Era of plastic planes

- Chandrshekhar Shrivastava   09-01-2017

          



Think of plastic and plethora of items made of this malleable material and used in households on day to day basis crop up in your imagination. Never have you imagined about aeroplanes made of plastic and flying over large distances over the globe. But aeroplanes made of a new material – carbor-reinforced plastic composites – could be a possibility in the year 2017 and probably having a pleasant effect on travel, making flying more comfortable despite airlines making efforts to cram passengers in tighter cabins and charge for the most basic amenities.
 
Carbon fibre reinforced plastic (CFRP or CRP), is a very strong and lightweight composite material or fiber-reinforced plastic. It is similar to glass-reinforced plastic; one uses commonly the name of its reinforcing fibers (carbon fiber) for the composite material. But it is expensive.
 
A composite material (also called a composition material or shortened to composite) is a material made from two or more constituent materials with significantly different physical or chemical properties, that when combined, produce a material with characteristics different from the individual components.
Fibre-reinforced plastic (FRP) (also fibre-reinforced polymer) is a composite material made of a polymer matrix reinforced with fibres. The fibres are usually glass, carbon, aramid, or basalt. Rarely, other fibres such as paper or wood or asbestos have also been used.
 
When combined with a plastic resin and molded it forms carbon-fibre-reinforced polymer (often referred to as carbon fibre) which has a very high strength-to-weight ratio, and is extremely rigid although somewhat brittle. One would naturally be inclined to ask what planes have to do with this composite material.
 
Flying that nowadays stands for comfort has its own discomforts which arise from two factors: air pressure and humidity. Normally planes have to fly at very high altitudes to avoid turbulent air pockets. This could be as high as 35,000 feet. At this altitude, the air pressure outside an aeroplane is extremely low. So the cabin is pressurised to bring it to a level closer to the sea level pressure. But the trouble is that raising the cabin pressure all the way to sea-level pressure would put tremendous strain on the body of the plane, which has to cope with the sharp pressure differences on the inside and outside. That is why; most airliners maintain a cabin pressure equivalent to that at 8,000 feet above sea level. This is roughly equal to the mid elevations of Himalayan ranges.
 
Those who have visited these high altitude areas know well how exhausting it is to spend time there. For those not accustomed to the thinner air, lungs and heart have to work harder to deliver oxygen to their body and brain. People residing at these high altitudes naturally develop stronger hearts and lungs because of constant exposure to such stressful atmosphere. Flying, however, is more sedentary activity and during a flight of few hours no one can become accustomed to rare atmosphere. Besides, altitude can also interfere with sleep and cause exhaustion while flying.
 
Traditional aluminum bodies of most existing planes have to struggle to withstand the larger pressure differences that arise from bringing cabin pressure below the 8,000-foot level. But carbon-reinforced plastic composites can provide an answer to overcome this problem. New aircrafts are now being built with these stronger composites. The Boeing 787 Dreamliner, for example, is constructed with such plastic and features a cabin pressure equivalent to 6,000 feet. A study conducted in coordination with Boeing found that while flying at 8,000 feet can cause a 4 per cent decline in blood oxygen, while flying at 6,000 feet is literally similar to being on the ground.
 
Another nuisance while flying is humidity that is generated by passengers' breathing and perspiration. In order to maintain a certain humidity level, planes expel much of it; for if it is allowed to concentrate inside the plane, its metal frames may begin to corrode. So, planes generally have a level of humidity that is optimal for them, not for passengers. Very low humidity, however, can have some adverse effects of passengers’ body such as dry eyes and throats. Here again, carbon-reinforced plastic composites provide an answer, as a Boeing representative says, “Carbon fibre doesn’t care if it gets wet.”
 
The Boeing 787 is not the only plane being built of carbon composites. Now, an Airbus A350 has also been built with a composite plastic frame in which its cabin pressure is mainatined equivalent to 6,000 feet. Both aircrafts are in operation, but in limited numbers. They are likely to become more common — according to the respective manufacturers, there are currently 810 orders for the A350 and 1,210 for the 787 — and as other models follow suit, cabins with more pleasant pressure and humidity levels will become the norm. Even planes with metal frames could adopt these changes.
 
In other words, with each successive year, flyers’ likelihood of suffering fatigue, sleeplessness, scratchy throats and eyes, and the jet lag to which these symptoms contribute will diminish, thanks to the revolutionary material – carbon reinforce composite plastic.