Mid-air collision of 3 international flights averted over New Delhi!
 

According to the official, at the time of the incident, National Airlines' flight NCR 840 was on its way to Hong Kong from Bagram in Afghanistan while the KLM Flight KLM 875 was heading to Bangkok from Amsterdam. The Eva Air flight EVA 061 was flying to Vienna from Bangkok, the official said.
"First it was NCR 840, which was flying at flight level 310 (31,000 ft) and EVA 061 at flight level 320 (32,000 ft) which breached mandatory separation. The pilots of both the aircraft were alerted by the onboard TCAS warning system," the official said. Around the same time, the KLM flight was at 33,000 ft, he added.

Following the TCAS (Traffic Collision Avoidance System) warning, the pilot of NCR 840 sought to climb to 35,000 feet but was told to remain at that current level till the time it gets a go-ahead. "However, when the air traffic controller (ATC) observed it climbing, it was immediately asked to take a left turn. In the meantime, EVA also continued climbing at flight level 330, a level at which KLM was already flying, and at this time, another TCAS warning went off, alerting the pilots to steer the aircraft to a safer distance," the official said.

As the NCR 840 again descended to flight level 330, it came across the EVA flight, triggering another TCAS alarm, the official said.
https://www.dnaindia.com/india/repor...planes-2701651

FL 330 KLM 875 ->
FL 320 <- EVA 061
FL 310 NCR 840 ->

I stopped reading at "Stand by, expect FL350"...

yah, it's a bad call...I had an EY 320 departing Damascus read back an expect further climb...and next thing I know they climbed right up through my altitude, apparently ignoring the TCAS RA they must have been receiving as well...

FR24 History?
 

Is there any FR24 experts that can dig up and post a couple of screen shots for us?
Sounds like a fun day at the Fair, rolercoaster and all!

And you, BluSdUp, were the guy in another thread advocating TCAS as an alternative for aircraft to make approaches to a major airport which had an ATC systems failure! The above scenario enforces my point that TCAS is a useful aid but it's not by any means foolproof. In time, it will be interesting to see a factual report of the entire event.

Crossing traffic 1000ft above breaches mandatory separation?

Yes, puzzled me too. Delhi airspace is RVSM and I would have thought all three of those aircraft were RVSM compliant. That's why I'm waiting for more facts about what triggered this incident.

The Aviation Herald has one image that shows the positions quite neatly.
Incident: NAC B744 near New Delhi on Dec 23rd 2018, climb without clearance causes loss of separation with two aircraft
The reader's remarks below it (shown in anti-chronological order) strongly suggest what kind of misunderstanding developed resulting in the premature and unauthorized climb by the NCR 840 that created the loss of required separation.

<<got a clearance: EXPECT to climb to FL350>>

I've never heard that before; sounds inherently dangerous.

At FL320 EVA (level) and NCR (climbing) were on reciprocal headings,half a minute or so apart, when evasive action started
NCR was now trailing KLM by a mile or two, having been overtaken by KLM 10 min. before.

https://cimg9.ibsrv.net/gimg/pprune....c02d0f6c29.jpg

Redbeard

It's p*ss poor phraseology but if you, as a pilot, consider that to be a clearance-and I hope you don't and it's a language misunderstanding, you'd better be careful out there. It in no way constitutes a clearance. Did we learn nothing from Tenerife? If in doubt-ask

Hotel Tango
With regards to Your post nr 7 here:
You got me wrong, I did NOT advocate using TCAS as a replacement for ATC in a procedure separated approach!
I did try to correct a rather scaremongering chap that claimed aircraft would collide over Birmingham , without ATC and or Radar at the field.
Glad to sort that misunderstanding.
Regards Cpt B

Airbus a321.
Have You considered the fact that this is wrong terminology from ATC, due to the fact that one little Double transmission actually makes it sound like the format of a clearance, Ie: " NRC 840 ( Expect to) climb to FL350" the ( being the double)?
This is why I love the Dutch at Maastricht :" XYZ Request FL 350 to cruise "
MAS: " Expect so!"

Anyway, Airbus a321, when the day once come, and it will , when You make Your first mistake, lets hope it does not involve operating heavy machinery.

BluSdUp
Unfortunately, you were in such a hurry to insult me that you failed to understand the point of my post and that the extreme example I gave began with the word "IF". I did not suggest that it would happen but that it could happen. Many past aviation accidents have proved that anything can occur no matter how unlikely it may seem in theory. If you honestly believe that TCAS is 100% infallible in preventing a midair I beg to differ. Regardless what your personal point of view may be, there is no need to be insulting or condescending to make your point, especially when you failed to grasp the core issue which was that of liability.
Glad to sort that misunderstanding.

