And how is this useful practice and instruction to be consolidated?
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Originally Posted by Chris Scott
During the first few years as a copilot you slowly adapt to the demands of the routine chores, and much of what was covered in the conversion is gradually forgotten. That is particularly unfortunate if you happen to be on long-haul, and lucky to get your one landing a month. Six-monthly checks are formalised, and the areas to be covered in the next programme are promulgated in advance for study and discussion. Apart from the mandatory items, such as rejected T/O and EFTO, the exercises tend to revolve around the complexities of systems failures. In the LOFT exercises, use of automatics during problem-solving tends (rightly) to be emphasised. There is little or no "fat" in the simulator schedule to permit ad-hoc flying practice for youngsters (or the oldies).
Originally Posted by Chris Scott
In line operations, the selective withdrawal of automatics I'm advocating is done at the captain's discretion, and with prior agreement. It should not be done at times when PNF workload is already high, which of course is more likely when one of the pilots is relatively inexperienced. It would not be programmed, formalised, or recorded; just regarded as a routine interlude of enjoyable self-development for the PF.
My perception is that the above is frowned upon in many airlines. And I think that there are primarily 2 reasons for what we see today. First – airlines are in the business of making money – and, as almost anyone can understand, training does not make money … it only costs – and those costs are both direct (instructor salaries, salaries of students, equipment and facilities costs, etc.) and indirect (loss of line flying – which is the only source of income, transportation costs of moving the “students” into and back home from the training site, costs of per diem, lodging, etc.). Second – airlines are loathe to provide more training than is required by the regulations. Why? Certainly cost is a significant driver, but I’m of the opinion that conducting training beyond what is required by rule could be seen by some as management recognition, or at least suspicion, of the existence of a sub-par capability, attitude, or ability on the part of existing crewmembers. So, simply by having regulatory required standards, lessens the willingness of some to continue to provide training beyond that required by rules. Some airlines in the US have adopted training under what has been described by the regulators as a voluntary program which has a unique characteristic … and that characteristic is taking advantage of building a training program with “alternative” training goals, “alternative” standards, and uses “alternative” training equipment, which can be extended to “alternatively approved” intervals. Personally, I think this situation is one that has resulted in airlines being able to save significant amounts of money, prompting the appropriate industry training managers to go to great lengths to compliment the regulatory authority for such “forward thinking” … which, of course, does not hurt the professional aspirations of those few regulatory officials ultimately responsible for such authorizations. The problem is, as I see it – and I’m not alone - is that having multiple sets of “alternative” standards applicable to “alternative” programs, each using “alternative” equipment, to complete “alternative” task assignments, on “alternative” recurrent schedules results in a “drifting away” from standardized expectations of performance and capabilities of these crewmembers, particularly pilots … all based on the economic value being contributed to the airline bottom line. I am not about to apologize for believing it appropriate that airlines pay their employees a just wage for the skills and abilities they must possess and demonstrate; that airlines should provide their employees frequent and meaningful training, both initially and on an appropriate recurring basis – using equipment and facilities that are appropriate for the tasks that must be accomplished; that airlines should provide equipment and facilities to provide transportation services to those who choose to use this particular method of transportation; that airlines should charge those who use those services a fee that will provide an adequate income to meet expenses AND meet whatever profit margin they deem appropriate. It simply cannot be expected that the employees, or the skills of those employees, should be expected to be sacrificed for competitive advantage over other similarly situated competitors. Of all of these components, the only ones that should be governed by rules and regulations are those of competency and capability – and they should be equally applied to all who choose to participate in this industry. To me, this means that the regulatory authority should require that all participants have, and be able to regularly demonstrate, that the required capabilities and competencies are, indeed, addressed and that each appropriate person has satisfactory knowledge and experience to regularly and correctly exhibit those competencies and capabilities whenever and where ever called upon to do so. Clearly, this cannot be done through the authorization of individually approved deviations from established standards – particularly when those specifics (and any differences) are maintained as “confidential.” The requirement should be – no MUST be – a single set of demonstrable proficiency standards, using demonstrably appropriate equipment, for all who are depended upon to execute the duties and responsibilities of appropriate crewmembers (both cockpit and cabin) involved in delivering these services to the traveling public. If the regulatory authority should NOT do these things … I wonder why it is that a regulatory authority is involved at all. |
Chris
It is Entree Level Training/Jet Familiarisation/Multi Crew Cooperation. It can be consolidated during Refresher training and online but unless you know the symptoms and the correct procrdure of UAS you may not handle it competently and safely. Let us say a pilot is competent in hand flying but does not remember correct procedure of TCAS he can mess it up. |
I'll try different approach this time
Originally Posted by Gums
Glad to see a few that "believe" in a decent AoA indication that could have the "limit" AoA clearly marked for the pilot.
Originally Posted by rudderrudderrat
The pitots don't measure the angle of attack!
