At what altitude do most jet planes fly?
http://answers.yahoo.com/question/index?qid=20060913153433AAWR1gZ
Most passenger jets fly between around 31000 and 37000 feet depending on their weight and the distance being flown, however the smaller business jets typically operate up to 45000 feet and in the case of Concorde it went as high as 51000. At those kinds of altitudes you can see the curvature of the earth, it is quite spectacular.
The reason is that at high altitudes in thinner air jet engines work more efficiently by burning a lot less fuel and the ground speed of the aircraft is significantly higher than the airspeed the aircraft is measuring,
The reason is that at high altitudes in thinner air jet engines work more efficiently by burning a lot less fuel
.
So they were wasting gas too by flying at 1000 feet