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  1. #551
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    BOLLETTINO TECNICO N° 139-265
    The technical content of this document is approved
    under the authority of DOA nr. EASA.21J.005 DATE August 25, 2011


    SUBJECT: PRECAUTIONARY INSPECTION AND QUARANTINE OF TAIL ROTOR
    BLADES
    REASON: to introduce a precautionary inspection and quarantine on tail rotor blades.

    NOTE
    This Bollettino supersedes BT no. 139-251
    HELICOPTERS AFFECTED:
    Part I: All AB139/AW139 helicopters equipped with tail rotor blades P/N
    3G6410A00131 or P/N 4G6410A00131.
    Part II: All AB139/AW139 helicopters equipped with tail rotor blades P/N
    3G6410A00131 or P/N 4G6410A00131, having logged more than 600 flying
    hours or more than 1500 landings whichever occurs first.

    This almost mean the whole fleet.

    DESCRIPTION: as a result of the first available information of the AW139 event in Brazil, while the investigation is ongoing and waiting for additional
    information/analysis, as a precautionary measure this Bollettino prescribes
    inspection and quarantine of the tail rotor blades meeting the criteria reported in the above paragraph.
    In the meantime collection of all necessary evidence is going on in order to isolate the root cause and determine the final corrective actions.



    http://www.pprune.org/rotorheads/461...cussion-4.html

    http://www.pprune.org/rotorheads/461...-brasil-2.html
    Last edited by Helihead; 25th August 2011 at 16:30.

  2. #552
    Moderator DeV's Avatar
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    Is it not just a case of grounding aircraft after a certain amount of hours, checking the tail rotor blades and if they are not from the 2 effected batches carry on?

  3. #553
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    Dev.

    Here's the official piece of paper.

    http://www.agustawestland.com/system/files/139-265.pdf


    Maybe someone with engineering expertise could answer that one.

  4. #554
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    Is it not just a case of grounding aircraft after a certain amount of hours, checking the tail rotor blades and if they are not from the 2 effected batches carry on
    Yes and No.

    The items quoted are not batch numbers they are part numbers. Therefore the 2 part numbers stated are likely to include ALL A139 tail rotor blades currently in service / storage / production.

    The maintenance regime then kicks in as follows:

    Part 1: If blades are under 600 hours or 1500 landings inspect for damage. If no damage found continue in service with new inspection every 25 hours until 600hrs or 1500 landings then Part 2 kicks in.

    Part 2: If over 600hrs or 1500 landing since new the blades must be removed, even if it has been inspected every 25 hrs up to this limit.
    Considering that landings are never logged for tail blades and if an operator cannot say how many a blade has been exposed to they must log 4 landings per FH that could have the limit for removal as low as 375 FH.


    To my mind the most significant item in this is the inclusion of landing cycles. Dynamic components do log cycles for starts etc but never landings. This would suggest that Augusta are concerned that the tail blades are potentially being damaged by the high torque segment of flights, ie the take off and landings. Thats all well and good for commercial operations but what about operators who spend increased time at high torque settings, for example SAR, USL, Fast Roping etc. These aircraft may only take off and land once in an operation but could spend many multiples of the flight time, of a take off or landing, in the hover at high torque setting. How are these operators going to be dealt with?
    I certainly wouldn't be comfortable sitting in a 139 for the foreseeable.
    Last edited by Tadpole; 25th August 2011 at 18:03.

  5. #555
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    Doesn't sound good at all. I wonder what the air corps will do? i certainly wouldn't feel comfortable in one after reading this.

  6. #556
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  7. #557
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    I took this pic yesterday.... Notice the wiring attached to the outside of the boom... looks like they were monitoring the tail....


    24-08-11 039 by Lucan Snapper, on Flickr

  8. #558
    Commander in Chief hptmurphy's Avatar
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    Buy in haste, repent at your leisure...
    Time for another break I think......

  9. #559
    Commandant Jetjock's Avatar
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    Quote Originally Posted by Seanachie View Post
    Buy in haste, repent at your leisure...
    There was nothing hasty about the procurement process.