Originally Posted by BOAC
Indeed, 100kts TAS is well enough to register an AoA on a balanced probe
Originally Posted by RetiredF4
why besides the AoA a speed indication is needed to determin wether you are in a full stall.
Originally Posted by rudderrudderrat
Why keep the 60 kt logic when airborne?
Originally Posted by RetiredF4
At the moment we are discussing the inconsistency of the stall warning, right?
Originally Posted by retiredF4
Due to an airspeed, which was inconsistent in itself?
And therefore rendered an available AOA indication as unreliable?
Originally Posted by RetiredF4
And you think, that is a logic system in itself and not worth improving?
Originally Posted by BOAC
That sounds suitably over-complicated.
Originally Posted by RetiredF4
I can understand that some input like speeds are necessary to compute the exact angle of attack.
Originally Posted by RetiredF4
Why not implement a logic, where an AOA value above the highest stall onset AOA bypasses the above logic and thus keeps the stall warning active?
Originally Posted by BOAC
no - the lack of stall warning when the Captain arrived in the cockpit was non-'trivial'.
Originally Posted by gums
I do not understand the "HUD resistance" here by several heavy pilots that seem to tolerate MFD's that are crowded with data and tapes and....
Originally Posted by ventus45
We all now know, definitively, that (a) the AoA resolver outputs were available, and (b) that they were valid. Discarding them is unforgivable.
Originally Posted by ventus45
The “below 60kias” is a classic case of such an arbitrary false premise “knock out filter”.
Originally Posted by ventus45
That allows the aeroplane to tell a pilot, “Everything else, air-data wise, is tits up guys, but I still have valid AoA, any use to you ?
Cheap provocation, eh? Think again, gentlemen. All of these questions are answered many times during the course of 11 threads we had on subject yet same old opinions resurface again and again. Please put some effort in answering these, I would really like to know what you didn't understand last time and time before that and before that...
Originally Posted by gums
I never worried about ":floors" or "protect" or any of that.
Originally Posted by Turbine D
As I understand it, the idea is for the PF to look through the center of the HUD and fly the flight path symbol, but incorporate the side displays in his periphery vision as to how they maybe changing.
Originally Posted by Chris Scott
My suggestion of an initial "knee-jerk" reaction implies, by definition, an absence of rationality. Explanation is not justification.
Originally Posted by Chriss Scott
So he handflew in the wrong way, but not because he was unable to handfly?
Originally Posted by Chris Scott
He knew that he wanted to maintain altitude but felt it necessary to keep pulling back on the stick to achieve such?
Originally Posted by Chris Scott
All that needed to be done in AF447 was to keep the wings level
and MAINTAIN a suitable pitch attitude and thrust for high-altitude cruise.
Originally Posted by Chris Scott
Firstly, you will not learn the very gentleness of any corrections that need to be made on the side-stick if you unexpectedly find yourself without the AP at high altitude.
How are we going to resolve this?
Originally Posted by Chris Scott
Well, I agree that the three main L.O.C. cases we have been discussing the last few months have involved different pilot reactions to problems in the cruise, but all have been seriously deficient:
Originally Posted by vilas
Pilots without jet experience have to undergo ELT MCC as part of Airbus type rating where Absolute raw data flying without ATHR, AP, FD, FPV is taught.It includes executing SIDs,Arrivals,Approach and landings. Out of eight sessions 6 are to be flown manually. So 447 pilots were not strangers to raw data flying.
OK I'll give up quoting for a bit but when making sweeping statements about general flying capabilities of modern pilots, bear in mind that more than 30 other crews passed through same ordeal without a scratch and at least four of them were Air France. |
Originally Posted by Clandestino
You suggest that A330 is sensitive beast that has to be treated gently. I say that it is exaggeration and you can throw her around hamfistedly at cruise altitude, in alternate law for 4 minutes with normal acceleration varying between +1.96 and -0.26G with end result being no worse than just utter mess in cabin and galleys.
Alternate1 and Alternate2 laws might work similarly in pitch, but they bear no resemblance in roll. |
In response to Cland, the three points where I was called out .....
