I’ve noticed that almost invariably planes start their takeoff after ATC says line up and wait but before getting the “cleared for takeoff” message. I would have thought that “line up and wait” meant something stationary. Just curious what I’m missing.

Line up and wait means turn onto the runway and stop there. If they are already taking off ATC would file a report.

tax1k wrote:

I’ve noticed that almost invariably planes start their takeoff after ATC says line up and wait but before getting the “cleared for takeoff” message. I would have thought that “line up and wait” meant something stationary. Just curious what I’m missing.

If you expect to be cleared in short order, you might keep rolling slowly for a short distance instead of coming to a complete stop. (Of course, you need to know you can "waste" some runway). But you certainly won't set takeoff thrust before "cleared for takeoff". That would be a rather serious violation.

LINE UP & WAIT
means Alingn to the Runway for Take off & Await clearence to proceed.
ATC needs to ensure Area is clear before giving further instructions & Aircraft need to obey, irrespective of impatience of wanting to move slowly while awaiting clearence.

tax1k wrote:

I’ve noticed that almost invariably planes start their takeoff after ATC says line up and wait but before getting the “cleared for takeoff” message. I would have thought that “line up and wait” meant something stationary. Just curious what I’m missing.

Where did you see this?

Starlionblue wrote:

If you expect to be cleared in short order, you might keep rolling slowly for a short distance instead of coming to a complete stop. (Of course, you need to know you can "waste" some runway). But you certainly won't set takeoff thrust before "cleared for takeoff". That would be a rather serious violation.

Your comment is right on the money. Most every pilot has great SA and is aware if the runway is being used for only departures or combination of arrival/departure. Without any known issues as required in-trail spacing for the departures nor wake issues they are usually ready to to set takeoff thrust not too long after the aircraft ahead has the gear coming up.

In order to help the crew know what my plan was when I was a Tower controller and long before "line up and wait" became the phraseology in the U.S., I'd often tell the crew "taking into position and hold, don't plan on stopping" just so they did not set the brakes and we'd keep the conga line moving. But never would they end up rolling more than a hundred feet if that far and thing was ever blatantly done before the take-off clearance was issued.

Yes, interested in knowing more of what the OP is referring to such a specifics.

Or “position and hold, be ready”, which meant have the power up, esp at KLGA with 40 waiting to go.

IAHFLYR wrote:

"taking into position and hold, don't plan on stopping"

Geez, meant "taxi into position" not taxing!!!

It's mostly used when it's safe for an aircraft to line up on the runway, but traffic downfield makes a takeoff unsafe. It could be an aircraft landing or departing on an intersecting runway, arrivals from an outer runway crossing the takeoff runway to taxi to the gate, or the previous departure hasn't achieved minimum separation yet. It's a time-saving technique, so when the runway is clear the departure is ready to go. If there are no apparent obstacles to takeoff, you won't hear "line up and wait" you'll just hear takeoff clearance.
As others have hinted, it used to be "taxi into position and hold," but that was changed to "line up and wait" in the last decade or so. I believe that was because "position and hold" sounded too similar to "hold short" or "hold position," which is practically the opposite instruction.

BWIAirport wrote:

but that was changed to "line up and wait" in the last decade or so. I believe that was because "position and hold" sounded too similar to "hold short" or "hold position," which is practically the opposite instruction.

While that may have happened a time or two not likely that was the reason the change was made. Just about every other state in the world used if not all of them "line up and wait" and finally the FAA and who knows who else determined to standardize the phraseology.

Starlionblue wrote:

tax1k wrote:

I’ve noticed that almost invariably planes start their takeoff after ATC says line up and wait but before getting the “cleared for takeoff” message. I would have thought that “line up and wait” meant something stationary. Just curious what I’m missing.

If you expect to be cleared in short order, you might keep rolling slowly for a short distance instead of coming to a complete stop. (Of course, you need to know you can "waste" some runway). But you certainly won't set takeoff thrust before "cleared for takeoff". That would be a rather serious violation.

