Pilots and ATC both at fault in TCAS incident
Pegase Driver
Low Vis RTO , in the absolute, I fully agree with you: humans are , and by far, superiors to computers as far as decision making is concerned. . However for monitoring processes, computers are, also by far, superiors to humans. I hope you can agree on this.
TCAS is basically for 80% a monitoring system ( checking the altitude reports of the Mode C and S transponders around you, coupled with a basic azimuth detection ). The remaining 20% is an algorithm issuing TAs and RAs when the system detects a collision risk.
This 20% is the problem as it mixes computer generated logic ( an RA) needed to be followed immediately with a human analytic mind (pilot) decision/action .This does not work well .
After many years (more than 25 to be precise)of testing and evaluation , the current version we have (7.0) dictates that to be most effective, initial RAs have to be followed within 5 sec and corrective RAs within 2,5 sec. This leaves very little time to analyze the situation and decide to follow it or not.
The many TCAS incidents I saw up to now, indicate that those pilots, when confronted with a sudden computer “ advice “ ( as an RA is in the current definition) trend to evaluate the options, try to make visual acquisition, take into account the last ATC clearance received, etc.. and , in those incidents, decide to follow their own logic , even if it means disregarding the RA or, worse, if it is opposed to the TCAS RA issued.
The pattern is recurrent, even after Ueberlingen. Until a couple of years ago, I also believed that the problem was lack of ACAS understanding and foremost lack of Training , and I pushed, like everyone else, for more training and for unified,, mandatory simplified guidelines and procedures.
Now, years later , the percentage of TCAS incidents involving pilots not following or acting against RAs has not changed much, it is still extremely high. Therefore I also, like many of my colleagues, now start to believe that coupling the ACAS to the AP is probably the best solution.Especially in the upper airspace ( let's say above 20.000 ft)
At this altitude , all the AP will probably do in most cases, is make an altitude change on 4 to 500 ft max with 0,25 G , but most importantly in the correct sense . That alone will prevent a metal to metal encounter, which is afer all what we expect this system to do.
I fear that we sadly will have to wait until another Ueberlingen type collision before the minds are ready to accept the AP coupling solution. But that is often the case in many other industries as well .
Ah, before you ask, I am not, even remotely, involved with Airbus . I just think they are correct is their thinking on that issue.
TCAS is basically for 80% a monitoring system ( checking the altitude reports of the Mode C and S transponders around you, coupled with a basic azimuth detection ). The remaining 20% is an algorithm issuing TAs and RAs when the system detects a collision risk.
This 20% is the problem as it mixes computer generated logic ( an RA) needed to be followed immediately with a human analytic mind (pilot) decision/action .This does not work well .
After many years (more than 25 to be precise)of testing and evaluation , the current version we have (7.0) dictates that to be most effective, initial RAs have to be followed within 5 sec and corrective RAs within 2,5 sec. This leaves very little time to analyze the situation and decide to follow it or not.
The many TCAS incidents I saw up to now, indicate that those pilots, when confronted with a sudden computer “ advice “ ( as an RA is in the current definition) trend to evaluate the options, try to make visual acquisition, take into account the last ATC clearance received, etc.. and , in those incidents, decide to follow their own logic , even if it means disregarding the RA or, worse, if it is opposed to the TCAS RA issued.
The pattern is recurrent, even after Ueberlingen. Until a couple of years ago, I also believed that the problem was lack of ACAS understanding and foremost lack of Training , and I pushed, like everyone else, for more training and for unified,, mandatory simplified guidelines and procedures.
Now, years later , the percentage of TCAS incidents involving pilots not following or acting against RAs has not changed much, it is still extremely high. Therefore I also, like many of my colleagues, now start to believe that coupling the ACAS to the AP is probably the best solution.Especially in the upper airspace ( let's say above 20.000 ft)
At this altitude , all the AP will probably do in most cases, is make an altitude change on 4 to 500 ft max with 0,25 G , but most importantly in the correct sense . That alone will prevent a metal to metal encounter, which is afer all what we expect this system to do.
I fear that we sadly will have to wait until another Ueberlingen type collision before the minds are ready to accept the AP coupling solution. But that is often the case in many other industries as well .
Ah, before you ask, I am not, even remotely, involved with Airbus . I just think they are correct is their thinking on that issue.
