Heavy delays at Heathrow this morning due to wind.
I am tired of crusty old Captains, mainly of a certain mainline airline, aggressively questioning the nature of the delay on a Sunday morning.
When confronted with the reply that it was due to wind (for brevity due to workload), the general ignorant response was that it ''wasn't that strong'', with the aggravating implication that it must be the fault of ATC.
So for the ignorant - the rocket science reply:
The wind at 3A was westerly at >65kt whereas, at surface level, it was 265/16. Groundspeeds of individual aircraft, supposedly flying at 160kts, were generally in the order of 112 KT at 10DME, increasing to around 130KT at 6 DME and as high as 145 KT at around 300ft.
We were positioning aircraft the minimum 2.5 miles apart at around 12DME only to see, due to the wind gradient, the preceding aircraft pull away and, by touchdown, gain almost a mile on the succeeding aircraft.
The result - a lower than scheduled for landing rate of around 34 movements per hour.
The solution - place aircraft an illegal 1.5 miles apart at 12 DME and see how
A. The CAA SRG and
B. The crusty old captain, respond.
Add to this scenario the fact that vortex wake spacing minima are the same in any wind condition, it shouldn't be beyond the wit of any pilot flying into any busy international airfield to deduce that, although the surface wind ''isn't particularly strong,'' it does influence the landing rate and consequent delays, particularly if no flow restrictions are in place.
So, although the surface wind is a mere 16 kts and ''not that strong'' it does in fact reduce the landing rate significantly.
