SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 43, ISSUE 13 - JULY 1, 2005

03 AIR TRANSPORTATION AND SAFETY
Includes passenger and cargo air transport operations; airport ground operations; flight safety and hazards; and aircraft accidents.

Systems and hardware specific to ground operations of aircraft and to airport construction are covered in 09 Research and Support Facilities (Air).

Air traffic control is covered in 04 Aircraft Communications and Navigation.

For related information see also 16 Space Transportation and Safety and 85 Technology Utilization and Surface Transportation.

20050177289 National War Coll., Washington, DC USA

Losing the War by Winning the Battle: John Warden’s Theory of Strategic Bombing Applied to Limited Conflict

Robinson, David M.; Jan. 2000; 12 pp.; In English Report No.(s): AD-A433117; No Copyright; Avail: Defense Technical Information Center (DTIC)

Air power is both a promise and a problem. The promise is that strategic bombing may shorten wars by striking at the heart of the enemy and sapping either his will or his ability to continue hostilities. In theory, aircraft have a more direct approach to an opponent’s center of gravity and are less susceptible, once air superiority has been attained, to defensive counter measures. The result should be a faster, and therefore more humane, end to the conflict. But the problem with bombing, aside from still unanswered questions about its actual effectiveness, is that in both planning and execution, it tends to blur or erase the distinction between combatants and civilians. At the very least, collateral damage claims unintended victims, especially in urban areas. While precision weapons may reduce the likelihood of noncombatant deaths, air power doctrine itself, which since the First World War has legitimated attacking enemy population centers, makes them all but certain. This unpleasant fact leaves strategistswith a dilemma. The potentially most effective use of air power also may be the most morally questionable. In wars for national existence, such as the Second World War, the suffering of innocents may be proportionate to necessary military objectives. But in the limited conflicts that have been fought since the end of the cold war, civilian deaths, especially if they outnumber combatants’, may undermine the political influence sought. In the late twentieth century, the problem with strategic bombing may eclipse its promise. DTIC

Target Acquisition; Warfare

20050177514 Air Force Inst. of Tech., Wright-Patterson AFB, OH USA

A Capacitated Facility Location Approach for the Tanker Employment Problem

Miller, Jeffrey R.; Mar. 2005; 152 pp.; In English; Original contains color illustrations Report No.(s): AD-A433483; AFIT/GOR/ENS/05-12; No Copyright; Avail: Defense Technical Information Center (DTIC)

Air refueling is conducted to provide rapid response, increased range, and extended airborne operations for bombers, fighters, airlift, command and control, and intelligence, surveillance, and reconnaissance aircraft. The planning and scheduling of limited tanker resources during employment operations is a major concern for Air Mobility Command (AMC). AMC does not currently have a simple tool that runs in a short amount of time to aid in planning operations. The tool developed allows AMC to input several sorties consisting of various aircraft types and armaments. Each sortie contains a base of origin, and is assumed to be attacking or patrolling in an engagement zone defined by the user. The user is also able to specify the locations of military tanker aircraft. The main goal of the tool is to assign the tankers to anchor areas, surrounding the engagement zone so that all receivers can be refueled during their attack operations. Secondary goals include minimizing the number of tankers required (or maximizing the number of receivers supported), and limiting the total flight distance for the tanker aircraft. The TET tool uses the heuristic technique tabu search to determine an assignment of tankers and sorties to anchor areas during employment. DTIC

Deployment; Military Operations; Planning; Position (Location); Refueling

20050177561 Osan AFB, Korea, Republic of

The Effectiveness of T-6A Instrument Flying Training as Compared to T-37B Training

Murphey, Arthur N.; Dec. 2004; 52 pp.; In English Report No.(s): AD-A433541; No Copyright; Avail: Defense Technical Information Center (DTIC)

The purpose of this graduate research project was to examine the effectiveness of instrument flying training conducted in the T-6A compared to training in the T-37B to prepare student pilots for follow-on advanced trainer aircraft. The USA Air Force’s newest primary trainer, the T-6A, has several technological advances over its predecessor, the T-37B. A general opinion exists among U. S. Air Force primary flying instructors and senior leadership that the T-6A is better equipped than the T-37B to prepare students for follow-on glass cockpits, and significant advances in cockpit technology suggest it might provide a better platform for instrument training. Data was collected for student grades achieved on T-38A advanced trainer instrument maneuvers at Laughlin Air Force Base, and was analyzed to compare performance of 39 prior T-6A students with 35 prior T-37B students. The overall mean of T-6A students’ grades surpassed the T-37A students, and the T-6A students had higher average scores on a majority of maneuvers. However, there was no statistically significant difference between the groups. Among other conclusions, this suggests that digital glass cockpits do not necessarily offer better fundamental instrument training than older, analog designs. DTIC

Education; Flight Training; System Effectiveness; Training Aircraft

20050180244 Cleveland State Univ., Cleveland, OH, USA

Rotordynamic Analysis and Feasibility Study of a Disk Spin Test Facility for Rotor Health Monitoring

Sawicki, Jerzy T.; April 2005; 103 pp.; In English; Original contains color and black and white illustrations Contract(s)/Grant(s): NAG3-2573; No Copyright; Avail: CASI; C01, CD-ROM; A06, Hardcopy

Recently, National Aeronautics and Space Administration (NASA) initiated a program to achieve the significant improvement in aviation safety. One of the technical challenges is the design and development of accelerated experiments that mimic critical damage cases encountered in engine components.