Join Date: Aug 2008
Location: Australia
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
Computer's and Automation's Logical Conclusion
The many TCAS incidents I saw up to now, indicate that those pilots, when confronted with a sudden computer “ advice “ ( as an RA is in the current definition) trend to evaluate the options, try to make visual acquisition, take into account the last ATC clearance received, etc.. and , in those incidents, decide to follow their own logic , even if it means disregarding the RA or, worse, if it is opposed to the TCAS RA issued.
The 'swimming in cold syrup' when an emergency occurs is a symptom of the lack of recency training. Well trained and recent pilots have no problems with what to do, and do it correctly time after time. A few do not. If it weren't for the passengers and cabin crew that they take with them, it's not a bad thing to cleanse the gene pool of such deep but self-effacing thinkers. Because of the few, must we assume all pilots are incapable of functioning properly and hand the reins over to computers and automation?
On account of the lowest common denominator among us pilots (eg the poorly trained ones), you may well be right about the AP being part of the solution in the future. But, having said that, the same sort of individuals, with certainty, will disconnect the autopilot during a TCAS RA while saying something akin to, "what is it doing now?" Try as one may, "You will never make the cockpit idiot proof".
With computerization and automation carried to their logical conclusions, we will have fully automated computer controlled takeoff, climb, cruise, TCAS avoidance, descent and landing, all without the need for a pilot. And ATC could uplink active CPDLC commands and fly the bugger from their comfortable swivel chairs on the ground like the various air forces do with their drones.
We have a name for such aircraft. They're called ICBM s (Inter-Continental Ballistic Missiles). I wouldn't allow my family to passenger on one, nor are you likely to allow your family on such an aircraft. There has to be a human pilot at the controls for safety. Safety will never be 100% as much as we would like it to be. That's not the world we live in.
Having run completely off the road and into the field of extremes, I rest my case for now. All this for a simple TCAS RA and the mere mention of an autopilot? LOL. Cheers. ;>)
Last edited by LowVizRTO; 23rd Aug 2008 at 14:53.
Join Date: Mar 2008
Location: Malaysia
Posts: 20
Likes: 0
Received 0 Likes
on
0 Posts
Hi All
Airbus procedure to switch BOTH FDs OFF is to revert the AutoThrust to SPEED mode. SPEED mode? Well, Airbus pilots should know. Otherwise better get your book out and study them. No FDs? No worries because the VSI is the main instrument/cue. Just fly to the green zone. Simple. Once clear of conflict, reverse the RA procedures. 1. FDs ON. 2. A/P ON. Please do not compare Boeing, Cessna or Bombadier procedures with Airbus. There are of different make and philosophy. Cheers!
Airbus procedure to switch BOTH FDs OFF is to revert the AutoThrust to SPEED mode. SPEED mode? Well, Airbus pilots should know. Otherwise better get your book out and study them. No FDs? No worries because the VSI is the main instrument/cue. Just fly to the green zone. Simple. Once clear of conflict, reverse the RA procedures. 1. FDs ON. 2. A/P ON. Please do not compare Boeing, Cessna or Bombadier procedures with Airbus. There are of different make and philosophy. Cheers!
LVRTO,
I understand where you're coming from, but when you write software or design a control system which has a safety related function you have to design it assuming that the "human link" is going to fail, for whatever reason....
I'm a low hour student pilot...so no expert. But if the response to an RA is always "disconnect the autopilot, switch off the FDs and fly as advised" then surely an automatic AP/FD disconnect simply means that's something additional which the pilot doesn't have to waste their time doing? I know people don't like it when there's too much control given over to the computer (even I'm wary of this, and I'm a controls engineer), but simply doing something which a pilot always has to do anyway is just saving time and thought processes, allowing them to concentrate on pushing/pulling the yoke and maintaining control of the a/c.
Please let me know if I've missed something or have misunderstood!
I understand where you're coming from, but when you write software or design a control system which has a safety related function you have to design it assuming that the "human link" is going to fail, for whatever reason....
I'm a low hour student pilot...so no expert. But if the response to an RA is always "disconnect the autopilot, switch off the FDs and fly as advised" then surely an automatic AP/FD disconnect simply means that's something additional which the pilot doesn't have to waste their time doing? I know people don't like it when there's too much control given over to the computer (even I'm wary of this, and I'm a controls engineer), but simply doing something which a pilot always has to do anyway is just saving time and thought processes, allowing them to concentrate on pushing/pulling the yoke and maintaining control of the a/c.
