Merciful lord, do I have to say this till I'm blue in the face???

 

PRS is NOT a reporting system. It a system for giving hints and tips to someone anonymously!!!! YOU ARE NOT REPORTING THEM!!!! THERE ARE NO LEGAL APPLICATIONS!!! THERE ARE NO INVESTIGATIONS BASED ON IT!!! IT IS NOT THE SAME AS GETTING REVIEWED OR CHECKED!!!

 

Sincerely,

Rónán O Cadhain.

 

 

Woah there, settle down chief!

 

I'm just comparing what happens in the US to other places. From flying the last 12 years of my life I've realized that we have a very open and reactionary culture here.

Yup, it's not just Air France to be fair.

 

Al

Granted, I do indeed not fly an A330 and nor am I qualified to do so, but I am however, qualified to comment on it, not least because I produced the SOPs for two airlines which operate the Airbus A330, so I do know a fair bit about the systems on the real aircraft. I am also a qualified pilot, who knows how to recover from a stall, which would appear to be quite pertinent too given the discussion at hand.

 

Being a staff member does not preclude me from expressing concern about getting on board an airliner belonging to an airline about whom I have some major concerns. And it's not just pilot training, it's a lot of other things too, for example, the way AF pilots converse in French with French ATC when everyone else in that airspace is monitoring in English, a phenomenon which anyone who has done a '100 Dollar hamburger' hop over to Northern France in Cessna will be familiar with. It's a genuine concern, and to be honest it was a genuine concern long before AF447 crashed.

 

Al

All right Al. I just felt you were getting too emotional there and, as a French guy, I couldn't resist telling an English bloke to keep his upper lip stiff !

 

I usually really appreciate your comments and look forward to reading more.

 

Kind regards,

 

Bruno

Woah there, settle down chief!

 

I'm just comparing what happens in the US to other places. From flying the last 12 years of my life I've realized that we have a very open and reactionary culture here.

Ireland is by no means has a closed culture, just as human beings we don't like insulting each other to each others faces. I'm positive that many many many American airlines have adopted such a system in their operations.... I'll fire off a few emails, let me get back to you....

 

Rónán O Cadhain

 

Woah there, settle down chief!

 

I'm just comparing what happens in the US to other places. From flying the last 12 years of my life I've realized that we have a very open and reactionary culture here.

Ireland is by no means has a closed culture, just as human beings we don't like insulting each other to each others faces. I'm positive that many many many American airlines have adopted such a system in their operations.... I'll fire off a few emails, let me get back to you....

 

Rónán O Cadhain

All right Al. I just felt you were getting too emotional there and, as a French guy, I couldn't resist telling an English bloke to keep his upper lip stiff !

 

I usually really appreciate your comments and look forward to reading more.

 

Kind regards,

 

Bruno

Nice to read the posts of two gentlemen from two different nations separated by a channel displaying such entente cordiale.

One last question that has been bugging me for a while and then I'm going to take a break from this thread.

 

What is everyone's opinion on the PNF selecting ATT on the overhead and the captain later asking them if they had tried anything with the prims?

 

That suggests to me that they believed the PF's PFD was faulty (not just UAS) and messing around with the prims suggest the captain believed there could be a flight control problem.

 

The most important one for me is selecting ATT

 

Regards

All right Al. I just felt you were getting too emotional there and, as a French guy, I couldn't resist telling an English bloke to keep his upper lip stiff !

 

I usually really appreciate your comments and look forward to reading more.

 

Kind regards,

 

Bruno

 

Stiff upper lip, LOL Just so you know, it's not a nationalist thing, there is at least one UK-based airline I wouldn't fly with either, for broadly similar reasons.

 

Al

One last question that has been bugging me for a while and then I'm going to take a break from this thread.

 

What is everyone's opinion on the PNF selecting ATT on the overhead and the captain later asking them if they had tried anything with the prims?

 

That suggests to me that they believed the PF's PFD was faulty (not just UAS) and messing around with the prims suggest the captain believed there could be a flight control problem.

 

The most important one for me is selecting ATT

 

Regards

 

Not being a pilot of any sort, what does selecting ATT do?

