Sikorsky S-92: From Design to Operations
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I wrote the S76 checklist, and in the intro paragraph to Chapter 3 gave the pilot the latitude to be more than a sweaty flight-manual reader. The difference between airmanship/wisdom and memorizing flight manuals is the difference between pilots and stick wigglers, IMHO. If the flight manual words say "XXX" and you think you must do it, then do so. However, if the PIC decides to actually try some airmanship, in many cases it would be welcomed.
The ease of saying and preaching (in the ease of a Sunday at the keyboard criticizing your fellow pilot) blind obedience to the flight manual, "land immediately" is often confounded by the actual conditions, and by the fact that the aircraft is still flying nicely, even if a few lights are on. I am reminded of the American Airlines DC10 Chicago engine drop-off accident: In simulator trials afterward, the crews that obeyed the checklist and slowed to Vy (while they were climbing at over 2000 fpm before the slow-down) all died like dogs, those that flew wisely like airmen landed successfully.
I do not know what happened with this specific aircraft, at all, but I am lead to believe from 212man's posts that it did not lose all or most of its oil, rather, it might be that it had an oil leak. Any pilot who ditches a load of passengers with an oil leak (even if he memorized the flight manual in that case) might deserve to be ppruned to death, afterwards.
212man, any comments?
A second illustration of what I mean:
The Air Florida National Airport icing crash occurred because the crew obeyed and believed the EPR gages in spite of the fact that they had no climb and were about to hit the ground. They were gloriously slaved to the checklist and the flight manual, and their slavish unairmanship doomed their passengers. Had they simply pushed the throttles up, they would have climbed. The difference between thinking and memorization might be a problem in some cultures (frankly, I am about to get into pprune trouble here) the typical European attitude that the lords of the flight manual and the CAA know more than mere vassels. This religeous following of every word is more likely to lead to airmanship problems than the attitude that these pubs are guidelines for smart people to follow, but not slave themselves to.
The ease of saying and preaching (in the ease of a Sunday at the keyboard criticizing your fellow pilot) blind obedience to the flight manual, "land immediately" is often confounded by the actual conditions, and by the fact that the aircraft is still flying nicely, even if a few lights are on. I am reminded of the American Airlines DC10 Chicago engine drop-off accident: In simulator trials afterward, the crews that obeyed the checklist and slowed to Vy (while they were climbing at over 2000 fpm before the slow-down) all died like dogs, those that flew wisely like airmen landed successfully.
I do not know what happened with this specific aircraft, at all, but I am lead to believe from 212man's posts that it did not lose all or most of its oil, rather, it might be that it had an oil leak. Any pilot who ditches a load of passengers with an oil leak (even if he memorized the flight manual in that case) might deserve to be ppruned to death, afterwards.
212man, any comments?
A second illustration of what I mean:
The Air Florida National Airport icing crash occurred because the crew obeyed and believed the EPR gages in spite of the fact that they had no climb and were about to hit the ground. They were gloriously slaved to the checklist and the flight manual, and their slavish unairmanship doomed their passengers. Had they simply pushed the throttles up, they would have climbed. The difference between thinking and memorization might be a problem in some cultures (frankly, I am about to get into pprune trouble here) the typical European attitude that the lords of the flight manual and the CAA know more than mere vassels. This religeous following of every word is more likely to lead to airmanship problems than the attitude that these pubs are guidelines for smart people to follow, but not slave themselves to.
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Gearboxes are different
Nick,
I hear what you are saying but,
Gearboxes are different. If the guidance that I am given is that there is a reasonable chance that the G/B is going to seize solid then I am going to get myself to a height and speed at which I am prepared to be strapped to a housebrick. And that aint a lot of either.
TD
I hear what you are saying but,
Gearboxes are different. If the guidance that I am given is that there is a reasonable chance that the G/B is going to seize solid then I am going to get myself to a height and speed at which I am prepared to be strapped to a housebrick. And that aint a lot of either.
TD
Night, Winter, North Sea....wind 60kts (perhaps a few small waves....like HUGE waves probably)....then the decision to park takes a bit more thinking about. Ditching would be the very last option as compared to the instant discussion.
That is the "airmanship" Nicks talks off.
It all gets back to the weighing of risk.....sometimes the checklist simply has to be chucked out the window and you roll the dice and take your chances.
That is the "airmanship" Nicks talks off.
It all gets back to the weighing of risk.....sometimes the checklist simply has to be chucked out the window and you roll the dice and take your chances.
