Originally Posted by
Red Four
I don't believe it is helpful to try and second guess the operational/safety decisions taken by the pilots on the night - we were not there.
For instance, a reported wind of 170/08 kts could actually be hiding a wind speed of up to 17 kts without it being reported as a gust, or even apparent - the crew would know this and factor it in appropriately. The direction of 170 degrees could also be hiding a significant element of variationin direction (up to 55 degrees) before it was reported as such, which could mean a further chunk of potential tailwind to be assessed rather than just the bare 170 direction might suggest. Any peaks of wind speed (up to 17 kts) would be more likely to have a veered (more westerly) tailwind component, compared to the lulls in speed.
On top of this, there is the forecast 2000ft wind to be taken into account immediately after getting airborne, which would have, on average, have been from a more westerly direction and at at a higher speed than 170/08 kts.
All that maybe fair enough but the original poster raised the subject in the context of SEN's efforts to minimise neighbourhood noise. Bearing in mind that 05 is officially the preferred noise abatement runway I think it's reasonable to discuss the prevailing conditions for that particular departure and whether or not might they have permitted a 05 departure. As a one time Ops Director I support the fact that the flight crew should make the decision on which runway to use and I'm sure they are used to preferred runways being suggested/offered in their line of work.
I'm familiar, for example, with the tailwind components that EZY accept on 05 at SEN for second segment climb restriction reasons on 23. I'm sure they take everything into consideration including the METAR wind history which had been very consistent in this case. On three other days last week that departure used 05 with winds of 170/05, 160/07 and 140/02.