I see this often at an airport like ATL. What benefit does an aircraft get by rolling slowly instead of stopping while awaiting takeoff clearance?

phatfarmlines wrote:

What benefit does an aircraft get by rolling slowly instead of stopping while awaiting takeoff clearance?

saves 1 brake application

Just a guess here but the OP may be watching the aircraft (either in person or on FR24) while listening to ATC via Live ATC or other. If so, there is often a slight delay in the audio which can give the impression the aircraft is moving before clearance/instruction is given.

Usually, the pilots can see the situation developing. Get the clearance, landing traffic touching down, so you know by the time you actually power up, taxi on the runway, get lined up, you’ll be cleared to go, no reason to come to a stop. Other times, perhaps landing traffic is just passing in front of you and it’s a heavy, so it’ll be a few moments for him to clear, you might take your time lining up and will anticipate stopping to wait for him to clear. Very situational.

Based on the airport, if you are familiar, you can also estimate when you'll be getting a clearance. Many airports that use LUAW have a fairly reasonable distance between the hold point and the point on the runway where you'll be lining up, so there's a good chance you'll get LUAW and then get takeoff clearance while still rolling anyway.

In the UK it’s quite common to get a clearance from the tower when you’re number one for the runway ‘behind the landing aircraft line up and wait’

I’ve only been given this clearance when the landing aircraft is on short final but it’s not one you’ll receive in the US

phatfarmlines wrote:

Starlionblue wrote:

tax1k wrote:

I’ve noticed that almost invariably planes start their takeoff after ATC says line up and wait but before getting the “cleared for takeoff” message. I would have thought that “line up and wait” meant something stationary. Just curious what I’m missing.

If you expect to be cleared in short order, you might keep rolling slowly for a short distance instead of coming to a complete stop. (Of course, you need to know you can "waste" some runway). But you certainly won't set takeoff thrust before "cleared for takeoff". That would be a rather serious violation.

I see this often at an airport like ATL. What benefit does an aircraft get by rolling slowly instead of stopping while awaiting takeoff clearance?

As r6russian says, it saves one brake application. Carbon brake wear is per application.

Also, it keeps things moving. If you get on the brakes, then release, and start moving, it adds a little bit of complexity to the operation. Keep things simple if you can. Especially if you there is an aircraft on final. Tower might see you stop and get antsy.

Obviously, it is all dependent on the situation. Not quite stopping may help you and/or tower out, but if you're unfamiliar with the airport, or feel you should not keep rolling, or whatever else, by all means, stop. It isn't wrong to stop. It just might be more "smooth" if you don't in some cases.

Max Q wrote:

In the UK it’s quite common to get a clearance from the tower when you’re number one for the runway ‘behind the landing aircraft line up and wait’

I’ve only been given this clearance when the landing aircraft is on short final but it’s not one you’ll receive in the US

Don't forget the second "behind".

"Behind the landing aircraft line up and wait, behind."

Max Q wrote:

In the UK it’s quite common to get a clearance from the tower when you’re number one for the runway ‘behind the landing aircraft line up and wait’

I’ve only been given this clearance when the landing aircraft is on short final but it’s not one you’ll receive in the US

Fairly common across Europe. One day in Lisbon, hazy, I got that clearance only had the traffic’s lights in sight. Not a fan.

GalaxyFlyer wrote:

Max Q wrote:

In the UK it’s quite common to get a clearance from the tower when you’re number one for the runway ‘behind the landing aircraft line up and wait’

I’ve only been given this clearance when the landing aircraft is on short final but it’s not one you’ll receive in the US

Fairly common across Europe. One day in Lisbon, hazy, I got that clearance only had the traffic’s lights in sight. Not a fan.

Don’t follow your logic, why seeing only the lights makes at time of clearance makes you no fan?

It often goes like: United123, landing traffic A320 on short final in sight? - In sight, United123 - behind landing A320, line up Rwy xy and wait, behind.