    It was a case of civil servents making financial decisions beyond their aviation knowledge.

    As usual.

  10. #560
    Moderator DeV's Avatar
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    This kind of thing could happen with any aircraft, granted this particular problem may not happen with a more mature design.

    It looks to AW as if it is a component part (ie the tail rotor blades), if it is in the long run they just have to redesign it and replace them..... lets hope thats all it is.

  11. #561
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    TBH Id be concerned that it is indicative of bigger problems.

    When the AW139 first came into service it had serious problems with stress cracks in the tail boom. The modification to resolve this was to strengthen the tail construction. Unfortunately any engineer will know that a strengthened tail boom wont resolve the problem, it just moves it on to the next point of failure. The TR blades are at the tippy top of this stress path.

    Yes, strengthened blades will sort the problem but this entire saga is produced by manufacturers chasing high powered aircraft while trying to keep weight to a minimum. Failures happen, mods are incorporated and after some crashes / deaths the aircraft is at a structural strength and hence weight that it should have been at to start with. In general this means that payloads / performances etc are normally less then those advertised during the sale.
    Also if this is happening on 6400kg aircraft whats happening on 6800kg aircraft?

    Interestingly Agusta had very similar boom cracking problems with the early 109s. Lessons learnt??

    It was a case of civil servents making financial decisions beyond their aviation knowledge
    It was actually a case of Air Corps pilots, engineers and crew accompanied by members of the Army and a number of civil servants so plenty of aviation knowledge. The problem is that the project was hamstrung by a requirement for 'low maintenance' aircraft capable of 600+hrs per year. Therefore anything that looked reliable but maintenance intensive (By Don standards) effectively got binned. That, once more, left unproven airframes.

    Interestingly from the RTE News item quoted above:
    AW139 aircraft have been in service with the Air Corps since November 2006 and have flown over 5000 hours since becoming operational
    So in 57 months service 6 aircraft have produced 5000hrs. A fleet average of 1050hrs per year. 175hrs per aircraft per year!!! A little off the projected 600+hrs per year that put said prototypes in the frame.
    1050hrs per year is indicative of 2, maximum 3 airframes including maintenance downtime and just shows the gross underutilisation of these aircraft.
    I know many will say the Air Corps need more machines for large scale troop transport, mission flexibility etc but considering that Ive also heard from the Don that the average serviceability is somewhere close to 33%, ie 2 available at any one time, this isnt happening either. Maintenance issues in Baldonnel or maintenance issues with the 139?
    Last edited by Tadpole; 26th August 2011 at 09:00.

  12. #562
    Tim Horgan Goldie fish's Avatar
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    I'd say its hard to keep a maintenance schedule on aircraft available 365 days a year when you only do maintenance from 10am-3.30pm mon-thurs(10am-1.30pm friday).

    That said Augusta Westland provided figures that were fit for a brochure, not a tender. i.e they were ambitious, at best. They listed max external payload with one pilot, while sikorsky(being used to dealing with Military customers) listed it with full crew. They listed range in ideal conditions, not real world.
    I understand the real problem the donners had was to prevent the Civil Servants from selecting another eurocopter model which "just" met the criteria, when it became clear the Government were not keen on the Blackhawk.


    Catch-22 says they have a right to do anything we can't stop them from doing.

  13. #563
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    Poor civil servants getting blamed for a lot of stuff that wasn't their fault.
    Discussions on that particular aircraft were going on in Baldonnel for a long time prior to any tender, in the end it was never physically evaluated due to a lack of suitable gearbox dry run capability. Hence, it wasnt even in the running by the time the 139 was picked.

  14. #564
    Commander in Chief hptmurphy's Avatar
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    There was nothing hasty about the procurement process.

    It was a case of civil servents making financial decisions beyond their aviation knowledge.

    As usual.
    Interesting that we could have been classed as the launch customer for an aircraft which wasn't really tried and tested and we did buy in haste with this particular aircraft rather than seeing how it would perform before buying.

