Mid-Air Collision over Southern Germany (merged)
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We all seem to be saying the same things in different fashions, after all, we are ALL interested in safety, we do not choose to cause 2 aircraft to occupy the same position in space and time simultaneously.
FROM THE ATC SIDE.
Unless the pilot specifically (and clearly) tells the ATC that he is responding to an RA, there is no way that the ATC can KNOW this, and as such he/she will continue to try and keep two aircraft apart as long as they are on radar and/or frequency. This is a fact, and it is a simple truth. ATC's are trained to keep aircraft apart, and when things go wrong, the adrenaline flows, the heart pounds, and the mouth rattles. It is even possible that the ATC may experience temporal distortion in the death throws of a near-miss or mid-air.
The equipment solution could be by one of various means:
1. RA in cockpit forces special code (7400) to be transmitted by tx-ponder, causing RA to flash on the callsign block of the label. (This would probably be the cheapest solution). The problem is that the rate of update for different radar systems can vary between once every 5 seconds to once every 12 seconds.
2. The (ground based) radar software could be programmed with the same parameters as TCAS II (v7), and then, based on aircraft positions, indicate (by whatever means) that it (the software) "expects" that two specific aircraft would be receiving RA's at that point. I know that this is not a fool-proof system, but it may be a means to at least cause the ATC to "consider" that aircraft may be manoeuvring under RA instructions. (This method would require development of ATC software and updating of existing systems).
3. Mode-S or ADS-B systems that communicate specific data to and from ATC software and airborne software, to immediately update (in near real time) each other of their actions. (This would probably be best, as there are other major benefits). This concept is still only partially operational, but still has some major development to undergo, is costly, and requires vast & major upgrades when it goes fully operational.
As a side-thought, the ATC is responsible for keeping the aircraft apart (by means of Standard Separation). Once the ATC, for whatever reason, has allowed that separation to become eroded, the pilot has TCAS to avoid "a hit".
Methinks that there is sufficient technology available to avoid the mid air collisions, all that remains to "perfect" it, is the GLOBAL acceptance of the requirement to standardise procedures with regard to TCAS as well as the mandatory fitting of TCAS II (and latest version software) to all commercial aircraft. Yes, this (retro-fitting) is expensive, but what price do we place on a single life? 10 lives? 100 lives? 1000 lives?
Best Regards
SID
FROM THE ATC SIDE.
Unless the pilot specifically (and clearly) tells the ATC that he is responding to an RA, there is no way that the ATC can KNOW this, and as such he/she will continue to try and keep two aircraft apart as long as they are on radar and/or frequency. This is a fact, and it is a simple truth. ATC's are trained to keep aircraft apart, and when things go wrong, the adrenaline flows, the heart pounds, and the mouth rattles. It is even possible that the ATC may experience temporal distortion in the death throws of a near-miss or mid-air.
The equipment solution could be by one of various means:
1. RA in cockpit forces special code (7400) to be transmitted by tx-ponder, causing RA to flash on the callsign block of the label. (This would probably be the cheapest solution). The problem is that the rate of update for different radar systems can vary between once every 5 seconds to once every 12 seconds.
2. The (ground based) radar software could be programmed with the same parameters as TCAS II (v7), and then, based on aircraft positions, indicate (by whatever means) that it (the software) "expects" that two specific aircraft would be receiving RA's at that point. I know that this is not a fool-proof system, but it may be a means to at least cause the ATC to "consider" that aircraft may be manoeuvring under RA instructions. (This method would require development of ATC software and updating of existing systems).
3. Mode-S or ADS-B systems that communicate specific data to and from ATC software and airborne software, to immediately update (in near real time) each other of their actions. (This would probably be best, as there are other major benefits). This concept is still only partially operational, but still has some major development to undergo, is costly, and requires vast & major upgrades when it goes fully operational.
As a side-thought, the ATC is responsible for keeping the aircraft apart (by means of Standard Separation). Once the ATC, for whatever reason, has allowed that separation to become eroded, the pilot has TCAS to avoid "a hit".
Methinks that there is sufficient technology available to avoid the mid air collisions, all that remains to "perfect" it, is the GLOBAL acceptance of the requirement to standardise procedures with regard to TCAS as well as the mandatory fitting of TCAS II (and latest version software) to all commercial aircraft. Yes, this (retro-fitting) is expensive, but what price do we place on a single life? 10 lives? 100 lives? 1000 lives?
