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Comment by brunohaid | Hacker News Reader

Re clearance/cause: VASA https://www.youtube.com/watch?v=fItu5qM7QfE also couldn't make it out, but it sounds like the Coast Guard Dash 8 got a not really perfect taxi instruction (neither "hold short" nor "line up and wait") to one of the other C* intersections leading onto 34R while a Delta flight occupied C1, but entered the runway anyway. The A350 got a proper clearance it read back correctly.

Also looks like all C hold short lines have embedded guard lights - ie the stop "bar" on the way to the runway should have been flashing brightly.

* https://www.anaas.ana-g.com/img/business/general_aviation/pd...

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Whether it was perfect or not, there are only a few words/phrases that allow an aircraft to cross the hold short bars at an airport with an active control tower. "Cross", "line up and wait", and "cleared for takeoff" are pretty much it. Runway incursions are very dangerous, as this incident shows, and pilots must be very sure they have clearance before entering a runway. If anything is ambiguous in an instruction, pilots are trained to ask ATC for confirmation before proceeding.

It's also possible that there was more ATC communication that was not recorded. LiveATC comes from feeds provided by volunteers, whose receivers may be some distance from the airport and which may not receive signals 100% reliably. The investigators will have access to the official recordings made by JCAB (the Japanese aviation authorities).

Is "line up and wait" really the new approved terminology? Way back when I was a PP student, it was "taxi into position runway XX and hold. Acknowledge hold."

Line up and wait sounds like something you tell preschoolers to do :-)

Line up and wait (meaning, on the runway, prior to actual takeoff clearance) is very common during busy periods. This is in America.

I've never seen planes line up and wait on the runway since there is only supposed to be one on there at any time.

Line up and wait will be used after the preceding departure has started their takeoff roll, so the following aircraft can be ready to take off once the required spacing is achieved.

It could also be used while other aircraft/vehicles are crossing the runway at other intersections.

The “line up” in this case refers to an instruction given to a single airplane to position itself on the runway in preparation for departure (as in “line up with the departure runway heading”).

It is not “hey, multiple airplanes get yourself into a queue on the runway”.

There can be multiple aircraft on the runway at multiple times, so long as there's no conflicting operations.

It's used quite regularly at any moderately busy airport to reduce delays.

Examples where I've seen/heard it used in ATC comms:

Aircraft departing in sequence. eg A, then B. So: "Flight A (already lined up on runway 35L), cleared for takeoff runway 35L." (some short time later while Flight A is still in the process of taking off) "Flight B, runway 35L line up and wait"

Aircraft departing after an arrival. eg "Flight A cleared to land, 35L", and right as flight A has crossed the threshold: "Flight B, runway 35L line up and wait"

Also, as mentioned by others, when there are other movements to cross a runway between departures. eg "Flight A, at Foxtrot 5, cross Runway 35L. Flight B, runway 35L line up and wait"

Maybe not with big airliners. It's common for small planes to be told to line up and wait while the current aircraft (also usually another small aircraft) is in the midst of taking off.

"Line up and wait" unambiguously means to do so on the runway.

https://www.faa.gov/airports/runway_safety/resources/luaw

"Line up and wait" is, historically, the ICAO phraseology, which the FAA adopted (and ditched the "taxi into position and talk for thirty more seconds and block comms" phrase). The phrase adoption went into effect Oct 2010 in the States.

"position and hold" was the old phraseology in the US. It changed to "line up and wait" on 2010/09/30 to match ICAO standards and because "hold (on the runway)" might be confused with "hold short (of a runway/taxiway), or "hold position (wherever you are now)".

https://www.faa.gov/airports/runway_safety/resources/luaw

I do love how we try so hard to disambiguate language. Especially hard when working across languages too. And it shows how badly things can go if left to fuzzy language protocols.

And on relatively ancient analog radio systems, no less.

"Line up and wait" is indeed correct!

https://www.faa.gov/air_traffic/publications/atpubs/aim_html...

"Take off power" has caused at least 2 crashes before that phrase was banned.

Go on?

Because it can be confused with "take off" as in "turn off"?

When an airplane is taking off, takeoff power is maximum power. But it can (and was) sometimes interpreted as "turning the power off".

What’s your vector, Victor?

Absolutely right!

Point was that if the taxi clearance didn't include "hold (short of 34R)" it might be seen as contributing factor in line with ICAO[1] or FAA recommendations.

Also quite terrifying that, given all the equipment at Haneda and according to https://www.youtube.com/watch?v=6NbVdIoJsHY, around 2:45, with taxi lights fully visible at 2:53, the DH8 was lined up on the runway for more than a minute before being run over by the A350.

But as you say, preliminary report should already have a clear timeline of the tower tapes.

1: https://www.icao.int/safety/runwaysafety/documents%20and%20t...

> and pilots must be very sure they have clearance before entering a runway

The word "clearance" is used uniquely in the context of landing and departing exactly to avoid mistakes and has to be repeated again by the aircraft before ATC confirms.

True in terms of phraseology (i.e. the actual word is not used in voice ATC communications), but all ATC instructions are generally referred to as clearances.

The terms "cleared to land" and "cleared for takeoff" are extremely specific (a regulation written in blood like many aviation rules), but "cross runway" and "line up and wait" also give permission for aircraft to enter the runway.

The word "cleared" is often used for IFR clearance delivery as well which gives you permission to navigate via a planned route to a particular point, so it's much more common than just takeoffs and landings.

> the stop "bar" on the way to the runway should have been flashing brightly

They were out of service:

https://www.reuters.com/world/asia-pacific/police-probe-poss...

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