2.1 Essense of the stage .

Design - the process of first creating a prototype product , the prediction of its functions and properties. Industrial design phase of an aircraft includes preliminary , conceptual and detailed design . Preliminary design lies in the development of flight - tactical and technical requirements , and assess their feasibility . Preliminary constructor when it strikes sketches the main components and assemblies of the aircraft determines its design , shape, configuration. By conceptual design includes: determining the mass of the aircraft, its layout and calculation centering , aerodynamic calculations and the approximate calculation of the strength of the main parts of the plane

2.2 Boeing had been studying short-haul jet aircraft designs and wanted to produce another aircraft to supplement the 727 on short and thin routes. Preliminary design work began on May 11, 1964, and Boeing's intense market research yielded plans for a 50- to 60-passenger airliner for routes 50 to 1,000 mi (80 to 1,600 km) long. Lufthansa became the launch customer on February 19, 1965, with an order for 21 aircraft, worth $67 million (1965, $190.28 million in 2008), after the airline, received assurances from Boeing that the 737 project would not be canceled. Consultation with Lufthansa over the previous winter resulted in an increase in capacity to 100 seats.

The prototype 737, a -100 operated by NASA for testing

On April 5, 1965, Boeing announced an order by United Airlines for 40 737s. United wanted a slightly larger airplane than the 737-100. So Boeing stretched the fuselage 91 centimeters (36 in) ahead of, and 102 cm (40 in) behind the wing. The longer version was designated 737-200, with the original short-body aircraft becoming the 737-100.

Detailed design work continued on both variants at the same time. Boeing was far behind its competitors when the 737 was launched, as rival aircraft BAC-111, Douglas DC-9, and Fokker F28 were already into flight certification. To expedite development, Boeing used 60% of the structure and systems of the existing 727, the most notable being the fuselage cross-section. This fuselage permitted six-abreast seating compared to the rival BAC-111 and DC-9's five-abreast layout. Design engineers decided to mount the nacelles directly to the underside of the wings to reduce the landing gear length and kept the engines low to the ground for easy ramp inspection and servicing. Many thickness variations for the engine attachment strut were tested in the wind tunnel and the most desirable shape for high speed was found to be one which was relatively thick, filling the narrow channels formed between the wing and the top of the nacelle, particularly on the outboard side. Originally, the span arrangement of the airfoil sections of the 737 wing was planned to be very similar to that of the 707 and 727, although somewhat thicker. However, a substantial improvement in drag at high Mach numbers was achieved by altering these sections near the nacelle. The engine chosen was the Pratt & Whitney JT8D-1 low-bypass ratio turbofan engine. With the wing-mounted engines, Boeing decided to mount the horizontal stabilizer on the fuselage rather than the T-tail style of the Boeing 727.

Engines

737-800 engine with non-circular "hamster pouch"

Engines on the 737 Classic series (300, 400, 500) and Next-Generation series (600, 700, 800, 900) do not have circular inlets like most aircraft. The 737 Classic series featured CFM56 turbofan engines, which yielded significant gains in fuel economy and a reduction in noise over the JT8D engines used on the -100 and -200, but also posed an engineering challenge given the low ground clearance of the 737. Boeing and engine supplier CFMI solved the problem by placing the engine ahead of (rather than below) the wing, and by moving engine accessories to the sides (rather than the bottom) of the engine pod, giving the 737 a distinctive non-circular air intake.

2.3 Designing an aircraft starts with the calculation of aerodynamic characteristics. Created computer models of the aircraft and its components units of functional systems. This is due to a number of programs AutoCAD, SolidWorks, KATIA, COMPASS.

In my work I used SketchUp

2.4 Designing stage cost

Stage 3

Testing