【四级】Elon Musk's SpaceX aims to send an unmanned aircraft to Mars by 2018.
【四级】king willem-Alexander of the Netherlands said that he recently ended his role as a regular "guest pilot" after 21 years with the national airlines fleet of now-outdated aircraft.
荷兰国王威廉·亚历山大（willem Alexander）表示，在国家航空公司（national airlines）机队服役21年后，他最近结束了作为一名定期“客座飞行员”的角色，该机队现在已经过时。
【六级】Energy.systems, like an aircraft carrier set in motion, have huge momentum.
【考研】They found that the aircraft consumed as much as 15% less fuel.
【考研】Dr Kroo points out that the aircraft could be separated by several nautical miles, and would not be in the intimate groupings favoured by display teams like the Red Arrows.
【六级】It could also insist on checking private manned spacecraft as thoroughly as it does commercial aircraft.
【四级】The aircraft cost 25 million pounds and can carry heavier loads than huge jet planes while also producing less noise and emitting less pollution.
【四级】The world's largest aircraft has taken to the skies for the first time.
【六级】Unfortunately for them ( ' , and often the taxpayers), our energy systems are a bit like an aircraft carrier: they are unbelievably expensive, they are built to last for a very long time, they have a huge amount of inertia ( ' , meaning it takes a lot of energy to set them moving), and they have a lot of momentum once they are set in motion.
【四级】The aircraft is massive as long as a football field and as tall as 6 double decker buses and capable of flying for up to 5 days.
【考研】There are reports that some military aircraft flew in formation when they were low on fuel during the Second World War, but Dr. lissaman says they are unsubstantiated.
【考研】Both Boeing and airbus have trumpeted the efficiency of their newest aircraft the 787 and A 350 respectively.
【四级】The lower oxygen pressure found in an aircraft cabin is equivalent to that at 6, 000-8, 000 feet of altitude.
【考研】But a group of researchers at Stanford University, led by Ilan Kroo, has suggested that airlines could take a more naturalistic approach to cutting jet-fuel use and it would not require them to buy new aircraft.
【四级】As far as sunken planes go, this airbus A0 is the largest intentionally sunk aircraft ever.
【考研】When applied to aircraft, the principles are not substantially different.
【六级】Unfortunately for them and often the taxpayers, our energy systems are a bit like an aircraft carrier : they are unbelievably expensive, they are built to last for a very long time, they have a huge amount of inertia meaning it takes a lot of energy to se
【六级】Maybe so, but someone managed to get that hand gun onto the aircraft or it couldn't have been there.
【考研】It might also be hard for airlines to coordinate the departure times and destinations of passenger aircraft in a way that would allow them to gain from formation flight.
【四级】The makers believe it's the future of aircraft and one day we'll be using them to go places.