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Not sure of the failure mechanism, but there was a runway incursion at Atlanta's Hartsfield Airport

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JohnRBaker

Mechanical
Jun 1, 2006
35,479
The CRJ was short of the stop short line when the collision occurred. The next question is whether they were taxiing still when hit (A350 fault) or had they truly stopped short (CRJ fault).
 
I think the rules are, don't run over other planes, regardless of official right of way.

From a comment on avweb

"The centerline of TW-E to the hold short line of TW-H entering RW-8L is 164 feet. A CRJ-900 is 119 feet long and the wingspan of an A350-900 is 212 feet The wingspan halved (assuming the A350 was on the CL), is 106 feet. That's a margin of safety of 45 feet. Somebody was somewhere they shouldn't have been. Either way, the A350 is at fault here. Just find the measurements interesting."
 
Seems like the A350 is at fault; no different than driving a car, hitting someone's behind leaves little doubt as to who was at fault, unless one can show that the plane in front backed up into the A350's wing.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
Depends where the two aircraft are and who is incharge in that area.

ATC are responsible for deconfliction during taxing.

You can't see your wing tips when taxing. And it's a couple of meters off these big heavys and the tails on stand.

If the small one wasnt were it was instructed to be then it maybe deemed it's a primary reason for collision.
 
Sounds like no one watched the video. I guess the side windows can't open when it might be useful to take a look.
 
Thanks for just pointing the video out.

The a350 is on a unrestricted taxiway aka 32 Meter wing span.

We haven't had direct vision windows in years..

It will be the moving aircraft deemed at fault for insurance reasons.

Europe the atc would have more to discuss with the investigation body than the pilots.

The ATC ground radar conflict would have been triggered in most large European airports. I have had it a couple of time with A220 V other aircraft. Hold position then a ops vehicle turns up and either marshalls us past or we hold until it's sorted.
 
Man that is some complicated runway and taxiway system there.

not possible to really say what was going on there from the photos and videos released.

If anyone knows can you work out where in that maze of runways and taxiways this was?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Not technically a runway incursion. That's when a plane or vehicle enters the runway without permission from ATC. This incident would be a Ground Collision. Both of these aircraft were taxiing (DL295) or holding short (EDV5526) as directed by ATC. You can go back on liveATC.net to hear archived ATC radio with comms between DL295 and ATL Ground. [URL unfurl="true"]https://www.liveatc.net/archive.php?m=katl_gnd_0826[/url] (you'll want ground for RW 08-26). At one point you can hear DL295 say "we just hit something, can you (tower) see what we hit?" EDV5526 will be on Tower frequency for RW 08-26, they don't say much.

I whipped this up this morning in AviPlan. This is to scale. A350-900 is TDG V.

Snipaste_2024-09-11_09-24-57_ay3cam.jpg


It looks like either DL295 was taxxing north of the centerline of TW E, or EDV5526 was further south of the runway hold position marker for RW08R on TW H. I suspect the latter. Either way, this is a pretty crowded TW intersection.

Snipaste_2024-09-11_09-00-24_gr8wvr.jpg


Snipaste_2024-09-11_08-20-11_ltv6mt.jpg
 
But as far as the failure goes, I think this one falls on Ground Control. If anyone is interested the current design standard for airports (in the US) is FAA AC 150/5300-13B. There you can read all about runway/taxiway separation, safety areas, object free areas, intersection design, etc.
 
Think this tells you all you need to know.... Now why he's so short is the key.

From the linked video.

Screenshot_2024-09-11_171306_ljck7q.png


Interestingly the hold point on runway 8L is a lot shorter for some reason so maybe he got confused?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Here is the audio from ATC, found by looking at audio archives of interest.

Very hard to understand audio, which is sad to think we are so far behind on radio technology at airports. The female voice (assumed gender) is very hard to understand, and a very critical criteria for hiring of air traffic controllers is clear easy to understand speech.....

I understood the DL295 pilot to say he was off center line and the smaller air craft had stopped short of line....

and perhaps one place where english is still the default language in US?

Question for experts. Is the ATC tower looking at software tracking screens of air craft locations and flow more often that actually looking out the window to see real time there is problem? It sure seems like way too much constantly changing information in real time, to be able to keep up with every detail. And then the mouth full of lingo it takes or packet overhead if you will, for each transmission.......



 
 https://files.engineering.com/getfile.aspx?folder=b5e55517-a923-4d6a-94d8-d7fc2225478d&file=deltaclippedKATL-Gnd-0826-Sep-10-2024-1400Z.mp3
A short plane stopped short.
Forgive my "What-about" but;
If an A-350 was stopped exactly on the Stop-line,would the other A-350 have cleared It?
With over 30 meters difference in length, probably not.
Waiting to hear if the A-350 was off of the center-line.


--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
I hope that the CRJ doesn't have a direct mechanical connection from the tail surfaces to the stick.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
Per it appears that the controls are via cables going back to hydraulic actuator inputs. In the video it looks like quite a spray of fluid into the engine exhaust stream. Since they operate on the differential between the control surface and the stationary surface, probably the only kickback would be when the tail hit the runway and put a sideload on the rudder.

I wonder if this case was examined as part of any safety analysis.
 
As the entire tail assembly left the fuselage, lets hope that the force on both cables for each function remained equal and that both cables for each function broke at the same time.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
If an A-350 was stopped exactly on the Stop-line,would the other A-350 have cleared It?

They wouldn't even attempt to do that.
 
I thought that the female voice was one of the most clear ATC controllers I've heard in some time. The only time she was hard to understand was when the other male voices were talking over her.
 
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