Heathrow suffering from increased A380 ops

[markis10]

Ever-increasing A380 operations at Heathrow could also potentially have a negative impact on what is the world’s busiest two-runway international airport, suggest officials from the U.K.’s air navigation service provider, NATS.


Senior NATS air traffic controllers say the biggest impact comes from the spacing requirement for the aircraft, which is in the “super” wake vortex category. As an A380 departs, it requires up to 3 min. of spacing between it and the next aircraft if—as it often is at Heathrow—it is a smaller narrowbody type, such as an Airbus A320 or Boeing 737.


Because the airport routinely operates at around 99% of its runway capacity, the 3-min. hold time before the aircraft behind the A380 can depart can have a significant impact on the number of aircraft that can use the runway per hour.

http://m.aviationweek.com/commercial-aviation/a380-continues-pose-challenges-heathrow

 

[samh004]

Good news for people that don't like aircraft noise... they should be asking for more A380 services (as it'll result in less overall services).

 

[RooFlyer]

Easy solution. Emirates (either the airline or the country) buys Heathrow and bans aircraft < 200pax.

 

[TomVexille]

I've often wondered about this. Airbus markets the a380 as THE solution to slot constrained airports, yet with the spacing required you can't get as many flights in and out. Sort of a catch-22 scenario.

 

[dajop]

Out of curiosity is there/what is the wake time behind a 747?

 

[Sparra]

Out of curiosity is there/what is the wake time behind a 747?

For a Medium (A320, B737 etc) 2 minutes.

 

[markis10]

For a Medium (A320, B737 etc) 2 minutes.

Depends on the scenario and location, under Australia law an intersection departure would require 3 minutes using time or 5nm. MOS 172 part 10 refers http://www.casa.gov.au/wcmswr/_assets/main/rules/1998casr/172/172m10.pdf

 

[Sparra]

Depends on the scenario and location, under Australia law an intersection departure would require 3 minutes using time or 5nm. MOS 172 part 10 refers http://www.casa.gov.au/wcmswr/_assets/main/rules/1998casr/172/172m10.pdf

If you want to talk about intersection departures its 4 minutes for anything (Light, Medium or Heavy) behind a Super (A380).

 

[dajop]

Ok, thanks. So the 747's also would have impacted runways operating capacity too, although slightly less than A380. I guess most carriers flying the A380 (with the notable exception of EK) used to fly 747's on their previous services.

 

[markis10]

If you want to talk about intersection departures its 4 minutes for anything (Light, Medium or Heavy) behind a Super (A380).

In the context of the discussion that's not the case in the UK, who don't follow ICAO recommendations entirely but earlier this year did adopt fully the ICAO PANS ops refs for Supers.

 

[Sparra]

In the context of the discussion that's not the case in the UK, who don't follow ICAO recommendations entirely but earlier this year did adopt fully the ICAO PANS ops refs for Supers.

I didn't think the context of the discussion was intersection departures either. They don't use time at all for departures but a distance standard.
Interestingly at LHR they have recently (March I think) started using time based wake turbulence separation for arrivals instead of distance.

 

[NM]

So does that mean ATC will want to line up as many A380 aircraft in a departure sequence so they can them all out without the additional wait needed between ops when mixing A380 (super) with smaller types? So will we see A380 ops all bunched to a specific departure "window" and if they miss the window they have to wait for the next one? If Super to Super take-off separation needs 2 mins, and Super-Smaller needs 3 mins, ensuring there are say 5 consecutive Super movements could save 4 mins over the case where each Super is followed by something smaller.

 

[RooFlyer]

Can a (relative) ATC no-idea interject here? (Bows)

If you are talking about a certain time OR distance separation, aren't you talking about one flight following then other, straight down the line?

But if plane A goes a bit to the left on take-off, and the following plane goes a bit to the right (to use technical language) AND/OR has a higher /lower trajectory, doesn't that allow a closer take-off temporal 'separation' than a 'straight down the line' take-off, because the wake disturbance is physically displaced?

So an A380 going right and high followed 2 min later by a Dash 8 going left and low might be possible because they occupy different ascent volumes?

A genuine question to those who know better.

 

[markis10]

Can a (relative) ATC no-idea interject here? (Bows)

If you are talking about a certain time OR distance separation, aren't you talking about one flight following then other, straight down the line?

But if plane A goes a bit to the left on take-off, and the following plane goes a bit to the right (to use technical language) AND/OR has a higher /lower trajectory, doesn't that allow a closer take-off temporal 'separation' than a 'straight down the line' take-off, because the wake disturbance is physically displaced?

So an A380 going right and high followed 2 min later by a Dash 8 going left and low might be possible because they occupy different ascent volumes?

A genuine question to those who know better.

With wake turbulence you would be okay if close enough to the extended centreline of the aircraft and smaller than the width, that's how air to air works, outside if that it could be easily encountered.

http://www.pilotfriend.com/safe/safety/images/4.jpg

http://www.pilotfriend.com/safe/safety/wake_turb.htm

 

[Sparra]

Can a (relative) ATC no-idea interject here? (Bows)

If you are talking about a certain time OR distance separation, aren't you talking about one flight following then other, straight down the line?

But if plane A goes a bit to the left on take-off, and the following plane goes a bit to the right (to use technical language) AND/OR has a higher /lower trajectory, doesn't that allow a closer take-off temporal 'separation' than a 'straight down the line' take-off, because the wake disturbance is physically displaced?

So an A380 going right and high followed 2 min later by a Dash 8 going left and low might be possible because they occupy different ascent volumes?

A genuine question to those who know better.

The wake turbulence starts to generate when an aircraft rotates, so it would hard for following aircraft to guarantee they could it avoid it regardless of their planned flight path. In Australia the wake turbulence zone is considered 760m laterally, 1000ft below and the appropriate distance behind depending on size.

 

[Sparra]

So does that mean ATC will want to line up as many A380 aircraft in a departure sequence so they can them all out without the additional wait needed between ops when mixing A380 (super) with smaller types? So will we see A380 ops all bunched to a specific departure "window" and if they miss the window they have to wait for the next one? If Super to Super take-off separation needs 2 mins, and Super-Smaller needs 3 mins, ensuring there are say 5 consecutive Super movements could save 4 mins over the case where each Super is followed by something smaller.

ATC and the airport may like that but in practice almost impossible to organise. Different schedules, loading delays, tech problems etc.