Please let me know if I've missed something or have misunderstood!
Join Date: Aug 2008
Location: Australia
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
TCAS & Autopilot/Computerization
Please let me know if I've missed something or have misunderstood!
However, the jury is still well and truly out for me (and most other pilots) as far as the AP automatically flying an RA maneuver on its own. The aversion is not to automation making the job easier, but to being relegated to SLF (self loading freight) status by computers flying in loose formation.
If my understanding is correct about history, the early Airbuses killed some of their own test pilots because of the priority given to the computers over the pilot's control input. Airbus learned that lesson the hard way because the engineers had too much control over the final design. Pilots (humans) are indispensable to the safe operation of commercial aircraft. At the risk of repeating myself from an earlier post, computers are not afraid to die - pilots are; and so pilots will do whatever it takes to stay alive. Unfortunately, they do get tired, fatigued and tend toward laziness and occasionally overlook things. This is where the rub occurs. Just trying to be realistic here.
Having said that, there have been some tremendous advances in automation over the years to make the job of the pilot much easier and do the heavy lifting of monitoring and taking initial action steps in the event of an emergency. The latter improvements did away with the Flight Engineer requirement altogether. Where does computerization and automation stop though? Can we fly with only one pilot in a commercial aircraft in the near future, or without any pilots whatsoever?
Maybe it stops only after thousands of people are killed by the computers flying aircraft into each other, following the logic of engineers that can't possibly think of everything that could possibly ever happen. Interestingly enough, the accident, incident and death rates are the very same reasons for taking the pilot out of the loop now. Hopefully some common sense, which seems to be not so common anymore, will prevail before the above scenario comes to fruition. Please do not misunderstand me here, I am not taking a shot at you or anyone else - I'm being far more global than that.
I've even considered the possibility that I'm suffering from Alvin. Toffler's 'Future Shock', or just passed my 'use by date', but I'm certainly not senile or stupid. There are natural limits to the human being's capacity, as there there are natural limits to computerization. We need to go slowly down that slippery slope is all I'm saying.
This discussion brings to mind the old joke about this very issue on future aircraft designs. It goes like this:
'The totally computerized aircraft of the future will have one pilot and one large dog. Everything will be fully automated and the pilot only needs to monitor the progress - the computers do everything from takeoff, cruise, descend and land. "What you may ask, is the role of the dog?" The dog is there to bite the pilot if he touches anything.'
Thanks for that LVRTO. I entirely agree with you. I wouldn't be in a hurry to get on a fully automated aircraft....I still get nervous on the Docklands Light Railway.
Join Date: Aug 2008
Location: Australia
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
FDs Off during TCAS RAs on Airbus aircraft
The below quote is word for word copy-pasted out of Airbus A330 FCOM 1.
Because there seems to be some confusion or incredulity that the FD left on makes any difference in an Airbus TCAS RA maneuver, hopefully this will put it to rest. Unless you have been trained on Airbus, you wouldn't have any frame of reference to such interrelationships on the Bus. It is a different kettle of fish to other aircraft manufacturers, and it works just fine, albeit differently.
Effectively, what happens when you descend off a cruise altitude with A/P off and FD(s) on, the thrust will increase resulting in higher speeds than desirable. Conversely, climbing with the A/P off and FD(s) on, the thrust will decrease reducing speeds to lower than that desirable.
With both A/Ps and both FDs off, the AutoThrust reverts to Speed mode and maintains the correct thrust for the current Speed/Mach whether in a descent or climb throughout the TCAS maneuvers.
There is no question that the FDs have to be turned off in a TCAS RA maneuver, and not just because Airbus says so - there's very good reason for doing it. Whether that occurs automatically (which is currently not programmed in Airbus) or occurs manually (which is the current Airbus procedure for dealing with a TCAS RAs), it doesn't matter, the FDs have to be turned off to avoid a potentially dangerous secondary situation from developing during a TCAS RA maneuver.
The quote below from the A330 FCOM 1 demonstrates that automatic disengagement and removal of the FDs currently occur in various situations, and so would more than likely not be a major issue to include the FD removal during TCAS RAs.