What’s not to like? Expedites traffic flow, easy procedure. And if you are unsure about the aircraft meant you at the latest can identify as it flies past you before touchdown. Any doubt, ask again.

Just one example, hard to identify the traffic the tower referring to. Like MaxQ, we’re accustomed to the clearance to enter the runway AFTER the landing traffic touches down. I don’t see where it speeds things up.

GalaxyFlyer wrote:

Just one example, hard to identify the traffic the tower referring to. Like MaxQ, we’re accustomed to the clearance to enter the runway AFTER the landing traffic touches down. I don’t see where it speeds things up.

Well, opinions differ and thats plenty alright. I never had difficulties identifying the traffic, though.

In the US, you'll get a LUAW once the landing aircraft has crossed the threshold or the point at which you're holding, but not necessarily after it touching down.

GalaxyFlyer wrote:

Just one example, hard to identify the traffic the tower referring to. Like MaxQ, we’re accustomed to the clearance to enter the runway AFTER the landing traffic touches down. I don’t see where it speeds things up.

I see your points, but I've never found it ambiguous which traffic tower is referring to. Often they'll tell you the aircraft type as well. "Behind landing Airbus A320, line up and wait, behind."

If visibility is so low you can't see the landing lights from a fair distance, tower probably won't give you a line up behind clearance.

There is a bit of time saved, I think. When you see the landing traffic cross the threshold, you can release the park brake and start moving. It saves a bit of time versus getting a clearance first.

N1120A wrote:

In the US, you'll get a LUAW once the landing aircraft has crossed the threshold or the point at which you're holding, but not necessarily after it touching down.

That’s reasonable, but the FAA procedure of issuing the landing clearance to two planes both on final sounds fishy to me, too, as it does for many non-US pilots.

GalaxyFlyer wrote:

N1120A wrote:

In the US, you'll get a LUAW once the landing aircraft has crossed the threshold or the point at which you're holding, but not necessarily after it touching down.

That’s reasonable, but the FAA procedure of issuing the landing clearance to two planes both on final sounds fishy to me, too, as it does for many non-US pilots.

I think much of it is what you are used to. Where I typically fly, a "behind" clearance just means it is Tuesday. Hearing the plane behind us also being cleared to land makes me antsy.

If I mainly flew in the US, I might feel the opposite way.

n92r03 wrote:

Just a guess here but the OP may be watching the aircraft (either in person or on FR24) while listening to ATC via Live ATC or other. If so, there is often a slight delay in the audio which can give the impression the aircraft is moving before clearance/instruction is given.

Sorry for the delay. Was out of pocket for awhile. This is exactly spot on. Listening to the LiveATC app while “watching” planes. There doesn’t seem to be a delay on the radio but it’s hard to tell. But I do know the plane is a few seconds down the runway by the time the clearance comes through over the app.

I guess, hypothetically, this could be the best argument for “airplane mode”.

GalaxyFlyer wrote:

N1120A wrote:

In the US, you'll get a LUAW once the landing aircraft has crossed the threshold or the point at which you're holding, but not necessarily after it touching down.

That’s reasonable, but the FAA procedure of issuing the landing clearance to two planes both on final sounds fishy to me, too, as it does for many non-US pilots.

Absolutely agree with you here. It kinda takes away the sense in being cleared to land in the first place, as it should imply a clear runway, safe to land on.

On busy airports I like "line up behind" clearances because it often gives maybe 10-30 seconds of extra time to do the before takeoff checks. In our company line up clearance is the trigger for line up checklist and to inform cabin crew that takeoff is imminent. Those actions don't take much time but I think it's better if those can be accomplished before actually moving to the runway. Then when the landing aircraft has passed the holding position the whole flight crew can solely concentrate on lining up the aircraft at the right spot and be ready for takeoff procedure. This obviously depends on the airline's procedures and the type of aircraft and the complexity of the checks. Small thing but in my opinion makes a smoother operation.

Of course if there's any ambiguity about the clearance it's our responsibility to confirm the clearance from the atc. But mostly I've found clearances pretty clear and precise.

