At high altitudes where commercial jetliners operate, bleed air is used to supply crew and passengers with fresh air at the right temperature. This bleed air is taken from the engine and mixed with recirculated cabin air. The bleed air is compressed to cabin pressure by the engine compressor, which is lubricated with synthetic oils, containing poisoning components. If the seals used are not a 100%, crew and passengers are at a risk of inhaling toxic air, leading to aerotoxic syndrome.
Other than the 787, all commercial aircraft, even the A350 (and most probably 777X) use bleed air for the cabin air supply. This is due to the fact that the engine compressor is overall the most efficient air compressor on-board jetliners. Besides, an additional compressor adds more weight, which translates in less payload and/or range. In recent years, most efficiency improvements on aircraft… Continue reading
Boeing’s 767 was introduced on September 8, 1982. In about five weeks time the 767 program will be 33 years old! Yet the program just got its biggest order to date. FedEx ordered 50 and 50 options. This is an amazing performance. Continue reading
We hear it all the time – fuel costs are the airlines’ biggest input cost. When looking at the data, it certainly is the largest input on flight operations. However, what does it look like for the aircraft airlines depend on most? The workhorse aircraft seating from 125 to 200 passengers? Airbus and Boeing dominate these segments and their aircraft set the tone.
In the chart below we use the US DoT Form 41 data to illustrate what fuel costs are on a per seat per flight hour basis for the past six years.
Of course, fuel prices and hedging contracts also influence these costs, and each airline has a different net cost per gallon over the period. Another potential bias in the data is route length, which differs for each of these aircraft. Shorter routes tend to have higher fuel costs because there… Continue reading