This is a story of trouble and action—of an industry's trouble—of a company's, and in particular a division's actions, to ensure that there would be, in fact, a path to the future. The future, it turns out, probably will never be quite the same as the past—and I will cover some of that too. I have titled the three parts of the story Reduction in Cost, Increase in Sales, and Results and Comments.

Part of the material contained in this paper was originally written in early 1972 when I was Vice-President and General Manager of Boeing's largest commercial division, the one with which the paper is primarily concerned. The material was written for presentation to the management of another company in serious trouble. The story is that of a traumatic series of years in the life of one of the world's major companies. It is viewed of necessity from my position at that time as head of the company's largest division and does not constitute an official history of that period of life of The Boeing Company, even though some of the charts apply to the company as a whole rather than to just the division involved.

The noise nuisance caused to communities around airports is one of the greatest problems besetting present-day civil aviation. Considerable effort is being expended to meet the challenge of lessening the nuisance without impairing the continued development of air transport. Governments, operators, manufacturers and research institutions are all playing a part. In addition to local regulations designed to control noise near specific airports, legislation based on international agreements has for some years required new types of subsonic jet airliner to be certificated as meeting given noise levels. Currently, the successful development of “hushkits” is enabling many older types to be brought within these levels. At the same time, it appears likely that still more stringent limits will be set for new types as the future unfolds.

IN 1970, Skylab planners decided to provide the astronauts with extendible booms to convey film cassettes weighing 125 earth pounds between the Airlock Module and the Apollo Telescope Mount. This paper describes the boom and its dispensing mechanism, and discusses problems encountered with the mechanism during the test programme. These problems were mainly associated with operation in cold temperature, lubrication, and the motor/ gearhead assembly. Another set of problems which arose during crew training in the MSFC water tank is also discussed.

Experience from this programme leads to the conclusion that attention to detail is the cardinal rule for mechanisms designers. Such things as the correct choice of lubricant, the build-up of tolerances, and the effect of differential contraction of metals can make or break a design.

Two Film Transfer Booms were used during six separate EVAs over the almost nine-month Skylab mission. At these times, film for five solar physics experiments was replenished and retrieved from two work stations on the Apollo Telescope Mount (ATM), and the touch of a button sent extendible stainless steel booms carrying bulky cassettes at six inches a second across thirty feet of space.

As an introduction to this paper, it would be worth defining a QSTOL aircraft, although it is not important that this be a rigid definition. The letters QSTOL stand for “Quiet Short Take-Off and Landing”, and may sometimes be abbreviated to STOL. A true STOL aircraft is capable of taking off and landing on a 2000 ft runway, this distance including the safety requirement to clear a 35 ft obstacle.

From the point of view of quietness, which is a subjective matter, dependent upon many factors, a quiet aircraft (according to one method of measurement) would produce a noise intensity no higher than 90 perceived noise decibels over an area of about 0·9 sq miles, of length 4 m, compared with an area of 16 sq m, length 14 m for such relatively quiet aircraft as TriStar and the DC-10, already in service (Fig. 1).

For the purposes of this paper, I shall call aircraft STOL if they can get in and out of runways up to 4000 ft long with a full payload, and any aircraft needing a longer distance will be conventional or CTOL aircraft.

Two-dimensional flow past a bluff body can be constrained under two important circumstances. For single models, the side walls of a testing facility can impose a constraint on the flow past the model. On the other hand, for single row configurations the adjacent members impose a constraint on the flow past an intermediate member of the row. Both these effects are a consequence of boundary interference.

Ealier investigations related to the interference effects of side walls on the vortex shedding frequency and drag coefficient of single bluff bodies were limited to weakly constrained flows. Recently, side wall interference effects have been reported for severely constrained two-dimensional flows past normal plates, inclined plates, triangular prisms and circular cylinders Constraint or blockage for two-dimensional flow is defined as the ratio of the model width to the test section width. While defining blockage for single rows of bodies, the width of the test section has to be replaced by the spacing between adjacent rows of bodies.

Vortex shedding is an important factor in the design of structural elements subject to flow induced vibrations. Several reviews have appeared on this topic. However, in model testing, the vortex shedding frequency of a bluff body may change when the model mounting is eccentric (Fig. 1). This has not been studied in detail. Available information in this regard is restricted to the data of Shaw whose tests were conducted in a towing tank.

This technical note presents experimental data on the vortex shedding characteristics of equiangular prisms (Fig. 2) mounted eccentrically in a wind tunnel. Explanations for the possible flow behaviour are also presented.