ECON SPEED
Earnest, the ECON cruise speed depends on the cost factor the company uses and the wind direction and velocity. The average ECON speed would be .75 for the B737-300/500 and .78 for the B737 700/900. The B767-300 does about .81
and the B777 has about .84. This is then for no wind standart optimum cruising level.
NG