Although this is bit of a rabbit trail, I hope this is of some interest to those who have no Airbus technical exposure. Fellow 'Bus drivers' already know this in spades.
Cheers, LowVizRTO
– If no AP/FD pitch mode is engaged, the A/THR mode reverts to SPD/MACH mode. In other words, the selection of a pitch mode determines the associated A/THR mode.
Effectively, what happens when you descend off a cruise altitude with A/P off and FD(s) on, the thrust will increase resulting in higher speeds than desirable. Conversely, climbing with the A/P off and FD(s) on, the thrust will decrease reducing speeds to lower than that desirable.
With both A/Ps and both FDs off, the AutoThrust reverts to Speed mode and maintains the correct thrust for the current Speed/Mach whether in a descent or climb throughout the TCAS maneuvers.
There is no question that the FDs have to be turned off in a TCAS RA maneuver, and not just because Airbus says so - there's very good reason for doing it. Whether that occurs automatically (which is currently not programmed in Airbus) or occurs manually (which is the current Airbus procedure for dealing with a TCAS RAs), it doesn't matter, the FDs have to be turned off to avoid a potentially dangerous secondary situation from developing during a TCAS RA maneuver.
The quote below from the A330 FCOM 1 demonstrates that automatic disengagement and removal of the FDs currently occur in various situations, and so would more than likely not be a major issue to include the FD removal during TCAS RAs.
AUTOMATIC DISENGAGEMENT DUE TO SPEED PROTECTION
When APs are not engaged and if you do not fly the FD bars, an automatic disengagement of FDs and corresponding FMA modes will occur if the aircraft speed reaches VMAX in climb with CLB or OP CLB mode engaged or if the aircraft speed decreases to VLS in descent with DES, OP DES mode engaged.
Refer to Automatic speed protection in this chapter.
AUTOMATIC FD REMOVAL
– The FD pitch bar is removed when no vertical mode is engaged or when ROLL OUT is engaged.
– The roll FD bar is removed when no lateral mode is engaged or when the RWY or ROLL OUT mode is engaged.
– Both FDs are removed when the aircraft pitch exceeds 25° up or 13° down, or bank angle exceeds 45°.
When APs are not engaged and if you do not fly the FD bars, an automatic disengagement of FDs and corresponding FMA modes will occur if the aircraft speed reaches VMAX in climb with CLB or OP CLB mode engaged or if the aircraft speed decreases to VLS in descent with DES, OP DES mode engaged.
Refer to Automatic speed protection in this chapter.
AUTOMATIC FD REMOVAL
– The FD pitch bar is removed when no vertical mode is engaged or when ROLL OUT is engaged.
– The roll FD bar is removed when no lateral mode is engaged or when the RWY or ROLL OUT mode is engaged.
– Both FDs are removed when the aircraft pitch exceeds 25° up or 13° down, or bank angle exceeds 45°.
Cheers, LowVizRTO
Last edited by LowVizRTO; 26th Aug 2008 at 15:01.
Don't want the AP to fly an RA ie gentle wings-level push down or pull up over a few hundred feet but are quite happy to let it take you to within metres of the ground in complete IMC. Something not logical there. Let's face it, following an RA would hardly be rocket science for a FD/AP.
An RA is an emergency manoeuvre that could spring up at any time with very little notice, perhaps preceded by "Traffic Traffic". I for one would be quite happy to let the AP do it. Had the Russian jet had this feature (I know that particular model couldn't have due to old technology, but had it been a modern jet...), all would have lived. This is one scenario where a crew's instant reaction was completely wrong and automation would have saved the day.
Man will still have his place in the cockpit way past the time when you and I retire. But I'm for APs to follow RAs.
An RA is an emergency manoeuvre that could spring up at any time with very little notice, perhaps preceded by "Traffic Traffic". I for one would be quite happy to let the AP do it. Had the Russian jet had this feature (I know that particular model couldn't have due to old technology, but had it been a modern jet...), all would have lived. This is one scenario where a crew's instant reaction was completely wrong and automation would have saved the day.
Man will still have his place in the cockpit way past the time when you and I retire. But I'm for APs to follow RAs.
Join Date: Aug 2008
Location: Australia
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
APs and RAs
Man will still have his place in the cockpit way past the time when you and I retire. But I'm for APs to follow RAs.
