Aeronautical Technologies for the Twenty-First Century (1992) / Chapter Skim
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Pages 39-60
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From page 41... ...
in furthering those technologies. The boxed material summarizes the primary recommendations discussed in this chapter arid the benefits to be gained from research and technology aimed at advanced subsonic transport aircraft.
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From page 42... ...
The technology of subsonic transports has progressed enormously since the introduction of the first jet transports in the late 1950Se Maior improvements have been effected in .safelv 1 ~· ~^_ __ J ~ _^ ~ ^^- _~ _ ~; ~ navlgauon, mrusl management, aircraft control, flight path control, engine noise, engine emissions, and all-weather operation.
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, direct operating costs (as shown in Figure 2-4) have remained approximately constant because of the offsetting effects of reductions in fuel burned.
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44 AERONAUTICAL TECHNOLOGIES 200 180 160 co =~ 140 ~5 c 1 m a) 100 80 60 Dual Class (38~/347 1,00~nmi Tnp Long-Range Cruise -55% 1960 1970 1980 1990 2000 Certification Year FIGURE 2-2 Fuel burn comparison for long-range aircraft (design range molest.
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From page 45... ...
SUBSONIC TRANSPORT AIRCRAFT An o ~ 2 ._ Cd Cl) En \ Piston Engine \ Propeller Dnven I' o Turbofan ~1 1 1 1 1 1 1 1930 1940 1950 FIGURE 2-4 Direct operating cost trends.
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From page 46... ...
The forecast market for 1991 to 2005 is for 9,000 transport aircraft worth $600 billion in sales in 1990 dollars. The follow-on market to the year 2020 will be comparable-more than a trillion dollars in three decades.
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Though modest in terms of revenue passenger-miles and total sales compared to large subsonic transports, this class of aircraft comprises a large total of the departures and contributes significantly to the congestion problem (Figure 2-7)
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48 AERONAUTICAL TECHNOLOGIES for commuter use and some portion will move into the greater-than-100 passenger class, as represented by the middle portion of Figure 2-7. Transport aircraft used by commercial airlines can be broadly categorized by their seating capacity and their range capability The solid elliptical-shaped areas in Figure 2-8 depict classes 800 700 600 CO CO 5 CO o CD :]
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From page 49... ...
For example, it has been pointed out that a long-range, advanced subsonic aircraft with a cruise Mach number of 0.9 may provide a significant competitive edge. Rather, the Committee believes that sufficient safety and performance advancements can be realized by proceeding along the same general paths in structures, propulsion, aerodynamics, safety research, human factors, and cognitive engineering as have traditionally been followed.
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For the future, composite structures appear to provide the most attractive improvements (Figure 2-11) , but a great deal of research is needed into processes for evaluation, maintenance, and repair of composite structures.
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51 O Long-Range /\ Shor~Medium-Range lo 1 1 1 1 1 1 1 _ nan~ 20 Years +9% 1960 1970 1980 1990 2000 2010 2020 Certification Year are deemed by the Committee to be of primary importance in providing these required capabilities. Environmental Compatibility The environmental compatibility of large subsonic transports is a major barrier to the growth of the worldwide market and, thus, to the growth of U.S.
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From page 52... ...
2010 2020 NASA'S CONTRIBUTIONS TO ADVANCED SUBSONIC TRANSPORTS The contributions that NASA can make to the development of technology for advanced subsonic aircraft are grouped below into the five categories of need that were defined in Chapter 1: cost/convenience, system capacity, safety, environment, and aircraft performance. As might be expected, much of this discussion overlaps with the corresponding discussion of NASA's contributions to the advancement of H5rT and short-haul aircraft (Chapters 3 and 4, respectively)
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From page 53... ...
It should be noted that performance improvements required for future advanced subsonic transport aircraft are heavily dependent on the realization of significant advances in avionics and controls. Chapter 10 discusses these issues in detail.
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From page 54... ...
Pressure for this continuing increase comes from the disproportionate increase in labor costs associated with a given level of inspection and repair. Composite structures promise major improvements in aircraft weight but will not be widely used in commercial aircraft until their cost is reduced and confidence in their structural life has increased greatly.
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NASA should work toward a significant improvement in the understanding of corrosion resistance in an effort to help lengthen the period between mandatory inspections. A major element of airline operating costs is spare parts with the associated maintenance arid man-hour costs.
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Further, no design guidance is available to answer the question of whether the weight penalty is better spent in this way Tan in using it to reduce noise or vibration, for example. NASA should use its experts In cognitive engineering to guide the designers of advanced aircraft In achieving real gains in passenger comfort and corresponding gains in the competitiveness of U.S.
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System Capacity System capacity was identified in the previous section as one of the primary barriers to grown of the advanced subsonic aircraft market. The Committee has identified a number of areas In which NASA can contribute to increasing the capacity of air and ground systems.
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Noise and emissions levels must be controlled without increasing costs or degrading performance. It is the Comm'ttee's belief that NASA can and should play a lead role In addressing the problems associated with noise and emotions from advanced subsonic aircraft.
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Potential applications include reduced cost, improved reliability, and overall fidelity. Aircraft Performance NASA's role in pushing the state of the art in performance for advanced subsonic transports is clear: aircraft that have greater fuel economy, better lift-to-drag ratios, and lower structural weight are required to keep U.S.
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1972. Study of the Application of Advanced Technologies to LongRange Transport Aircraft.
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