 

Attempting to keep up with the AF447 threads on pprune is quite difficult but from what I can gather there is no record in the data recorder of what was being shown on the RHS PFD? If your assertion of a faulty RHS PFD (or more importantly the PF believed his PFD was showing incorrect data) is true then, in my opinion, we are heading towards a plausible explanation for what happened and why - starting with the stall warnings that were false, a PF that believed he was going to overspeed and took the appropriate action for that whilst also being fixated on keeping the wings level at the expense of pitch and airspeed. If by the time the aircraft was actually stalling he didn't believe his PFD was good and had no references to go by looking out of the window then the confusion is almost complete. The final piece will be that the stall warning has stopped yet his sink rate is massive. We're not stalling. Don't want to push the nose down because if I don't believe I'm stalling then I'll just make that sink rate worse and every time I do push forward on the stick for any amount of time the stall warning restarts.

Another thought - crazy as it seems but could the PF have thought he still had stall protections?

Another thought - crazy as it seems but could the PF have thought he still had stall protections?

 

The “Cavalry Charge” sounded from 2:10:05 to 2:10:07 as the autopilot disengaged and the system changed to Alternate Law at 2:10:06 when the PF said “I have the controls”. The PNF called “Alternate Law Protections” at 2:10:22

I am aware of all of that - he should have known that he didn't have the protections but a good part of the evidence points to the fact that he didn't. It was the PNF that called the alternate law - there seems to be no acknowledgement or confirmation of this from the PF. He appears to be fighting a non-existent overspeed and even tries deploying the airbrakes at 2h12m04s!

As regards the video on page 7 the "stall warning" is rather benign compared to some a/c. Take the VC10 just as one example. The stall warning consists of a very noisy rattling stick shaker and a VERY loud klaxon. I would post the .wav file here but I don't think files can be. My point being is that there is no doubt at all that the stall warning has sounded. The reaction should be and must be instinctive. You mught be dealing with a hundred and one other issues but if the stall warning goes off you ditch everything and get out of the stall.

Not being a pilot of any sort, what does selecting ATT do?

 

ATT means Attitude. When the inertial navigation goes off line or cannot be trusted then ATT is set.

vololiberista

Not being a pilot of any sort, what does selecting ATT do?

 

 

The simple answer is that it switches the nav system from NAV providing full navigation data on the primary flight displays (PFDs - i.e. the big TV screens on the panel), and into a simpler ATT mode where you only get attitude data on the PFDs (heading, roll and pitch data only, no positional stuff).

 

The more complicated answer...

 

The data provided by the system is shown on the PFDs, but where you mess about with all that navigation data stuff is up on the back of overhead panel, being the display and control switches for the inertial navigation system, otherwise known as the ADIRU panel (air data inertial reference unit). The IRS uses gyros located at the front and rear of the fuselage which are 'spun up' at the start of a flight, and these are the basic way that the aircraft knows where it is even without radio signals.

 

At the start of a flight, the crew can either key in the known geographic coordinates on a little keypad on the ADIRU, to tell the aeroplane where it is (these coordinates are often painted on the wall where the aircraft is at the gate), or, the crew can let the aeroplane detect where it is by leaving it to analyse the Earth's rotation, and it will (eventually) work out its location from stuff such as changes in the magnetic field, rotation of the Earth and other nerdy crap like that. Automatic detection can take a while sometimes, depending on your location, since there are different detectable rotations depending on whether you are near the equator or very far north or south, which is why aircraft making polar flights need more fancy avionics and often feature a 'polar' switch on the overhead which will make the nav systems track the aircraft's position from other sources such as GPS, GLONASS, VORs and NDBs etc.

 

INS/IRS was originally a system for use on board submerged submarines, which worked by detecting the movement of the submarine from a known initial position, this was so that they could drive around underwater and still know where they were, allowing them to sneak undetected into Tokyo harbor to torpedo japanese flat-tops and all that kind of war movie stuff, although older inertial navigation systems (INS) used traditional gyroscopes. These days, IRS uses more sophisticated ring laser gyros, which fire a laser at a rotating mirror to detect minute intertial (movement) changes, and this is how an aircraft knows where it is and how it is moving even when out of range of radio aids and GPS signals.

