Crash-Cork Airport

[Big Pistons Forever]

Originally Posted by Sunnyjohn

From what I have read, and I have read the whole report, I don't see how you could know that. Could you explain?

Read the METAR's, vis was way below landable mins the whole morning.

[Jack1985]

I did read every page of the report. The accident would not have happened if the crew had not busted the minimums. Which bit of that is not clear to you, or the investigators (if they happen to be reading).

So you can say with certainty that following the application of -9% torque on the No. 1 engine and the left roll followed by the subsequent hard roll to the right which resulted in the loss of control had happened at minima it would not have crashed? Please could you do my lotto numbers when you get a chance? What rubbish.

The crew on both approaches 1 and 2 descended below minima to 101ft on approach 1 and to 91ft on approach 2 - It was a case of multiple factors combining on the 3rd approach that caused this accident not a single one.

[Sunnyjohn]

Thanks, Jack - that was the point I was seeking to clarify. With this hidden problem with the torque, it just seemed to me that this preponderance to roll sharply to left with certain flight settings could have happened at any time, regardless of the weather. Would that be correct?

[Jack1985]

Thanks, Jack - that was the point I was seeking to clarify. With this hidden problem with the torque, it just seemed to me that this preponderance to roll sharply to left with certain flight settings could have happened at any time, regardless of the weather. Would that be correct?

Basically in the latter stages of the final approach to 17 the Commander (PNF) took control of the Power Levers - Which was acknowledged by the Co-pilot (PF). This is an unusual move, as normally the PF handles both flight and engine controls in a coordinated manner to achieve the required flight path - When the PNF took control of the Power Levers they were subsequently retarded below Flight Idle - an action which would have been unexpected by the PF.

Recorded data showed that the No. 1 engine retarded to -9% torque in beta range, whilst the No. 2 engine stayed at 0%.

Then to quote the AAIU,

''This thrust asymmetry was coincident with the aircraft commencing a roll to the left (maximum recorded value of 40 degrees bank). It is possible that the PF may have made a control wheel input to the right in response to the unanticipated left roll. However, without FDR parameters of control wheel or control surface position the Investigation could not determine if such an input was made. The subsequent application of power to commence the go-around, at approximately 100 feet, coincided with the commencement of a rapid roll to the right and loss of control. The roll continued through the vertical, the right wingtip struck the runway and the aircraft inverted.''

And again to quote the AAIU,

''A torque split between the powerplants, caused by a defective Pt2/Tt2 sensor, became significant when the power levers were retarded below Flight Idle and the No. 1 powerplant entered negative torque regime. Subsequently, when the power levers were rapidly advanced during the attempted go-around, this probably further contributed to the roll behaviour as recorded on the FDR.''

So basically to answer you question Sunnyjohn, yes this could have happened in another situation - however as with all accidents its a number of factors which line up together to cause it and as the AAIU have provided 54 findings, a probable cause, 9 contributing factors and 11 safety recommendations to show this.

Again to Big Pistons Forever, trying to pin this down to a single factor is both nonsensical and dangerous - We need to learn from all the factors of which descending below minima is one.

[viren51]

Busting Minimas may not be very uncommon especially in operations where Flight Data Monitoring is not in vogue. One can see just such an example in the recently released investigation report of the CRJ accident, available in African Aviation Section of PPrune:
http://www.pprune.org/african-aviati...-dr-congo.html

While busting Minimas by a little bit, the crew may believe that he/she is not going to cause an accident, he/she may believes that it may be a way to get the job done.
But Minimas are supposed to provide the safety margin, hence any compromise on Minimas reduces the safety margin.
On most days, one may be able to get away but when chips are loaded against you, busting Minimas may be just another factor in the accident.

[mad_jock]

Perhaps you could explain your verbose and totally meaningless statement above too?

Its only meaningless if your a Microsoft flight sim ATPL.

[Big Pistons Forever]

Originally Posted by Jack1985

Again to Big Pistons Forever, trying to pin this down to a single factor is both nonsensical and dangerous - We need to learn from all the factors of which descending below minima is one.