[QUOTE " Expect so!"
][/QUOTE]

More non standard phraseology. How about "maintain FL??? I will call you when/if higher becomes available"

Dear Hotel Tango

I must apologize!
I do get to sarcastic at times.
I do appreciate Your comments.
I agree, TCAS is good but, not perfect!
Humbly
Cpt B

We train our boys and girls to make no reference to actual levels when referring to expectations of climb/descent; e.g. "copy your request; expect higher in approx. (so many) minutes/miles. Reason being, you can get interrupted / distorted comms and everything goes belly up, like this incident.

0' vertical and 2.2nm horizontal separation on almost reciprocal headings. :eek:

http://avherald.com/img/nac_b744_n91...181223_map.jpg

250kts, just for info, from my recollection (for what it's worth), I have never heard "expect so" from my time there. But, a younger generation of controllers (from many nationalities) work there and it's possible that one or some use this odd phraseology! When it was known/planned that higher was available a little further on, generally it was quite simply "maintain FL???, you may expect higher". Again, depending on the individual, some would add, " in X minutes" or "with the next sector" etc. The requested FL would never be mentioned by the controller unless in an actual clearance.

No, you are misinterpreting the GE graphic.

It was the KLM 777 and NAC 747 that were 2.2 nm apart at the same FL, but both had been on the same south-easterly heading until the 747 was turned left by ATC.

Gotcha, ta!

WOW....
From the US AIM pilot controller glossary
I know, not in the USA, but I can find that document

Folks,
For those of you familiar with the area, what is the current published airspace classification, in which the incident occurred??
Tootle pip!!

No time nor fix was given in this case

Having seen additional information given above some observations might be drawn from the plan view time-lapse sequence:

KLM 875, SE-bound at FL 330, did not change from his assigned FL.

BR 61, initially NW-bound at FL 320, did not change from his assigned FL but turned towards the West as instructed by ATC.

N8-840, initially SE-bound at FL310 whilst climbing turned towards the East as instructed by ATC.

It would appear that it was the turn instructions given by ATC that mitigated most effectively the risk of these encounters becoming too close.

As regards TCAS, it could be that the pilots of KLM 875 at FL 330 were advised not to descend, and that those in BR 61 were advised to neither climb nor descend - if indeed they saw more than a TA as at the closest point of approach they were diverging from the flight path of N8-840.

I would have expected the TCAS in N8-840, if operating, to have posted advice not to climb. As this aeroplane was relatively close to the two B777s I would have expected its TCAS display to have indicated the presence of the KLM 2,000 ft above and also of the BR 61 1,000 ft above on the reciprocal track.

I wrote, ‘if operating’ since the decision to initiate a climb and to have ascended 2,000 ft into close proximity of the KLM suggests that the display was either not visible or that the information it posted (proximate aircraft symbols and possibly TA/RA alerts) was not acted upon.

I do hope that more and accurate data is forthcoming!

The KLM flight did not get a RA.

Nugget 90, You seem to be exonerating NR 840. My understanding is that it was maintaining assigned level of 310 and asked for 350 which understandably was not granted but it climbed anyway. ATC saw it and averted the danger by turning him and EVA 661 left, away from each other. Flights at 310 320 and 330 ( including opposing traffic) are legally separated but 840's action upset that apple cart. Flights are in this close proximity every day everywhere I should think, so TCAS ought not to be a factor surely? ATC saying expect 350 was presumably misunderstood by 840.

is TCAS designed/specc'd to give guidance when more than two planes are involved in an alert?

G

Its an extensive subject. Look it up via google.

Until all the facts are known ( e.g. what was the readback of NCA and what was the reaction of the controller to that readback) we can only speculate wildly on this case
A few points however :
The title of this post is based on a sensationalist newspaper headline and is what I would describe as "fake news" . 2.2 NM same direction with the faster one in front is hardly a risk of collision . loss of separation yes, risk no. The EVA opposite was turned away after STCA alert , no loss of separation and no risk either.
That said
Delhi FIR is RVSM and seen the 3 types involved the 1000ft sep is absolutely normal . they were in controlled airspace under positive radar surveillance, as the STCA and vectors issued confirmed.
There also seems to be some RAs involved and it would be interesting to know who got one, who followed the RA and possibly who did not and if possibly the controller issued instructions contrary to the RAs. That could in fact be the core of the problem here . We'll see when we get the facts .
In the meantime wish you all a happy new year , and my advice for 2019 would be : always follow the RA even if the controller tells you otherwise .. Safe landings too :E

Absolutely! You should have written that in bold letters ATC Watcher!

It is a standard CPDLC message look up the ICAO 'GOLD' document.
It is normal practice in many oceanic centers to precede any request for a level change with MAINTAIN LEVEL ###; followed by any further instruction on level change exactly because of the problem in this case.

Wait. Wait. Wait. Why are people questioning whether NCA's TCAS was working? All the stories say its climb was a result of a TCAS warning.

One would assume a TCAS warning requires an instant response, not waiting 2 or 3 minutes for ATC to get back to you.

If planes on opposite courses are going to be assigned FL's 1,000 feet apart, TCAS needs to be programmed no to go off in the situation.