Midterm Report

The Saab 340A is a Swedish twin turboprop passenger plane which was first produced in 1983. Although they are no longer in production, they are still actively used. It was designed in a partnership between Saab and Fairchild with each company being responsible for certain aspects. Fairchild’s portin included the wings, engine housing, and empennage, while Saab handles the fin, fuselage, and final assembly. They agreed upon a General Electric CT7-5A2 engine and a Dowty Rotol 4 Bladed Composite propeller. This engine is just the commercial version of the General Electric T700 which was already being used to power military helicopters.

Once everything was completed, the first prototype was flown in early 1983, four years after the two companies initially agreed to work together. Depending on the configuration, the Saab340A can seat between 30 and 36 passengers, and a cargo version also exists. Specifications of both the plane and engine are provided in Tables 1 and 2 below. Table 1. Saab 340A Specifications Maximum Takeoff Weight 28500 lbs. Maximum Landing Weight 27200 lbs. Maximum Zero Fuel Weight 25700 lbs. Avg. Operational Empty Weight 18800 lbs. Max Payload 6900 lbs. Max Fuel Capacity (weight) 5690 lbs.

Max Fuel Capacity (volume) 849 gallons Max Cruise Speed 271 knots Max Operating Altitude 25000 ft. Wing Span 70. 333 ft. Wing Area 450 ft2 AR 10. 993 Max Range with Full Load 490 nm Max Range with No Payload ?1550 nm Table 2. General Electric CT7-5A2 Specifications Max Continuous at S/L Shaft 1660 hp Thrust 150 lbs. Normal Takeoff (5 min) at S/L Shaft 1735 hp Thrust 164 lbs. TSFC max 0. 476 (lb/hr/shp) One of the biggest drawbacks of the Saab 340 is its limited range. As seen in Table 1 it can only travel 490 nautical miles, or about 563 miles, when filled with passengers and their baggage.

This is a very small distance and is approximately as far as flying from New York to North Carolina. Part of the reason for such a short range is the fact that it is a small plane, so it wouldn’t be as economical to fly just a few people so far. However, this is still a very short distance and increasing its maximum range could open up many more flight options for airlines. For that reason, increasing its range will be one of the goals of this project. The other goal will be to increase its speed. A cruise speed of 271 knots is about 311 mph, which is slower than many other commercial aircraft.

As with the range, because it is usually used for shorter flights the speed is not as crucial, but because the first goal was to increase the range, increasing its speed goes hand in hand with this. There would be no reason to use this plane for longer distances if another one can be used that will get passengers to their destination faster, and for that reason it would be a good idea to increase both the speed and the range. The exact way these improvements will be made has not been decided yet, but there are some options that need to be looked into.

Because it was designed in the 1980s, its engine is old and outdated and there are now may be newer engines that can burn fuel more efficiently and provide more thrust, which would help increase its range and velocity. Another option is changing the airfoil it uses. Replacing its current airfoil with one that is more aerodynamic and would lower drag would increase both its speed and its range. Analyzing the profile and fineness ratio of the fuselage is another aspect that must be considered since it may be possible to lower the drag created by the shape of the fuselage.