I respectfully disagree. The accident chain started with the deliberate decision to continue the approach below minimums. By removing all of the altitude margin they made a crash inevitable when the engine asymmetry caused the fatal roll.

The airplane may have still crashed if the missed approach had been commenced at the Cat 1 limit but the extra altitude may also have allowed a successful recovery. Where they started the go around there was no possible recovery.

You are correct in the fact that there are many lessons to be learned from this terrible tragedy but for professional pilots the primary take away should IMO be Do not descend below minimums EVER. We pilots can't control many of the mechanical and operational issues that contributed to this accident but not busting minimums is totally and completely under our control.

BTW the FAA accidents stats show that you are 15 times more likely to have a fatal crash on approach if you are flying your third attempt at the same approach.....

[mad_jock]

Have you got a link for that stat BPF I would like to include that stat in some training material.

[Chronus]

Cork crash

The all too important question for debate is why did this crew bust minima. The RT transcscrpit perhaps gives some clues, too many "Sirs" and the unsolicited offer of ATC of a suitable diversionary field.

Have a look at the following link which was published in February 2012, for the main contributory factor and for what now remains to follow.

Lawyer claims pilots' decisions were main cause of Cork air crash.

[mad_jock]

There should be maybe be a change in the phraseology of Irish ATC.

In the UK there is no confusion if you try and bust the approach ban they won't give a landing clearance just "nothing know to affect" after a set phrase ending with "what are your intentions"

[reportyourlevel]

Not so any more, they changed that ages ago.

[mad_jock]

What's it these days?


Last time I heard it was 2011

[Jack1985]

I respectfully disagree. The accident chain started with the deliberate decision to continue the approach below minimums. By removing all of the altitude margin they made a crash inevitable when the engine asymmetry caused the fatal roll.

The airplane may have still crashed if the missed approach had been commenced at the Cat 1 limit but the extra altitude may also have allowed a successful recovery. Where they started the go around there was no possible recovery.

You are correct in the fact that there are many lessons to be learned from this terrible tragedy but for professional pilots the primary take away should IMO be Do not descend below minimums EVER. We pilots can't control many of the mechanical and operational issues that contributed to this accident but not busting minimums is totally and completely under our control.

So basically what you are saying they bust the minima 3 times and its pilot error?

And that's the precise reason you're view of the accident would actually contribute to it happening again - because in essence its a dismissal of every contributory part of the accident.

Look back through aviation - for every accident that the pilots are just blamed there is a repeat, one only has to look at Air France since AF447 in 2009 we've had 3 near stalls and about 5 major incidents which are directly attributable to training and understanding of in-flight upsets.

The reason your single view point will not stand is because;

Had the PF had full control the aircraft wouldn't have encountered the thrust issue or rolls and would have climbed away again - even when they bust the minima.

[reportyourlevel]

It was changed in 2011, we don't say anything at all now. I think this is to remove any ambiguity about responsibilities.

[Big Pistons Forever]

Originally Posted by Jack1985

.

The reason your single view point will not stand is because;

Had the PF had full control the aircraft wouldn't have encountered the thrust issue or rolls and would have climbed away again - even when they bust the minima.

Yes but they did have a malfunction. So to me the question is if they had gone missed at the correct DH would they have not lost control even with the malfunction ? There is by no means certainty that this would be the case but I submit there is certainty that starting the miss approach from where he did made a crash inevitable when the engine malfunction occured.

I absolutely agree that there are many lessons here, but deliberately placing the aircraft in such a perilous position made it almost inevitable that any malfunction would doom the aircraft.

So I reiterate my central point. The lesson us pilots should take away from this is Never bust minimums !

[Jack1985]

Yes but they did have a malfunction. So to me the question is if they had gone missed at the correct DH would they have not lost control even with the malfunction ? There is by no means certainty that this would be the case but I submit there is certainty that starting the miss approach from where he did made a crash inevitable when the engine malfunction occured.

