Yet another AW139 tail incident at Gulf helis
TukTuk BoomBoom, thanks for the clarification. It is the seemingly inconsequential things that lead to catastrophic failures.
Like the Colgate BK117 fin failure, which brought to light the improper and potentially disastrous substitution of solid rivets with blind rivets by some AME's during repairs and modifications, and the FU-24 fin failure in New Zealand due to the abrasion boot being trimmed with a knife after installation, which scored the skin, eventually leading to the departure of the complete fin assy in flight.
Sorry for the thread drift.
Like the Colgate BK117 fin failure, which brought to light the improper and potentially disastrous substitution of solid rivets with blind rivets by some AME's during repairs and modifications, and the FU-24 fin failure in New Zealand due to the abrasion boot being trimmed with a knife after installation, which scored the skin, eventually leading to the departure of the complete fin assy in flight.
Sorry for the thread drift.
0.1 IPS Radial, 0.2 IPS Axial according to the manual I have (using Chadwick).
Easily achieved although I am used to using HUMS which is an excellent piece of kit.
If doing Tail rotor adjustments, do the weights first and then go do another run. You'll more often than not find that just doing weight adjustments will bring the axial vibe in to limits as well. Adjusting the Pitch Links is a bit of a pain and they are VERY sensitive
Easily achieved although I am used to using HUMS which is an excellent piece of kit.
If doing Tail rotor adjustments, do the weights first and then go do another run. You'll more often than not find that just doing weight adjustments will bring the axial vibe in to limits as well. Adjusting the Pitch Links is a bit of a pain and they are VERY sensitive
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Since this being a rumour network I feel that I can air what I heard;
That a tool mounted on the root of one of the tail rotor blades had not been removed after maintenance/prior to start up. And that the tool was found on the apron a long way from the helicopter.
The suspicion being that the major imbalance caused the blade to separate soon followed by the collapse of the tail fin.
RD
That a tool mounted on the root of one of the tail rotor blades had not been removed after maintenance/prior to start up. And that the tool was found on the apron a long way from the helicopter.
The suspicion being that the major imbalance caused the blade to separate soon followed by the collapse of the tail fin.
RD
Actually doesn't mean a lot 500e. People are pulling their blades for the slightest imperfection that they don't want to say is Ok, even if it is. They would rather hand that responsibility over to someone else (Agusta).
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Hi, maybe another view is, 70% have passed the inspection, 30% have been removed as being suspect and not passing the inspection. Generally they may seem to be repairable.*
I guess they will be inspected and form part of the ongoing investigation and not release after any repair.
I also guess that those in the know are familiar with the history of the blade in question. So will look forward to the final report to emerge in the fullness of time.
I guess they will be inspected and form part of the ongoing investigation and not release after any repair.
I also guess that those in the know are familiar with the history of the blade in question. So will look forward to the final report to emerge in the fullness of time.
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I think the key parts are on Page 2
Sub para 1 "Cracks found on the fork area are superficial and do not involve components on the main load path"
Sub para 2 "affect only the filler material which is not structural"
Any item from any manufacturer subjected to minute scrutiny will be flag up imperfections. That is what has happened here and as Nooby said blades are being returned to the Manufacturer for second opinions. Not heard of any blades being scrapped - anybody else?
Awaiting the final report with interest!
Sub para 1 "Cracks found on the fork area are superficial and do not involve components on the main load path"
Sub para 2 "affect only the filler material which is not structural"
Any item from any manufacturer subjected to minute scrutiny will be flag up imperfections. That is what has happened here and as Nooby said blades are being returned to the Manufacturer for second opinions. Not heard of any blades being scrapped - anybody else?
Awaiting the final report with interest!
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I am still in the sand pit here in Qatar. Have just received an email from our company that AW139 flights will continue from the 10th July 2011. Heli briefing is being carried out at GH, telling all personnel waiting to fly how safe the AW 139 is.
