Originally Posted by
mbcxharm
165 vs 160 could mean the difference between needing to lower the gear or not.
e.g. at 235T, Vref = 145. You can maintain 165 kts with F15 (Vref+20), however to decelerate further you would have to select G/D F20 and then a further stage to F25/F30 which would allow you to reduce to 160 kts. If this was required at some distance before your stabilisation point then this would be undesirable, hence the request to maintain 165 kts.
If they were lighter, e.g. at 220T landing weight, Vref = 140 and they would have been able to maintain 160 with F15.
I don't fly the 777, but what prevents you from selecting F20 with gear up? Do you get the gear warning horn in that configuration?