I absolutely agree that there are many lessons here, but deliberately placing the aircraft in such a perilous position made it almost inevitable that any malfunction would doom the aircraft.

So I reiterate my central point. The lesson us pilots should take away from this is Never bust minimums !

You're lack of reading of the report is now evident, the malfunction was only evident because the PNF retarded the Power Levers unbeknown to the PF, which resulted in the left roll and subsequent loss of control - So had the PF had absolute control on the 3rd approach and had they still decided to go-around as they did at approx 100ft the accident would not have happened - So you're view of they just bust the minima is wrong! That is a factor.

[Big Pistons Forever]

Originally Posted by Jack1985

You're lack of reading of the report is now evident, the malfunction was only evident because the PNF retarded the Power Levers unbeknown to the PF, which resulted in the left roll and subsequent loss of control - So had the PF had absolute control on the 3rd approach and had they still decided to go-around as they did at approx 100ft the accident would not have happened - So you're view of they just bust the minima is wrong! That is a factor.

Or one could speculate that if the exact circumstances that led to the crash had occurred at the correct DH, not at the less than 100 feet AGL the aircraft was at at the time of the go around, would it still have crashed ?

Leaving aside the very poor CRM that had the Captain controlling the power levers with the copilot flying, the crew had no control or advance knowledge of the impending power asymmetry. They did have total control and knowledge of the DH though.

I guess we will have to agree to disagree on this one.

Finally I would like to make one general point aimed specifically at the newer less experienced commercial pilots reading this thread. Sadly the accident record has many examples of aircraft that crashed after busting minimums even when everything was working perfectly. It is just not worth it......

[Jack1985]

Or one could speculate that if the exact circumstances that led to the crash had occurred at the correct DH, not at the less than 100 feet AGL the aircraft was at at the time of the go around, would it still have crashed ?

Leaving aside the very poor CRM that had the Captain controlling the power levers with the copilot flying, the crew had no control or advance knowledge of the impending power asymmetry. They did have total control and knowledge of the DH though.

I guess we will have to agree to disagree on this one.

Finally I would like to make one general point aimed specifically at the newer less experienced commercial pilots reading this thread. Sadly the accident record has many examples of aircraft that crashed after busting minimums even when everything was working perfectly. It is just not worth it......

If I had been presented with an immediate 40 degree left roll but at the decision height with IRVR's of 500/400/400 I would have rejected as I'm sure the crew would have (The fact the crew even commenced the approach with those IRVR's on all 3 occasions is a factor - they shouldn't have), even at 200ft with 40 degree left roll followed by the command to execute the go-around and which resulted in an immediate hard right roll of over 70 degrees I'm pretty sure the aircraft would have crashed, especially with the terrain approaching 17. However that is speculation and as it happened 100ft the consequences were immediate, I agree breaking the DH was wrong of course it is, but to me its a factor in a litany of errors and contributory failings by other parties. But as you said we will have to agree to disagree.

[SloppyJoe]

Think about the events that happen when conducting an approach to minimums with the intention of going around if you are not visual at the DH. Would any of you just prior to DH reduce the power to idle whilst not visual or would you maintain a stable approach with stable power and speed until either visual or going around? I assume there was not much wind or a need to change power setting much due to the conditions in the final stages of the approach.

Having flown turboprops with splits in the power application I can tell you it is only really an issue when advancing from idle or near to it. If they were not land minded they would not have had the power at idle and going around at DH would not have caused a roll.

[mad_jock]

Its the half cocked busting of mins which has an effect.

I am sure most of the experienced TP drivers if they had decided that they were busting mins because they had to, would have just driven the thing to the ground with 20-30 % torque on sticking to the ILS then pitched the nose up slightly when the TWAS said 20 and taken the power off.

I know I have done it in LOFT exercises in the sim a few times in zero rvr.

But then again I think I have had significantly better training over the years. Well I have had training which it seems these two didn't.

There is loads of runway for an aircraft that size.