"Cleared to land" = Pointless use of words?

[Dronepiper]

"Cleared to land"

What does this mean?

I know that sounds like a dumb question, but it seems like at some airports it means absolutely nothing.

When I started flying, I always thought you could not be issued landing clearance by Tower until you were #1, and the runway was clear of other traffic. This makes perfect sense to me. They needed to make sure the runway is clear before they issued landing clearance. This is why it was always important for me to ensure I received a clearance before landing.

As I started flying into larger airports in Canada and the US, I would receive landing clearances immediately after switching from arrival controllers to tower controllers....even though I was like #3 or #4 on final, and there was still traffic on the runway. This doesn't make any sense to me. Like what is the purpose of the landing clearance in this situation? Seems like a pointless use of words that serves no purpose anymore.

Perhaps someone in ATC can comment on this? I would love to know in what instances you are allowed to say "cleared to land." Does it change depending on the traffic level at an airport?

I know Canada is of course different from the US, so if anyone has any insight into US controller SOPs that would also be appreciated.

[dontcallmeshirley]

"Cleared to land"

What does this mean?

I know that sounds like a dumb question, but it seems like at some airports it means absolutely nothing.

When I started flying, I always thought you could not be issued landing clearance by Tower until you were #1, and the runway was clear of other traffic. This makes perfect sense to me. They needed to make sure the runway is clear before they issued landing clearance. This is why it was always important for me to ensure I received a clearance before landing.

As I started flying into larger airports in Canada and the US, I would receive landing clearances immediately after switching from arrival controllers to tower controllers....even though I was like #3 or #4 on final, and there was still traffic on the runway. This doesn't make any sense to me. Like what is the purpose of the landing clearance in this situation? Seems like a pointless use of words that serves no purpose anymore.

Perhaps someone in ATC can comment on this? I would love to know in what instances you are allowed to say "cleared to land." Does it change depending on the traffic level at an airport?

I know Canada is of course different from the US, so if anyone has any insight into US controller SOPs that would also be appreciated.

It means

1. You are given permission to land
2. There is no other aircraft taking off or taxiing across the runway
3. You get to flick the taxi light on

[DanWEC]

It's just a small slice of workload alleviation and risk assessment. The incidence of GA's are minor, and in an airline IFR environment with normal spacing it's easier and more productive to pass along clearance ahead of time and cancel if need be, rather than creating work to assess and give a clearance when clear, every single time, which then had to has has to be communicated over the radio at the last critical moment.

Personally, I'd be good with a practice whereas in normal ops, for a standard landing clearance once switched to tower, or even "cleared approach and landing" prior at a busy airport.

[CaptDukeNukem]

As mentioned above, at busy airports, trying to pipe in on frequency short final can be problematic. Getting a landing clearance 10 miles back on initial call reduces frequency congestion. It’s really not that big a deal, if landing cannot be safely made; the call is go around, either from you or the ATC unit.

[canadianfly]

That's just a US thing, you won't see it elsewhere in the world.

[16SidedOffice]

At the 4 major Canadian airports you can be given a sequence and cleared to land. This was requested by the users (ACA or WJA most likely). It means the runway WILL be clear for you when it comes time that you require it. Tower may still taxi aircraft across in front of your arrival, but the required runway separation will exist when it becomes your turn to land.

[CaptDukeNukem]

That's just a US thing, you won't see it elsewhere in the world.

Again, mentioned at previous post, it is not just a US thing. I don’t mind being cleared to land at number 3 on final. Separation is what Is mandated, and it works out fine 99.9 percent of the time. I’m not sure why this is bothering anyone. If you can’t land safely, go around.

[digits_]

I feel exactly the same and can't help how it's turning from something that provides a vital layer of safety (2 parties that both confirm the landing area is clear for the landing aircraft) into a 'let's just say it to get it over with and see what happens'. So yes, in effect, its becoming a pointless use of words IMO.

As mentioned above, at busy airports, trying to pipe in on frequency short final can be problematic. Getting a landing clearance 10 miles back on initial call reduces frequency congestion. It’s really not that big a deal, if landing cannot be safely made; the call is go around, either from you or the ATC unit.

If getting a landing clearance is problematic due to a congested frequency, is this new set up of giving the clearance and then only calling back when something is going wrong not a magnitude worse?
Old situation: 'Dammit, I can't get word in, time for a go around into protected airspace planned out well ahead'
New situation: 'Oh no, that plane is crossing the runway in the middle of the runway. The landing aircraft probably didn't see it because it's blending in with the background. I sure wish the frequency was available to tell him to go around!'

