Agusta AW139
Join Date: Nov 2005
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Hi Blackmax and Co,
as a blackhander I have seen what I think to be early traces of something similar to this. You may note that there is some missing paint at the paint edge. To me this is the key.
I have dealt with operators where the washing program is poor to say the least. What can happen over time is you will see small orange dots of corrosion appear all over the leading edge,,,and sometimes under the paint at the paint edge. I have pics of this but am unable to attach. More than willing to share if you give me an email etc.. Once this starts it will continue and if not treated...well you get the picture.
Just me 2 cents worth
as a blackhander I have seen what I think to be early traces of something similar to this. You may note that there is some missing paint at the paint edge. To me this is the key.
I have dealt with operators where the washing program is poor to say the least. What can happen over time is you will see small orange dots of corrosion appear all over the leading edge,,,and sometimes under the paint at the paint edge. I have pics of this but am unable to attach. More than willing to share if you give me an email etc.. Once this starts it will continue and if not treated...well you get the picture.
Just me 2 cents worth
Join Date: Jul 2008
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My two cents worth
Hi Swinging Spanner.
Like you, I think that the theory of resonance causing this problem is a bit of smoke and mirrors. There may be some truth in the fact that resonance may* occur and failure may* result. (The asterisk * denotes only under specific and ill-defined circumstances, a bit like Macdonalds Big Mac is healthy* food*.)
I suggest that another possible explanation is that failure occurs only because of the weakened adhesive bonds caused by the same micro-voiding that causes the boom disbonds. This is a processing deficiency caused by poor environmental controls during manufacture. Moisture absorbed by the uncured adhesive during fabrication evolves as steam, resulting in an excessive number of small voids. These reduce the strength of the bond. Reference data shows that peel strength may fall by as much as about 60% due to short term exposure at 29C and 80% RH.
Now your paint blister issues may have similar causes. Please PM me your email address and I will contact you.
Regards
Blakmax
Like you, I think that the theory of resonance causing this problem is a bit of smoke and mirrors. There may be some truth in the fact that resonance may* occur and failure may* result. (The asterisk * denotes only under specific and ill-defined circumstances, a bit like Macdonalds Big Mac is healthy* food*.)
I suggest that another possible explanation is that failure occurs only because of the weakened adhesive bonds caused by the same micro-voiding that causes the boom disbonds. This is a processing deficiency caused by poor environmental controls during manufacture. Moisture absorbed by the uncured adhesive during fabrication evolves as steam, resulting in an excessive number of small voids. These reduce the strength of the bond. Reference data shows that peel strength may fall by as much as about 60% due to short term exposure at 29C and 80% RH.
Now your paint blister issues may have similar causes. Please PM me your email address and I will contact you.
Regards
Blakmax
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RB Actuator Failure
102% used only during CAT A operations and hoist operations.
- one heli ( about 500 hrs) with two rotor brake actuator failure
- about 4 CAT A T/O and LDGs per hour
- about 1 hoist operation per hour
second chopper ( about 300hrs) with no rotor brake actuator failure till now.
Pigi
- one heli ( about 500 hrs) with two rotor brake actuator failure
- about 4 CAT A T/O and LDGs per hour
- about 1 hoist operation per hour
second chopper ( about 300hrs) with no rotor brake actuator failure till now.
Pigi
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Swinging Spanner
Ok, been waiting for your PM, but then I tried to PM you and I could not find that facility any more. Either it has been withdrawn or it is an old dog trying new tricks issue. Try contacting me at max at adhesionassociates dot com. I'd love to see the pictures.
Regards
Blakmax (note: No "c")
Regards
Blakmax (note: No "c")
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Outwest-RB Failure
Hello Outwest,
interesting regarding harmonics @ 102% Nr causing problems with RB actuators. I will see if I can get any feedback from my sources in AW.
Something to consider in the meantime-I have long seen...and still see problems from RB actuators. Each time I begin to deal with the problem there is always some simple checks I do 1st:
-electrical cannon plug connected to RB actuator has a regular problem with the backshell coming loose causing intermittent CAS messages...always check to see if backshell is tight.