 

INS is not as accurate as getting triangulated radio fixes, and does drift out of alignment over a long flight, perhaps by maybe a mile or so after a transatlantic flight, but generally speaking, the system cross-references with radio aids and GPS signals in order to update itself, so it is ultimately pretty accurate, and is one of the reasons why more precise approaches are now a possibility, however, if it goes belly up, then you will probably lose the Primary Flight Displays. You might even have seen this on some fancy FS aircraft, where the PFDs are black apart from an ATT message, which is the aeroplane telling you to set up the INS so it can learn its position. There have been one or two occasions where crews have forgotten to do this, for example, a few years ago the crew of a Polish B737 did this, then took off from London and lost all that data on the PFDs whilst climbing out. They had to faff about all over the place trying to figure out how to get back for an emergency landing, using mainly the standby artificial horizon for reference data. If you can find the ATC recording of it, it is unintentionally hilarious.

 

On the Airbus, the IRS ADIRU panel has numerous switches and selectable displays: TK/GS shows current track and groundspeed, PPOS shows present position, WIND shows wind speed and direction, HEADING shows heading and also alignment info, STS shows error codes and stuff like that. There is a keypad which will allow you to enter geographic coordinates N,S,E and W of the prime meridian, and then there are three three-position switches labeled: OFF, NAV, ATT. Off is self-explanatory, NAV is full navigation mode (i.e. the mode you would typically be in), ATT is attitude, and will only provide heading and and attitude data, but even then you have to keep updating it manually with heading data once in a while via the keypad, or it will be very innaccurate. There is also a set of triple lights with FAULT/ALIGN on there too, ALIGN lights up when the thing is working properly and is aligned, and flashes if there is a problem. FAULT lights up if there is a problem, but it flashes if there is a possibility of gaining some useful info via switching to ATT mode. Last but not least, there are three ADR/FAULT Lights/switches (air data reference, i.e. stuff from the pitot tubes and static ports etc), ADR can be isolated with the switches, but when on, FAULT illuminates if there is a problem with the air data.

 

So basically, if you switch from NAV to ATT, it would be because you lost some position data on PFD and suspected all three INS systems had gone wrong and were then choosing to revert to a more basic system whereby you would still have pitch, roll and heading info on the instruments.

 

Al

Merciful lord, do I have to say this till I'm blue in the face???

 

PRS is NOT a reporting system. It a system for giving hints and tips to someone anonymously!!!! YOU ARE NOT REPORTING THEM!!!! THERE ARE NO LEGAL IMPLICATIONS!!! THERE ARE NO INVESTIGATIONS BASED ON IT!!! IT IS NOT THE SAME AS GETTING REVIEWED OR CHECKED!!!

 

 

I'd never heard of PRS before, but it sounds like a very good system. Once thing to remember though is that the lack of legal implications is only guaranteed if you have a solid legal framework protecting the system. In some countries they fortunately realise that accidents are generally accidental and that it's far more beneficial to safety to allow people to admit to their mistakes without consequences, rather than punishing a scapegoat and pretending that solves the problem. This is for example why NTSB reports are not admissible as evidence in a court of law.

 

Unfortunately in other countries the first response to an accident is to slap anything that (still) moves with a manslaughter charge, followed by a bloody battle between the justice department and the accident investigators over who gets to read-out the FDR and CVR. In those countries (and France certainly leans that way) I can imagine pilots would be quite a bit more hesitant to use a PRS, knowing that anything you report there can and will be used against you or your fellow pilots at some point in the future. I realise this is not the case in Ireland, but other countries may not be so fortunate.

 

 

One last question that has been bugging me for a while and then I'm going to take a break from this thread.

 

What is everyone's opinion on the PNF selecting ATT on the overhead and the captain later asking them if they had tried anything with the prims?

 

That suggests to me that they believed the PF's PFD was faulty (not just UAS) and messing around with the prims suggest the captain believed there could be a flight control problem.

 

The most important one for me is selecting ATT

 

Regards

 

It's been a while since I browsed the reports, but I do believe the PNF spent quite some time flipping through various display sources for the PFD / ND, so your hypothesis sounds plausible.

 

Thanks to all the people in this thread for the highly knowledgeable posts, it's been a pleasure (if that is the right word to use in this context) reading them.

This is for example why NTSB reports are not admissible as evidence in a court of law.

 

 

And why nothing gets done in the US!!!. MD knowingly marketed an a/c that was faulty. Namely the DC10. After a number of accidents and "gentlemen's agreements" between them and the NTSB they still didn't fix the problems. They are out of business now. I wonder why??!!

vololiberista