The Nondestructive Evaluation (NDE) Group at the NASA Glenn Research Center (GRC) is currently addressing the goal concerning propulsion health management and the development of propulsion system specific technologies intended to detect potential failures prior to catastrophe. For this goal the unique disk spin simulation system was assembled at NASA GRC, which allows testing of rotors with the spinning speeds up to 10K RPM, and at the elevated temperature environment reaching 540 C (1000 F). It is anticipated that the facility can be employed for detection of Low Cycle Fatigue disk cracking and further High Cycle Fatigue blade vibration.

The controlled crack growth studies at room and elevated temperatures can be conducted on the turbine wheels, and various NDE techniques can be integrated and assessed as in-situ damage monitoring tools. Critical rotating parts in advanced gas turbine engines such as turbine disks frequently operate at high temperature and stress for long periods of time. The integrity of these parts must be proven by non-destructive evaluation (NDE) during various machining steps ranging from forging blank to finished shape, and also during the systematic overhaul inspections. Conventional NDE methods, however, have unacceptable limits.

Some of these techniques are time-consuming and inconvenient for service aircraft testing. Almost all of these techniques require that the vicinity of the damage is known in advance. These experimental techniques can provide only local information and no indication of the structural strength at a component and/or system level. The shortcomings of currently available NDE methods lead to the requirement of new damage detection techniques that can provide global information on the rotating components/system, and, in addition, they do not require direct human access to the operating system.

During this period of research considerable effort was directed towards the further development of experimental facility and development of the vibration-based crack detection methodology for rotating disks and shafts. A collection of papers and reports were written to describe the results of this work. The attached captures that effort and represents the research output during the grant period. Author

Crack Propagation; Detection; Gas Turbine Engines; Nondestructive Tests; Rotating Disks

20050181430 NASA Langley Research Center, Hampton, VA, USA

Technology-enabled Airborne Spacing and Merging

Hull, James; Barmore, Bryan; Abbott, Tetence; [2005]; 9 pp.; In English; 23rd Digital Avionics Systems Conference, 24-28 Oct. 2004, Salt Lake City, UT, USA Contract(s)/Grant(s): 23-727-01-10; No Copyright; Avail: CASI; A02, Hardcopy

Over the last several decades, advances in airborne and groundside technologies have allowed the Air Traffic Service Provider (ATSP) to give safer and more efficient service, reduce workload and frequency congestion, and help accommodate a critically escalating traffic volume. These new technologies have included advanced radar displays, and data and communication automation to name a few.

In step with such advances, NASA Langley is developing a precision spacing concept designed to increase runway throughput by enabling the flight crews to manage their inter-arrival spacing from TRACON entry to the runway threshold. This concept is being developed as part of NASA s Distributed Air/Ground Traffic Management (DAG-TM) project under the Advanced Air Transportation Technologies Program. Precision spacing is enabled by Automatic Dependent Surveillance-Broadcast (ADS-B), which provides air-to-air data exchange including position and velocity reports; real-time wind information and other necessary data.

On the flight deck, a research prototype system called Airborne Merging and Spacing for Terminal Arrivals (AMSTAR) processes this information and provides speed guidance to the flight crew to achieve the desired inter-arrival spacing. AMSTAR is designed to support current ATC operations, provide operationally acceptable system-wide increases in approach spacing performance and increase runway throughput through system stability, predictability and precision spacing.

This paper describes problems and costs associated with an imprecise arrival flow. It also discusses methods by which Air Traffic Controllers achieve and maintain an optimum interarrival interval, and explores means by which AMSTAR can assist in this pursuit. AMSTAR is an extension of NASA s previous work on in-trail spacing that was successfully demonstrated in a flight evaluation at Chicago O Hare International Airport in September 2002. In addition to providing for precision inter-arrival spacing,AMSTAR provides speed guidance for aircraft on converging routes to safely and smoothly merge onto a common approach. Much consideration has been given to working with operational conditions such as imperfect ADS-B data, wind prediction errors, changing winds, differing aircraft types and wake vortex separation requirements.Aseries of Monte Carlo simulations are planned for the spring and summer of 2004 at NASALangley to further study the system behavior and performance under more operationally extreme and varying conditions. This will coincide with a human-in-the-loop study to investigate the flight crew interface, workload and acceptability. Author

Aircraft Approach Spacing; Air Traffýc Control; Air Transportation; Technology Utilization

Source: NASA.