GalaxyFlyer wrote:

Fairly common across Europe. One day in Lisbon, hazy, I got that clearance only had the traffic’s lights in sight. Not a fan.

There's a reason why it's so popular. Gives you shorter takeoff (some 10-20secs from rwy threshold vs runway).

However, in usual conditions it is always a conditional. Usually either "report in sight - behind line up" sequence to give you "negative visual" call, if you have any doubts. And even after simple "behind", anyone can give their "unable/not ready at this moment". This will make ATC unhappy, but it's still safety at its best, just trying to get some more ops from runway.

Where I live (EPWA), it's also fairly useful to really raise the ops bar. Due to its layout (crossing runways), departing traffic from one and arriving to other, lining up is no brainer. You get one waiting, while other lands on other runway. Once landing traffic clears runways crossing, departing goes. This really saves time on arrivals sequence.

Cheers,
Adam

Yes, KLGA with crossing runways does that a lot, too. Love Warsaw, spent 10 days during the Great Iceland Volcano shutdown.

GalaxyFlyer wrote:

Yes, KLGA with crossing runways does that a lot, too. Love Warsaw, spent 10 days during the Great Iceland Volcano shutdown.

Great example with KLGA as there are many others. KHOU is familiar to me and they also do an outstanding job of handling crossing runways with arrival/departures....or at least they used to when I was still in the approach control facility . Who knows how they are doing these days.

My favorite one is still Aspen... Rwy 15/33 same piece of concrete - 8000ft runway.

(holding short of Runway 33) "Line up and wait, opposite direction landing traffic on 9 mile final runway 15, call traffic in sight."

sure enough there are the landing lights of the opposite direction traffic lined up down the centerline of the runway we are on. "Traffic in sight"

"Cleared for takeoff Runway 33"

Tower now addressing the aircraft landing on 15 "Cleared to land Rwy 15, traffic departing Rwy 33, has you in sight."

"Cleared to land Runway 15."

as we fly towards each other at 240kts... and play the game of airway chicken that the departing aircraft always loses because it turns right after departure and then left to fly under the landing aircraft.

As we're under the landing traffic, the next guy is checking in " Tower, aircraft xyz, visual 15."

"aircraft xyz, aspen tower, continue, traffic to depart runway 33 prior to your arrival..."

the controller then proceeds to tell the next aircraft to line up and wait on 33.

The reason the phrase was changed was that the previous command "Line Up and Hold" was believed to have been misinterpreted by the KLM 747 flight crew in the worlds worst aircraft accident in Tenerife when the 2 747s collided in the fog. It was believed that the KLM 747 crew while multiple radio transmissions were taking place at the same time on the same frequency somehow thought that they had been cleared for takeoff and the rest is history. The International Civil Aviation Organization (ICAO) adopted this phase quite a while ago along with most countries and the United States was one of the later countries to adapt it.

CanukinUSA wrote:

The reason the phrase was changed was that the previous command "Line Up and Hold" was believed to have been misinterpreted by the KLM 747 flight crew in the worlds worst aircraft accident in Tenerife when the 2 747s collided in the fog. It was believed that the KLM 747 crew while multiple radio transmissions were taking place at the same time on the same frequency somehow thought that they had been cleared for takeoff and the rest is history. The International Civil Aviation Organization (ICAO) adopted this phase quite a while ago along with most countries and the United States was one of the later countries to adapt it.

AFAIK, "line Up and Hold" has never been a thing. In the US, it used to be "(runway xx) position and hold".

In the Tenerife Air Disaster, Tenerife Tower did not say "Line up and Hold" to KLM4805. The transmission was "Ok. Standby for take-off, I will call you." There was a squeal heard over the radio during the transmission, which is probably the reason KLM4805 did not hear it clearly. It is easy to see how it could be misinterpreted given some confirmation bias.

Verbiage has since changed to remove "take-off" from all communications except take-off clearance. Hence why we say "ready for departure" and not "ready for take-off". This makes any instruction including "take-off" unambiguous.


