"Stress factors""Psychologists put pilots' stress levels at the top of the league alongside surgeons, although the latter have an advantage--if the scalpel slips they do not accompany the patient to the mortuary. The pilot's stress is rarely apparent, except when the airline loses his suitcase.""" "Tick off""Pre-flight checks are a vital part of the operation and cover virtually every aircraft system--electrics, hydraulics, pressurization, flight controls, and autopilots, down to the windscreen wipers. Someone also has to do an outside check to make sure that all the bits of an airplane are still there.""" "Fuel consumption""Because of the extra weight, up to three percent of any extra fuel taken aboard will be used each hour simply to carry it. Thus, on a ten hour flight an extra thirty tons of aviation kerosene can use almost ten tons of itself simply by being there.""" "Burning rubber""Airlines like their pilots to make firm landings. The wheels are stationary. The runway is passing by at around 150 mph. The two have to meet up. If the pilot does a smoothie, the tires drag along the runway surface without spinning up which burns off rubber. A firm landing gets the wheels spinning with less loss of expensive tread.""" "Manual controls""If the weather is fine, enthusiastic pilots often disengage the autopilot in the latter stages of the descent and fly the aircraft by hand. Not only is it enjoyable, but with the relentless increase in automation it is sometimes a comfort to discover they still can."