Reducing headwind additives on final approach
B737 on final at 2000 ft - auto-throttle disconnected. Runway 27 - wind 270/30 knots. Boeing say add half the headwind component to Vref and to bleed back the additive approaching touch-down so as to cross fence at Vref.
Met people advise that the free stream wind starts above 3000 feet and that below that altitude the wind gradually reduces due friction effect with ground. . .Question: When does the pilot deliberately start reducing the IAS half headwind component additive in order to cross fence on Vref as per Boeing FCTM?. . . .My guess is around 1500 feet, so that there is a gradual bleeding off of the 15 knots (of half the HW component) by the time you arrive at Vref at the fence. Certainly in a steady wind condition you cannot expect to suddenly get rid of the 15 knots in the flare.
Any thoughts on this? Reason I ask is that I have seen countless occasions when the pilot fails to get rid of the additive and crosses the fence far too fast, eventually landing long. I suggest that not getting rid of the half HW component particularly if landing on wet runway, is contributory cause of over-runs on limiting length runways.