Haddon-Cave, Airworthiness, Sea King et al (merged)
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DV and others,
I would very much hope that this SI on the DECU connectors was removed many years ago following corrective action to address the cause, or at least some palliative action in service (e.g. application of wire locking) to negate the need for in flight checks.
Can anyone confirm that?
It's the basics here - in my view you just don't carry out in flight checks of anything unless the aircraft is signed up for a Check Test Flight, or a specifically documented In Flight Check. For an engine control connector, this would normally be a 'one off' to investigate a problem. In any case, you are checking for something that you really can't tolerate happening - it's got to be fixed, not checked.
If (and I really hope that I'm wrong here) this SI is still in use, then there is something seriously wrong in the State of Denmark here. It's a threaded electrical connector - it must have been fixed by now. If not, the RAF have some explaining to do.
Best regards as ever to those actually trying to do the job at the front line
Engines
I would very much hope that this SI on the DECU connectors was removed many years ago following corrective action to address the cause, or at least some palliative action in service (e.g. application of wire locking) to negate the need for in flight checks.
Can anyone confirm that?
It's the basics here - in my view you just don't carry out in flight checks of anything unless the aircraft is signed up for a Check Test Flight, or a specifically documented In Flight Check. For an engine control connector, this would normally be a 'one off' to investigate a problem. In any case, you are checking for something that you really can't tolerate happening - it's got to be fixed, not checked.
If (and I really hope that I'm wrong here) this SI is still in use, then there is something seriously wrong in the State of Denmark here. It's a threaded electrical connector - it must have been fixed by now. If not, the RAF have some explaining to do.
Best regards as ever to those actually trying to do the job at the front line
Engines
If it was threaded, that would perhaps explain why 15mins may have mitigated the hazard (easy to spot, early indication of onset, probably take a while & several turns to fully loosen).
Thats not to say its acceptable and should not have been fixed ASAP - just that the mitigation, however undesirable, was probably effective. If the check was conducted of course - but the crews were probably keen to ensure the connectors stayed connected.
As you say engines, I'm surprised some form of interim wire locking solution could not have been developed.
DV
Is your conclusion that the DECU is susceptible based on the type of connectors used? Designing to avoid EMC problems in an aircraft environment (e.g. through connector choice) is common practice - it doesn't necessarily indicate that there is a known weakness or history of problems with a specific equipment.
Thats not to say its acceptable and should not have been fixed ASAP - just that the mitigation, however undesirable, was probably effective. If the check was conducted of course - but the crews were probably keen to ensure the connectors stayed connected.
As you say engines, I'm surprised some form of interim wire locking solution could not have been developed.
DV
I believe that the connector pins used are of the EMI/EMP type. So clearly the DECU is very susceptible to EMI, RFI and EMP.
I'm not a helicopter man, as you know, but it seems to me that a crew flying over badlands in a shooting war, all busy performing their roles, might have better things to think about than checking a simple, but critical connector every time the egg timer goes off.
"Sorry, Captain, I've go to stop looking after the machine gun and the casualties while I go and check the MoD's mistake to make it's not going to kill us."
Don't even bother telling me who does what or even if they have a mchine gun. You know the point I'm trying to make!
"Sorry, Captain, I've go to stop looking after the machine gun and the casualties while I go and check the MoD's mistake to make it's not going to kill us."
Don't even bother telling me who does what or even if they have a mchine gun. You know the point I'm trying to make!
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Courtney,
Absolutely spot on. Crews on ops simply can't be required to check that bits of their aircraft are still attached. Crews on training shouldn't be doing that. Crews on SAR shouldn't be doing it. Crews just flying around on GFP shouldn't be doing it. No one should be doing it. At all. Ever. It's not their flaming job. It's the engineers, and until it's fixed, the aircraft stays on the ground.
JF, the point is not that 'it's threaded, so 15 minutes mitigates'. 'Easy to spot' is not the point. 'Several turns to fully loosen' is definitely NOT the point. The point is that no aircraft should ever be allowed to get into the air with an electrical connector that affects the integrity of the engine controls not properly secured so that it might come loose. Especially, especially, if you know about it.
It's not rocket science, honestly. It's stopping a plug falling off, and we've been doing this for years. This is basic aircraft engineering standards and practices. Our crews deserve far better than this, and if people are still signing this one off they need retraining until they stop doing it.
I hope I'm not coming over as too judgemental here, but honestly, the fact that we might still have some people who are prepared to tolerate this sort of thing sacres the bejeesus out of me....