Capn Bloggs, what do you do with such failures of the TCAS systems when you hook an AP up, to vault one way of the other at will, and possibly into oncoming traffic in RVSM airspace just 1000' above or below you?
Auto FD's off - YES. Auto AP maneuvers - NO thank you.
Cheers, LowVizRTO
Join Date: Mar 2006
Location: Southern Turkey
Age: 82
Posts: 171
Likes: 0
Received 0 Likes
on
0 Posts
There's a simple formula to calculate the pitch change required to achieve the climb or descent required for a RA: 1000/TAS (in knots) = Pitch Change. I used to train all my pilots to be aware of their approx TAS at all times in readiness. The maximum pitch change is obviously at low speeds and in an intermediate approach phase usually around 5-7 degrees. 5 seconds to adjust 7 degrees is not aerobatic and hardly enough to spill coffee. At high level cruising speeds the pitch change required is usually in the order of 1-2 degrees. When properly executed by both conflicting aircraft (initially in level flight) an RA should not cause either aircraft to diverge more than about 300 feet (i.e. they miss by 600 feet vertically).
The above info was true for TCAS II - maybe things have moved on since I retired 4 years ago - if so I'm happy to stand corrected.
This incident was a GROSS over-reaction by the crew - don't they practice RAs in the simulator? In my last (cargo) airline all pilots had thorough initial TCAS training and testing and regular refreshers during LOFT sim exercises. I always thought both TCAS and windshear training served a useful secondary purpose in refreshing crews in the effects of controls (not coupled to an AP for a change).
The above info was true for TCAS II - maybe things have moved on since I retired 4 years ago - if so I'm happy to stand corrected.
This incident was a GROSS over-reaction by the crew - don't they practice RAs in the simulator? In my last (cargo) airline all pilots had thorough initial TCAS training and testing and regular refreshers during LOFT sim exercises. I always thought both TCAS and windshear training served a useful secondary purpose in refreshing crews in the effects of controls (not coupled to an AP for a change).
Last edited by rodthesod; 26th Aug 2008 at 17:11. Reason: grammar
Join Date: Jan 2001
Location: Isle of Wight, UK.
Posts: 35
Likes: 0
Received 0 Likes
on
0 Posts
Having been on an aircraft that had a TACAS RA ( http://www.pprune.org/rumours-news/2...166-tampa.html ) can I just say that as SLF I would rather suffer a few bumps and bruises than collide with another aircraft, I am sure that any Captain on receving that instruction for real would be very keen to take the nessesary action and quickly.
I am still very gratefull to the Captain of that aircraft, heavy handed or not for he may well have saved my life!
MP
I am still very gratefull to the Captain of that aircraft, heavy handed or not for he may well have saved my life!
MP
LowViz,
Fair enough, but I can't see what erroneous RAs have to do with the method of following them. I hope you are not suggesting that pilots assess whether the RA is valid and then follow it if they believe it is?
Again, I hope you are not suggesting pilots make up their own minds about the validity of an RA before following it. A typical RA would not use more than 500ft of altitude (unless the aircraft is already climbing and descending) and therefore the "third party" aircraft would still be adequately separated. I would expect that if it's TCAS thought there was an issue, it would issue an avoiding RA too. It is easy to create a scenario where TCAS would be overwhelmed, but in reality, does it happen often, and would we have been better off without it? I suspect the answer is "no".
It would also be interesting to know how many false RAs are now occcurring with Change 7 software.
Over the last ten years, i have had a half dozen FALSE TCAS RAs. Don't know why they happened but in several cases a TA rapidly progressed into RAs and we took the required maneuver but there was no one there, not visually, not on TCAS after the event and not on radar with ATC.
what do you do with such failures of the TCAS systems when you hook an AP up, to vault one way of the other at will, and possibly into oncoming traffic in RVSM airspace just 1000' above or below you?
It would also be interesting to know how many false RAs are now occcurring with Change 7 software.
Join Date: Aug 2008
Location: Australia
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
TCAS RA & A/Ps
Fair enough, but I can't see what erroneous RAs have to do with the method of following them. I hope you are not suggesting that pilots assess whether the RA is valid and then follow it if they believe it is?