Best Regards
SID
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I really can't see coordination taking account of selected MCP altitude as the way forward.
2 Reasons:
Firstly, there is no certainty that an aircraft will be manoeuvering towards its MCP selected altitude. In fact, when considered in terms of an ATC commanded avoiding action that happens just before an encounter (and lets say just before an RA), it is quite likely not to be the case.
If ATC say 'avoiding action' anyone with a healthy sense of self preservation is going to punch the a/p disconnect and manoeuvre the aircraft, only catching up with the MCP selections later.
Secondly, what you are talking about is effectively a system inhibition against manoevering opposite to the MCP altitude direction. Don't forget, TCAS already has inhibitions built into it for various reasons, and if we add any more we will start to get situations where one (or perhaps both!) aircraft are unable to manouevre in either sense!
I would never claim TCAS is flawless, hence my advice on this and other threads with regards to handling TCAS incidents, however the area that the system can best be improved has got to be crew training IMHO. Searching for a technical solution to what is a training issue is not the way forwards I feel.
CPB
2 Reasons:
Firstly, there is no certainty that an aircraft will be manoeuvering towards its MCP selected altitude. In fact, when considered in terms of an ATC commanded avoiding action that happens just before an encounter (and lets say just before an RA), it is quite likely not to be the case.
If ATC say 'avoiding action' anyone with a healthy sense of self preservation is going to punch the a/p disconnect and manoeuvre the aircraft, only catching up with the MCP selections later.
Secondly, what you are talking about is effectively a system inhibition against manoevering opposite to the MCP altitude direction. Don't forget, TCAS already has inhibitions built into it for various reasons, and if we add any more we will start to get situations where one (or perhaps both!) aircraft are unable to manouevre in either sense!
I would never claim TCAS is flawless, hence my advice on this and other threads with regards to handling TCAS incidents, however the area that the system can best be improved has got to be crew training IMHO. Searching for a technical solution to what is a training issue is not the way forwards I feel.
CPB
ICAO Guidelines on the Use of ACAS/TCAS
'Proceed as Cleared' asked what ICAO had done about providing guidelines on action to be taken by pilots when presented with an RA. The answer is that ICAO published, several years ago, guidance material described as, 'ACAS Performance-Based Training Objectives' to supplement other material that can be read in ICAO PANS-OPS Volume 1 (Doc 8168), PANS-RAC Part X paragraph 3.1.2, and Annex 10 Volume 4.
All this good stuff was used by the JAA Operations Committee, as it was then called, to develop and publish Temporary Guidance Leaflet No 11, which is referred to in JAR/ACJ OPS 1.398.
Now, do JAA States actually require (through their national legislation) air operators whose aeroplanes are on their register to teach pilots what this TGL contains?
Well, the JAA Operations Division initiated earlier this year a State by State audit programme that requires the team, after visiting each Authority, to visit a selection of operatiors and ask a series of questions to confirm that what the Authority had told them was true. One of these questions is, 'Confirmation that TCAS/ACAS II is installed and operating in all aeroplanes that are required to have it, and that crew training reflects policies contained in TGL 11. (See Operations Manual Volume D)': and the operator is obliged to open the manual and show where this forms part of the training schedule.
What I have described above shows - I hope - that ICAO has indeed addressed the issue of training in the use of ACAS/TCAS, and that the European Nations (JAA Member States) have taken this forward and have sought to 'close the loop' by ensuring that this vital information reaches those who need to know how to use TCAS II. I'm not pretending that the system is perfect or that it cannot be improved, but I think it right that readers should know that ICAO and some authorities have not ignored this vital subject.
All this good stuff was used by the JAA Operations Committee, as it was then called, to develop and publish Temporary Guidance Leaflet No 11, which is referred to in JAR/ACJ OPS 1.398.
Now, do JAA States actually require (through their national legislation) air operators whose aeroplanes are on their register to teach pilots what this TGL contains?
Well, the JAA Operations Division initiated earlier this year a State by State audit programme that requires the team, after visiting each Authority, to visit a selection of operatiors and ask a series of questions to confirm that what the Authority had told them was true. One of these questions is, 'Confirmation that TCAS/ACAS II is installed and operating in all aeroplanes that are required to have it, and that crew training reflects policies contained in TGL 11. (See Operations Manual Volume D)': and the operator is obliged to open the manual and show where this forms part of the training schedule.
