Aircraft approach question?

Question

why does the captain keeps calling out all the pluses for in this video?? I've heard this on other videos and I want to know what it means.

http://youtube.com/watch?v=8g-ArLYsloI

Answer 1

It's speed in relation to Vref (approach speed).  Say Vref was 140 KIAS, then a "plus 10" callout would be made if the pilot was at 150 KIAS.  I don't know for sure, but I wouldn't be surprised if pilots kept their speed up a bit on the Hong Kong approach in the video because of the large margin for error.  That could be the reason the pilot seemed to fly +10 the whole way.

Answer 2

I think it's the copilot who is calling out the numbers. "Plus ten" means "Vref speed plus ten knots," Vref being the calculated landing speed for touchdown.

Answer 3

He's calling out the difference in knots between the indicated airspeed and the approach speed.