Additionally, I have no idea on the TCAS 7 failure or false RA rates. I am not against automation per sea, just against hooking the A/P up to TCAS RAs. You're entitled to your own opinion which is opposite to mine. That's fine. I remain with others on this thread that the solution is more TCAS training in recurrent Simulator sessions and not A/Ps. From your comments, I don't expect you to agree, and that's fine as well. Best regards. LowVizRTO
Pegase Driver
It would also be interesting to know how many false RAs are now occcurring with Change 7 software.
The "false RAs" are due to many factors, one of them was identified to a perticular brand of transponder ( fixed by now I presume ), another with the antenna picking up responses by its own transponder : hence the sudden appearance of a red square with 00 and an RA Descend descend without prewarings (TAs) . These also should be eliminated by now. But we heard of some other cases, difficult to replicate .
Back to the AP coupling issue, as it was said earlier, if you have or suspect a false RA, you'd better follow it first and ask questions later. So the AP coupling idea is still valid , wether it is following a false RA or not.
The only problem I have with the AP coupling is let's say below 10.000 ft.
But, to be fair, in the upper airspace there is no valid reason , other than resistance due fears of automation, to have the AP move you 3 or 400 feet in any direction.
As someone else said very correctly, you have no problem on automation following an ILS signal down to the ground in near zero visibility, (and we know how easy it is to garble or bent an ILS signal !) so why not automatically following an RA ?
Join Date: Aug 2008
Location: Australia
Posts: 7
Likes: 0
Received 0 Likes
on
0 Posts
Good info TwoOneFour
ATC Watcher & Capn Bloggs - I currently fly CAT III A & CAT III B approaches both in the sim and 'in anger' but we're using two (2) APs coupled together in FAIL OPERATIONAL mode. B744s use three (3) APs for the same approach. CAT III B No DH has a 75 Meter visibility requirement and No cloud base DH, so I understand what you are saying about APs close to the ground, but still disagree.
Two or three APs engaged produces a huge difference in the margin of safety as compared to operating with only one AP. There's very good reasons why low viz approaches employ multiple (all the available) APs. So still not convinced guys. Cheers.
Collision risk demands rapid roll-out of new TCAS: analysis
As someone else said very correctly, you have no problem on automation following an ILS signal down to the ground in near zero visibility, (and we know how easy it is to garble or bent an ILS signal !) so why not automatically following an RA ?
Two or three APs engaged produces a huge difference in the margin of safety as compared to operating with only one AP. There's very good reasons why low viz approaches employ multiple (all the available) APs. So still not convinced guys. Cheers.
Interesting that both of the TCAS events that are to be fixed by revision 7.1 would not be occurring if the AP was allowed to respond to the RA.
The sooner the AP is allowed to manage RAs the better, IMO. It's now not if but when.
The sooner the AP is allowed to manage RAs the better, IMO. It's now not if but when.
Join Date: Jul 2008
Location: Sydney
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
While the FD could be automatically switched off during an RA and be an improvement for response time (possibly), I do not agree that the AP automatically following RAs is the answer. More TCAS RA Sim training is the answer.
Pegase Driver
This is getting interesting ;
LowvisRTO, thanks for the info on the 3 AP on CATIII, I was not aware of that. Indeed a big difference. However they will all 3 still be following an ILS signal, which is my opinion still the weakest link of the whole procedure.
Capn Bloggs : I agree with your last comment (not a question of “if” but “when” ) I think that with the next collision, the AP will most probably be mandated.
Magnet 77 : more training is the solution : we tried that, but it does not work, we are now more than 10 years after implementation and the percentage of “TCAS pilot errors” is still abnormally high. And , with TCAS you need everyone in the loop ( i.e. including the guy in front of you that you do not know ) trained with the same standards all around the world. Very , very difficult to accomplish.
Finally on the version 7.1 ( if they decide to call it that way ) my last info was that the FAA was against making it mandatory. ( as they would have to pay for it and they do not have a budget for this, plus some lawyers said that mandating a new version would be an admission that the previous versions were not safe , etc.. ) The European might do it , but not the USA.(in fact a repeat of the version 7.0 debate )
Whether this retrofit will be free (paid by Eurocontrol ?) or for a fee ( paid by the aircraft operator) is still under debate. But , the next collision will probably settle that issue as well. Sad, very sad.
LowvisRTO, thanks for the info on the 3 AP on CATIII, I was not aware of that. Indeed a big difference. However they will all 3 still be following an ILS signal, which is my opinion still the weakest link of the whole procedure.
