Very long time lurker here, finally had a sufficiently arcane topic so as to warrant starting a new thread.

Saw something a few weeks back that I had never seen before and, to be honest, was shocked that it existed.

Was departing SYD. We were taxiing to 34L when I realized that aircraft were landing and departing on both 34L and 16L. Listening to ATC made for some really (at least to me) unusual instructions, including (to paraphrase) you're cleared for takeoff, but watch out for the landing A380 at 1000 feet and 2 miles, followed by the landing 777 at 3000 feet and 7 miles, followed by the landing A320 at 4000 feet and 12 miles as you depart. It also made more unusual (much longer/higher before the turn over the ocean than normal) departure procedures.

I know better than to ask if this is safe, but it seems to me like an elevated risk if something off-kilter (e.g. a go-around or error on departure instructions) occurs. Maybe not?

Mostly just curious if this happens with any frequency...at SYD? At another major airport? Anywhere?, and what would cause this (winds?) to be the most prudent solution to the situation rather than using mono-directional (e.g. 16L & 16R) or perpendicular (e.g. 34L and 07) runways?

It is quite common on some airports (HAM comes to my mind) in the late evening and night to have opposite runway operations fo noise abatement.
That way all flights, departing and arriving are only going above the least dense populated areas.

But that's probably not the valid answer for SYD as only 34 landings and 16 departures would have that benefit.

I am a firm believer that airports should be able to do this in suitable weather/winds. LHR is a prime example of where it could work. The runways are a mile apart and it could greatly reduce the need to fly over Central London on the approach. It would also help reduce noise complaints during the very early morning 4am - 6am period. Of course others on the ground will be affected, but like LGW, much less so.

Arrivals tend to be below 3000' for many miles on their approach, so the conflict with departures is minimal as most would be above that pretty quickly. The westerly preference (due to wind) is not a reason either, as the average wind speed at LHR is less than 7kts. That's not much of an issue for most pilots on a 12000' runway.

It would even do away with the present 6am curfew. Currently the four stacks are very busy for up to 30 minutes beforehand wasting fuel and 'frying' the planet allegedly.

stevenshev wrote:

Mostly just curious if this happens with any frequency...at SYD? At another major airport? Anywhere?, and what would cause this (winds?) to be the most prudent solution to the situation rather than using mono-directional (e.g. 16L & 16R) or perpendicular (e.g. 34L and 07) runways?

SODPROPS - Simultaneous Opposite Direction Parallel Runway Operations. It is the preferred runway mode at Sydney from a noise abatement perspective, with departures on 16L and arrivals on 34L. To see the full list of preferred runway modes and the limiting wind components go to https://www.airservicesaustralia.com/ai ... UG2018.pdf and https://www.airservicesaustralia.com/ai ... UG2018.pdf

V/F

Interesting I haven't heard of that combination being used at SYD before. I know they have noise abatement procedure when conditions allow which is 16L for departures (34L for flights which require the longer runway) and 34L for arrivals. This keeps most aircraft over Botany bay.

I've landed in Brisbane a few times (11pm) when they are operating like that. Not sure how common it is

I think back in the good old days, this was an approved procedure at ORD. Planes could operate in this manner on the old configuration 27/9's. Never saw it in person, but old school ORD had a tendency to change the plan up quickly at various times during the day depending on winds and traffic.

I think back in the good old days, this was an approved procedure at ORD. Planes could operate in this manner on the old configuration 27/9's. Never saw it in person, but old school ORD had a tendency to change the plan up quickly at various times during the day depending on winds and traffic.

midway7 wrote:

I think back in the good old days, this was an approved procedure at ORD. Planes could operate in this manner on the old configuration 27/9's. Never saw it in person, but old school ORD had a tendency to change the plan up quickly at various times during the day depending on winds and traffic.

YES, I remember being no. 1 for departure and then suddenly 25 with a wind shift!

I believe LAX departures are generally always westbound but — unlike arrivals up to 23:59 — late-night arrivals (after 23:59 local time) can be eastbound — I arrived LAX at around 01:30 local and we landed on one of the 7s IIRC.

stevenshev wrote:

I know better than to ask if this is safe, but it seems to me like an elevated risk if something off-kilter (e.g. a go-around or error on departure instructions) occurs. Maybe not?

