Flex,is the same as derated power,just another Co's name for it.
Derated thrust meets the 'cert' criteria for the 2.4%gradient on ONE.The additional thrust at TOGA was a YAW consideration on the 747(wait until airborn).having said that some Co's call for TOGA thrust(on twins),every little bit helps, after takeoff.
It has been said that since the advent of 'reduced'thrust,in the 60's,the trend for full thrust when needed has been trained out of the knowledge loop(natural common sense).Ergo aircraft still flutter out o'the sky when a good handfull to the firewall would have helped.....
2.4% climb gradient=@150knts=2.5miles@min.
2.4% mile =144'/
[email protected]=360'/minute rate o'climb
