Advanced Supersonic Technology concept AST-100 characteristics developed in a baseline-update study

The advanced supersonic technology configuration, AST-100, is described. The combination of wing thickness reduction, nacelle recontouring for minimum drag at cruise, and the use of the horizontal tail to produce lift during climb and cruise resulted in an increase in maximum lift-to-drag ratio. Lighter engines and lower fuel weight associated with this resizing result in a six percent reduction in takeoff gross weight. The AST-100 takeoff maximum effective perceived noise at the runway centerline and sideline measurement stations was 114.4 decibels. Since 1.5-decibels tradeoff is available from the approach noise, the required engine noise supression is 4.9 decibels. The AST-100 largest maximum overpressure would occur during transonic climb acceleration when the aircraft was at relatively low altitude. Calculated standard +8 C day range of the AST-100, with a 292 passenger payload, is 7348 km (3968 n.mi). Fuel price is the largest contributor to direct operating cost. However, if the AST-100 were flown subsonically (M = 0.9), direct operating costs would increase approximately 50 percent because of time related costs

Occasional Identity or Occasional Reference?

André Gallois argues that individuals that undergo fission are on some occasions identical, but on others distinct. Occasional identity however, is metaphysically costly. I argue that we can get all the benefits of occasional identity without the metaphysical costs. On the proposed account, the names of ordinary material objects refer indeterminately to stages that belong to reference classes determined by the context of utterance or temporal adverbs. In addition, temporal markers indicating the perspective from which we count objects and assign properties to them determine how many count and what is true of them. So, as Gallois holds, the truth value of claims about what is true at a time may change over time and, where fission or fusion occur, does change. The current account, however, secures this result without commitment to occasional identity: reference, predication and counting are “occasional”; identity is not

Stage-theoretical naming and counting

According to the stage view, ordinary objects are instantaneous stages, which “persist” by being counterpart-related to stages that exist at other times. In this paper, I consider the respective merits of current proposals for a stage-theoretical semantics of proper names of ordinary objects and sketch what I argue is a better alternative. On any stage-theoretical account, names of ordinary objects refer to stages. I argue that names should be understood as temporally flexible, referring indeterminately over stages that constitute an object’s history, and sketch a stagetheoretical semantics for names of ordinary objects that yields the intuitively correct results for reference and counting in both ordinary cases and extraordinary puzzle cases of fission

Utilization survey of prototype structural test article

A survey was conducted of six aerospace companies and two NASA agencies to determine how prototype structural test articles are used in flight operations. The prototype structures are airframes and similar devices which are used for testing and generally are not flown. The survey indicated the following: (1) prototype test articles are not being discarded after development testing is complete, but are used for other purposes, (2) only two cases of prototypes being refurbished and flown were identified, (3) protective devices and inspection techniques are available to prevent or minimize test article damage, (4) substitute programs from design verification are availabel in lieu of using prototype structural articles, and (5) there is a trend away from dedicated test articles. Four options based on these study results were identified to reduce test and hardware costs without compromising reliability of the flight program

Left Libertarianism: What\u27s in It for Me?

Left libertarianism cannot effectively promote equal opportunity for well-being. Neither direct distributions from the rent fund nor financial incentives for firms will significantly reduce gross, ongoing discrimination which locks most women into a narrow range of boring, dead-end, pink collar drudge jobs and puts minorities at a disadvantage in hiring, housing, and access to credit. Left libertarianism: What\u27s in it for me? Not much

Task analysis for error identification: Theory, method and validation

This paper presents the underlying theory of Task Analysis for Error Identification. The aim is to illustrate the development of a method that has been proposed for the evaluation of prototypical designs from the perspective of predicting human error. The paper presents the method applied to representative examples. The methodology is considered in terms of the various validation studies that have been conducted, and is discussed in the light of a specific case study

WESTT (Workload, Error, Situational Awareness, Time and Teamwork): An analytical prototyping system for command and control

Modern developments in the use of information technology within command and control allow unprecedented scope for flexibility in the way teams deal with tasks. These developments, together with the increased recognition of the importance of knowledge management within teams present difficulties for the analyst in terms of evaluating the impacts of changes to task composition or team membership. In this paper an approach to this problem is presented that represents team behaviour in terms of three linked networks (representing task, social network structure and knowledge) within the integrative WESTT software tool. In addition, by automating analyses of workload and error based on the same data that generate the networks, WESTT allows the user to engage in the process of rapid and iterative “analytical prototyping”. For purposes of illustration an example of the use of this technique with regard to a simple tactical vignette is presented

Characteristics of the advanced supersonic technology AST-105-1 configured for transpacific range with Pratt and Whitney aircraft variable stream control engines

Credence to systems weights and assurance that the noise study AST concept can be balanced were studied. Current titanium structural technology is assumed. A duct-burning turbofan variable stream control engine (VSCE), with noise reduction potential through use of a coannular nozzle was used. With 273 passengers, range of the AST-105-1 for a cruise Mach number of 2.62 is essentially transpacific. Lift-to-drag ratio is slightly higher than for previous AST configurations. It is trimmable over a center-of-gravity range of 4.7m (15.5 ft). Inherent high positive effective dihedral, typical of arrow-wing configurations in high-lift approach, would limit AST-105-1 to operating in crosswinds of 11.6 m/sec (22.4 kt), or less, with 75 percent of available lateral control. Normal power takeoff with cutback results in noise in excess of Federal Aviation Regulation Part 36 but less than for conventional procedure takeoff. Results of advanced (noncertificated) programmed throttle takeoff and approach procedures, not yet optimized, indicate that such can be an important additional method noise reduction