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'Then dont write manuals that say 'land immediately'
Write if you think youre arse is surrounded by alligators land immediately if not fly at 5 feet to somewhere there is no alligators. Or have a dry run capability.!
Write if you think youre arse is surrounded by alligators land immediately if not fly at 5 feet to somewhere there is no alligators. Or have a dry run capability.!
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I have to agree with NL here. I work on the maintenance side of the house and we see the same thing these days. Every one wants a get out of jail free letter from the manufacturer for doing simple maintenance actions. I could write you a letter that says it is ok to fly upside down in bad weather single engine but it doesn't mean you'll live through it. It just means I will be liable when your widow sues. Just like pilots blindly following what is written in the RFM. They cannot be written to cover every possible event and situation so you still have to make a concious decision to save your own arse. If a manufacturer is going to write anything they are going to make sure they reduce their liability. This is why the books might say land imediately...not because it wont make it but because they don't want to be the one who told you it would, when it wouldn't! I like using the tactics as Nick has in the S76 RFM leaving room for the pilot to do what is right for the situation and not mandating that he will be wrong if he doesn't follow the rule book to the letter. In the case here of the S92 MGB I would gather that it will probably run ok without oil for the 30 minutes advertised for the simple reason that Sikorsky wouldn't have said so unless they were pretty darn sure it would to reduce or eliminate their liability. My hat is off to 212man for making a decision that allowed him to have a beer at the end of the day! I wasn't there but from my vantage point in front of the TV next to my sunday morning cup of coffee I can say I would have done the same thing.
Moral of the story is "beware the written word" it is there to cover somebody's backside and most likely it is the authors not only yours!
Max
Moral of the story is "beware the written word" it is there to cover somebody's backside and most likely it is the authors not only yours!
Max
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Nick et al
1. In my role as a teacher I find it necessary to carefully explain to my customers the fact that the guys who write the checklists have to do so in advance of the aircraft entering service. They therefore have to guess at what malfunctions are likely to occur. (particularly avionics and electrical)
2. Nick is right, checklists achieve almost religious (ie. biblical) status, as if written by Gods. Certainly we in the UK/NL had to change the S76B FM vital actions in the event of a fire warning that did not go out because the NL part of the team at first refused to add a line that said 'Check for signs of fire' (before proceeding). When my colleague safely landed his (full) 'B' model on the offshore platform rather than obey the 'Land Immediately' call in the FM (and put pax and crew in the North Sea) it raised some eyebrows. It is pleasing to note that the 139 FM includes this requirement. One must consider that the effects of the KLM/PAN AM Azores debacle has left a traumatic legacy for Dutch pilots, a generation of whom have had it drummed into them that the most important thing is obeying the rules.
3. The most fantastic thing about sim training is that you can give the candidate his head when presented with any kind of malfunction scenario. In a world where reliability is the norm we have to work hard to equip the modern young pilot with 'airmanship' skills. The debriefs afterwards are often worth their weight in gold. I wish I could package them and sell them.
If you arrive at the right outcome and did not follow the FM then YOU WERE RIGHT. write to the manufacturer and tell him your experience and I am sure he will be pleased to receive it.
G
2. Nick is right, checklists achieve almost religious (ie. biblical) status, as if written by Gods. Certainly we in the UK/NL had to change the S76B FM vital actions in the event of a fire warning that did not go out because the NL part of the team at first refused to add a line that said 'Check for signs of fire' (before proceeding). When my colleague safely landed his (full) 'B' model on the offshore platform rather than obey the 'Land Immediately' call in the FM (and put pax and crew in the North Sea) it raised some eyebrows. It is pleasing to note that the 139 FM includes this requirement. One must consider that the effects of the KLM/PAN AM Azores debacle has left a traumatic legacy for Dutch pilots, a generation of whom have had it drummed into them that the most important thing is obeying the rules.
3. The most fantastic thing about sim training is that you can give the candidate his head when presented with any kind of malfunction scenario. In a world where reliability is the norm we have to work hard to equip the modern young pilot with 'airmanship' skills. The debriefs afterwards are often worth their weight in gold. I wish I could package them and sell them.
If you arrive at the right outcome and did not follow the FM then YOU WERE RIGHT. write to the manufacturer and tell him your experience and I am sure he will be pleased to receive it.
G
Run Dry is a Qual., not something to bet yur butt on
Nick can correct me if I am wrong, but I believe that run dry does not necessisarily imply an impending gear box failure. It is a qualification. Thirty minutes with no oil pressure or the loss of oil. In some boxes the run dry qualification of the gear box requires residual oil in the sump and an aux pump operating. Also, a 30 minute run dry qualification implies no other gear box problems. i.e. fractured gears, bad bearings ….
