Landing clearances (USA) while runway occupied

[Mijitman 147]

"Ahhhhh Deeyah Wawwey tahwah, ahhhh TransaPock ree-too-ninah, ah, inbound ohver the prison, with Arlpha."

Is this an impression of an Asian pilot?

[Flamin_Squirrel 71]

I believe Canada does something similar, but we only have a couple of those, and they're few and far between. I've flown out of a non-towered field since I first started flying in 2003, and I'd say that calling it dangerous is a gross mischaracterization. I've normally found those who are "raised" at tower fields make similar statements, but I've found JYO to be very manageable and safe. Heck, a month ago, I flew into a non-towered field that used the most common airport frequency in US Aviation (122.8), so not only did I have to coordinate with the aircraft and helicopter at the airport I was flying into, I had to wait for breaks in the chatter from other airports in radio range. Still, we managed to coordinate well enough to operate safely.

 

I wasn't saying that all non-towered airports are dangerous. I was simply saying that they certainly can be if the traffic levels reach a certain point (and that you can't claim it's safe simply because there hasn't been an accident - yet). I think the primary risk at such an uncontrolled airfield is midair collision in the circuit, not runway incursions (as most aircraft at such a field are relatively slow being flown in day vfr conditions, so you can see if anyones on the runway); this isn't really relevant to the large international airports I originally had in mind when I posted this topic.

 

Informative discussion though, and I've got the answer to my question; it's just two different ways of doing the same thing.

[crazy voyager 13]

It not physically harder, no, but being held in suspense like that is, mentally. To me, it's a lot better to have an expectation and a contingency than it is to have nothing. In the case of anticipated sep, your expectation is that you're going to set down, with the contingency that you might have to go around. In the case of "continue approach" (not using anticipated sep), you don't have anything. You're waiting for either a clearance to land, or an instruction to go around. That delayed instruction places the pilot in a void of instruction. Continue inbound to the airport, but continue to wait for further direction. It's like driving with a friend who's the navigator. You see the junction up ahead and know you'll need to do one thing or another, but your friend just says "I'll tell you which way to go when we get closer." Mentally, it's a lot less stressing if he said "take exit 118B" well ahead of time. If that exit was packed when you got closer, you can still continue down and take another exit, but at least you're not stressing about what the next instruction is.

 

 

 

They may manage without it, but that doesn't mean that it's the optimum solution. Our system over here has been helping aircraft get from point A to point B for quite some time, but that isn't stopping us from moving forward with better technologies like ADS-B.

 

 

It is, but it does cut the safety margin, as you're putting a stationary object on a runway that needs to be clear for the next arrival. Most of the facilities that have traffic levels high enough to need it have a safety logic system in place such that they are able to use it, however.

 

 

 

This post is very UK oriented, since that's where I am being taught. But to say that the UK is not moving forward is an understatement.

 

The UK handles 25% of european traffic (due to all the atlantic overflights we get). It also has very complex airspace. NATS as an ANSP ranks as nr2 in Europe in complexity

http://www.eurocontrol.int/sites/default/files/content/documents/single-sky/pru/publications/other/complexity-report.pdf

 

The NATS lower airspace complexity is by far the most complex in Europe.

 

NATS handles the 3rd most flights in Europe, only being beaten by France and Germany.

 

This is all done with a very good safety record, I haven't been able to find a source to quote but from what I was told the other week the average time between airproxes in Swanwick AC is now 10 years. However if anyone can find a number then please quote it here.

 

ADS-C is used in projects over the atlantic (of which a large part is managed by NATS) and ADS-B is used for offshore flights in the north sea (also controlled by NATS controllers). So we do use it. There is also a lot of work on Mode-S (the UK requires mode-S in CAS now and has mode-S in use at both Swanwick and Prestwick).

 

 

So the UK system does take aircraft from A to B and does so in very complex airspace in a very safe manner. I would say that is exactly what ATC aims to do?

 

 

As for the "continue approach" I think that's the only reasonable clearance to give if you can not ensure the runway is going to be free. It is not a void, it means continue the approach but if no clearance is recived, go around. This is a fail safe procedure because if someething does turn up, a mic does get stuck etc, the safe option is performed, which is a go around. To land on a potentially unsafe runway is not the safest option. An anticipated separation may work most of the time, but it is not fail safe becaues if the system breaks an incident has a higher risk of occuring compared to a go around.

 

All in my own opinion obvisouly, but that's my view on it.

 

 

To line something up when a landing clearance is given is very dangerous in my opinion, and has caused at least one fatal accident (in Los Angeles, I belive it was linked earlier?). Once again, if the runway is not gauranteed to be safe, I do not see why a clearance is given?

 

 

Also the comparison between the US and Europe. The UK has Heathrow and Gatwick, Heathrow is the world's busiest two runway airport. It also runs in segregated ops which means one runway for departures and one for landings (with a few exceptions when traffic can land on the departing runway, but only a few aircraft a day can do that). This means it is running at 98% of theoretical capacity. Just consider the figure, 98% of theoretical max. I've seen the operation from the inside, to say it's amazing is an understatement.

 

Then we have Gatwick, the busiest single runway airport in the world. I have not seen it from the inside but they also run a very tight operation. This all on one runway.

 

 

These two airports are 22NM away from eachother. And on top of that we add in EGLC which is literally underneath the EGLL approach for 27R.

 

And then we have EGSS, EGGW, the farnborough clutch, southend, manston, the solent airports.

 

 

The UK airspace is complex, it is busy, and it is safe. This is without any anticipated separations being used. It still works and I see no reason to change any of it to a system which, as I explained above, I consider fail dangerous rather than fail safe. In my opinion it's not worth it. Especially not when the UK system works.

