O-ring / seals replacement
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It comes down to common sense & experience.
Would you reuse a seal when there is no urgent need for the aircraft back into service? No way.
However, when you are in a situation either away from your main base or out station, would you want to lose a flight due to a problem that can be solved? In the hyd filter case, firstly you wouldn't disturb it until you could identify you had spares, but if you did need to refit the old one, at least you could inspect & leak test the system to prove it is safe & functional. Even fitting a new seal is no guarantee of a good seal, manufacture error or damage whilst fitting ( you DO inspect new seals & back up ring before fitting don't you?
) can easily cause problems.
Are you going to ground a SAR helicopter or HEMS machine that is urgently needed due to not having a seal for the mag chip detectors, or are you going to leak check it then make a decision?
Are you going to stop the C-130 flying that is air dropping water ammo & rations to a forward operating base because the Lp oil filter on one engine needing to be checked ( very common spurious fault due to cold oil popping the button!)? Again, common sense dictates that you refit the old seal that is perfectly serviceable & leak test, then make a decision.
Simple blanket statements saying "all seals MUST be replaced" simply don't work in the real world I'm afraid. Part of being an LAE is applying common sense & saying no when it needs to be said, and getting the aircraft flying safely when possible , in my humble opinion.
I am also a big fan of the "would I fly on it" test!
Would you reuse a seal when there is no urgent need for the aircraft back into service? No way.
However, when you are in a situation either away from your main base or out station, would you want to lose a flight due to a problem that can be solved? In the hyd filter case, firstly you wouldn't disturb it until you could identify you had spares, but if you did need to refit the old one, at least you could inspect & leak test the system to prove it is safe & functional. Even fitting a new seal is no guarantee of a good seal, manufacture error or damage whilst fitting ( you DO inspect new seals & back up ring before fitting don't you?
) can easily cause problems.Are you going to ground a SAR helicopter or HEMS machine that is urgently needed due to not having a seal for the mag chip detectors, or are you going to leak check it then make a decision?
Are you going to stop the C-130 flying that is air dropping water ammo & rations to a forward operating base because the Lp oil filter on one engine needing to be checked ( very common spurious fault due to cold oil popping the button!)? Again, common sense dictates that you refit the old seal that is perfectly serviceable & leak test, then make a decision.
Simple blanket statements saying "all seals MUST be replaced" simply don't work in the real world I'm afraid. Part of being an LAE is applying common sense & saying no when it needs to be said, and getting the aircraft flying safely when possible , in my humble opinion.
I am also a big fan of the "would I fly on it" test!
Thought police antagonist
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K Eng,
I realise you are newly arrived in the real world ( we all were at some point ) however, whilst expediency is one facet and wholly dependent on the circumstances at the time ( and we ALL face making these decisions at some point ) I would suggest you need to review some of the basics....as a matter of urgency.
If you would be prepared to sign an aircraft off with the mag chip seals missing, then maybe a new vocation calls because I would certainly not wish to fly in any aircraft you deemed fit for flight with these missing.....
Here's a helpful clue.....
Eastern Air Lines Flight 855 - Wikipedia, the free encyclopedia
I realise you are newly arrived in the real world ( we all were at some point ) however, whilst expediency is one facet and wholly dependent on the circumstances at the time ( and we ALL face making these decisions at some point ) I would suggest you need to review some of the basics....as a matter of urgency.
If you would be prepared to sign an aircraft off with the mag chip seals missing, then maybe a new vocation calls because I would certainly not wish to fly in any aircraft you deemed fit for flight with these missing.....
Here's a helpful clue.....
Eastern Air Lines Flight 855 - Wikipedia, the free encyclopedia
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Kengineer130....
Kengineer130,
I agree with you totally !!!
And come to a conclusion 180° diametrically opposed to you !
"I'm sorry, we don't have the seals required so NO, your aircraft isn't going anywhere until we get them"
"And as soon as the seals get here we'll get you back in the air".