What I have described above shows - I hope - that ICAO has indeed addressed the issue of training in the use of ACAS/TCAS, and that the European Nations (JAA Member States) have taken this forward and have sought to 'close the loop' by ensuring that this vital information reaches those who need to know how to use TCAS II. I'm not pretending that the system is perfect or that it cannot be improved, but I think it right that readers should know that ICAO and some authorities have not ignored this vital subject.
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Standard_Departure ..."From The ATC Side"
No need to belabor the technical parameters of TCAS, because when an RA is commanded it's because ATC already has failed in its traffic separation duties.
Because of the delayed descent of one airplane, and therefore because of obvious questionable vertical separation, as "extra insurance," the controller's duty should have included vectors for lateral separation.
Just four words to each airplane would have insured positive separation and would have saved the day.
DHL, IMMEDIATE LEFT TURN
BASHKIRIAN, IMMEDIATE RIGHT TURN
No need to belabor the technical parameters of TCAS, because when an RA is commanded it's because ATC already has failed in its traffic separation duties.
Because of the delayed descent of one airplane, and therefore because of obvious questionable vertical separation, as "extra insurance," the controller's duty should have included vectors for lateral separation.
Just four words to each airplane would have insured positive separation and would have saved the day.
DHL, IMMEDIATE LEFT TURN
BASHKIRIAN, IMMEDIATE RIGHT TURN
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Would have, could have and should have...
It's always easy to have a better solution at hand in the aftermath.
Besides, if you want two acft on a crossing track to avoid each other, you either turn both left or both right.
To turn one left and the other right would have probably just delayed the crash...
It's always easy to have a better solution at hand in the aftermath.
Besides, if you want two acft on a crossing track to avoid each other, you either turn both left or both right.
To turn one left and the other right would have probably just delayed the crash...
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IMHO Lateral actions at one minute to meeting point and at upper airspace is really bad idea, you were already too late, but it case all the things went wrong and totally lost contact or comm. you rather choose parallel heading instruction to remaining under control traffic, but should note, not a point in our mentioned case.
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HugMonster, I've been an ATCO for 14 years, so I believe I know what I'm talking about.
Turning both aircraft left or right is basic business when solving a crossing-track-at-same-level situation, and it would also apply, when issuing an avoiding action, and, as you've stated correctly, also head-on conflictions.
Turning both aircraft left or right is basic business when solving a crossing-track-at-same-level situation, and it would also apply, when issuing an avoiding action, and, as you've stated correctly, also head-on conflictions.
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Glueball,
I thought I had perhaps explained myself badly, but after re-reading my post, I found that my point was as I intended it.
Perhaps you could also read it again, and see for yourself.
Regards
SID
I thought I had perhaps explained myself badly, but after re-reading my post, I found that my point was as I intended it.
Perhaps you could also read it again, and see for yourself.
Regards
SID
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Sky9 : Remember difference between TA and RA is max 13 seconds ( above FL200 with SL7, 48 sec versus 35 ) or a litle more than one radar return.
On the turning issue :
Turning both aircraft a min of 30 degr to avoid collision is still very effective , even at short range.
In the ZRH collision this would have worked , even 30 sec before , both a/c would have been cleared by more than 1NM . If the turns would have been combined with the descent clearance as the one issued, they would have had 700 ft vertical as well.
But of course afterwards everyone is wiser...
On the turning issue :
Turning both aircraft a min of 30 degr to avoid collision is still very effective , even at short range.
In the ZRH collision this would have worked , even 30 sec before , both a/c would have been cleared by more than 1NM . If the turns would have been combined with the descent clearance as the one issued, they would have had 700 ft vertical as well.
But of course afterwards everyone is wiser...
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Condolences to all souls on board both DHL and Bashkirian aircraft.
I was sitting in the office at work with my collegue watching the news and the events that then unfolded in the following hours and days.
When I was back on shift with him later I made a point of saying that I was sure the delay of the crew on-board the Bashkirian was due to the fact that he was in utter confusion as to whether to follow TCAS or ATC instruction.
Excuse my ignorance but isn't the training given in Instrument flying to rely 100% totally on your instruments? Or do ATC have the ability and power to give instruction over them?
Maybe this just goes to show how good the TCAS technology is and that close RVSM in airspace needs to be computer controlled, with no human intervention!
