B777-200LR/F VREF floor
 

I noticed the -200LR/F has a VREF floor of 137kt up to a landing weight of of 220t. Only above that weight does it start to increase.

I assume boeing put this VREF floor in place to maintain the margin to VMCA. Considering the GE90-110BL1 increased thrust.

I have heard that some operators recommend flaps 25 when "light" to prevent floating and to decrease pitch attitude by 1º on landing. However looking at pictures online it seems most landings are done at flaps 30 regardless.

For the guys flying the LR/F is there a rule of thumb weight you use to decide on Flaps 30 vs. 25 under normal circumstances. Flaps 25 < 200t etc.

Flap 25 is a normal landing flap setting, but flap 30 is recommended unless there is a good reason to use 25.

On the LR/F 25 is recommended when Vref25 is ALSO the " floor" value of approximately 137kts ( the FMC does vary that with different conditions-I've seen as low as 135)

This happens at about 195T.