You know, in all my years as a LAE, and there's a great many of them, never, not once, ever, has a pilot asked me to take a short cut or deviate from approved procedures to get them back flying again.
I'll end this post as I ended my previous........
Question...........
If I should ignore THAT approved data, what other approved data should I ignore ?
ST
I agree with you totally !!!
And come to a conclusion 180° diametrically opposed to you !
Originally Posted by Kengineer130
..............Part of being an LAE is applying common sense & saying no when it needs to be said....
Originally Posted by Kengineer130
.........and getting the aircraft flying safely when possible , in my humble opinion.
You know, in all my years as a LAE, and there's a great many of them, never, not once, ever, has a pilot asked me to take a short cut or deviate from approved procedures to get them back flying again.
I'll end this post as I ended my previous........
Originally Posted by SpannerTwister
Question...........
If I should ignore THAT approved data, what other approved data should I ignore ?
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OK what if a gasket is deemed 'reusable' would you still fit it despite it being damaged or would you use your engineering judgement.
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@krystal and chips
The mechanic said that he did not examine the replacement magnetic chip detectors to insure that the 0—ring seals were installed.
That's negligence, not making a judgement.
The mechanic said that he did not examine the replacement magnetic chip detectors to insure that the 0—ring seals were installed.
That's negligence, not making a judgement.
Last edited by blackhand; 5th Jul 2012 at 07:59.
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Bring out the straw men !
Originally Posted by jxk
OK what if a gasket is deemed 'reusable' would you still fit it despite it being damaged or would you use your engineering judgement.
As to your post, apart from being in the running for "Silliest Post Of The Year" award, it just doesn't make sense.
Reusable parts (in accordance with the applicable Approved Data) are ALWAYS checked by the LAE prior to fitment.
The gasket you referred to MAY be reused, subject to satisfactory inspection, it is NOT required to be reused if it is faulty !
Troll.
ST
Krystal n chips said:
If you would be prepared to sign an aircraft off with the mag chip seals missing, then maybe a new vocation calls because I would certainly not wish to fly in any aircraft you deemed fit for flight with these missing.....
Good eyesight is a requirement for aircraft and component inspection. Where exactly did Kengineer state that he'd put the chip detector back without using any seals?
If you would be prepared to sign an aircraft off with the mag chip seals missing, then maybe a new vocation calls because I would certainly not wish to fly in any aircraft you deemed fit for flight with these missing.....
Good eyesight is a requirement for aircraft and component inspection. Where exactly did Kengineer state that he'd put the chip detector back without using any seals?
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Krystal, I fear you've mistaken what I have written regarding mag chips, obviously no seals at all is a 100% stopper, give me some credit!
.
I was referring to inspecting the used seals, and reusing them if they were in perfect condition & could be verified with a leak check by way of an EGR etc.
. I was referring to inspecting the used seals, and reusing them if they were in perfect condition & could be verified with a leak check by way of an EGR etc.
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Bloody hell,lets make this real simple
If the approved data says "speed limit 70mph" and you do 90 and kill someone because you can't stop in time-how do you think you would feel while you sit in jail....
So all those who choose not to "follow the approved data" to the letter,
think about this when there's a smoking hole that was your last signoff
Many people dead,many lives wrecked,company name destroyed,
END OF JOB for you and many others..
Get it yet
Change the bloody seal, no if's or but's
If the approved data says "speed limit 70mph" and you do 90 and kill someone because you can't stop in time-how do you think you would feel while you sit in jail....
So all those who choose not to "follow the approved data" to the letter,
think about this when there's a smoking hole that was your last signoff
Many people dead,many lives wrecked,company name destroyed,
END OF JOB for you and many others..
Get it yet
Change the bloody seal, no if's or but's
To the 'Noes':
Just to drift slightly, let's take a scenario whereby you're stuck in the middle of nowhere (say on a recovery) and you need a split pin before you can get airborne. You haven't got one of that size. However... there are commercial pins available from the mud hut automotive store or there is some .040" locking wire in your toolbox that would do the job.
What would you do in that situation?