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I could see two scenarios:
1. North sea hero pilot saves everyone- AAIB said despite no oil in gearbox pilot managed to fly 15 minutes to rig and land safely. Medal from the Queen on Saturday.
2. Everyone dies on helicopter- AAIB says pilot blatantly disregarded the check list- that was the cause of the tragedy -parents are forming a committee of lawyers to sue operator. Why were procedures not followed?
Jack - S92 -from what I read in these threads it does NOT have a dry run capability- hence Land Immediately.
1. North sea hero pilot saves everyone- AAIB said despite no oil in gearbox pilot managed to fly 15 minutes to rig and land safely. Medal from the Queen on Saturday.
2. Everyone dies on helicopter- AAIB says pilot blatantly disregarded the check list- that was the cause of the tragedy -parents are forming a committee of lawyers to sue operator. Why were procedures not followed?
Jack - S92 -from what I read in these threads it does NOT have a dry run capability- hence Land Immediately.
Last edited by nbl; 28th Jan 2008 at 00:27. Reason: extra
I think that, once he is able to say, you will find that they did not land because the checklist said so but because it was the only right thing to do in view of the existing conditions and indications at the time.
Once again I say congrats on a job very well done.
Once again I say congrats on a job very well done.
I am just a stupid airframe driver so can someone tell me how they do the run dry tests.
I assume the main gearbox and inputs is placed on a sturdy test stand and with all accessories such as generators and Hydraulic pumps running underload it is run at normal cruise torque or thereabouts
Is the oil drained out before or during the test? I would assume during as we normally do not attempt aviation with the pressure at zero.
Everybody stands around behind a safety screen with stopwatches ticking away waiting for it all to come to a smoking, screaching halt.
Question is do they also do it with oil in the XMSM and fail the oil pump (s)?
I guess I am asking if the test faithfully duplicates the "real world".
Sorry if this has already been covered elswhere in the thread.
I assume the main gearbox and inputs is placed on a sturdy test stand and with all accessories such as generators and Hydraulic pumps running underload it is run at normal cruise torque or thereabouts
Is the oil drained out before or during the test? I would assume during as we normally do not attempt aviation with the pressure at zero.
Everybody stands around behind a safety screen with stopwatches ticking away waiting for it all to come to a smoking, screaching halt.
Question is do they also do it with oil in the XMSM and fail the oil pump (s)?
I guess I am asking if the test faithfully duplicates the "real world".
Sorry if this has already been covered elswhere in the thread.
nbl, please stop talking speculative cr*p! You said:
I can tell you that they gearbox did not loose it's oil. I can tell you that the S92 FM does not say to Land Immediately with low MGB oil pressure, the Land Immediately comes into play when secondary indications of impending gearbox failure are present, such as unusual noises, smoke in cabin, etc. I do not have access to the EC225 FM but I suspect it will also say something similar. The 225 30 minute capability is at Vy, followed by a Land Immediately. With low oil pressure in the S92 there is no such limitation, it is continue flight and Land ASAP.
NL's comments were also way off the mark
and I suspect 212man will be back with a few comments of his own when he has the time. There are obviously some pretty weak elements in the S92 design, one being when the pilot gets an INPUT CHIP caption when there is no chip, but only hot oil 
I could see two scenarios:
1. North sea hero pilot saves everyone- AAIB said despite no oil in gearbox pilot managed to fly 15 minutes to rig and land safely. Medal from the Queen on Saturday.
2. Everyone dies on helicopter- AAIB says pilot blatantly disregarded the check list- that was the cause of the tragedy -parents are forming a committee of lawyers to sue operator. Why were procedures not followed?
Jack - S92 -from what I read in these threads it does NOT have a dry run capability- hence Land Immediately.
1. North sea hero pilot saves everyone- AAIB said despite no oil in gearbox pilot managed to fly 15 minutes to rig and land safely. Medal from the Queen on Saturday.
2. Everyone dies on helicopter- AAIB says pilot blatantly disregarded the check list- that was the cause of the tragedy -parents are forming a committee of lawyers to sue operator. Why were procedures not followed?
Jack - S92 -from what I read in these threads it does NOT have a dry run capability- hence Land Immediately.
I can tell you that they gearbox did not loose it's oil. I can tell you that the S92 FM does not say to Land Immediately with low MGB oil pressure, the Land Immediately comes into play when secondary indications of impending gearbox failure are present, such as unusual noises, smoke in cabin, etc. I do not have access to the EC225 FM but I suspect it will also say something similar. The 225 30 minute capability is at Vy, followed by a Land Immediately. With low oil pressure in the S92 there is no such limitation, it is continue flight and Land ASAP.
