7 ms·

I got my PPL in EU and here it was drilled into me that in Europe there can be exactly ONE plane cleared to use a runway at any time. When the approaching plan

I got my PPL in EU and here it was drilled into me that in Europe there can be exactly ONE plane cleared to use a runway at any time. When the approaching plane is cleared then there is no allowance for anyone and anything to be on the runway. So if there is a departing plane waiting on the runway or someone crossing then the approaching plane is given "cleared approach runway 08" but never "cleared to land". Which also means that if you are piloting the landing plane then at your decision height you have to go around. Also when someone is cleared to land no-one can be given a permission to enter the runway. There is one clearance that kinda-sorta allows which is "BEHIND landing Boeing 737, line up and wait BEHIND". It intentionally has "BEHIND" before and after the call to be extra clear that the waiting pilot has to confirm that the plane has passed their nose and they can enter the runway while the landing plane is on rollout. But that plane can not be given a takeoff clearance before the plane on the rollout has exited the runway. We were told that the americans do it differently and I've always found it dangerous.

cjrp 4y ago
It seems that the US also has different rules about Low Visibility Procedures / protection of the ILS sensitive area; I don't believe you'd clear anyone for takeoff with someone on a 2-3 mile final, under LVPs.
- jnsaff2 4y ago
  Yes, this! In Europe, I have heard, you can't operate CAT III ILS (or even maybe CAT II) when your ground radar is inop. It seems that in Austin they don't even have a ground radar. How the hell is CAT III a thing there?
mulmen 4y ago
Europe uses pessimistic runway locks but the US prefers optimistic locks. This improves throughput at US airports with the risk of a rollback on a dirty runway.
- 0xFF0123 4y ago
  I'd be curious to know how much it actually improves throughput. It seems strange to use optimistic locks in such a safety critical process, when a more fail-safe approach is available.
  - deleted 4y ago
    [deleted]
  - mcv 4y ago
    Sounds like a money problem to me. Less time between planes means more planes means more money. It sounds to me like far too many critical safety decisions are being made with an eye on money rather than safety. There were reports warning that Fukushima wasn't safe in case of a tsunami, but the company in charge of the plant decided to ignore that. Deep Water was caused by cost cuts. The Boeing 737 Max was made for financial reasons, fixing a fundamental hardware problem in software. Safety engineers clearly need a bigger say in these things.
    - dsfyu404ed 4y ago
      > Sounds like a money problem to me. Less time between planes means more planes means more money. Everything is a money/greed problem if you look at it through the lens of motivated reasoning. The usage of infrastructure is mutually beneficial. The airport, the various businesses operating at it, the customers, everyone benefits per flight. Likewise you want to make that infrastructure get used as much as possible. Would you be complaining about greed if a subway was running trains close together?
      - xwolfi 4y ago
        But why does it work fine everywhere else ? It's not like we all follow the US model, yet our airports are fine and our airplanes dont crash over silly cost cuts. There must be something the americans do wrong, somewhere, and optimisation cannot be an excuse for mediocrity. Do it fast and safe or do it slow and safe: the passengers can wait, or build their own planes and airports if they think they can do better.
sokoloff 4y ago
Not only can multiple planes be cleared to use a runway: one to depart, one to land in this example, cleared to land in a sequence, but also: Multiple landing planes are allowed on the same runway surface at the same time in the daytime as in Oshkosh arrivals, but also a Category I (light single) can be cleared to land if the Category I or II aircraft to follow will be 3000 feet from the threshold, a Cat II (light twin) behind a I or II with 4500 feet of separation. https://www.faa.gov/documentLibrary/media/Order/ATC.pdf https://www.faa.gov/documentLibrary/media/Order/ATC.pdf
mnw21cam 4y ago
> So if there is a departing plane waiting on the runway or someone crossing then the approaching plane is given "cleared approach runway 08" but never "cleared to land". Which also means that if you are piloting the landing plane then at your decision height you have to go around. My understanding was that the word "cleared" was to be avoided when you aren't actually cleared to land/take off, and the correct wording was now "continue approach runway 08". There has been a decent amount of study of the cognitive interpretation of exact wordings, resulting in a standardised phrasing that avoids misinterpretation. It's a good thing. Using the word "cleared" could easily cause a lazy/tired/overloaded pilot over a noisy channel to think they are cleared to land.
- jnsaff2 4y ago
  You are correct, it is indeed "continue" for the approach. Also the word "takeoff" is protected, I believe it can only be said within giving and reading back a takeoff clearance. Everywhere else it has to be "departure".
Gordonjcp 4y ago
> I got my PPL in EU and here it was drilled into me that in Europe there can be exactly ONE plane cleared to use a runway at any time. * ONE vehicle of any kind! You can't use the runway because there's a bloody great Volvo in the middle of it, because I put the bloody great Volvo there, because I'm picking up bits of the last guy's wheel spat that fell off, because I don't want to have to write a long long tale about how your prop got chipped. True story.
deleted 4y ago
[deleted]
paulmd 4y ago
I was wondering if maybe the long-term change from all this was going to be that two clearances can't be issued without visual/instrument confirmation from the tower of execution of movements. Sort of an IFR/VFR rules for tower operations. Given how advanced ILS is nowadays you could probably automate all of this - if the plane taking off isn't committed to takeoff (traveling at V1) by the time the landing aircraft reaches decision altitude, an automatic go-around is issued. Basically treat the runway as a "control zone" like trains do, and if the plane on the runway hasn't "cleared the zone" (by whatever definition) then the landing aircraft can't enter the zone. Certainly that's something that could be conveyed as part of the ILS data at least. Maybe it's undesirable to automate it in the sense of the automation causing more problems (more aborts = more chances for something to go wrong, although the assertion is that by V1 you're committed and by decision altitude you can still abort safely, so this all fits inside the "theory of movements") but you can at least let the landing plane know at decision altitude that there's an aircraft still on the runway. Sort of a "green = runway clear, yellow = committed traffic, yellow bars = moving but uncommitted traffic, red = runway occupied/clearance not granted" type indicator perhaps. Or maybe if the tower can't visually/instrument confirm execution of movements, the pilot on takeoff has to verbally confirm commit before the landing clearance can be granted. Then it just becomes something specific to zero-visibility operations. It really seems like there should be some change in how movements are handled/clearances are issued. Maybe we don't need to go to full "one clearance at a time" all the time, but it certainly seems like there should be some tighter rules if the tower can't independently confirm movements are being executed, and perhaps convey that information to the pilot as well (although again, I know that pilots are already information-overloaded, but "is there someone on my runway" is seemingly pretty important and straightforward info).
kcg 4y ago
Interestingly, in the US, for all its "optimistic" procedures, a controller isn't allowed to issue a conditional ("behind X") line-up-and-wait. But, if an arriving aircraft is still on the runway, a controller can clear a departing aircraft for takeoff if there will be adequate separation when the departing aircraft starts takeoff roll (i.e., the arriving aircraft will be clear of the runway at that point). [1] 7110.65 3-9-5 Anticipating Separation
throw0101c 4y ago
> So if there is a departing plane waiting on the runway or someone crossing then the approaching plane is given "cleared approach runway 08" but never "cleared to land". In ICAO phraseology, "cleared to land runway 08" is allowed. Further: > If the runway is obstructed when the aircraft reports ‘final’, but it is expected to be available in good time for the aircraft to make a safe landing, the controller will delay landing clearance by issuing an instruction to ‘continue approach’. * https://www.skybrary.aero/sites/default/files/bookshelf/115.pdf https://www.skybrary.aero/sites/default/files/bookshelf/115....

