I was a passenger in an A340 during a famous storm 65kts gusting 95kts. Resulted in a go around, but the plane sunk quite fast several times. Is this rare? Are there limits to headwind component? The captain said we experienced extreme wind shear, is that an official grade? Checked the metar for the kts.
Wind shear is also gusts, but the difference is that wind shear involves changes in speed and direction, where gusts are generally in the same direction. 65kt gusting 95kt is a very rare situation that no airline captain would want to tackle unless the situation demands it (low fuel, some other emergency) and the winds are straight as an arrow down the runway. You could land the airplane that way, but a 95 kt gust can certainly lift a wing or cause weathervaning when the aircraft is taxiing off the runway.
Now, if the report is for wind shear gusting that high, it would be crazy to try to land an A340 (or any other aircraft for that matter) unless the pilot had zero other choices (or just didn't know that there was low-altitude wind shear). The max crosswind component for landing on an A340 is around 37 kts.
From what you are describing, it seems they experienced wind shear, and not just gusts.