    It was an unknown quantity and to base almost your entire helicopter force on something which didn't have a proven track record was mindless to say the least, but we did the same with the Dauphin so its not that surprising.

    The process and policy is there to see that every thing is compliant to the requirement of the end user, but in this case the end user wasn't going to get what it needed or wanted and yet again tried to combine the whole package in to one type , took a gamble and may have a heavy price to pay.
    Time for another break I think......

  15. #565
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    Quote Originally Posted by Tadpole View Post
    Poor civil servants getting blamed for a lot of stuff that wasn't their fault.
    Discussions on that particular aircraft were going on in Baldonnel for a long time prior to any tender, in the end it was never physically evaluated due to a lack of suitable gearbox dry run capability. Hence, it wasnt even in the running by the time the 139 was picked.
    More importantly the Blackhawks at the time did not come with a glass cockpit

    so it was not to the Donners liking

  16. #566
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    Hi Sofa,
    Not entirely true Im afraid.

    Sikorsky also offered the S70 ADV which included 5 screen Rockwell Collins EFIS (as per S92) and a full 4 axis autopilot system. Of course it was more expensive but then again with what the 139s actually costed after modification to 'military' helicopters the gap closed. Too late though.

  17. #567
    Tim Horgan Goldie fish's Avatar
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    I think the recurring problem here is the tendering process, or some part of it, does not allow for a contract to be cancelled when it becomes clear that what is being delivered is not the same as what was specified.


    Catch-22 says they have a right to do anything we can't stop them from doing.

  18. #568
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    The problem is that the Air Corps is run by pilots, who select aircraft mainly from a pilot's point-of-view. That should only be one of the considerations. When it comes to utility/transport helicopters, they're mainly flying trucks: their job is to carry people and cargo, so factors such as capacity, reliability, availability etc. should be the priorities. The Army - as the main customer - should have had a stronger role in selecting which heli to buy. Leave it to the pilots and they'll always go for the sleekest, the fastest, the one with the all the fancy widgets etc.

  19. #569
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    The problem is that the Air Corps is run by pilots, who select aircraft mainly from a pilot's point-of-view. That should only be one of the considerations. When it comes to utility/transport helicopters, they're mainly flying trucks: their job is to carry people and cargo, so factors such as capacity, reliability, availability etc. should be the priorities. The Army - as the main customer - should have had a stronger role in selecting which heli to buy. Leave it to the pilots and they'll always go for the sleekest, the fastest, the one with the all the fancy widgets etc.
    Yet more ill informed speculation.
    Do you know who was on the selection board?
    While you know the outcome of the overall tender do you know the outcome of the operational evaluation?
    Was it the same as the overall result do you think?

  20. #570
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    Quote Originally Posted by Tadpole View Post
    Yet more ill informed speculation.
    Do you know who was on the selection board?
    While you know the outcome of the overall tender do you know the outcome of the operational evaluation?
    Was it the same as the overall result do you think?
    Please share.

  21. #571
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    Please share.
    Sorry, unfortunately not the forum for that.
    However, Im sure that a correctly worded FOI would provide all the information you would like.

  22. #572
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    If you can't back it up, maybe you shouldn't have brought it up?

  23. #573
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    I didn't bring anything up.
    I just suggested that perhaps you aren't aware of the full circumstances of what did or didn't win the phase of the evaluation controled by Air Corps personnel and how you can actually find out.

    Just out of interest which do you think is more operationally capable as a military transport helicopter?
    Have you just answered the question?

  24. #574
    Commandant Jetjock's Avatar
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    Operational evaluation? There was an operational evaluation?

    And the AW139 won out?

    That begs the question: what were the parameters?

  25. #575
    Commander in Chief hptmurphy's Avatar
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    Black hawks were out of the price range but rated in the same category as UH 1s...and its derivatives almost diposable.

    EH 90 was a better machine and a better size.
    Time for another break I think......

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