Bookworm - there will always be holding.
Being held on the ground before departure is OK for short flights, but not for medium to long haul flightsd - too many variables en-route.
flying more slowly and efficiently enroute.
won't work if everybody does it!! There was a 270Kt trial for A/C inbound to LTMA traffic recently.
Complete rubbish because all it did was made the same aircraft turn up to the holds in a bunch, just a couple of minutes later than they would have normally.
You need speed differentials to prevent holding. Yes, sequencing could be done from further out - NATS are developing equipment thta will give the EAT of every A/C inbound to LTMA airfields - this may help en-route to stream them more efficiently for TC (by the time A/C hit TC airspace, there is little time/room to stream effectively).
However the problem will still exist to an extent as AC get the A/C late (and the very fact that UK airspace is actually pretty miniscule for what it achieves).
Similarly, different AC sector groups control A/C inbound to the same hold, but you can bet they won't consult each other about streaming 3 or 4 flows into one, because they have not got the time.
Some improvements are possible, but your answer is too simplistic. In theory, a good idea, but to achieve it...
BravoMike
idea of flow is to keep us controllers working with a constant flow ( maximum traffic without holding)
Not quite correct, there is a mismatch between aircraft efficiency and ATC efficiency. To ensure that a runway that is in almost constant use e.g. Heathrow is used to maximum capacity, there is a need to have some aircraft in the hold, usually planning on Heathrow to have just under 10 mins holding. This gives the Director the flexibility to optimise runway utilisation.
Obviously when something happens to that runway, for example as mentioned in your very good post, then holding starts to increase hugely.
On Normal dyas, flow worksto a degree, but putting measures on to counter say, an incident, take time - and are only really effective for short haul flights... everything else is already in the air and inbound!!
Saying that, the message could be passed down th eline to external agencies to slow things up for us, but that does not always work, as they either want to get rid of traffic ASAP, which means getting it our of their airspace, or they have their own issues to deal with i.e. it is just to difficult.