Lhr Holds
 

CAN ANYONE ANSWER THE FOLLOWING FOR ME:-

1. WHAT APPROX PERCENTAGE OF A/C INBOUND TO LHR GO INTO A HOLD?

2. IS THERE A PATTERN OF THE BUSIEST TIMES?

3. WHERE SEEM TO BE THE BUSIEST ONES?

MANY THANKS

1. Most of them
2. Morning, (lunch time) and teatime
3. all of them! (but primarily Lambourne)

1. Depends on the weather - at the field (which determines arrival rates), in the pattern (which determines the capacity of the circuit), and en route (abnormal winds will distort the pattern of arrivals). However, on a good day, there may be no more than 10 minutes holding all day, and less than 20% of flights actually enter the hold. Bear in mind that changing the radar pattern, controlling speed etc effectively delay aircraft outside of the physical stacks.

2. The peak hours for arrival are just about all hours with the exception of 1125 to 1130 am on Tuesdays. However, the times at which you are most likely to hold are around 6.30-10 am - in the transatlantic arrival rush, followed by the European early arrival rush. Also, if weather is uncooperative, delays will build during the day.

3. Transat's would think that Ockham was the busiest. Europeans would think Lambourne. But it just depends where the bulge of traffic is predominantly coming from - they all take their turn. Biggin is possibly the least busy of the four stacks, IMHO.

I though flow control was supposed to fix that :E

Just as an addition to YP's post, Lambourne predominately is the bussiest stack. Biggin isa prime candidate for flights that have been "stack-swapped" from Lambourne to reduce the requirement for outer holding, plus gets the traffic closer to the airfield.