At the 4 major Canadian airports you can be given a sequence and cleared to land. This was requested by the users (ACA or WJA most likely). It means the runway WILL be clear for you when it comes time that you require it. Tower may still taxi aircraft across in front of your arrival, but the required runway separation will exist when it becomes your turn to land.

If it WILL be clear, then again: why bother with landing clearances at all? You can't guarantee anything if there's still aircraft landing or crossing runways ahead of you. Either one of those planes can screw up.

[CaptDukeNukem]

I feel exactly the same and can't help how it's turning from something that provides a vital layer of safety (2 parties that both confirm the landing area is clear for the landing aircraft) into a 'let's just say it to get it over with and see what happens'. So yes, in effect, its becoming a pointless use of words IMO.

As mentioned above, at busy airports, trying to pipe in on frequency short final can be problematic. Getting a landing clearance 10 miles back on initial call reduces frequency congestion. It’s really not that big a deal, if landing cannot be safely made; the call is go around, either from you or the ATC unit.

If getting a landing clearance is problematic due to a congested frequency, is this new set up of giving the clearance and then only calling back when something is going wrong not a magnitude worse?
Old situation: 'Dammit, I can't get word in, time for a go around into protected airspace planned out well ahead'
New situation: 'Oh no, that plane is crossing the runway in the middle of the runway. The landing aircraft probably didn't see it because it's blending in with the background. I sure wish the frequency was available to tell him to go around!'

At the 4 major Canadian airports you can be given a sequence and cleared to land. This was requested by the users (ACA or WJA most likely). It means the runway WILL be clear for you when it comes time that you require it. Tower may still taxi aircraft across in front of your arrival, but the required runway separation will exist when it becomes your turn to land.

If it WILL be clear, then again: why bother with landing clearances at all? You can't guarantee anything if there's still aircraft landing or crossing runways ahead of you. Either one of those planes can screw up.

Tower frequencies at big airports often have higher power transmissions that step over others. I’m sure you may have encountered this at some point with someone having a stuck mic.

I see your point, but extra communication is often not required.

[digits_]

Tower frequencies at big airports often have higher power transmissions that step over others. I’m sure you may have encountered this at some point with someone having a stuck mic.

I see your point, but extra communication is often not required.

Ok, but if the tower has higher power transmissions availability, why can't they use that to issue a landing clearance on a congested frequency?

If we're still issuing landing clearances, let's make sure they actually mean something. At the moment, they mean very little.

[Grey_Wolf]

According to the FAA AIM:

https://www.faa.gov/air_traffic/publica ... ion_4.html

Section 4. ATC Clearances and Aircraft Separation

Clearance

A --- A clearance issued by ATC is predicated on known traffic and known physical airport conditions. An ATC clearance means an authorization by ATC, for the purpose of preventing collision between known aircraft, for an aircraft to proceed under specified conditions within controlled airspace. IT IS NOT AUTHORIZATION FOR A PILOT TO DEVIATE FROM ANY RULE, REGULATION, OR MINIMUM ALTITUDE NOR TO CONDUCT UNSAFE OPERATION OF THE AIRCRAFT.

B --- 14 CFR Section 91.3(a) states: “The pilot-in-command of an aircraft is directly responsible for, and is the final authority as to, the operation of that aircraft.” If ATC issues a clearance that would cause a pilot to deviate from a rule or regulation, or in the pilot's opinion, would place the aircraft in jeopardy, IT IS THE PILOT'S RESPONSIBILITY TO REQUEST AN AMENDED CLEARANCE. Similarly, if a pilot prefers to follow a different course of action, such as make a 360 degree turn for spacing to follow traffic when established in a landing or approach sequence, land on a different runway, takeoff from a different intersection, takeoff from the threshold instead of an intersection, or delay operation, THE PILOT IS EXPECTED TO INFORM ATC ACCORDINGLY. When the pilot requests a different course of action, however, the pilot is expected to cooperate so as to preclude disruption of traffic flow or creation of conflicting patterns. The pilot is also expected to use the appropriate aircraft call sign to acknowledge all ATC clearances, frequency changes, or advisory information.

C --- Each pilot who deviates from an ATC clearance in response to a Traffic Alert and Collision Avoidance System resolution advisory must notify ATC of that deviation as soon as possible. (REFERENCE- P/CG Term - TRAFFIC ALERT AND COLLISION AVOIDANCE SYSTEM).