I'm sure there are specific rules regarding this (probably unique to each airport where it's practiced), but generally speaking, it seems to me that this would actually be *safer* than same-direction parallel takeoffs and landings. Assuming the winds are relatively calm and visibility is good, that is.

First, there's going to be less chance of a runway incursion, which is far more likely than any sort of midair collision. Something like the USAir 1493 crash could not have happened with opposite direction takeoffs and landings in operation. That accident happened because both planes were cleared onto the same runway, but we're talking about mistakes here, and it's just as possible for a pilot to fly onto the wrong runway (or a taxiway) as it is for a controller to clear a plane onto a runway that he/she shouldn't. The point is that the possibility is always there, and it's higher than the possibility of midair collision. But with landings and takeoffs at opposite ends, pilots both have more time to stop if there are two planes on the same runway and they can see each others' lights pointing directly at them, making it a lot easier to tell when there's traffic on a runway. So even if two planes are cleared onto the same runway by mistake, a crash would be extremely unlikely.

As for go-arounds, there are published procedures for this for every runway at every major airport, and these would just be written such that they wouldn't interfere with planes landing on the parallel runway. This is not really any different than what happens for go-arounds at airports with same-direction parallel takeoffs and landings - procedures still need to be written so that go-arounds don't interfere with go-arounds or takeoffs on the parallel runway.

An error on departure instructions shouldn't really be possible, but even if one does happen, again it's not much different than same-direction parallel runways. There's always potential for conflict with traffic from another runway or even another airport if a crew flies the wrong procedure; that's why these procedures exist in the first place. But this seems almost inconceivable to me in a modern airliner with a FMC (though I'm sure it has happened; Murphy's Law definitely applies to aviation).

This could also make sense for geographic reasons, for example at SEA, where most flights come from the south and east. Landing 34s and taking off 16s would shorten flight times and save a decent amount of fuel. A midday switch for all the inbound Europe and Asia flights to all-16 ops would make sense as well. That said, the airport doesn't seem to prioritize efficiency over NIMBYs, many of the departure SIDs converge, which reduces spacing capacity.

DEN also uses this type of scenario, but those runways are miles apart.

33lspotter wrote:

I believe LAX departures are generally always westbound but — unlike arrivals up to 23:59 — late-night arrivals (after 23:59 local time) can be eastbound — I arrived LAX at around 01:30 local and we landed on one of the 7s IIRC.

Opposite direction departures/arrivals are common late at night in LAX to keep all of the noise over the ocean.

Noise abatement at night for DTW is land north and depart south if winds permit. Midnight flow at IAH, if weather permits, is land 8R and 27.

gpasternak wrote:

I've landed in Brisbane a few times (11pm) when they are operating like that. Not sure how common it is

It's a nightly thing IIRC. 01 for departures and 19 for arrivals. Not sure but I would hazard a guess it's for noise abatement reasons.

LH707330 wrote:

This could also make sense for geographic reasons, for example at SEA, where most flights come from the south and east. Landing 34s and taking off 16s would shorten flight times and save a decent amount of fuel. A midday switch for all the inbound Europe and Asia flights to all-16 ops would make sense as well. That said, the airport doesn't seem to prioritize efficiency over NIMBYs, many of the departure SIDs converge, which reduces spacing capacity.

I'm not sure it would help all that much. For one thing, SEA is running south flow something like 65% of the year (north flow is mostly in summer) and there are certainly going to be plenty of days where you wouldn't want a significant number of aircraft landing with the wind. I would also think that SEA's runway spacing might present some issues, as I'm fairly certain there are still fairly tight rules regarding parallel approaches as things stand now.

