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Del Prado
19th Nov 2023, 13:20
http://www.bbc.co.uk/news/business-67468108

BBC story (http://www.bbc.co.uk/news/business-67468108)



Wind is 18 gusting 28 from WSW so delays and cancellations would be expected anyway.

ex-EGLL
19th Nov 2023, 13:46
Ideal weather for RW23 operations :bored:

dixi188
19th Nov 2023, 15:41
Ideal weather for RW23 operations :bored:
23L and 23R:)

Fly3
20th Nov 2023, 02:27
Ah, memories..

Capn Bloggs
20th Nov 2023, 02:37
Sad state of affairs when 18G28 from 30° off the QFU causes "delays and cancellations"...

Fursty Ferret
20th Nov 2023, 04:17
The delays aren’t because people can’t land in a crosswind, it’s because the headwind component is slowing everything thing down even with TBS. On top of that a 737 might have a ground speed of 80kts at 1000’ while the A320 behind has a ground speed of 120kts.

Capn Bloggs
20th Nov 2023, 04:39
On top of that a 737 might have a ground speed of 80kts at 1000’ while the A320 behind has a ground speed of 120kts.
So, "160 to the OM" (or similar) isn't a thing?

condor17
20th Nov 2023, 06:49
Dixi , that's showing our ages ....
CB , some clever mathematical pilot explained it 30+ yrs ago ...160 to OM or 4D helps ... However it's the time taken from 4D/OM to landing which governs the flow rate .
120kts ground speed takes 2 mins from 4D , with approx 2 mi. spacing and ' Land After ' , that 1 ldg. every min. Flow rate 60 per hr. LHR works .
60 kt G/S takes 4 mins from 4D , same 2 mi. space , 'land after' 1 ldg every 2 mins . Flow rate 30ph .. That really messes up the arrivals !
Thus it's better for flow rates to land with a tailwind !

rgds condor ..

Capn Bloggs
20th Nov 2023, 07:17
Thanks Condor, I understand.

DaveReidUK
20th Nov 2023, 08:27
Don't NATS claim that Time-Based Separation recovers most (though not quite all) of the landing slots lost due to headwinds ?

dixi188
20th Nov 2023, 09:13
Here's an idea. Lets build another runway!

Capt Fathom
20th Nov 2023, 09:42
And strong winds also affect the departure rate as aircraft climb into the increasing headwind. I’ve seen 80kts at 1000’ which really slows ones progress into the SID and delays the following departure.

pax britanica
20th Nov 2023, 10:10
So after 70 years of LHR windy weather, in Europes windiest country, still causes problems and it seems there is very little that can be done about it except build another runway like Arlanda ,Schiphol, Frankfurt or CDG (who already had 4 to start with). Incredible for once provision was made to leave a large area of land for a third E-W runway but not much provision to access it. And of course the residents of Kew are against it even though many of whom travel a lot and then complain about their flight being delayed .

Perhaps one solution would be like France and cut back on domestic flights and divert people onto high speed trains , that would be a good idea , oh........................................

dixi188
20th Nov 2023, 10:20
In 2007 I went to work for EAT (DHL). One of the first flights I did was into Heathrow from Brussels and we spent about 20 mins holding. One of the pilots commented that the new runway will stop all this holding.
I said that I would be retired before it gets built.
I'm now 70 and plan on living to 100. I doubt I will ever see another runway at Heathrow.

Bogner
20th Nov 2023, 11:34
I know it was reported as being due to the wind, but I think controller sickness was a bigger issue.
(which is absolutely fine - I’d rather have a slot and a controller that is properly rested, than no delay and an overworked controller!)

Del Prado
20th Nov 2023, 14:03
Don't NATS claim that Time-Based Separation recovers most (though not quite all) of the landing slots lost due to headwinds ?

TBS does a fantastic job and the landing rate is now much more predictable and resilient, however TBS only applies for vortex wake pairs and not minimum radar spacing so a pair of mediums will still be spaced according to the minimum radar separation (2.5 mile distance).

Gonzo
20th Nov 2023, 17:39
Don't NATS claim that Time-Based Separation recovers most (though not quite all) of the landing slots lost due to headwinds ?

I think it was that TBS has halved the delays due to strong winds.

As has been pointed out above, currently TBS only works on wake pairs. The next version comnig next year will work on all pairs, predict runway occupancy times, and use a minimum radar separation of 2.0NM rather than 2.5NM

Del Prado
20th Nov 2023, 18:55
and use a minimum radar separation of 2.0NM rather than 2.5NM

which is what we used to do on runway 23 when no one was looking. ;-)

Gonzo
20th Nov 2023, 20:11
Ah the days before SMF