D --- When weather conditions permit, during the time an IFR flight is operating, it is the direct responsibility of the pilot to avoid other aircraft since VFR flights may be operating in the same area without the knowledge of ATC. Traffic clearances provide standard separation only between IFR flights.

[VFS]

"Cleared to land"

What does this mean?

I know that sounds like a dumb question, but it seems like at some airports it means absolutely nothing.

When I started flying, I always thought you could not be issued landing clearance by Tower until you were #1, and the runway was clear of other traffic. This makes perfect sense to me. They needed to make sure the runway is clear before they issued landing clearance. This is why it was always important for me to ensure I received a clearance before landing.

As I started flying into larger airports in Canada and the US, I would receive landing clearances immediately after switching from arrival controllers to tower controllers....even though I was like #3 or #4 on final, and there was still traffic on the runway. This doesn't make any sense to me. Like what is the purpose of the landing clearance in this situation? Seems like a pointless use of words that serves no purpose anymore.

Perhaps someone in ATC can comment on this? I would love to know in what instances you are allowed to say "cleared to land." Does it change depending on the traffic level at an airport?

I know Canada is of course different from the US, so if anyone has any insight into US controller SOPs that would also be appreciated.

Get a life

[digits_]

1977: Tenerife crash. Result: We're only allowed to use 'CLEAR' for take off and landing situations to prevent confusion and unsafe situations.

2024: 3 aircraft on final, 2 crossing the active runway? You're cleared to land sir!

[DHC-1 Jockey]

As a current tower controller and former airline pilot with extensive operational experience flying across North America, the Caribbean and Europe, I feel I can speak to this topic.

Perhaps someone in ATC can comment on this? I would love to know in what instances you are allowed to say "cleared to land." Does it change depending on the traffic level at an airport?

We are allowed to say "cleared to land" when the runway and the Runway Protected Area (RPA) are free, or will be free, of all known obstacles
including taxiing aircraft and ground traffic. The kicker is that will be free allows us (in very specific situations) to send a vehicle across a runway after a landing clearance has already been issued. If something happens to the vehicle such that in the controller's opinion that the RPA will not be free of any obstacles, we then issue instructions for the aircraft to go-around.

This operation actually reduces frequency congestion of requiring us to cancel the landing clearance, cross the vehicle and then re-issue the landing clearance. Keep in mind that we have to "advise the incoming pilot of the location and type of crossing traffic" so everyone is on the same page.

As well, a pilot is expecting a landing clearance in an appropriate timeframe to safely complete the landing. At very busy airports with constant arrivals, this may be the only way to get a vehicle across the active runway. Otherwise, the landing clearances are being issued extremely short final, which I argue is less safe than having a landing clearance and being told about crossing traffic.

As someone else said, at the 4 major airports, aircraft can be issued a sequence (#2, #3 etc) and be cleared to land because the runway will be free by the time the aircraft reaches the threshold, otherwise the aircraft is instructed to go around. I might be wrong, but I believe there are extra systems in place (MLAT, RIMCAS, ASDE) to allow this operation, and if those systems are down, the controller can no longer issue multiple landing clearances. At the rest of the towered airports in Canada that don't have this equipment, you can only have one valid landing clearance at a time.

If it WILL be clear, then again: why bother with landing clearances at all? You can't guarantee anything if there's still aircraft landing or crossing runways ahead of you. Either one of those planes can screw up.

Because the absence of a verbal landing clearance is even less of a guarantee that the runway is clear.

Scenario 1: You are 5 miles final and have received a landing clearance. The controller then tells you to "continue with your landing clearance, a vehicle will be crossing at the far end of your runway." You are now aware of the presence of the vehicle, are visually scanning for it and are satisfied that it will be gone prior to your arrival. If not, you are told to go-around. Because you are aware of the vehicle, you are looking for it. If you are short final and still see the vehicle (maybe it stalled), but haven't heard anything from the tower controller (maybe they had a radio failure), you'll go around on your own.

Scenario 2 (No verbal landing clearances are issued anymore): You are 5 miles final and start to see a vehicle cross your runway. You have no idea why it's there, whether it will stop on your runway, cross the runway and then double-back or anything else. Without this information, how far do you continue your approach before you start a go-around? Maybe the controller was telling you to go around all this time, but had a radio failure. However, since we don't give landing clearances anymore, the absence of any radio traffic is now meaningless.