Also, if you look at this traffic flow map from the Port of Seattle, you'll note that a significant number of the flights coming from the east follow the "EPHRATA" EIGHT STAR, which brings them into the terminal airspace well to the northeast of the airport. Approach to the 34s wouldn't be of much help for them, as they would have to fly south a considerable distance to set up approach.

https://www.portseattle.org/projects/flight-patterns

Then there’s Aspen! Opposite direction in a valley

GF

gunsontheroof wrote:

LH707330 wrote:

This could also make sense for geographic reasons, for example at SEA, where most flights come from the south and east. Landing 34s and taking off 16s would shorten flight times and save a decent amount of fuel. A midday switch for all the inbound Europe and Asia flights to all-16 ops would make sense as well. That said, the airport doesn't seem to prioritize efficiency over NIMBYs, many of the departure SIDs converge, which reduces spacing capacity.

I'm not sure it would help all that much. For one thing, SEA is running south flow something like 65% of the year (north flow is mostly in summer) and there are certainly going to be plenty of days where you wouldn't want a significant number of aircraft landing with the wind. I would also think that SEA's runway spacing might present some issues, as I'm fairly certain there are still fairly tight rules regarding parallel approaches as things stand now.

Also, if you look at this traffic flow map from the Port of Seattle, you'll note that a significant number of the flights coming from the east follow the "EPHRATA" EIGHT STAR, which brings them into the terminal airspace well to the northeast of the airport. Approach to the 34s wouldn't be of much help for them, as they would have to fly south a considerable distance to set up approach.

https://www.portseattle.org/projects/flight-patterns

The winds dictate south flow a decent amount in the winter, but many times in the day or season the winds are fairly light, so they use south flow as a default. Regarding the STARs, the EPHRATA EIGHT is used to get them to that point so they can do vectors for the 16s. If they had flights coming into the southwest corner, they could make a right base to the 34s. To your point though, runways spacing and wind shifts might complicate that to te point of not making it worthwhile.

LH707330 wrote:

gunsontheroof wrote:

LH707330 wrote:

This could also make sense for geographic reasons, for example at SEA, where most flights come from the south and east. Landing 34s and taking off 16s would shorten flight times and save a decent amount of fuel. A midday switch for all the inbound Europe and Asia flights to all-16 ops would make sense as well. That said, the airport doesn't seem to prioritize efficiency over NIMBYs, many of the departure SIDs converge, which reduces spacing capacity.

I'm not sure it would help all that much. For one thing, SEA is running south flow something like 65% of the year (north flow is mostly in summer) and there are certainly going to be plenty of days where you wouldn't want a significant number of aircraft landing with the wind. I would also think that SEA's runway spacing might present some issues, as I'm fairly certain there are still fairly tight rules regarding parallel approaches as things stand now.

Also, if you look at this traffic flow map from the Port of Seattle, you'll note that a significant number of the flights coming from the east follow the "EPHRATA" EIGHT STAR, which brings them into the terminal airspace well to the northeast of the airport. Approach to the 34s wouldn't be of much help for them, as they would have to fly south a considerable distance to set up approach.

https://www.portseattle.org/projects/flight-patterns

The winds dictate south flow a decent amount in the winter, but many times in the day or season the winds are fairly light, so they use south flow as a default. Regarding the STARs, the EPHRATA EIGHT is used to get them to that point so they can do vectors for the 16s. If they had flights coming into the southwest corner, they could make a right base to the 34s. To your point though, runways spacing and wind shifts might complicate that to te point of not making it worthwhile.

They could move further southwest, but those flights currently head into their base leg over the Duvall-Carnation area when north flow is in effect rather than continuing west over Woodinville-Redmond during south flow. Not saying that couldn't change, but it would be a big shift and could possibly present some congestion issues with the traffic coming from the southeast.

N353SK wrote:

33lspotter wrote:

I believe LAX departures are generally always westbound but — unlike arrivals up to 23:59 — late-night arrivals (after 23:59 local time) can be eastbound — I arrived LAX at around 01:30 local and we landed on one of the 7s IIRC.

Opposite direction departures/arrivals are common late at night in LAX to keep all of the noise over the ocean.

I experienced this just last month. On my way from Kona, HI to EWR i connected through LAX early morning (pre-6am) we landed 6R and departed 25R about an hour later. Its a great strategy for airports that are located near water.

I presume that the runways have to be configured in a certain way to be able to do this (i.e. a certain length apart or thresholds certain distance apart). This would be a great technique for JFK but I don't think it is practiced there (although I could be wrong).