a) Seems to be confusion here, even amongst the 'bus drivers about the various "alpha" limits or protections or whatever. And when one is the actual FCS limit. So if the FCS doesn't have an absolute AoA limit, then at least show the pilot the stall AoA. My system had AoA limits depending upon A2A loadout, heavy iron on the wings or in landing configuration. We could only select the A2A or A2G limits, not the gear down limits. b) Looking at my HUD video you will see what most considered the minimum displayed data for a safe and precise approach. The ILS cross bars are easy to understand. AoA bracket shows where you are and when aligned with the flight path marker( FPM), where you should be. Heading, altitude ( AGL or baro) and speed. If you want some kinda "magenta line" to helpsteering , fine, but that can be a symbol that you keep aligned with the FPM. Had that on my A-7D, but no autopilot connection to anything. Viper was pure manual, as seen in the video. c) We had one important backup mode - Standby Gains, which is extremely relevant to our discussions here the last three years. If air data was deemed unreliable the FCS used a fixed value for "gains". One with gear up, and the other gear down. Sure, if way off of the Q that the system used, it got touchy or sloppy. but very easy to fly, much like the "old days" when we didn't have all that stuff. We did not worry about a myriad of alpha stuff, as we had one with gear up and the other gear down. Both limited the jet to stall AoA ( roughly). You could not command above those limits as the AF447 folks did. Could still run outta energy in a steep climb and momentum would allow the jet to exceed the limts because the flight controls could not react quickly enough ( very hard for our jet, and even more so for the heavies, IMHO). Having an ACES II seat was very comfortable, and several of my friends are true believers. One, and main reason I never wanted to fly the heavies after getting out was the responsibility of many SLF behind me. If I screwed up, or the jet screwed up, so it was just me. Ain't gonna talk about that anymore. .....and I assume Cland and maybe one or two others have bothered to look at my HUD tape of the emergency landing. Otherwise, much of my views could be misunderstood. |
Chris Scott - I have just found your post #800 buried in the grass at the bottom of a page (missed it previously). Your point about 'trigonometry' is irrelevant when we were talking AoA signals and is only relevant in terms of IAS which only enters the fray due to some software code. Therefore it would not matter if the jet was flying backwards or upside down - an airflow of that magnitude would, I suggest, generate a 'useable' AoA signal. Whether the designers choose to ignore that signal is another matter. That was one of the errors of design.
Clandestino said
Originally Posted by post #850
How many medium and heavy jets vent below 60 kias while airborne, ever?
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@BOAC
Firstly let me say that I am NOT arguing that the A330 design does not need any change - on the contrary I think the stall warning logic should be altered. However the discussion relating to validity or otherwise of the AoA signal does, I think, ignore some relevant facts: Your point about 'trigonometry' is irrelevant when we were talking AoA signals and is only relevant in terms of IAS which only enters the fray due to some software code. Therefore it would not matter if the jet was flying backwards or upside down - an airflow of that magnitude would, I suggest, generate a 'useable' AoA signal. Whether the designers choose to ignore that signal is another matter. That was one of the errors of design. More to the point, if an equipment manufacturer declares in his formal paperwork that his equipment will work to specification only inside a given range of ambient parameters then the aircraft designer has no option but to conform to those limits. It is not a case of design error but one of a fully auditable certification trail. The problem comes of course when the system sees input conditions which say that the operating limits of the equipment have been transgressed, but the measurement of those ambient parameters is itself false. To that extent Chris Scott's comment on trigonometry is relevant - the input data, in this case airspeed, was rendered false by the angle at which the airflow entered the pitots. Was it then a design error to fail to consider this case? - not sure what 'vent' means here, but it does appear that the designers forgot this very important 'trigonometry' and that a jet in a fully developed stall can and did, in fact ?'vent'? below 60kts (IAS). So what of their treatment of the stall warning which is, when you go back to basics, the reason for all this discussion? With hindsight the logic is faulty, but I don't see any need to alter the logic governing validity of AoA signals which might well bring on other problems we know nothing of. Instead I would propose a change of stall warning logic so that if triggered by a valid AoA signal it should stay latched on until it received another valid AoA signal that stall conditions were a thing of the past. That would have avoided the confusion found in the AF447 cockpit for a minimal change to the aircraft systems. It would also, incidentally, bring the aircraft into line with the latest EASA requirements on the subject. |
Indeed "tongue in cheek".
I don't think I have ever argued that AB was partly 'responsible' for the accident due to the Stall warning 'logic', but just that it was significantly contributory. I agree people would not 'expect' the crew to take an airliner to these realms. However, why WoW was 'abandoned' I do not know - I thought it was a well-proven input? Surely the point is, Owain, that as far as we know there was a 'useable' AoA input available, probably throughout the episode, and indicating a stalled wing. The fact that 'trigonometry' rendered the USE of this signal impossible due to the IAS constraint is indeed relevant, but I cannot see why posters are going on about 'non-swivelling pitot tubes' etc etc. Surely we all understand why the IAS reading was invalid? I agree with your last paragraph and if that is also the EASA thinking, then good, although as with all ever-increasing complexity of systems there may well be a hidden pitfall in that approach. |
BOAC,
The post of mine that you refer to was merely an attempt to explain to you and rudderrudderrat that you were misunderstanding Clandestino's cryptic remark about trigonometry, and taking seriously his reference to "no swivelling pitots". It was not a statement of my own opinion, merely an attempt to help you understand his point in his absence (for which, predictably, he has offered me not a word of thanks). It's well known that Clandestino's style of response sometimes invites irritable misunderstanding by the passing objects of his contempt, myself included. Did my polite, but non-didactic, explanation go over your head? Should I have tried the long version? (Ah, I see OG has done a far better job!) |
....and I hope you understood my t-i-c remark about there always being a reading from an AoA probe (given enough wind to 'swivel' - that's for real) regardless of 'trig'?