The key is that you can't prove a negative. By a controller not saying anything, that has no bearing on whether the runway is actually clear or not. But by positively saying "cleared to land," you are satisfied that the runway is unobstructed. If you think about it for more than 5 seconds, you'll see that getting a verbal confirmation of a clear runway (or one that WILL be clear) is far superior to no verbal confirmation and the assumption that the runway is clear. Landing clearances are used across the entire globe. Stop overthinking it or trying to re-invent the wheel.

[DHC-1 Jockey]

Ok, but if the tower has higher power transmissions availability, why can't they use that to issue a landing clearance on a congested frequency?

If we're still issuing landing clearances, let's make sure they actually mean something. At the moment, they mean very little.

As a follow-up to my previous post, some major airports (in the U.S. at least) are running 2.5 miles in trail on final. If the controller had to wait until the preceding aircraft had exited the runway to issue the landing clearance to the following aircraft, that following aircraft would be extremely short final.

If controllers didn't issue landing clearances anymore (as you advocate), I argue that there will be exponentially far more pilot-initiated go-arounds because pilots will not have the assurance that the aircraft ahead will actually vacate the runway in time. Having a controller on the frequency with positive control of the situation enables busy airports like DTW, DFW, ORD, LAX, ATL, etc to run things efficiently and not have pilots going around on their own all the time.

[digits_]

Scenario 2 (No verbal landing clearances are issued anymore): You are 5 miles final and start to see a vehicle cross your runway. You have no idea why it's there, whether it will stop on your runway, cross the runway and then double-back or anything else. Without this information, how far do you continue your approach before you start a go-around? Maybe the controller was telling you to go around all this time, but had a radio failure. However, since we don't give landing clearances anymore, the absence of any radio traffic is now meaningless.

That's a hard question to answer, both with the conditional landing clearance and without. Depends on how you phrase it. It might even make things worse. If you're about to land and you see an unexpected vehicle on the runway, you might go around at 200 ft. If you got a landing clearance and are informed about the vehicle, but it's moving a bit slower than expected, you might drag it out a bit longer and not go around till 20 ft. It doesn't necessarily make things safer. It makes things more efficient, but not safer.

The key is that you can't prove a negative. By a controller not saying anything, that has no bearing on whether the runway is actually clear or not. But by positively saying "cleared to land," you are satisfied that the runway is unobstructed. If you think about it for more than 5 seconds, you'll see that getting a verbal confirmation of a clear runway (or one that WILL be clear) is far superior to no verbal confirmation and the assumption that the runway is clear.

To clarify: I'm not advocating to get rid of landing clearances. I'm advocating to switch back to a system where landing clearances are given when the runway is free for landing.

Landing clearances are used across the entire globe. Stop overthinking it or trying to re-invent the wheel.

Are landing clearances with traffic on final or on the runway used across the entire globe? We've established it's used frequently in the US and also in some Canadian airports. What about the other parts of the world? I can't recall ever having received a landing clearance outside of North America with traffic ahead of me on final or on the runway. But my experience in that area is limited.

[DHC-1 Jockey]

To clarify: I'm not advocating to get rid of landing clearances. I'm advocating to switch back to a system where landing clearances are given when the runway is free for landing.

I guess I misunderstood what you were saying. But I believe I address this point in my follow-up post.

With some airports running jets 2.5 miles in trail, or at my small airport running Cessna's and Piper's sometimes only a mile in trail, it can be impossible to wait for an arrival to cross the intersection, then cross the vehicle, and then issue a landing clearance at sufficient time for the pilot to not just go around on their own.

So, we wait for the first aircraft to cross the intersection, issue the landing clearance to the second aircraft and then the very next transmission being to the vehicle to expedite across the runway. Keep in mind that we can only cross the vehicle AFTER a landing clearance has been issued, as opposed of issuing a landing clearance while the vehicle is still in the process of crossing the runway. It is only allowed to work one-way.

Consider an airport running 6+ aircraft in the circuit. To make the space to comply with your idea of issuing the clearance only when the runway is ACTUALLY clear would require many more transmissions (Extend the departures runway heading, extend aircraft on crosswind and extend aircraft on downwind). The current system only requires one extra transmission to the pilot on final advising them of the crossing vehicle.

[digits_]

To clarify: I'm not advocating to get rid of landing clearances. I'm advocating to switch back to a system where landing clearances are given when the runway is free for landing.

I guess I misunderstood what you were saying. But I believe I address this point in my follow-up post.

With some airports running jets 2.5 miles in trail, or at my small airport running Cessna's and Piper's sometimes only a mile in trail, it can be impossible to wait for an arrival to cross the intersection, then cross the vehicle, and then issue a landing clearance at sufficient time for the pilot to not just go around on their own.