[EGLL77W 1,508]

So the UK system does take aircraft from A to B and does so in very complex airspace in a very safe manner. I would say that is exactly what ATC aims to do?

 

Not forgetting at the same time we have some of the most professional Air Traffic Controlers in the world. You really have to fly in the Airspace to appreciate it! Flying here in the states and other countries made me realise they really are second to none.

 

Lots will judge the UK by flightradar and Wikipedia. But you'd get a shock being smack bang in the middle of it!

[Andreas Stangenes 1,628]

In this youtube clip one can clearly see how misunderstanding and voice comms interference could possibly lead to accidents (as it has in the past). The plane that was lined up and waiting for takeoff actually got his takeoff clearence. He didnt receive it. The tower re-stated the clearence later. We dont know, but I just assume that the plane on the runway never started his takeoff roll. If he did he could have caused some interesting moments in the air when the plane behind did an aborted takeoff on runway heading.

 

I would think the atc would give vectors to the go-around airplane to avoid collision, but still...

 

I understand that giving the "clear to land" while still no. 2 can save some bandwidth. In Europe that command simply means something else: The runway is actually clear, and you can land. In the US, the command doesnt say anything about the runway being clear. For us Europeans that feels strange.

 

By the way, I assume that "clear to land" is never issued by the tower untill the runway is free in reduced visibility?

[crazy voyager 13]

Andreas I can't see a link, did you miss to paste it?

[ryanbatc 13,103]

OBTW - I hate "Line up and wait"...

 

Regards,

Scott

 

You're not alone... I'm a controller in Duluth it sounds so wrong. I started with taxi into position and hold. Then it was position and hold. (There might have even been a Ry XX, position and hold). And of course everyone's favorite LUAW!

 

I've seen an incredible amount of change in procedures/phraseology for the short time I've been with the FAA. 90% of it doesn't make any sense. Most of it just increases verbiage.

[crazy voyager 13]

compare: "hold position" and "position and hold".

The difference is the order and the word "and". To a non naitive speaker this is not a very obvious difference. Now compare

"hold position" with "line up and wait"

 

There are no words in common at all, thereby the risk of confusion is virtually eliminated.

 

I don't see the downside of the change?

[Andreas Stangenes 1,628]

compare: "hold position" and "position and hold".

The difference is the order and the word "and". To a non naitive speaker this is not a very obvious difference. Now compare

"hold position" with "line up and wait"

 

There are no words in common at all, thereby the risk of confusion is virtually eliminated.

 

I don't see the downside of the change?

 

Good point. AFAIK I think thats one of the major reasons they changed it - that, and progressing a uniform phraseology across the globe.

 

By the way, the change from "Position and hold" to "Line up and wait" didnt change anything other than the phrase itself, right? So in effect, they mean the exact same thing.

[ryanbatc 13,103]

For you guys it's nothing but for us it's just more and more change... there's nothing wrong with change... but I've got big issues with changes that don't do anything. Maybe the guys @ JFK like it... I don't know anyone working out there. The only non USA flyers we get are planes stopping for customs and Canadian pilots.

 

I'm sure we'll have some new phraseology out by the time we start getting used to LUAW

[crazy voyager 13]

The UK has the same thing, it has used (and still uses) national differences in many areas and it is changing a lot due to the Single European Sky being brought in, for example.

 

Millibars changed to hectopascals (with an associated phraseology change, which is btw there only to stop americans thinking millibars are inches, yes there have been incidents reported)

 

The word "after" used instead of "behind" when giving conditional clearances

 

No VFR at night was allowed up until very recently

 

A lot of Class A used (but only below FL195)

 

No information of indetification given inside of controlled airspace unless the turn method is used

 

I can probably find a bunch more if you're interested...

[JBZ 13]

 

 

You're not alone... I'm a controller in Duluth it sounds so wrong. I started with taxi into position and hold. Then it was position and hold. (There might have even been a Ry XX, position and hold). And of course everyone's favorite LUAW!

 

I've seen an incredible amount of change in procedures/phraseology for the short time I've been with the FAA. 90% of it doesn't make any sense. Most of it just increases verbiage.

 

My favorite was the day LUAW went into effect, the British pilots would still say, position and hold.

 

As far as clearing every aircraft to land, here at Las Vegas if we didn't, we would have a go-around every other aircraft and have to increase our spacing on final...which would cause delays in the chain. We run aircraft as tight as 2 miles between, it's just enough space. As one aircraft is rolling off the runway, another is crossing the threshold.

 

As far as the safety aspect goes, as a controller, you learn your "players". For example, I know that if I have a SWA in front, I can let the spacing squeeze down to 2 miles, because he'll exit fast. But if it's AeroMexico, I won't let the spacing get less than 3 miles, because they roll long and exit slow....that's when I use the words "go around".

[crazy voyager 13]

Once again, Heathrow does the same every day without the anticipated separation. Why does it work there when it apperently would not work in the US?

[JBZ 13]

I guess the simple answer would be....we don't want it to be that way in the US.....

[dmwalker 613]

As far as clearing every aircraft to land, here at Las Vegas if we didn't, we would have a go-around every other aircraft and have to increase our spacing on final...which would cause delays in the chain. We run aircraft as tight as 2 miles between, it's just enough space. As one aircraft is rolling off the runway, another is crossing the threshold.

I see from Wikipedia that, for aircraft landing, the separation should be at least 4 miles to avoid problems from wake turbulence. Is that not such a big problem or am I misunderstanding your comment?