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Affirm, BOAC :ok:
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BOAC
I don't think I implied that you were arguing about responsibility - if I gave that impression then my apologies. Nobody is going to contradict a statement about the S/W anomalies being a contributory cause though. So far as WOW is concerned I don't think I have ever seen anything from Airbus on the subject - mostly the argument about it being 'abandoned' seems to emanate from PPRuNers speculating - but I stand to be corrected. What I would say is that leaving aside the AF447 affair, the existing logic functioned without complaint for several decades; why take the head off if it is working? Now if your objective is to supply an AoA signal pure and simple and which is not going to be used as an input into some more flight critical system then I would agree there may be no need to complicate life by making that signal contingent on some other input - it being tacitly assumed that the aircraft will not be flying at a real 60 kts indicated or otherwise. Implicitly here I am taking the view that since airline pilots have been flying without AoA information since the year dot such information cannot really be classed as flight critical no matter how useful it might be in certain circumstances. [pace gums!] I entirely agree your point about non-swivelling pitots etc. To be clear, my remark about EASA requirements simply reflects the latest stall warning requirement CS25 207 (c) which, as I have said before, differs from the requirement applicable at the time the A330 requirements were frozen. |
Good thots, OG.
To be honest, I don't know when the Viper FCS ignored AoA or didn't. Best I have in documents is that it was used as long as we had WoW switch decompressed. When I did a tail slide one day all the warning lights came on ( AoA sensors at limits, calibrated speed below 120 knots) and without resetting them, I had complete control once the nose fell thru. Reset the FCS panel and fight was still on, heh heh. OTOH, the A-7D and other jets displayed the AoA whether the plane had a FBW system or not. Viper didn't, as some folks the braket was a nuisance symbol in the HUD. I learned in planes that had very clear warnings you were approaching a stall. In later planes, we had buffet and wing-rocking and such to let us know we were reaching the edge of the envelope. It was a different feel than when nearing critical mach, which usually exhibited stuff like aileron reversal, nose tuck and a pronounced "buzz" in the airframe as the shock waves formed. So my thot is that a display should be available and right in front of the pilot whether the FCS or Otto is using it. |
Originally Posted by Owain Glyndwr
(Post 8163557)
So far as WOW is concerned I don't think I have ever seen anything from Airbus on the subject - mostly the argument about it being 'abandoned' seems to emanate from PPRuNers speculating...
Lufthansa Flight 2904 - Wikipedia, the free encyclopedia In response to that, Airbus reduced the required pressure on the WoW sensors, but they never abandoned it as a systems input. OG, I'm almost certain you're correct in that the <60kts AoA NCD flag has nothing to do with determining air/ground mode - it's purely an attempt to enforce the AoA vane manufacturer's specified limitation of minimum 60kts airspeed for valid data, and prevent junk data from being used in FCS calculations. |
Just a reminder - the Final Report para. 1.6.11 says it thus:
If the CAS measurements for the three ADR are lower than 60 kt, the angle of attack values of the three ADR are invalid and the stall warning is then inoperative. This results from a logic stating that the airflow must be sufficient to ensure a valid measurement by the angle of attack sensors, especially to prevent spurious warnings. |
...and should read
If the CAS measurements for the three ADR are lower than 60 kt, the angle of attack values of the three ADR are considered to be invalid and the stall warning is then rendered inoperative. |
Originally Posted by BOAC
(Post 8163789)
...and should read and hopefully re-thought, having seen vanes moving on walk-rounds in a stiff breeze!
I'm sure the intention was well-founded, but hindsight tells us the application was not, and WoW would have been far better. |
Dozy
I'm wondering if that speculation stems from the 1993 LH A320 accident at Warsaw, where the WoW timing was not sufficient to allow deployment of spoilers: In response to that, Airbus reduced the required pressure on the WoW sensors, but they never abandoned it as a systems input. |
@OG - check the Wiki link.
Originally Posted by Wiki
The spoilers [were] only activated if at least one of the following two conditions is true:
- there must be weight of at least 6.3 tons on each main landing gear strut - the wheels of the plane must be turning faster than 72 knots (133 km/h)
Originally Posted by Wiki
As a result of the accident, Airbus Industrie changed the required compression value from 6.3 tons to just 2 tons per main landing gear.
[EDIT : I'm aware that it's a totally different application, I was simply trying to distinguish the air/ground mode criteria, which are not relevant to AF447, from the AoA vane maker's specified NCD threshold of 60kts, which is. ] |
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