So, we wait for the first aircraft to cross the intersection, issue the landing clearance to the second aircraft and then the very next transmission being to the vehicle to expedite across the runway. Keep in mind that we can only cross the vehicle AFTER a landing clearance has been issued, as opposed of issuing a landing clearance while the vehicle is still in the process of crossing the runway. It is only allowed to work one-way.

Consider an airport running 6+ aircraft in the circuit. To make the space to comply with your idea of issuing the clearance only when the runway is ACTUALLY clear would require many more transmissions (Extend the departures runway heading, extend aircraft on crosswind and extend aircraft on downwind). The current system only requires one extra transmission to the pilot on final advising them of the crossing vehicle.

I'm not a controller, so I'm happy to accept that it works much easier that way. The question I think that should be asked in that case is: with 6 aircraft in the circuit spaced one mile apart, does that vehicle really need to cross? In your experience, if you were to -hypothetically- only issue landing clearances to empty runways, would the capacity of the airports be drastically affected? If the result of that change would be that ground vehicles or taxiing aircraft would have to wait a bit longer to cross active runways, or circuits get extended by 15 seconds, then from my perspective, that would be a price I think we all should be willing to pay.

[DHC-1 Jockey]

I'm not a controller, so I'm happy to accept that it works much easier that way. The question I think that should be asked in that case is: with 6 aircraft in the circuit spaced one mile apart, does that vehicle really need to cross?

In my normal day-to-day operation, I don't cross vehicles after a landing clearance has been given, because it's usually not that busy. I'll either delay the landing clearance and cross the vehicle, or just wait for the aircraft to land before crossing the vehicle.

However, there are days after a big snow event where there are multiple plows criss-crossing my secondary runway because to plow the taxiway from the main runway to the apron, they have to continually cross back and forth across the secondary runway. If the winds are favouring the secondary runway and there are 6+ aircraft in the circuit on that secondary runway, my operation will become terribly inefficient to build the space to allow the plows to go back and forth every minute or so.

So yes, those vehicles do need to cross and so either my circuit is extended out to the edge of the zone (or beyond) and pilots only get 4 touch and goes per hour, or we can use anticipated separation to issue a landing clearance and then cross the plows. Or think about YYZ, with all of the traffic (vehicles and aircraft) that operate from the north of RWY 23. There are tons of crossings every day back-and-forth across RWY 23, and there might not be space on final to wait for the arrival to land and clear the runway, get the vehicle across the runway and then issue a landing clearance at a reasonable time for the pilot. The only way it works is to issue the landing clearance, advise the pilot that a vehicle will be crossing, and then cross the vehicle.

I would like to point out that our rules are much more strict than the FAA. I read their reports of their close calls with aircraft having simultaneous takeoff and landing clearances and that seems crazy to me. In Canada, we are a lot more limited in our abilities to do such operations, which in turn makes our larger airports more inefficient than our American counterparts.

That being said, people want it both ways though. They complain that Canadian airports with much less traffic are more inefficient than American airports with more traffic, but then those same people tend to forget that we also have a better safety record than the Americans and much fewer close calls (even accounting for overall traffic numbers). You can't have it both ways. You can either be super efficient and have tight arrival spacing with the knowledge that you can cross traffic after a landing clearance has been issued, or you need much more space on final to accommodate crossing traffic which greatly reduces efficiency.

[rookiepilot]

I'm not a controller, so I'm happy to accept that it works much easier that way. The question I think that should be asked in that case is: with 6 aircraft in the circuit spaced one mile apart, does that vehicle really need to cross?

In my normal day-to-day operation, I don't cross vehicles after a landing clearance has been given, because it's usually not that busy. I'll either delay the landing clearance and cross the vehicle, or just wait for the aircraft to land before crossing the vehicle.

However, there are days after a big snow event where there are multiple plows criss-crossing my secondary runway because to plow the taxiway from the main runway to the apron, they have to continually cross back and forth across the secondary runway. If the winds are favouring the secondary runway and there are 6+ aircraft in the circuit on that secondary runway, my operation will become terribly inefficient to build the space to allow the plows to go back and forth every minute or so.