Page 3, and also pages 24-25 show how several transmissions from both tower and KLM4805 include the word "take-off"
https://www.faasafety.gov/files/gslac/c ... report.pdf

Woodreau wrote:

My favorite one is still Aspen... Rwy 15/33 same piece of concrete - 8000ft runway.

(holding short of Runway 33) "Line up and wait, opposite direction landing traffic on 9 mile final runway 15, call traffic in sight."

sure enough there are the landing lights of the opposite direction traffic lined up down the centerline of the runway we are on. "Traffic in sight"

"Cleared for takeoff Runway 33"

Tower now addressing the aircraft landing on 15 "Cleared to land Rwy 15, traffic departing Rwy 33, has you in sight."

"Cleared to land Runway 15."

as we fly towards each other at 240kts... and play the game of airway chicken that the departing aircraft always loses because it turns right after departure and then left to fly under the landing aircraft.

As we're under the landing traffic, the next guy is checking in " Tower, aircraft xyz, visual 15."

"aircraft xyz, aspen tower, continue, traffic to depart runway 33 prior to your arrival..."

the controller then proceeds to tell the next aircraft to line up and wait on 33.

An airport I’m very happy to not fly into anymore. As an old friend, who went in there I’d Falcons for years said, “if I ever get control over it meteor, it’s hitting KASE”.

I am not going to get into an argument on this but I am certain the phase came from ICAO and as far as I understand it was related to the Tenerife accident. I took a look at the accident reports from Spain, the Netherlands and ALPA reports from the accident and I cannot pin down what logic ICAO used to come up with this phase. I assume that one would have to dig into this at ICAO and I no longer have access to a lot of ICAO documents since I retired from a large aircraft manufacturer in the Pacific Northwest in the US and I have not lived and worked in Montreal for a number of years where ICAO has its headquarters and has its document library. I am guessing that they were trying to come up with a phase that avoided "Stand-by for takeoff" and/or "We are now at takeoff" but if you know of any more details please provide them. I will do more digging to see what I can find. All of the Spanish, Netherlands and ALPA reports are online at:
http://www.project-tenerife.com/engels/index.htm
The report you sent me is only the Dutch report which I appreciate and have saved and filed away for future reference and they obviously have differences with the Spanish report as is stated in their attachment to the Spanish report. There is also an ALPA report on that site as I presume the Pan-Am crew were ALPA members that has some differences from both the Spanish and Dutch reports
I know that the "Line Up and Wait" phase was in use in Canada where I grew up and did most of my early flying on my Canadian licenses and was surprised when I later moved and obtained US licenses that it had not been adapted yet in the US and was later adapted years after Canada adopted it.

I know that there were significant communications changes implemented after the Tenerife disaster, aimed at standardising verbiage. However, I don't know when the phrase "line up and wait" was adopted, but it may well have been after Tenerife.

I think the US moved to "line up and wait" in 2010.

GalaxyFlyer wrote:

N1120A wrote:

In the US, you'll get a LUAW once the landing aircraft has crossed the threshold or the point at which you're holding, but not necessarily after it touching down.

That’s reasonable, but the FAA procedure of issuing the landing clearance to two planes both on final sounds fishy to me, too, as it does for many non-US pilots.

Not all controllers do, but I don't see a problem with it either. A clearance can always be cancelled and it saves the problem of a very late landing clearance in a critical phase.

N1120A wrote:

Not all controllers do, but I don't see a problem with it either. A clearance can always be cancelled and it saves the problem of a very late landing clearance in a critical phase.

Exactly, last thing I want to do is have to get a readback of a landing clearance when they are almost at the threshold which is what would happen when using the 2.5 NM reduced separation on final. I cannot be certain, but I think the most I've given was "number three following an A320 three miles ahead, Runway XX, cleared to land". It normally worked out that the first of the three would be almost turning at a high speed when the now third plane on final checked on the frequency.