HUMS is now fitted to the aircraft we are flying in and we have been told safe flying operations are assured????
Yeah right.......
HUMS is now fitted to the aircraft we are flying in and we have been told safe flying operations are assured????
Yeah right.......
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GHC aircraft have HUMS fitted to all the 139's.
If the company wasn't happy with the fleet then they would just continue to fly the 412's, which as you probably know is no fun for either crew or pax in the 40 degree plus heat of summer.
The 139's have daily inspections and crews are happy to be flying them with the AC rather than the 412's that do not.
Most crew have families. Do you really think that if they were concerned with their safety then they would be flying them!
If the company wasn't happy with the fleet then they would just continue to fly the 412's, which as you probably know is no fun for either crew or pax in the 40 degree plus heat of summer.
The 139's have daily inspections and crews are happy to be flying them with the AC rather than the 412's that do not.
Most crew have families. Do you really think that if they were concerned with their safety then they would be flying them!
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^^
So explain to me why with all AW139 aircraft fitted with HUMS and the system in operation,that two aircraft had failures in their tail sections and this was not foreseen by HUMS?
1. Tail Boom Failure
2. Tail rotor blade failure
So explain to me why with all AW139 aircraft fitted with HUMS and the system in operation,that two aircraft had failures in their tail sections and this was not foreseen by HUMS?
1. Tail Boom Failure
2. Tail rotor blade failure
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So explain to me why with all AW139 aircraft fitted with HUMS and the system in operation,that two aircraft had failures in their tail sections and this was not foreseen by HUMS?
1. Tail Boom Failure
2. Tail rotor blade failure
1. Tail Boom Failure
2. Tail rotor blade failure
Not sure you actually understand HUMS re your post but it's used to monitor vibrations to key components, drive trains, gear boxes, engines etc. It is also integrated with the FDR.
It's 'on-demand info' using accelerometers around the aircraft so whilst the aircraft is running then HUMS can see if the rotors are out of track or balance or there is anything unusual happening in one of these critical components. The pilot can access this data. If there are any issues of concern then the pilot will inform MX.
On the ground the MX guys can then take the data card and analyse that!
Helicopters vibrate as you well know. They are all different too.
The tail boom failed due to a previous incident, along with possible de-bonding in that area.
The blade departed (yet to be proved) at the fork area of the blade.
As I said earlier, HUMS is on demand. There is a cockpit based unit that can be accessed anytime in flight or on the ground.
The crew wouldn't have had any indication that these issues were about to take place, or are you suggesting that the MX had gathered this data but decided to say nothing and have a cuppa instead!
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HUMS also need to "learn" it's limits of operation. Across a fleet or type, data is gathered and compared across the monitored parameters and as the flying hours build, a set of maximum acceptable limits starts to emerge and these become the "baseline" that is used to decide if a particular component is in or out of limits.
If as stated earlier, the tail fracture was a consequence of a previous incident and/or delamination, it is possible the HUMS would not have registered at all.
If as stated earlier, the tail fracture was a consequence of a previous incident and/or delamination, it is possible the HUMS would not have registered at all.
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My question concerning HUMS was that I was not sure if the AW139 aircraft belonging to GH had HUMS fitted, and would/should it have detected any of the pre-flight abnormalities that happened on both aircraft?
I suppose it is better late than never to have HUMS fitted after the events, however this is a only one small step in air safety, there are many more to be taken to ensure safe flying operations here in the sand.
We are told here that maintenance is the number one concern at GH for all customers and passengers.
Why was HUMS not ordered as part of the aircraft delivery specification if the customers and passengers are so important to their core business?
I suppose it is better late than never to have HUMS fitted after the events, however this is a only one small step in air safety, there are many more to be taken to ensure safe flying operations here in the sand.
We are told here that maintenance is the number one concern at GH for all customers and passengers.
Why was HUMS not ordered as part of the aircraft delivery specification if the customers and passengers are so important to their core business?
