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Aircraft manufacturing in the 21st century sees a future much different to that seen one and two decades before. Manufacturers of both military and commercial aircraft are challenged to become Lean, Agile and Flexible. As progress is slowly made toward introducing advanced assembly systems into production, the overall cost of automation is now more closely scrutinized. After spending tens of millions of dollars on large automated systems with deep foundations, many manufacturers find themselves locked into high cost manufacturing systems that have specific, inflexible configurations. This kind of scenario has caused a shift in the attitude of airframe assemblers, to go back to basics. Lean manufacturing is seen as a way to build aircraft with very low investment in equipment and tools. Today's advanced systems developers do understand the need for more affordable assembly systems.

The utility of airplane flow-field measurements for wind-tunnel testing is reviewed. The methods and equipment developed at Boeing for these measurements are also described. The details of the latest system are presented along with typical results from recent wind-tunnel tests. Using the latest system, flow-field surveys of airplane configurations in industrial low-speed and transonic wind tunnels provide spatial distributions of lift and drag (profile and induced) with good repeatability. In addition, the probe speed and survey region is optimized so that typical full-wake surveys take 20-30 minutes to complete. Final data, displayed as total pressure, velocity vectors, vorticity contours, and distributions of lift and drag (profile and induced) are available approximately 10 minutes after survey completion.

A review of the current extended-range twin-engine operations (ETOPS) and the modifications to the standards and processes that led to its successful operational record has contributed to the feasibility of developing an airplane and preparing an operator for ETOPS at entry into service. The airplane and engine manufacturers and component suppliers have continued to expand on these modified standards and processes in their design, build, test and support programs to meet regulatory authority ETOPS requirements and to facilitate the development of regulatory authority criteria for substantiating ETOPS capability prior to entry into service. Airlines, in conjunction with the manufacturers, have also developed improved processes that meet regulatory authority requirements for preparing an operator to integrate a new airplane into its existing ETOPS programs at entry into service.

Passengers and flight attendants often notice a haze of smoke under the overhead stowage bins in aircraft cabins when cigarette smoking is allowed. As normally operated, the ventilation system in Boeing 737/757 aircraft does not rapidly remove this smoke haze. Air ionization systems from three vendors were tested in a 10 foot long Boeing 737/757 cabin test section with a cruise condition ventilation rate and two cigarette smoking rates to assess their effectiveness in removing smoke haze from the local breathing areas of passengers and flight attendants. Smoke particulate densities were monitored at five breathing areas and at an exit grill in the test section. All of the ionization systems significantly increased the rate of smoke removal after smoking had stopped, increasing the removal rate by about 25%. None of the systems showed a statistically significant reduction of smoke levels at the individual monitoring points while cigarettes were being smoked.

The need for achievement of low community noise levels has had a major influence on the configuration selected for the United States Supersonic Transport (Boeing 2707-300). The selection and development of design features which affect community noise are presented. The configuration has a relatively large span delta wing of moderate sweep and wing loading, with full span leading and trailing edge flaps. An all moving horizontal tail with geared flap is used for trim and control. The use of an unusually far aft center of gravity range is achieved through a fulltime stability augmentation system. All of these design features contribute to low drag at high lift, resulting in high takeoff performance and low levels of thrust required during flight over the community during both takeoff and landing. The resulting airplane has the versatility to use operational techniques which further reduce noise.

The traditional method of determining the net thrust of an engine in cruise is explained. It is shown to result in a satisfactory net thrust uncertainty for jet and low bypass ratio engines but to be unsuitable for high bypass ratio engines. A redefinition of net thrust results in a new thrust determination method, called continuity method, which yields acceptable levels of net thrust uncertainty. The new method no longer requires supporting tests in a simulated altitude facility. The question is raised whether in future programs the demonstration of guaranteed cruise performance of an engine should not be carried out in flight tests rather than in an altitude test facility.