Just to drift slightly, let's take a scenario whereby you're stuck in the middle of nowhere (say on a recovery) and you need a split pin before you can get airborne. You haven't got one of that size. However... there are commercial pins available from the mud hut automotive store or there is some .040" locking wire in your toolbox that would do the job.
What would you do in that situation?
Last edited by stevef; 5th Jul 2012 at 18:13.
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Originally Posted by stevef
you're stuck in the middle of nowhere (say on a recovery) and you need a split pin before you can get airborne. You haven't got one of that size. However... there are commercial pins available from the mud hut automotive store or there is some .040" locking wire in your toolbox that would do the job.
What would you do in that situation?
What would you do in that situation?
I guess the OP has the answer to his question........and indeed he did a couple of pages ago, some would stick to the Approved Data and some would evaluate the situation case-by-case.
It seems fair to say that those of us sticking to the "Follow approved data" line cannot understand those who deviate from it, while equally those in the "use common sense" camp see us as inflexible dinosaurs
.I guess we'll have to agree to differ
!On a serious note though, those of us in the "blindly follow approved data camp" might wonder just how far those in the other camp are prepared to deviate from the approved data ?
If you haven't got a torque wrench is F.T 'tight enough", if you haven't got a tyre pressure gauge is "round and black" good enough ?
How about a bit of honesty, "Apart from o-rings, when do you deviate from approved data ?"
ST
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Back to original question...
Thanks for all your views so far, but coming back to the original question:
My scenario is: Aircraft in hangar for scheduled maintenance for 3 days. On day 2 I replaced hyrdaulic case drain filter & o-rings (routine replacement). On day 3 during functionals, the hydraulic filter suffered some problems. As part of trouble shooting I am to remove & inspect this same case drain filter which I replaced in day 2. I inspect it & found all ok, and reinstall the case drain filter.
NOW comes the question - I replaced this filter yesterday with new o-rings, today I remove & reinstall the same filter - do I need to change the o-ring? It's only 1 day old!
Ok, I'm sure all of you would say just change it, it's only a few cents.
BUT what if there's no more stock....??? Again, the existing o-ring is only a day old...
My scenario is: Aircraft in hangar for scheduled maintenance for 3 days. On day 2 I replaced hyrdaulic case drain filter & o-rings (routine replacement). On day 3 during functionals, the hydraulic filter suffered some problems. As part of trouble shooting I am to remove & inspect this same case drain filter which I replaced in day 2. I inspect it & found all ok, and reinstall the case drain filter.
NOW comes the question - I replaced this filter yesterday with new o-rings, today I remove & reinstall the same filter - do I need to change the o-ring? It's only 1 day old!
Ok, I'm sure all of you would say just change it, it's only a few cents.
BUT what if there's no more stock....??? Again, the existing o-ring is only a day old...
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I follow the AMM.
The expectation is to do so without deviation where I work now. Even if it is considered overkill. AMMs are written to account for dumbos working on aircraft and for them to have a chance to get maintenance tasks right.
It has not always been that way for me. I'm in my 4th decade as a LAE and have done things that would make your hair curl to get a ship home using my judgement ie Teheran or Karachi surrounded by machine gun toting types. In such cases the culture was different and use of approved data was nowhere near as strong or enforced. The "can do" thing was encouraged.
For the checker / non changers I understand you guys are very likely in a different environment. been there done that.
Just a question for those guys who dont always change O rings ( for example) , how do you sign off tasks where such things are mandatory and a tracking number of all parts used are required?
If you are going to cut any corners it needs to be plausibly deniable in the event of a stuff up. And it may not be a stuff up you caused. You may just be collateral damage in the inevitable book checking that occurs looking for someone to hang.
Personally , I dont give a rats ring gear about delays these days and if it's because of following approved data so be it. Fire proof. I get paid the same whether I cut corners or stick by the book. In these days of EASA regs , human factors and the mandatory entering of every release note and P/No / S/No of equipment used into the tech log for tests and part changes its just not worth it for me.
