The Boeing Company is among the largest aircraft manufactures in the world. In fact, the American aviation juggernaut is the largest exporter in the United States, not only for aircraft, but also rockets, satellites, and rotorcraft. Boeing may not be the largest producer of aircraft in the world, but they take the lead when it comes to using innovate manufacturing process and lightweight composite materials. This has become ever so evident when the Boeing 787 Dreamliner hit the skies in 2011.
The 787 may look quite similar to its earlier counterparts, but hidden in the manufacturing process lies a secret – 50% of the materials used in the 787 are made up of advanced composite materials. No other commercial airplane in Boeing’s history have ever used so many composites in its airframe and primary structure. So what does this all boil down to? This building approach has a weight savings on average of 20% over conventional aluminum designs. Less weight mean less fuel is needed which leads to less operating costs for the airline companies.
In order for Boeing to choose the optimal materials for every application of the aircraft, they had to analyze every single section of the airframe. An example of this is that composites are not very efficient at handling compression loads while they are good at handling tension. On the other hand, aluminum is quite sensitive to tension loads, but it can handle compression very well. By increasing the amount of composite materials in high tension areas of the fuselage, the amount of maintenance needed to repair fatigued aluminum parts is greatly reduced.
After Boeing’s engineers completed the analysis on the primary structure, they realized that thy needed to increase the amount of titanium in specific areas in which aluminum was considered to be a poor choice due to environmental factors. Titanium can withstand a considerable higher load than aluminum, it has minimum fatigue, and it is very resistant to corrosion. Having replaced a large amount of aluminum with advanced composite materials and titanium leads to much less scheduled maintenance which also translates to lower operational costs for the airlines as well.
Another maintenance advantages of using composite materials is that a typical bonded repair on the standard aluminum airframe sometimes requires more than 24 hours of downtime, but Boeing has created a new way of repairing composite materials in less than an hour. This leads to quicker turnarounds and offers the opportunity for a quick in-and-out for minor damage that might make an aluminum airplane unable to fly.
Also, the fuselage is constructed in tubular segments that are joined together during their final assembly and since the use of composites saves up to 50,000 rivets per plane, this drastically reduces the amount of time needed for checking every rivet during routine maintenance.
Aside from the composite materials used in the airframe and fuselage, a vast number of engine components are made from composites as well. For starters, the inlet and outlet fan cowls are perfectly suited for composites, but surprisingly, even the fan blades are made partly of composites. This technology has come a far way since the 1970′s when carbon fiber fan blades failed miserably in bird tests. This weight that is saved in the turbine blades also dramatically increases the power/weight ratio too.
Steel makes up for the remainder of the materials used in the 787, but this is primary in the landing gear due to the amount of stress it undergoes during landing. This is a far cry from the bulky steel commercial planes of the 1930′s in which a 25,000 pound aircraft could carry 25 passengers about 350 miles (3 pounds per passenger mile), to the Boeing 787 which weighs in at 550,000 pounds and carries 290 passengers a staggering 8,000 miles (¼ pound per passenger mile) – That’s an impressive increase!
Boeing continues to take the lead when it comes to fuel efficiency and minimizing environmental impact and safety. They have reduced weight, lowered levels of maintenance, and significantly reduced the operating costs for the airline industry. Only time will tell what next great advancement in aviation Boeing will discover next.