So yes, those vehicles do need to cross and so either my circuit is extended out to the edge of the zone (or beyond) and pilots only get 4 touch and goes per hour, or we can use anticipated separation to issue a landing clearance and then cross the plows. Or think about YYZ, with all of the traffic (vehicles and aircraft) that operate from the north of RWY 23. There are tons of crossings every day back-and-forth across RWY 23, and there might not be space on final to wait for the arrival to land and clear the runway, get the vehicle across the runway and then issue a landing clearance at a reasonable time for the pilot. The only way it works is to issue the landing clearance, advise the pilot that a vehicle will be crossing, and then cross the vehicle.

I would like to point out that our rules are much more strict than the FAA. I read their reports of their close calls with aircraft having simultaneous takeoff and landing clearances and that seems crazy to me. In Canada, we are a lot more limited in our abilities to do such operations, which in turn makes our larger airports more inefficient than our American counterparts.

That being said, people want it both ways though. They complain that Canadian airports with much less traffic are more inefficient than American airports with more traffic, but then those same people tend to forget that also have a better safety record than the Americans and much fewer close calls (even accounting for overall traffic numbers). You can't have it both ways. You can either be super efficient and have tight arrival spacing with the knowledge that you can cross traffic after a landing clearance has been issued, or you need much more space on final to accommodate crossing traffic which greatly reduces efficiency.

Good comments DHC for pilots. SFO seems to have their share of interesting moments…

[DHC-1 Jockey]

Good comments DHC for pilots. SFO seems to have their share of interesting moments…

Thanks.

I'd encourage any pilot to reach out to their local FSS/Tower/ACC and ask for a tour. You'll be able to learn a lot more about why we do/don't do things compared to here on AvCanada.

When I was contemplating leaving flying for ATC, I toured several facilities just to get a sense of the job and I asked lots of questions, both as a curious airline pilot as well as a prospective ATC candidate. During those tours, I learned some things that I think made me a more aware and patient pilot. I got to see what is going on up in the tower, some of the rules and procedures controllers use, and I got lots of answers to questions I've always had as a pilot.

Now that I'm on the other side of the microphone and not in a 737 anymore, the ATC systems' procedures makes a lot more sense.

[cjp]

1977: Tenerife crash. Result: We're only allowed to use 'CLEAR' for take off and landing situations to prevent confusion and unsafe situations.

2024: 3 aircraft on final, 2 crossing the active runway? You're cleared to land sir!

ADS-B/C as well as high resolution ground radar has allowed this in VFR conditions to be a perfectly safe maneuver so as to kinimize frequency congestion. This is the only time you'll see this practice.

That said, this transfers the decision onto the pilot. Is the runway clear? Yes, well, you're cleared to land.

[16SidedOffice]

ADS-B/C as well as high resolution ground radar has allowed this in VFR conditions to be a perfectly safe maneuver so as to kinimize frequency congestion. This is the only time you'll see this practice.

That said, this transfers the decision onto the pilot. Is the runway clear? Yes, well, you're cleared to land.

I wouldn't say high res ground radar and it's not weather dependent until Cat II and III approaches are in progress.
But it also doesn't transfer or change any decisions any differently to the flight crew. ATC is there to ensure that the runway is properly vacated when required, otherwise they issue the go around. They don't just issue multiple landing clearances and not watch or monitor the situation.

[cjp]

ADS-B/C as well as high resolution ground radar has allowed this in VFR conditions to be a perfectly safe maneuver so as to kinimize frequency congestion. This is the only time you'll see this practice.

That said, this transfers the decision onto the pilot. Is the runway clear? Yes, well, you're cleared to land.

I wouldn't say high res ground radar and it's not weather dependent until Cat II and III approaches are in progress.
But it also doesn't transfer or change any decisions any differently to the flight crew. ATC is there to ensure that the runway is properly vacated when required, otherwise they issue the go around. They don't just issue multiple landing clearances and not watch or monitor the situation.

Where have you experienced multiple landing clearances being issued in CAT 1 conditions?

PIC has ultimate responsibility when accepting a clearance. If ATC fails to monitor situation due to distraction when multiple clearances have been issued, PIC must ensure separation is maintained prior to landing. There are same runway separation limitations listed in the FARs.

[16SidedOffice]

Where have you experienced multiple landing clearances being issued in CAT 1 conditions?

PIC has ultimate responsibility when accepting a clearance. If ATC fails to monitor situation due to distraction when multiple clearances have been issued, PIC must ensure separation is maintained prior to landing. There are same runway separation limitations listed in the FARs.

Oh absolutely the PIC still has ultimate responsibility, but nothing changes using Multiple Landing Clearances or not. ATC still is there to ensure that the required runway separation exists.
As for where? The 4 Canadian majors do them.