I will not be thanked for saving time by cutting corners but will be held accountable if it goes tits up because I have not.
The expectation is to do so without deviation where I work now. Even if it is considered overkill. AMMs are written to account for dumbos working on aircraft and for them to have a chance to get maintenance tasks right.
It has not always been that way for me. I'm in my 4th decade as a LAE and have done things that would make your hair curl to get a ship home using my judgement ie Teheran or Karachi surrounded by machine gun toting types. In such cases the culture was different and use of approved data was nowhere near as strong or enforced. The "can do" thing was encouraged.
For the checker / non changers I understand you guys are very likely in a different environment. been there done that.
Just a question for those guys who dont always change O rings ( for example) , how do you sign off tasks where such things are mandatory and a tracking number of all parts used are required?
If you are going to cut any corners it needs to be plausibly deniable in the event of a stuff up. And it may not be a stuff up you caused. You may just be collateral damage in the inevitable book checking that occurs looking for someone to hang.
Personally , I dont give a rats ring gear about delays these days and if it's because of following approved data so be it. Fire proof. I get paid the same whether I cut corners or stick by the book. In these days of EASA regs , human factors and the mandatory entering of every release note and P/No / S/No of equipment used into the tech log for tests and part changes its just not worth it for me.
I will not be thanked for saving time by cutting corners but will be held accountable if it goes tits up because I have not.
Last edited by ampclamp; 6th Jul 2012 at 09:37.
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Aircraft in hangar for scheduled maintenance for 3 days.
If you are going to cut any corners it needs to be plausibly deniable in the event of a stuff up.
Only do what you can justify amongst your peers, and in a court of law.
Contact my engineering department and ask them to issue an Engineering Approval for the proposed deviation from approved data.
Last edited by blackhand; 6th Jul 2012 at 10:21.
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The textbook answer is you should do what the Approved Data tells you to do, otherwise if anything goes wrong your ass is most surely grass.
However there are applications where it is quite normal to re-use packings, subject to inspection for cuts, flats, chips and rolling. These are not all 10-cent items by any means - some larger ones can be well over $100 apiece, and if they are being exposed on a regular basis it can make a big difference to your maintenance costs to re-use serviceable parts. And it's perfectly safe as long as it's done in a controlled manner with subsequent leak checks.
The key is in how you do it. For seals that get exposed once in a blue moon you're probably better off being safe and changing them. But if you're in an environment where you have control of your processes (and I'm thinking processes derived from CMMs and adapted to local working practices) you can then write into YOUR OWN approved data which packings can be re-used, along with the circumstances and any associated leak checks post assembly.
If you read the introduction section of just about every CMM in the world you will see a statement that the manual contains RECOMMENDED procedures and the manufacturer permits deviation from these to suit local working practices if an equivalent or better standard of safety can be achieved. The art is in justifying your own procedures in line with this statement, and everyone does this to a greater of lesser degree whether it's use of different paint, cleaning systems, tooling, etc.
However there are applications where it is quite normal to re-use packings, subject to inspection for cuts, flats, chips and rolling. These are not all 10-cent items by any means - some larger ones can be well over $100 apiece, and if they are being exposed on a regular basis it can make a big difference to your maintenance costs to re-use serviceable parts. And it's perfectly safe as long as it's done in a controlled manner with subsequent leak checks.
The key is in how you do it. For seals that get exposed once in a blue moon you're probably better off being safe and changing them. But if you're in an environment where you have control of your processes (and I'm thinking processes derived from CMMs and adapted to local working practices) you can then write into YOUR OWN approved data which packings can be re-used, along with the circumstances and any associated leak checks post assembly.
If you read the introduction section of just about every CMM in the world you will see a statement that the manual contains RECOMMENDED procedures and the manufacturer permits deviation from these to suit local working practices if an equivalent or better standard of safety can be achieved. The art is in justifying your own procedures in line with this statement, and everyone does this to a greater of lesser degree whether it's use of different paint, cleaning systems, tooling, etc.