Originally Posted by
WojtekSz
<snip>
i used the term 'flying level' as a short version of saying: to stay as close to level flight as possible with the existing plane configuration and airspeed, in order to achieve best horizontal progress with lowest loss of flight height.
<snip>
The two are incompatible - losing height as slowly as possible and making best forwards progress. What you need is the second one - getting the best forwards progress. You fly at best L/D for that, and what that is will depend on the configuration of the plane and it's wing loading. However, it is faster than min/sink - losing height as slowly as possible.
Since the 777 has many different configurations, each one will have it's own best l/d and speed to fly, STF that will always be faster than the min/sink for that configuration.
I did find a nice animation on the Internet once which illustrating the differences between flying too slowly, at the right speed and too fast, but can't find it now.
There are a couple of Wikipedia articles which explain the theory:
http://en.wikipedia.org/wiki/Polar_curve_(aviation)
http://en.wikipedia.org/wiki/Lift-to-drag_ratio
However, my own view is that whatever the theory, MMM managed the situation well enough that everyone survivied and nearly everyone was (physically) unhurt. Will be very interested to see the final outcomes of the work going on at Boeing about handling this thankfully very rare occurence.