cjrp 4y ago

It seems that the US also has different rules about Low Visibility Procedures / protection of the ILS sensitive area; I don't believe you'd clear anyone for takeoff with someone on a 2-3 mile final, under LVPs.

jnsaff2 4y ago
Yes, this! In Europe, I have heard, you can't operate CAT III ILS (or even maybe CAT II) when your ground radar is inop. It seems that in Austin they don't even have a ground radar. How the hell is CAT III a thing there?

mulmen 4y ago

Europe uses pessimistic runway locks but the US prefers optimistic locks. This improves throughput at US airports with the risk of a rollback on a dirty runway.

0xFF0123 4y ago
I'd be curious to know how much it actually improves throughput. It seems strange to use optimistic locks in such a safety critical process, when a more fail-safe approach is available.
- deleted 4y ago
  [deleted]
- mcv 4y ago
  Sounds like a money problem to me. Less time between planes means more planes means more money. It sounds to me like far too many critical safety decisions are being made with an eye on money rather than safety. There were reports warning that Fukushima wasn't safe in case of a tsunami, but the company in charge of the plant decided to ignore that. Deep Water was caused by cost cuts. The Boeing 737 Max was made for financial reasons, fixing a fundamental hardware problem in software. Safety engineers clearly need a bigger say in these things.
  - dsfyu404ed 4y ago
    > Sounds like a money problem to me. Less time between planes means more planes means more money. Everything is a money/greed problem if you look at it through the lens of motivated reasoning. The usage of infrastructure is mutually beneficial. The airport, the various businesses operating at it, the customers, everyone benefits per flight. Likewise you want to make that infrastructure get used as much as possible. Would you be complaining about greed if a subway was running trains close together?
    - xwolfi 4y ago
      But why does it work fine everywhere else ? It's not like we all follow the US model, yet our airports are fine and our airplanes dont crash over silly cost cuts. There must be something the americans do wrong, somewhere, and optimisation cannot be an excuse for mediocrity. Do it fast and safe or do it slow and safe: the passengers can wait, or build their own planes and airports if they think they can do better.