I was sitting in the office at work with my collegue watching the news and the events that then unfolded in the following hours and days.
When I was back on shift with him later I made a point of saying that I was sure the delay of the crew on-board the Bashkirian was due to the fact that he was in utter confusion as to whether to follow TCAS or ATC instruction.
Excuse my ignorance but isn't the training given in Instrument flying to rely 100% totally on your instruments? Or do ATC have the ability and power to give instruction over them?
Maybe this just goes to show how good the TCAS technology is and that close RVSM in airspace needs to be computer controlled, with no human intervention!
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Official Statement
It seems now that the Russian Crew is to be mainly blamed.
From the Official BFU website:
Press release
Mid-air collision near Lake of Constance
2002-07-19 10:00 MESZ
08:00 UTC
Status of the investigation
The readings of the Flight Data Recorder and Cockpit Voice Recorder were undertaken at BFU. The data collection process is basically completed; the final analysis of all facts will be done in due course.
These facts, to a great extent, confirm earlier information released, but some changes in the sequence of events are evident as more accurate information from various sources has become available:
The Flight Data Recorders reveal no technical problems on either aircraft.
Both aircraft were fitted with the same collision warning system (TCAS; Honeywell 2000) with identical modification state. The functioning of both units was correct and as designed.
The flight paths of the aircraft were at right angles with respect to each other. Where as the Boeing 757 was on a northerly course (heading 004o), the Tupolev 154 was on westerly course (heading 274o).
The collision occurred at around 35 000 feet (FL350). A more precise altitude fix is not possible at this time.
The recordings suggest that a few seconds before the collision, both crews have detected the other aircraft, and reacted to avoid the collision by attempting appropriate flight manoeuvres.
According to the basic findings the sequence of events was:
Time
Event
23:34:42 hrs
The TCAS systems onboard both aircraft warns of a potential conflict traffic.
23:34:49 hrs
Air Traffic Control in Zurich instructs the crew of the Tupolev to descend quickly ("expedite") to 35 000 feet (FL 350); this instruction also advises of a conflict with other traffic. There is no reply to this instruction.
23:34:56 hrs
The crews of both aircraft receive a command ("Resolution Advisory") from their TCAS system to take evasive action. The crew of the Boeing receive a command to descend, while the crew of the Tupolev receive a command to climb.
The crew of the Boeing follow their command without delay; and the Tupolev remains in cruising flight at FL360.
23:35:03 hrs
The radar controller at Zurich repeats the instruction for the crew of the Tupolev to expedite a descend to 35 000 feet (FL350). This instruction is acknowledged by the crew and descent is initiated soon after. Immediately after these calls, the radar controller advise of other traffic in the 2 o‘clock position.
23:35:10 hrs
The crew of the Boeing receive a command ("Resolution Advisory") from the TCAS system to increase their rate of descent ("increase descent").
23:35:19 hrs
The crew of the Boeing reports to the controller that they are descending in accordance with a command from the TCAS system ("TCAS descent").
23:35:24 hrs
The crew of the Tupolev receive a command ("Resolution Advisory") from the TCAS system to increase their rate of climb ("increase climb").
23:35:32 hrs
Collision of the aircraft.
So it seems that the russian crew did not react to the TCAS RA with preference to the ATC instruction.
From the Official BFU website:
Press release
Mid-air collision near Lake of Constance
2002-07-19 10:00 MESZ
08:00 UTC
Status of the investigation
The readings of the Flight Data Recorder and Cockpit Voice Recorder were undertaken at BFU. The data collection process is basically completed; the final analysis of all facts will be done in due course.
These facts, to a great extent, confirm earlier information released, but some changes in the sequence of events are evident as more accurate information from various sources has become available:
The Flight Data Recorders reveal no technical problems on either aircraft.
Both aircraft were fitted with the same collision warning system (TCAS; Honeywell 2000) with identical modification state. The functioning of both units was correct and as designed.
The flight paths of the aircraft were at right angles with respect to each other. Where as the Boeing 757 was on a northerly course (heading 004o), the Tupolev 154 was on westerly course (heading 274o).
The collision occurred at around 35 000 feet (FL350). A more precise altitude fix is not possible at this time.
The recordings suggest that a few seconds before the collision, both crews have detected the other aircraft, and reacted to avoid the collision by attempting appropriate flight manoeuvres.