Best Regards as ever to those at the sharp end
Engines
Absolutely spot on. Crews on ops simply can't be required to check that bits of their aircraft are still attached. Crews on training shouldn't be doing that. Crews on SAR shouldn't be doing it. Crews just flying around on GFP shouldn't be doing it. No one should be doing it. At all. Ever. It's not their flaming job. It's the engineers, and until it's fixed, the aircraft stays on the ground.
JF, the point is not that 'it's threaded, so 15 minutes mitigates'. 'Easy to spot' is not the point. 'Several turns to fully loosen' is definitely NOT the point. The point is that no aircraft should ever be allowed to get into the air with an electrical connector that affects the integrity of the engine controls not properly secured so that it might come loose. Especially, especially, if you know about it.
It's not rocket science, honestly. It's stopping a plug falling off, and we've been doing this for years. This is basic aircraft engineering standards and practices. Our crews deserve far better than this, and if people are still signing this one off they need retraining until they stop doing it.
I hope I'm not coming over as too judgemental here, but honestly, the fact that we might still have some people who are prepared to tolerate this sort of thing sacres the bejeesus out of me....
Best Regards as ever to those at the sharp end
Engines
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JFZ, you said
I do not know your background, but the only way to mitigate this hazard is not to fly. The only way that Nimrod's AAR hazard was minitgated was to avoid AAR. It took a long time to sink in with the RAF Chiefs, but that was the final solution.
The DECU is shown as having a threaded connector. Why did the BOI not go down this road, and why does it take a "retiredee" to discover it 17 years later?
DV
If it was threaded, that would perhaps explain why 15mins may have mitigated the hazard (easy to spot, early indication of onset, probably take a while & several turns to fully loosen).
The DECU is shown as having a threaded connector. Why did the BOI not go down this road, and why does it take a "retiredee" to discover it 17 years later?
DV
Last edited by Distant Voice; 9th Jan 2012 at 20:05.
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Engines, in answer to your question,
MoD's answer is that "this SI was withdrawn from use in 1995 and the details incorporated into he normal Chinook Maintenance Manual". So it looks as though the connectors remained and the SI just became part of normal servicing.
DV
I would very much hope that this SI on the DECU connectors was removed many years ago following corrective action to address the cause, or at least some palliative action in service (e.g. application of wire locking) to negate the need for in flight checks.
DV
Another dubious assumption:
"MoD's answer is that "this SI was withdrawn from use in 1995 and the details incorporated into he normal Chinook Maintenance Manual". So it looks as though the connectors remained and the SI just became part of normal servicing."
'Withdrawn' may be for any one of several restorative reasons, including a possible modification action, the details of which would be placed in the AMM.
Please keep this thread's discussion to 'speculation' and try to avoid 'wild' speculation.
Also:
Engine's missive that "Engineers should do it" implies blame on the shop floor when in reality they can only react (legally) to "Servicing Instructions" from design engineers/PT staff.
Clarification, not criticism.
"MoD's answer is that "this SI was withdrawn from use in 1995 and the details incorporated into he normal Chinook Maintenance Manual". So it looks as though the connectors remained and the SI just became part of normal servicing."
'Withdrawn' may be for any one of several restorative reasons, including a possible modification action, the details of which would be placed in the AMM.
Please keep this thread's discussion to 'speculation' and try to avoid 'wild' speculation.
Also:
Engine's missive that "Engineers should do it" implies blame on the shop floor when in reality they can only react (legally) to "Servicing Instructions" from design engineers/PT staff.
Clarification, not criticism.
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Another dubious assumption:
"MoD's answer is that "this SI was withdrawn from use in 1995 and the details incorporated into he normal Chinook Maintenance Manual". So it looks as though the connectors remained and the SI just became part of normal servicing."
"MoD's answer is that "this SI was withdrawn from use in 1995 and the details incorporated into he normal Chinook Maintenance Manual". So it looks as though the connectors remained and the SI just became part of normal servicing."
Are there any current DECU tradesmen out there?
DV
DV,
Your photgarphs may be misleading you.
Threaded they may be - but are they sealed and/or locked?
There are many ways of locking joints, even mere threaded Plugs and Sockets.
I'm afraid you'll have to do better than quoting a photgarph from "Training Notes in 2006".
I assume from your location that you are amongst Bristols 'finest'. If so, find someone who can back up your proposition rather than wildly speculate on some unpublished picture from more than 5 years ago.
I have a picture of Fairies at the bottom of my garden...
...we were having a BBQ.
Your photgarphs may be misleading you.
Threaded they may be - but are they sealed and/or locked?
There are many ways of locking joints, even mere threaded Plugs and Sockets.
I'm afraid you'll have to do better than quoting a photgarph from "Training Notes in 2006".