sokoloff 4y ago

Not only can multiple planes be cleared to use a runway: one to depart, one to land in this example, cleared to land in a sequence, but also: Multiple landing planes are allowed on the same runway surface at the same time in the daytime as in Oshkosh arrivals, but also a Category I (light single) can be cleared to land if the Category I or II aircraft to follow will be 3000 feet from the threshold, a Cat II (light twin) behind a I or II with 4500 feet of separation. https://www.faa.gov/documentLibrary/media/Order/ATC.pdf https://www.faa.gov/documentLibrary/media/Order/ATC.pdf

mnw21cam 4y ago

> So if there is a departing plane waiting on the runway or someone crossing then the approaching plane is given "cleared approach runway 08" but never "cleared to land". Which also means that if you are piloting the landing plane then at your decision height you have to go around. My understanding was that the word "cleared" was to be avoided when you aren't actually cleared to land/take off, and the correct wording was now "continue approach runway 08". There has been a decent amount of study of the cognitive interpretation of exact wordings, resulting in a standardised phrasing that avoids misinterpretation. It's a good thing. Using the word "cleared" could easily cause a lazy/tired/overloaded pilot over a noisy channel to think they are cleared to land.

jnsaff2 4y ago
You are correct, it is indeed "continue" for the approach. Also the word "takeoff" is protected, I believe it can only be said within giving and reading back a takeoff clearance. Everywhere else it has to be "departure".

Gordonjcp 4y ago

> I got my PPL in EU and here it was drilled into me that in Europe there can be exactly ONE plane cleared to use a runway at any time. * ONE vehicle of any kind! You can't use the runway because there's a bloody great Volvo in the middle of it, because I put the bloody great Volvo there, because I'm picking up bits of the last guy's wheel spat that fell off, because I don't want to have to write a long long tale about how your prop got chipped. True story.

deleted 4y ago

[deleted]

paulmd 4y ago

I was wondering if maybe the long-term change from all this was going to be that two clearances can't be issued without visual/instrument confirmation from the tower of execution of movements. Sort of an IFR/VFR rules for tower operations. Given how advanced ILS is nowadays you could probably automate all of this - if the plane taking off isn't committed to takeoff (traveling at V1) by the time the landing aircraft reaches decision altitude, an automatic go-around is issued. Basically treat the runway as a "control zone" like trains do, and if the plane on the runway hasn't "cleared the zone" (by whatever definition) then the landing aircraft can't enter the zone. Certainly that's something that could be conveyed as part of the ILS data at least. Maybe it's undesirable to automate it in the sense of the automation causing more problems (more aborts = more chances for something to go wrong, although the assertion is that by V1 you're committed and by decision altitude you can still abort safely, so this all fits inside the "theory of movements") but you can at least let the landing plane know at decision altitude that there's an aircraft still on the runway. Sort of a "green = runway clear, yellow = committed traffic, yellow bars = moving but uncommitted traffic, red = runway occupied/clearance not granted" type indicator perhaps. Or maybe if the tower can't visually/instrument confirm execution of movements, the pilot on takeoff has to verbally confirm commit before the landing clearance can be granted. Then it just becomes something specific to zero-visibility operations. It really seems like there should be some change in how movements are handled/clearances are issued. Maybe we don't need to go to full "one clearance at a time" all the time, but it certainly seems like there should be some tighter rules if the tower can't independently confirm movements are being executed, and perhaps convey that information to the pilot as well (although again, I know that pilots are already information-overloaded, but "is there someone on my runway" is seemingly pretty important and straightforward info).

kcg 4y ago

Interestingly, in the US, for all its "optimistic" procedures, a controller isn't allowed to issue a conditional ("behind X") line-up-and-wait. But, if an arriving aircraft is still on the runway, a controller can clear a departing aircraft for takeoff if there will be adequate separation when the departing aircraft starts takeoff roll (i.e., the arriving aircraft will be clear of the runway at that point). [1] 7110.65 3-9-5 Anticipating Separation

throw0101c 4y ago

> So if there is a departing plane waiting on the runway or someone crossing then the approaching plane is given "cleared approach runway 08" but never "cleared to land". In ICAO phraseology, "cleared to land runway 08" is allowed. Further: > If the runway is obstructed when the aircraft reports ‘final’, but it is expected to be available in good time for the aircraft to make a safe landing, the controller will delay landing clearance by issuing an instruction to ‘continue approach’. * https://www.skybrary.aero/sites/default/files/bookshelf/115.pdf https://www.skybrary.aero/sites/default/files/bookshelf/115....