According to the basic findings the sequence of events was:
Time
Event
23:34:42 hrs
The TCAS systems onboard both aircraft warns of a potential conflict traffic.
23:34:49 hrs
Air Traffic Control in Zurich instructs the crew of the Tupolev to descend quickly ("expedite") to 35 000 feet (FL 350); this instruction also advises of a conflict with other traffic. There is no reply to this instruction.
23:34:56 hrs
The crews of both aircraft receive a command ("Resolution Advisory") from their TCAS system to take evasive action. The crew of the Boeing receive a command to descend, while the crew of the Tupolev receive a command to climb.
The crew of the Boeing follow their command without delay; and the Tupolev remains in cruising flight at FL360.
23:35:03 hrs
The radar controller at Zurich repeats the instruction for the crew of the Tupolev to expedite a descend to 35 000 feet (FL350). This instruction is acknowledged by the crew and descent is initiated soon after. Immediately after these calls, the radar controller advise of other traffic in the 2 o‘clock position.
23:35:10 hrs
The crew of the Boeing receive a command ("Resolution Advisory") from the TCAS system to increase their rate of descent ("increase descent").
23:35:19 hrs
The crew of the Boeing reports to the controller that they are descending in accordance with a command from the TCAS system ("TCAS descent").
23:35:24 hrs
The crew of the Tupolev receive a command ("Resolution Advisory") from the TCAS system to increase their rate of climb ("increase climb").
23:35:32 hrs
Collision of the aircraft.
So it seems that the russian crew did not react to the TCAS RA with preference to the ATC instruction.
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Not sure we can 'mainly' blame the Russian crew. The prime cause seems to be that ATC did not provide the appropriate separation, which is why we are all supposed to be doing the job after all. My own opinion is that ATC will take the rap as the main cause, compounded by the inappropriate actions of the Tupolev pilot.
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Immediately after these calls, the radar controller advise of other traffic in the 2 o‘clock position.
---
Advised WHOM? The DHL was at 10-11 o'clock for Tupolev and if he was addressing the DHL - WHY didn't he give them any FL clearance?
---
Advised WHOM? The DHL was at 10-11 o'clock for Tupolev and if he was addressing the DHL - WHY didn't he give them any FL clearance?
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Second on that.
BFU remains to give a word from transcript, “the radar controller advise of other traffic in the 2 o‘clock position” – it looks well unclear for me, should we made any decision based on that press release except time schedule …
BFU remains to give a word from transcript, “the radar controller advise of other traffic in the 2 o‘clock position” – it looks well unclear for me, should we made any decision based on that press release except time schedule …
The Reverend
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Ruslan,Tovarich, I'm sorry but:
23:34:56 hrs
The crews of both aircraft receive a command ("Resolution Advisory") from their TCAS system to take evasive action. The crew of the Boeing receive a command to descend, while the crew of the Tupolev receive a command to climb.
The crew of the Boeing follow their command without delay; and the Tupolev remains in cruising flight at FL360.
23:35:03 hrs
The radar controller at Zurich repeats the instruction for the crew of the Tupolev to expedite a descent to 35 000 feet (FL350). This instruction is acknowledged by the crew and descent is initiated soon after. Immediately after these calls, the radar controller advise of other traffic in the 2 o‘clock position.
Radar update time 12 seconds; too late. ATC should have resolved this potential conflict in good time to avoid the collision but they didn't. Tu-154 crew should have obeyed their TCAS RA but they didn't. May they all rest in peace and may all of us have learnt a lesson you could not pay for.
23:34:56 hrs
The crews of both aircraft receive a command ("Resolution Advisory") from their TCAS system to take evasive action. The crew of the Boeing receive a command to descend, while the crew of the Tupolev receive a command to climb.
The crew of the Boeing follow their command without delay; and the Tupolev remains in cruising flight at FL360.
23:35:03 hrs
The radar controller at Zurich repeats the instruction for the crew of the Tupolev to expedite a descent to 35 000 feet (FL350). This instruction is acknowledged by the crew and descent is initiated soon after. Immediately after these calls, the radar controller advise of other traffic in the 2 o‘clock position.
Radar update time 12 seconds; too late. ATC should have resolved this potential conflict in good time to avoid the collision but they didn't. Tu-154 crew should have obeyed their TCAS RA but they didn't. May they all rest in peace and may all of us have learnt a lesson you could not pay for.
