) based on multi-time window convolutional neural network-Bidirectional Long Short-Term M...     

From the vineyards: why the services don't get the weapons theyneed and why they aren't likely to

It is argued that the procurement of weapons by the US armed services is in crisis. Even before the bribery scandals, there was ample evidence that the whole process was in disarray. The author, a retired civil service electronics engineer, offers his personal opinion of how this happened. Two unsuccessful programs are discussed: an airborne radar designed for the US Air Force to search for vehicles moving on the ground and the Sergeant York, the US Army's attempt to build a radar-pointed, long-range, anti-aircraft gun     

航空工业中的微动损伤及研究概况

本文介绍飞机及发动机中出现的微动损伤概况。飞机构件实验室实验中约有90％的破坏均发生在有微动环境处,微动作用使材料的疲劳强度降低了30～80％。本文还介绍了微动损伤的典型特征。     

An automated test approach for US Air Force fighter engines

In an effort to support the Air Force's new F-22 Fighter aircraft with its dual F119-PW-100 jet engines, a new approach has been taken to realize the benefits of automated jet engine testing. This paper describes an automated test approach that is currently under development and will be used by the Air Force to test the F119 jet engine; It also identifies; the equipment, methods and techniques that are being employed to accomplish this task     

Programs in higher levels of information fusion [USAF applications]

The US Air Force future vision for information fusion is presented in the context of results of a study of long-term challenges in the science and technology of command and control and the programs of the Air Force designed to meet them. A new approach to research is presented that takes advantage of scientific challenge problems that are operationally validated in collaboration with research laboratories in government and industry.     

E-CATS: First time demonstration of embedded training in a combat aircraft

Air Forces are facing difficulties in training pilots effectively for their missions. Due to a reduction of defense budgets, fewer resources can be made available for training. In addition, airspace available for training is limited, especially in Europe, and this is aggravated by the increase in the range of advanced weapon systems. Moreover, only few Surface-to-Air Missile (SAM) sites are available for suitable training.Embedded Training (ET) is considered to be a potential solution for these problems. ET for fighter aircraft is a capability installed in an operational fighter to train the pilot while operating the aircraft in a situation it was designed for, but which is not available in everyday life. Thereto, the ET capability generates simulated threats and feeds them into the various avionics systems of the aircraft. This allows pilots to train against a virtual force, or a virtually augmented real force. Benefits of employing ET include cost reduction (fewer real aircraft are needed to act as enemy), use of smaller training airspace (simulated threats may move outside this space), and the potential to train anywhere, at any time.NLR, Dutch Space, and the Royal Netherlands Air Force (RNLAF) have jointly developed an ET system to demonstrate the feasibility of current technology for implementing an ET capability in fighter aircraft. The system, installed in an RNLAF F-16B, supports training for ground-to-air and (one-versus-two) air-to-air engagements. It consists of two units; one unit executes the ET simulations and provides most of the required interfaces with aircraft systems, while the other unit is dedicated to interfacing with the radar processing chain.The system was evaluated by demonstrating it to a group of pilots and engineers and collecting their expert opinions. It was concluded that embedded training has considerable value for a variety of training objectives related to Beyond Visual Range tactics, and it is expected that embedded training will play an important role in the future mission training of fighter-aircraft pilots.     

航空兵部队飞行安全评估系统研究与实践

根据航空兵部队飞行安全的特点,基于“人、机、环境“系统工程理论,并结合航空兵部队的实际,开发了一套航空兵部队飞行安全评估系统.该系统具有客观评估安全形势、发现薄弱环节和引导航空兵部队安全行为的功能.最后,给出了对航空兵部队进行飞行安全评估的应用实例.     

现役燃气涡论发动机喘振监控系统的研制

本文对现役燃气涡转发动机发生的重大喘振故障作了分析,并提出防喘监控系统方案.依此方案研制出的FCJ-124防喘监控系统,在发动机试车台上和实际飞机发动机上进行多次监控喘振试验,取得了较满意的效果.     

Caution, contention, and consolidation

The Washington Watch column provides an overview of NASA's cautious approach to the launch of Space Shuttle Discovery STS-114, contention between the Air Force and administration about production of the F/A-22 Raptor aircraft, and consolidation among U.S. airline companies.     

The C-17 multifunction display: a building block for avionicsystems

The multifunction display (MFD) developed for use as the primary cockpit display system on the US Air Force C-17A military air transport is described. The 6-in by 6-in color cathode ray tube (CRT) display features a self-contained 1750 processor and vector generator capable of processing MIL-STD-1553B aircraft data and raster video into any of 10 formats as selected by the pilot or copilot. The MFD can display stroke, raster, or hybrid formats in 16 colors. Raster images are driven by sensor inputs with an RS-170 or RS-343 interface. The CRT uses a taut mask delta gun design and provides the best available brightness and line-width performance. The display features small size, low weight, low power, standard interface, and adaptable software. Reconfigurability in the aircraft is enhanced by using four identical cockpit displays     

基于模式重要度的航空电源系统可靠性估计

针对航空电源系统可靠性分析的需要,研究现有典型系统的结构特点,提出基于模式重要度的系统可靠性估计方法。该方法首先根据航空电源各子系统的组成,采用蒙特卡罗方法对各子系统可靠性进行分析。根据子系统中各部件的模式重要度,建立子系统可靠性估计模型,进而获取并联系统和总系统的可靠性估计模型。该方法结合了蒙特卡罗方法的优势和系统本身的结构特点,既解决了复杂航空电源系统可靠性分析的难题,又克服了单纯采用蒙特卡罗方法对其进行分析时,仿真效率较低的问题。最后,采用所提出的方法对两种类型的电源系统进行仿真分析,并与单纯蒙特卡罗方法仿真分析结果进行比较,验证了该方法的可行性和有效性。