I assume from your location that you are amongst Bristols 'finest'. If so, find someone who can back up your proposition rather than wildly speculate on some unpublished picture from more than 5 years ago.
I have a picture of Fairies at the bottom of my garden...
...we were having a BBQ.
I think we're straying too far.
To take a point made earlier that SIs were issued by MoD(PE), and as DV seems to have the actual Servicing Instruction, could he confirm who issued it? If PE haven't signed it, then what indication is there that it has been validated and verified? I did a tour in that PE department and from the info on this thread I'm fairly certain it would have been thrown back and a formal modification required.
The other point about Odiham apparently amending the SI to an in-flight SI is, as Engine says, not a recognisable procedure. You've got to wonder at what was going on higher up in the RAF if Odiham felt it necessary to resort to this.
With apologies to Tuc and Pulse1 who discussed this a long time ago on the ZD576 thread. The rest of us catch up eventually.
To take a point made earlier that SIs were issued by MoD(PE), and as DV seems to have the actual Servicing Instruction, could he confirm who issued it? If PE haven't signed it, then what indication is there that it has been validated and verified? I did a tour in that PE department and from the info on this thread I'm fairly certain it would have been thrown back and a formal modification required.
The other point about Odiham apparently amending the SI to an in-flight SI is, as Engine says, not a recognisable procedure. You've got to wonder at what was going on higher up in the RAF if Odiham felt it necessary to resort to this.
With apologies to Tuc and Pulse1 who discussed this a long time ago on the ZD576 thread. The rest of us catch up eventually.
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Rigga,
Sorry if you got the wrong end of the stick - my fault for using loose terminology, not in any way yours. It was most certainly not my intention to imply ANY criticism of the people on the shop floor.
My use of the term 'engineers' stems from my time in the RN - in FAA squadrons, the 'engineers' are the Air Engineering Officers (AEOs), RAF equivalent are the EngOs.
My point was that maintenance of the aircraft (including fixing loose connectors) should be directed and led by the EngOs on the station or base (or ship) alone. They are responsible for maintaining the airworthiness of the aircraft by making sure that the maintainers (the 'shop floor') service and repair them in accordance with the laid down instructions.
But, in my book, they are also responsible for taking bold and correct engineering decisions when they are faced with problems not in the book. It's what they are trained for and why they have the stripes and a commission. It's not a job for aircrew.
Once again, my sincere apologies if you thought I was criticising the maintainers.
Best regards
Engines.
Sorry if you got the wrong end of the stick - my fault for using loose terminology, not in any way yours. It was most certainly not my intention to imply ANY criticism of the people on the shop floor.
My use of the term 'engineers' stems from my time in the RN - in FAA squadrons, the 'engineers' are the Air Engineering Officers (AEOs), RAF equivalent are the EngOs.
My point was that maintenance of the aircraft (including fixing loose connectors) should be directed and led by the EngOs on the station or base (or ship) alone. They are responsible for maintaining the airworthiness of the aircraft by making sure that the maintainers (the 'shop floor') service and repair them in accordance with the laid down instructions.
But, in my book, they are also responsible for taking bold and correct engineering decisions when they are faced with problems not in the book. It's what they are trained for and why they have the stripes and a commission. It's not a job for aircrew.
Once again, my sincere apologies if you thought I was criticising the maintainers.
Best regards
Engines.
DV & Engines,
I wanted to correct the direction that I think the thread was heading - towards the shop floor and Line maintenance. This isn't about them.
I apologise for my sharp language - I never learnt proper english or studied diplomacy - so I am quite blunt in everything I write. And I have no respect for 'rank' anymore. I've seen too many wasters in life to worry about their status or feelings. I normally speak straight from the gut.
Whilst a great many Ppruners are evidently smarter than me I have no time for those that show an inordinate amount of ignorance of maintenance and Continued Airworthiness (don't confuse them with Airworthiness - I'm not that clever) considering their direct effect on day-to-day flying.
You should read what I write when I really mean business.
I wanted to correct the direction that I think the thread was heading - towards the shop floor and Line maintenance. This isn't about them.
I apologise for my sharp language - I never learnt proper english or studied diplomacy - so I am quite blunt in everything I write. And I have no respect for 'rank' anymore. I've seen too many wasters in life to worry about their status or feelings. I normally speak straight from the gut.
Whilst a great many Ppruners are evidently smarter than me I have no time for those that show an inordinate amount of ignorance of maintenance and Continued Airworthiness (don't confuse them with Airworthiness - I'm not that clever) considering their direct effect on day-to-day flying.
You should read what I write when I really mean business.
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I wanted to correct the direction that I think the thread was heading - towards the shop floor and Line maintenance. This isn't about them.