NL's comments were also way off the mark
and I suspect 212man will be back with a few comments of his own when he has the time. There are obviously some pretty weak elements in the S92 design, one being when the pilot gets an INPUT CHIP caption when there is no chip, but only hot oil
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Variable load- I am not speculating on this incident- I can read 212mans response- ''minor loss of oil'' -the symptems present dictated 'land immediately'. When he is able to respond we will know more.
I agree with SAS and a bit with some of NL comments. If I was placed in the 'night , '60 knots' 'north sea' scenario I would not give a toss the FM said land /ditch immediately - I would descend to ultra low level and head for the nearest 'anything'. Only if some noise, further complication occured would I ditch.
( after discussion with my colleauge of course!)
Nearly forgot. The line between 'pilot saves the day ' and pilot 'disregards procedures' and f"""'s up is very fine indeed!!
I agree with SAS and a bit with some of NL comments. If I was placed in the 'night , '60 knots' 'north sea' scenario I would not give a toss the FM said land /ditch immediately - I would descend to ultra low level and head for the nearest 'anything'. Only if some noise, further complication occured would I ditch.
( after discussion with my colleauge of course!)
Nearly forgot. The line between 'pilot saves the day ' and pilot 'disregards procedures' and f"""'s up is very fine indeed!!
Last edited by nbl; 28th Jan 2008 at 13:09. Reason: addition
Ok, nice to see things have branched off nicely, with the usual "I'd use airmanship and not follow the RFM" contributions. I like to think we did.
First thing: the oil loss was minor and only not a contributory factor - it was a consequence of superheated seals breaking down. The streaks were all vertical indicating post landing leakage. So no need to consider the 30 minute argument in this particular case.
Here's a scenario: you are presented with the following EICAS accompanied with that lovely burning paint/hot metal smell, and the cabin is full of white haze.
I'm glad it wasn't Cougar, CHC or BHL on a revenue flight.
First thing: the oil loss was minor and only not a contributory factor - it was a consequence of superheated seals breaking down. The streaks were all vertical indicating post landing leakage. So no need to consider the 30 minute argument in this particular case.
Here's a scenario: you are presented with the following EICAS accompanied with that lovely burning paint/hot metal smell, and the cabin is full of white haze.
I'm glad it wasn't Cougar, CHC or BHL on a revenue flight.
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212man,
Good work all the way around (not that you need to hear it from me). I certainly don't and didn't want to "second guess " your actions, as the rest of the thread seemed to be going that way.
Good work all the way around (not that you need to hear it from me). I certainly don't and didn't want to "second guess " your actions, as the rest of the thread seemed to be going that way.
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Originally Posted by nbl
Variable load- I am not speculating on this incident- I can read 212mans response- ''minor loss of oil'' -the symptems present dictated 'land immediately'. When he is able to respond we will know more.
I agree with SAS and a bit with some of NL comments. If I was placed in the 'night , '60 knots' 'north sea' scenario I would not give a toss the FM said land /ditch immediately - I would descend to ultra low level and head for the nearest 'anything'. Only if some noise, further complication occured would I ditch.
( after discussion with my colleauge of course!)
Nearly forgot. The line between 'pilot saves the day ' and pilot 'disregards procedures' and f"""'s up is very fine indeed!!
I agree with SAS and a bit with some of NL comments. If I was placed in the 'night , '60 knots' 'north sea' scenario I would not give a toss the FM said land /ditch immediately - I would descend to ultra low level and head for the nearest 'anything'. Only if some noise, further complication occured would I ditch.
( after discussion with my colleauge of course!)
Nearly forgot. The line between 'pilot saves the day ' and pilot 'disregards procedures' and f"""'s up is very fine indeed!!
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My first post said lucky it was not north sea , night, 60 knots,
After 212mans response (and again well done 212 man ) it is clear it was lucky it was not in that scenario. SAS and NL jumped on the bandwagon saying Rfm was there to be interpreted not slavishly followed. I suggested the line line between doing what the rule book says and using your own judgement is very fine. Ask any passing lawyer.
After 212mans response (and again well done 212 man ) it is clear it was lucky it was not in that scenario. SAS and NL jumped on the bandwagon saying Rfm was there to be interpreted not slavishly followed. I suggested the line line between doing what the rule book says and using your own judgement is very fine. Ask any passing lawyer.