Originally Posted by
yanrair
Perfect.
2500 ft tailwind 20
airfiel wind headwind 20
So your landing GS will be 20 kts less than V Ref. Say VRef 100, then fly whole approach at 120 GS. Your IAS will be 140 at 2500 and 100 on landing. Just what you were looking for- no? A perfect touchdown speed. Not approx.
more commonly one has reducing headwind during final descent. Say 30 kts HW at 1000 ,and 5 kts at touchdown. VRef 100.
Fly whole approach at 105 kts. GS. You will land at EXACTLY 100 VRef!
this is precision flying- not guesswork. Clearly you use manufacturer Pitch/power tables too to give you a clue but then refine the outcome using GS.
Hello Yanrair,
I did not say the wind was 20 kt headwind on ground lol. It usually goes from a strong tailwind around 2500 feet to a crosswind/ light headwind. Anyway I don't deny you should not use the GS as a tool. If you are 200kt GS on short final, something is wrong. But I think it's safer to keep it simple. Pitch and Thrust is all you need to fly safely to the ground. A quick look at the GPS can help but should not be relied on. If for some reasons I have Unreliable airspeed on final, I know with 4 degree pitch and 50% N1 with F3 and gears down on A320 I'm safe. No need to do maths in a critical phase of flight and that's how Airbus expect you to fly in that case according to the QRH. =)