I apologise for my sharp language -
I apologise for my sharp language -
DV
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and the net is starting to close
Sorry, but I have the feeling the subjects of your post make eels look like snails - Both are somewhat slimy...
DV,
If I believed that the "net is starting to close" on the likes of Alcock, the B-Word et al I would sleep easier at night. However, I doubt that they will ever be brought to account for their disgraceful part in the systemic failure of the MoD's airworthiness system.
If I believed that the "net is starting to close" on the likes of Alcock, the B-Word et al I would sleep easier at night. However, I doubt that they will ever be brought to account for their disgraceful part in the systemic failure of the MoD's airworthiness system.
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I doubt that they will ever be brought to account for their disgraceful part in the systemic failure of the MoD's airworthiness system.
The "Golden Boys" from this period are accountable for the deaths of at least 45 people (29 Chinook, 2 Tornado and 14 Nimrod)
DV
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JB said;
Seems as though they adopted the SI; for "alignment stripes" read "witness marks".
DV
Just a reminder that the US Army "Airworthiness Release for MH-47E Production Helicopters" dated 31 October 1995 still required (para 5f) that "a pre-flight inspection to check the DECU connectors for correct positioning of alignment stripes is required. These stripes shall also be checked while conducting the 30 minute ramp area check" Para 5e requires that any priority 1 software problems shall be reported to USAATCOM immediately.
DV
(Also posted on Apache wire strike thread)
Ministry of Defence | About Defence | Corporate Publications | Air Safety and Aviation Publications | Military Aviation Authority | Corporate Information
See Air Safety Annual Report, page 3;
“At this stage I have identified 3 strategic Air Safety operating risks.......(3) helicopter collisions with wires and obstructions. Ensuring they attract an appropriate profile and emphasis on their mitigation will be a priority for me in the coming period.”
And Annex A;
“A 2008 report....28 recommendations including technology and research....some significant ones remain outstanding, particularly in the technology and research area...”.
At the moment I can’t reconcile this with the fact it is well over 20 years since the multi-function, podded laser detector was offered to MoD and the fact the design team has been disbanded / made redundant while MoD’s R&D effort in this technology area has been more or less stopped. At the time, the pod would have been considered heavy for most helicopters (the requirement was FW) but technology has moved on since I saw the prototype working in 1985. If anyone in MAA is reading this, dig around the old files and engage the designer. He has his own company now and routinely advises NATS and other countries on similar applications of the same basic device. MoD should also bear in mind they probably retain the Intellectual Property Rights!
Ministry of Defence | About Defence | Corporate Publications | Air Safety and Aviation Publications | Military Aviation Authority | Corporate Information
See Air Safety Annual Report, page 3;
“At this stage I have identified 3 strategic Air Safety operating risks.......(3) helicopter collisions with wires and obstructions. Ensuring they attract an appropriate profile and emphasis on their mitigation will be a priority for me in the coming period.”
And Annex A;
“A 2008 report....28 recommendations including technology and research....some significant ones remain outstanding, particularly in the technology and research area...”.
At the moment I can’t reconcile this with the fact it is well over 20 years since the multi-function, podded laser detector was offered to MoD and the fact the design team has been disbanded / made redundant while MoD’s R&D effort in this technology area has been more or less stopped. At the time, the pod would have been considered heavy for most helicopters (the requirement was FW) but technology has moved on since I saw the prototype working in 1985. If anyone in MAA is reading this, dig around the old files and engage the designer. He has his own company now and routinely advises NATS and other countries on similar applications of the same basic device. MoD should also bear in mind they probably retain the Intellectual Property Rights!
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Chugalug re your 8 Jan post:
<<... , no definitive evidence from the wreckage.>>
For someone who has spent so much time on the Mull thread you are appallingly ignorant – perhaps people reading this thread who are interested in airworthiness should take the trouble of checking out the old Mull thread which should remove the Chinook tragedy from consideration as a consequence of airworthiness. As I pointed out in that thread, their course, control actions, and engine states had a rational explanation which predicted the use of certain kit which was eventually established to have been fitted – QED. Is it “idiosyncratic” to face up to the evidence, however unpalatable?
<<... , no definitive evidence from the wreckage.>>
For someone who has spent so much time on the Mull thread you are appallingly ignorant – perhaps people reading this thread who are interested in airworthiness should take the trouble of checking out the old Mull thread which should remove the Chinook tragedy from consideration as a consequence of airworthiness. As I pointed out in that thread, their course, control actions, and engine states had a rational explanation which predicted the use of certain kit which was eventually established to have been fitted – QED. Is it “idiosyncratic” to face up to the evidence, however unpalatable?