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To HotDog:
no need to argue with you here, you're absolutely right.
The problem is as follows -
Where as the Boeing 757 was on a northerly course (heading 004o), the Tupolev 154 was on westerly course (heading 274o).
Telling the Tu pilots they had crossing traffic at two o'clock could've been DEADLY wrong - they seem to spend their last seconds looking for Boeing from the right, not from the left...
no need to argue with you here, you're absolutely right.
The problem is as follows -
Where as the Boeing 757 was on a northerly course (heading 004o), the Tupolev 154 was on westerly course (heading 274o).
Telling the Tu pilots they had crossing traffic at two o'clock could've been DEADLY wrong - they seem to spend their last seconds looking for Boeing from the right, not from the left...
Props are for boats!
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Ok Hotdog your chain of events sounds fairly reasonable, except for one point. Radar update time, on modern Air Traffic Radars, is around 4-5 seconds, most radar heads spin at 12RPM which equates to a pass every four secs. Take a look at your reply light on your TXPDR one day, when your flying and time it ( assuming you are in a solementry RADAR environ). 
This makes the argument even far worse for the Controllers eh!
EX RAAF GRND TECHO TEN YEARS.
This makes the argument even far worse for the Controllers eh!
EX RAAF GRND TECHO TEN YEARS.
Last edited by Sheep Guts; 19th Jul 2002 at 15:26.
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Hi Sheep Guts
The above mentioned statements are correct. The update rate of the mosaic radar pic in Zurich is every 12 secs (which is less than the european average of 10 secs I think, but dont fix me on that.). Mosaic in this case means, that several radars are taking their sweps, feeding a computer which is approximating every aircrafts position. Approach radar which relies only on one radar update every 4 to 6 secs. Therefore the APP controller provides 3NM separation instead of the 5 to 6 NM in ACC.
It's already some 8 years, that I am on the airborn side of the radio. But I hope the facts are still about correct.
Fly safely
The above mentioned statements are correct. The update rate of the mosaic radar pic in Zurich is every 12 secs (which is less than the european average of 10 secs I think, but dont fix me on that.). Mosaic in this case means, that several radars are taking their sweps, feeding a computer which is approximating every aircrafts position. Approach radar which relies only on one radar update every 4 to 6 secs. Therefore the APP controller provides 3NM separation instead of the 5 to 6 NM in ACC.
It's already some 8 years, that I am on the airborn side of the radio. But I hope the facts are still about correct.
Fly safely
Missed Opportunities All Round
I expect Skyguide management will be found with the most responsibility as you can't expect always perfect performance from a single controller when both the conflict alert and several telephone lines are unavailable.
Subject to further CVR releases, it looks so far to me that everybody involved missed opportunities to avoid collision.
26 seconds elapsed after the initial RA before DHL advised ATC of its TCAS descent. During that time DHL must have heard ATC ordering the Russians to descend. If DHL had advised ATC sooner or asked if the other a/c had received a TCAS alert, the accident chain might have been broken.
And it would definitely have helped if the Russians had reported their Climb RA before accepting the descent instruction from ATC.
And there were 14 seconds from TA to RA where neither crew advised ATC about TCAS. That doesn't give ATC much time to sort things out, but it may clue him to let TCAS sort out the altitudes while he can help out with turns -- mind you, both crews may be more urgently occupied.
We've all had a couple weeks to pick over the TAs, RAs, FDRs and CVRs. They had less than minute and had the misfortune to zig when they should have zagged.
Subject to further CVR releases, it looks so far to me that everybody involved missed opportunities to avoid collision.
26 seconds elapsed after the initial RA before DHL advised ATC of its TCAS descent. During that time DHL must have heard ATC ordering the Russians to descend. If DHL had advised ATC sooner or asked if the other a/c had received a TCAS alert, the accident chain might have been broken.
And it would definitely have helped if the Russians had reported their Climb RA before accepting the descent instruction from ATC.
And there were 14 seconds from TA to RA where neither crew advised ATC about TCAS. That doesn't give ATC much time to sort things out, but it may clue him to let TCAS sort out the altitudes while he can help out with turns -- mind you, both crews may be more urgently occupied.
We've all had a couple weeks to pick over the TAs, RAs, FDRs and CVRs. They had less than minute and had the misfortune to zig when they should have zagged.