The math does not need to be complex to understand of the differences.
--- start part one ---
An average A320 with 140 PAX will have approach speed of 130 knots. If the aim is to bring the aircraft from 50 ft ILS THR crossing height to an identical touchdown point (say) about 450 m down the pavement...
... given just 3 knots of TWC vs. HWC ...
the kinetic energy to be managed is 513 MJ compared to 468 MJ. Now, the aircraft aerodynamically still flies Vapp = 130 kt at the beginning of the manoeuvre, so the "steering powers" of the pilot are essentially the same, however we drive a very different beast.
It seems rather unavoidable that a different set of inputs is required to obtain the same desired trajectory.
---- end part one ----
--- start part two ---
The manufacturer explains that typical loss of IAS during the flare is 7 kts. Somewhere between 30 and 10 feet, the wind does slow down by approximately 3 knots (my empirical observation). 10 feet being the reported anemometer value and close to bottom-of-flare, i.e. 3 kts on ground, 6 kts at the top of the flare.
Due to aircraft inertia and the short time-frame when this happens, relative airflow changes and that translates to change in IAS. Thus for a headwind situation: the partial loss of the component when entering the boundary layer over the ground "takes away" 3 knots and the pilot flies the flare whilst slowing down by 4 knots by his own making.
In a tailwind situation the loss of tailwind relative to the A/C creates an increase of IAS by those 3 knots. Here the pilot needs to fly the flare so to reduce IAS by 10 knots.
--- end part two ---
If we would discuss a situation of +/- 5 kt on the ground, I dare to draw the following illustration:
--- figure 1 (imagination required) ---
IDENTICAL for both TWC and HWC:
An aircraft of 58 tonnes and IAS 130 kt follows an asymptotic trajectory from ILS THR crossing height of 50 ft to a touchdown point 450 m down the runway.
DIFFERENT:
HWC: The kinetic energy is 432 MJ, and we need to slow down by 4 knots.
TWC: The kinetic energy is 552 MJ, and we need to slow down by 10 knots.
---- end ---
DISCLAIMER: None of the above should imply me advocating techniques outside the FCOM / FCTM guidance. On the contrary, myself I am a hard core believer in chapter, verse, word and letter of those books (with logical exceptions
). My claim is that a different colour of magic is required to achieve a similar result, just like two instruments playing the same acoustic tone.
WARNING: The above applies, in my opinion, even before we factor in the FLARE MODE and dynamics of handling the thrust levers on Airbus FBW designs. And that’s another potful of jambalaya!
CONFESSION: For those TWC landings that I am proud of, I personally cannot manage as described above. The touchdowns are flattish, at Vapp to Vapp -3.
---- to the OP ---
busav8r: I sympathize and feel the thrill of mastering tailwind landings with F3, the art and geekiness of it, honestly I do. At the same time, may I suggest to leave that animal locked-in with a blanket over the cage? It is a skill of zero practical benefit and anyone attempting to learn it, use it, or show it off would be considered foolish by my professional idols, mostly because a chance was lost to train something meaningful to your(my) self instead.
Hope you won’t mind, let me raise one to make all of this little worthwhile: What is the PAPI MEHT for standard ICAO runways longer than 2400 m?