B737 Vref ICE
I'm hoping this question hasn't already been covered at length, but does anyone know the reason/s that the B737 QRH calls for Vref ICE (+10kts) to be applied when landing flaps 15 i.e B hydraulic failure, 1 inop landing etc.
I can understand why you would want to use Vref Ice generally, but cannot understand why it is only applied to the Flap 15 approach speed and not flaps up or 40.
Kind regards.