On ground conflicting paths at JFK

[RooFlyer]

From The Oz on line:

 

[Hvr]

'Delta 1943, cancel take-off!': Agencies investigate averted plane collision at New York airport

Officials are investigating a close call at a New York airport on Friday night between a plane that was crossing a runway and another that was preparing for take-off.

www.abc.net.au

Radio transmission here:

 

[Quickstatus]

Victor from VasAviation about this
See his pinned comment also

The departure runway was 4L
AA 106 was instructed to cross 31L at K but instead crossed 4L at J.
Why will be the subject of some head scratching

 

[justinbrett]

Victor from VasAviation about this
See his pinned comment also

The departure runway was 4L
AA 106 was instructed to cross 31L at K but instead crossed 4L at J.
Why will be the subject of some head scratching

Not correct RT from the TWR controller (unless FAA is different, definitely not ICAO).

Should have been DAL1943 Stop Immediately, DAL1943, Stop Immediately, Aircraft ahead / Runway Occupied etc.

Fortunate that DAL could probably see AAL and understood the instruction. But it risked the pilot assuming it was a procedural lapse (eg incorrect coord from TWR to Departures or something trivial) and deciding to continue. The pilot has the right to continue with the take off roll in either situation.

 

[Quickstatus]

Initially AA106 was instructed to taxi on B then hold short of 4L at K by Ground controller.
This caused the pilots to be facing a runway (4L)
Then instructed by Tower to cross 31L at K,
The AA 106 pilots then crossed the runway in front of them which was 4L instead of turning right at K and crossing 31L
The pilots later queried the Tower - they thought they were cleared to cross. They didnt mention which runway.

Ground told AA106 to hold position when she noticed then encroaching onto 4L. But they didnt comply/didnt hear?
Were the pilots on Ground frequency or tower frequency because the last response from AA106 was to tower

 

[justinbrett]

Initially AA106 was instructed to taxi on B then hold short of 4L at K by Ground controller.
This caused the pilots to be facing a runway (4L)
Then instructed by Tower to cross 31L at K,

That's not quite correct, the transcript I read had "106 Heavy, Kennedy Ground, Runway 4 Left, Taxi Bravo, hold short of Kilo". There is no mention of J and you can't hold short of 4L at K without crossing 31L first, so that was definitely not the instruction. Stating runway 4L here is not a taxi instruction, it's confirming assigned departure runway.

That's a perfectly valid call - though ICAO phraseology is much clearer (taxi to holding point K RWY 31L // cross runway RWY 31L taxi to holding point K1 RWY 04L).

The crew messed up. You can hear it in the male's voice once told by ATC, he sounds completely deflated and I think he worked out what happened.

 

[jb747]

Not correct RT from the TWR controller (unless FAA is different, definitely not ICAO).

FAA and ICAO are from different planets. And the controllers at JFK are the just about the worst that I ever experienced. They are also the nastiest. I have no idea of their conditions or anything else, but they are unhelpful and snarky. The exact opposite of Heathrow.

I'll have to have a look at the entire event.

...Ah yes. Speak at 5 million miles an hour, so that those on the other end might catch part of the call. And if you query it, that's when they'll get stroppy. No need to speak that quickly, it doesn't make things happen any faster. It slows things down, because you'll get many 'say again' calls, especially from the foreign airlines. And then get triply snarky with them, 'cos they just don't listen fast enough.

 

[ayebee]

I imagine the pilots here will have original sources, but for others I found this to describe the situation well for me.

 

[Quickstatus]

1000 ft separation
DL instantaneous speed at reject was approx 185kmh. If it did not accelerate past 185kmh it would have taken about 5.8 seconds to traverse 1000ft if it did not reject

As it was accelerating, the time to traverse 1000 ft would be less than that if it did not reject

Anyone know what the acceleration is in m/s2 ?

 

[jb747]

1000 ft separation
DL instantaneous speed at reject was approx 185kmh. If it did not accelerate past 185kmh it would have taken about 5.8 seconds to traverse 1000ft if it did not reject

As it was accelerating, the time to traverse 1000 ft would be less than that if it did not reject

Anyone know what the acceleration is in m/s2 ?

There's not a fixed answer. It would vary with weight and chosen derate.

Assuming a fixed acceleration (it wouldn't be, but too hard to work out otherwise), it would have taken about 32 seconds to reach to point at which they aborted, and it would have taken 36.5 to reach the intersection if they had continued. Conversely, having aborted, you could just about stop from 90 knots in 1,000'. An abort uses a brake setting that is otherwise never touched, but basically maximum braking pressure is applied, and the anti skid system goes into overdrive.

If not for the order to abort, the take off distance would have been in the order of 5,000'. (Again, depending on derate, weight, wind, phase of the moon, etc).

 

[RooFlyer]

A follow-up from OMaaT, including a link to the NTSB initial report

Absurd: Reckless American 777 Pilots Refuse Recorded NTSB Interviews