Wide-body Aircraft Research Articles

Strategies for Alleviating Impact of Aircraft Noise

Reduction of the impact of noise can be achieved by three alternatives: (1) Reducing the amount of noise generated at the source (modification of aircraft engine; (2) altering flight procedures, flight paths, and frequency of operations; and (3) changing land use surrounding the airport. A general mathematical programming model is developed for the evaluation of the three alternatives. The model is then applied to the first alternative, i.e. (1) To retrofit the aircraft using a new nacelle with sound absorbing materials in the engine inlet and along the internal walls of the engine air duct; and (2) to replace the existing aircraft by new wide body aircraft that feature quieter single-stage fan engines with a high bypass ratio such as Boeing 747 and McDonnel Douglas DC-10. The cost and effectiveness functions associated with each of the alternatives are constructed and the model calibrated using the available data. The mathematical programming model is then reduced to a linear program and applied to a retrofitting and replacement problem.

Commercial Aircraft as a Source of Automated Meteorological Data for GATE and DST

Specially-equipped wide-body commercial aircraft which are flying tropical and Southern Hemispheric routes are providing a new and unique source of meteorological data with a 100 km spatial resolution. Data have been gathered for the GATE, and the planning for a similar effort for the DST is in progress. These aircraft not only provide synoptic data in critical areas devoid of conventional data, but are, in effect, meteorological research platforms that can provide valuable information on mesoscale phenomena. By 1976 it is anticipated that there will be over 80 such aircraft flying global routes. These specially-equipped jets could also be effectively used for FGGE by providing the nucleus of a supplementary observing system for gathering world-wide meteorological data.

Noise: How can the nuisance be controlled?

Aircraft noise is a major nuisance in residential communities around airports. If the air transport industries are to meet the ever increasing demand for air travel, determined efforts are required now to reduce the burden of noise upon these communities. Significant engine noise reductions have already been achieved in the latest generation of wide-bodied aircraft, and further reductions are being forcast by the engine manufacturers. Regardless of whether there are justifiable grounds for this optimism there are alternative steps to be taken. But the problem is basically an economic rather than a technological one — how much does noise reduction cost and how much can we afford to pay? The various costs of aircraft noise, both monetary and social, are discussed in relation to its effects upon people. Although an economic analysis of the problem is feasible, it is doubtful whether our understanding of the relationships between physical noise levels and human reaction is yet adequate for such purposes. Planning methods for estimating the extent of community noise nuisance are presented, and it is shown that consideration should be given to outlying regions exposed to relatively little aircraft noise.

Wide-Bodied Jet Aircraft Operating Cost and Performance Report. Civil Aeronautics Board, 1825 Connecticut Avenue, N.W., Washington, D.C. 20428. April 1973. 45p. Free

Wide-Bodied Jet Aircraft Operating Cost and Performance Report. Civil Aeronautics Board, 1825 Connecticut Avenue, N.W., Washington, D.C. 20428. April 1973. 45p. Free

The effect of growth in stratospheric flight operations

Pollution of the stratosphere by aircraft is increasing because of the growth in air traffic and a general increase in aircraft cruise altitudes. This paper analyzes aircraft route frequencies on those routes where aircraft routinely fly above the tropopause, and estimates the fuel burned per year above the tropopause since 1960. Predictions to 1990 incorporate the increasing numbers of high-flying, wide-bodied subsonic aircraft, and the introduction of the civil supersonic transport. The factors which are important in quantifying stratospheric pollution are discussed. It is suggested that by 1990, within the rather large uncertainties inherent in these predictions, about 40% of the total fuel burned in the stratosphere could be by civil supersonic aircraft. From a breakdown of the various engine types in service, it is possible to estimate the nitrogen oxides emitted by aircraft. Nitrogen oxides emitted by civil supersonic aircraft in the stratosphere are estimated to be about 50% of the total by 1990, but because of the higher cruise altitudes of the supersonic fleet, the contribution from this source to the overall effects of these pollutants will be greater than that from subsonic aircraft.

Technology for Low Noise Aircraft -- The NASA Quiet Engines

Review of the major goals, procedures, and results of the Quiet Engine Program that was initiated four years ago and is now nearing completion. This program has developed and demonstrated, in full-scale, experimental engine tests, technology advances which, if applied to the design of future aircraft, will help produce equipment with noise levels considerably lower than the older narrow-body aircraft and significantly lower than the new wide-body aircraft flying at present. However, the application of this noise reduction technology will result in increases in aircraft operating costs. Future aircraft noise reduction research should, therefore, consider improvements in the economics associated with noise reduction technology.