It happens. As some have mentioned, LAX has this procedure at night. I have also witnessed this at LAS (I posted something about this before) where a KE 788 departed the opposite direction of the traffic flow (LAS was using the 26s, but this flight took off of 8L) for performance reasons.

N47 wrote:

I presume that the runways have to be configured in a certain way to be able to do this (i.e. a certain length apart or thresholds certain distance apart). This would be a great technique for JFK but I don't think it is practiced there (although I could be wrong).

JFK does not have this procedure. The proximity of the region's airports, namely LGA, prevent this sort of airspace flexibility.

JFK could land on 31R and depart from 13R without interfering with other airports.

Landing from 31R causes a problem for LGA; ATC has to protect the missed approach airspace.

GF

Guess when they're landing on 31R at JFK, LGA arrivals are at 4000 ft northbound up the Hudson -- right? Think the LGA arrivals need to be higher?

It's well-know that the international airport of California airport has one one SINGLE runway. During heavy IFR/fog (very rarely), usually: Takeoff on 27, land on 09.

Any pilots here operated under these conditions at KSAN? Given the scarcity of substantial IMC in San Diego, everything seems to go smoothly. But certainly there must have been a day someone can remember when this could have resulted in all sorts of "fun" for ATC.

Anecdotes?.

LAX has done this for at least forty years. I remember sitting on a hill west of the airport (in an area now closed to the public) in the 1970's, watching the landing lights reflecting on the ocean water as airliners approached from the west for landing, while opposite direction takeoffs were occurring.

Duplicate post deleted.

I've seen DCA take off on 01, land 19. This was with poor visibility.

KICT wrote:

I've seen DCA take off on 01, land 19. This was with poor visibility.

That’s got to be backwards. Runway 1 has the ILS. Arrive 1, depart 19.

ilovelamp wrote:

KICT wrote:

I've seen DCA take off on 01, land 19. This was with poor visibility.

That’s got to be backwards. Runway 1 has the ILS. Arrive 1, depart 19.

Good point. Then again the RNAV (RNP) 19 minima are pretty low.

http://155.178.201.160/d-tpp/1811/00443RR19.PDF

rjsampson wrote:

It's well-know that the international airport of California airport has one one SINGLE runway. During heavy IFR/fog (very rarely), usually: Takeoff on 27, land on 09.

Any pilots here operated under these conditions at KSAN? Given the scarcity of substantial IMC in San Diego, everything seems to go smoothly. But certainly there must have been a day someone can remember when this could have resulted in all sorts of "fun" for ATC.

Anecdotes?.

KSAN was running this config just the other day.

Adispatcher wrote:

KSAN was running this config just the other day.

Quick question: In Santa Ana wind circumstances (which if strong enough, necessitate departures from 09 at KSAN): Would flights like the 787 to Japan, the 777/747 to England, and 340 to Germany (and others) incur a weight penalty for departure (with substantially less usable runway), or do they have the "oomph" to make it over not-insubstantial terrain on the departure side of 27? Would any other flights incur such a penalty?

Looks like obstruction height east of SAN is maybe 100 ft higher than to the west.

rjsampson wrote:

Adispatcher wrote:

KSAN was running this config just the other day.

Quick question: In Santa Ana wind circumstances (which if strong enough, necessitate departures from 09 at KSAN): Would flights like the 787 to Japan, the 777/747 to England, and 340 to Germany (and others) incur a weight penalty for departure (with substantially less usable runway), or do they have the "oomph" to make it over not-insubstantial terrain on the departure side of 27? Would any other flights incur such a penalty?

Good question, but I don't know. My airline doesn't do long-hauls out of KSAN, thus we generally don't have issues with a 09 departure. There are a handful of airports around that we fly to where, for example, a 5kt TW gives better performance than the opposite direction that has obstacles.

Aspen operates opposite direction as a matter of normal operations.

Aircraft approaching for landing on 15 are advised to continue the approach to 15 and that traffic will be departing 33.

Aircraft departing 33 are told to line up and wait 33. Then asked to call landing traffic in sight. Once the traffic is in sight the aircraft is cleared for takeoff 33 and after the aircraft is off the ground the landing aircraft is cleared to land 15.