Capn Bloggs : I agree with your last comment (not a question of “if” but “when” ) I think that with the next collision, the AP will most probably be mandated.
Magnet 77 : more training is the solution : we tried that, but it does not work, we are now more than 10 years after implementation and the percentage of “TCAS pilot errors” is still abnormally high. And , with TCAS you need everyone in the loop ( i.e. including the guy in front of you that you do not know ) trained with the same standards all around the world. Very , very difficult to accomplish.
Finally on the version 7.1 ( if they decide to call it that way ) my last info was that the FAA was against making it mandatory. ( as they would have to pay for it and they do not have a budget for this, plus some lawyers said that mandating a new version would be an admission that the previous versions were not safe , etc.. ) The European might do it , but not the USA.(in fact a repeat of the version 7.0 debate )
Whether this retrofit will be free (paid by Eurocontrol ?) or for a fee ( paid by the aircraft operator) is still under debate. But , the next collision will probably settle that issue as well. Sad, very sad.
Join Date: Jan 2008
Location: LONDON
Age: 51
Posts: 525
Likes: 0
Received 0 Likes
on
0 Posts
from a different angle...
I am purely SLF.... with a keen interest in aviation however as a software developer I have some questions to raise with the current discussion point of the a/p taking over.
Do we know if it has ever been simulated with the current a/p software that it would have coped adequately in a manner whereby firstly the situation was saved, secondly the pilot was able to quickly adapt to the change and whether it was an adequate response.
To explain the above, the first is obvious and the most critical as in no collision occured, the second is if the plane makes manouvers outside pilot control then when the pilot is expected to resume control there must be some sort of handover etc so the pilot knows exactly what occured. And my final was whether it was adequate i.e. was the response too extreme for what was required.
My basic understanding is that whilst on a/p there are a number of systems counter checking each other to come up with what is a considered acceptable manouvre, put in an emergency situation like this and you have those same systems crosschecking each other to see what is acceptable, add another plane into the equation and even more serious more than one then you have numerous systems cross checking their own paramters and not each others. I dont know enough to say that to leave it manually would be the best solution but at least if a visual ident can be made then the pilot would know at least where not to go.
Sorry but my understanding of TCAS is limited, I would hope they negotiate the best paths for avoidence between corrseponding planes on collission. If this is the case then it would make the a/p softwares (you never rely on a single set of code) easier to come to a decision.
I guess what I am saying is what seems like a perfectly reasonable request to avoid collision when handing control to the a/p can be over complicated by the different software each negotiating with each other which is the best solution. Combine that on two different platforms (planes) and should the software conflict without communicating with the opposing platform (plane) then in all possibility a collision may occur.
I have never looked at the software, so I would hope the above has already been addressed etc - just wondering if you pro's know more.
Do we know if it has ever been simulated with the current a/p software that it would have coped adequately in a manner whereby firstly the situation was saved, secondly the pilot was able to quickly adapt to the change and whether it was an adequate response.
To explain the above, the first is obvious and the most critical as in no collision occured, the second is if the plane makes manouvers outside pilot control then when the pilot is expected to resume control there must be some sort of handover etc so the pilot knows exactly what occured. And my final was whether it was adequate i.e. was the response too extreme for what was required.
My basic understanding is that whilst on a/p there are a number of systems counter checking each other to come up with what is a considered acceptable manouvre, put in an emergency situation like this and you have those same systems crosschecking each other to see what is acceptable, add another plane into the equation and even more serious more than one then you have numerous systems cross checking their own paramters and not each others. I dont know enough to say that to leave it manually would be the best solution but at least if a visual ident can be made then the pilot would know at least where not to go.
Sorry but my understanding of TCAS is limited, I would hope they negotiate the best paths for avoidence between corrseponding planes on collission. If this is the case then it would make the a/p softwares (you never rely on a single set of code) easier to come to a decision.
I guess what I am saying is what seems like a perfectly reasonable request to avoid collision when handing control to the a/p can be over complicated by the different software each negotiating with each other which is the best solution. Combine that on two different platforms (planes) and should the software conflict without communicating with the opposing platform (plane) then in all possibility a collision may occur.
I have never looked at the software, so I would hope the above has already been addressed etc - just wondering if you pro's know more.