-RB caliper bumper stop shimming...you may remember that when the AW139 1st came out that there was no rubber bumper under the caliper. It was introduced originally as a BT if not mistaken. Anyway, in the instructions there is a MIN and MAX dimension/height of rubber bumper as part of shimming. I always go for the MIN height. Quite often I have found that the RB actuators giving grief that the bumper stop is at the MAX side of bumper height tolerance. With CB's pulled in IGN and START, I operate the Engine Mode Select switch between IDLE and OFF and listen to the sound of the RB actuator moving through its travel. As the caliper swings down and rests on rubber bumper the RB actuator is still trying move to end of travel until it trips its internal microswitches...but it is having to push against the rubber bumper to do so-excessive load on RB actuator. You can actually hear the sound of the actuator change as this happens. Going for the MIN height on rubber bumper shimming has always given me great results
-Location of caliper bumper stop...after completing the shimming procedure it is as important to make sure that the caliper bumper assy is centrally aligned to the hole in caliper assy. The caliper bumper assy has 4 elongated holes at baseplate for this very reason. Failure to check this will also have the RB caliper arrive at the bumper stop slightly early and cause excessive load to the RB actuator as it tries to move through full travel.
-RB caliper assy pivot shaft...over time has a tendancy to bind-in particular in hot environs, causing excessive friction and therefore excessive load when RB actuator is trying to move. I have recommended many times to include a proactive maintenance step of introducing a regrease of RB caliper pivot shaft at 600hr intervals as 1 suggestion.
Just my 2 cents worth.
Hope it helps
interesting regarding harmonics @ 102% Nr causing problems with RB actuators. I will see if I can get any feedback from my sources in AW.
Something to consider in the meantime-I have long seen...and still see problems from RB actuators. Each time I begin to deal with the problem there is always some simple checks I do 1st:
-electrical cannon plug connected to RB actuator has a regular problem with the backshell coming loose causing intermittent CAS messages...always check to see if backshell is tight.
-RB caliper bumper stop shimming...you may remember that when the AW139 1st came out that there was no rubber bumper under the caliper. It was introduced originally as a BT if not mistaken. Anyway, in the instructions there is a MIN and MAX dimension/height of rubber bumper as part of shimming. I always go for the MIN height. Quite often I have found that the RB actuators giving grief that the bumper stop is at the MAX side of bumper height tolerance. With CB's pulled in IGN and START, I operate the Engine Mode Select switch between IDLE and OFF and listen to the sound of the RB actuator moving through its travel. As the caliper swings down and rests on rubber bumper the RB actuator is still trying move to end of travel until it trips its internal microswitches...but it is having to push against the rubber bumper to do so-excessive load on RB actuator. You can actually hear the sound of the actuator change as this happens. Going for the MIN height on rubber bumper shimming has always given me great results
-Location of caliper bumper stop...after completing the shimming procedure it is as important to make sure that the caliper bumper assy is centrally aligned to the hole in caliper assy. The caliper bumper assy has 4 elongated holes at baseplate for this very reason. Failure to check this will also have the RB caliper arrive at the bumper stop slightly early and cause excessive load to the RB actuator as it tries to move through full travel.
-RB caliper assy pivot shaft...over time has a tendancy to bind-in particular in hot environs, causing excessive friction and therefore excessive load when RB actuator is trying to move. I have recommended many times to include a proactive maintenance step of introducing a regrease of RB caliper pivot shaft at 600hr intervals as 1 suggestion.
Just my 2 cents worth.
Hope it helps
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Thanks Swinging Spanner, that is all very good info and I'm sure there are many here who will benefit from that. Would very much appreciate if you can find out from AW if there is any truth to the 102% rumor.
Thanks also to those who have commented on the 102%, good to know what is being practiced in the field.
Thanks also to those who have commented on the 102%, good to know what is being practiced in the field.
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102% NR
We use 102% for all take-off and landing including a "vertical cat.B take-off"
created from nowhere by our company because the aircraft is to heavy.When you are above 6400 kg all time in Summer, of course it is difficult to comply with a cat.A profile and you become creative......
And on 10 aircrafts, I believe only 2 have a rotor brake who is not US, it has been going on for months now.
On a different subject, we won't be using the FIPS again this Winter
,still have problem with the slip ring.But bying 139 for cat.A performance and FIPS and ending with no FIPS and doing "vertical cat.B" in Summer,what a waste.
created from nowhere by our company because the aircraft is to heavy.When you are above 6400 kg all time in Summer, of course it is difficult to comply with a cat.A profile and you become creative......And on 10 aircrafts, I believe only 2 have a rotor brake who is not US, it has been going on for months now.
On a different subject, we won't be using the FIPS again this Winter
,still have problem with the slip ring.But bying 139 for cat.A performance and FIPS and ending with no FIPS and doing "vertical cat.B" in Summer,what a waste.
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Hi Arcal,
The only reason for using 102% is so that during OEI recovery it will give you that little bit extra droop time.
It was never intended for better AEO performance.
The only reason for using 102% is so that during OEI recovery it will give you that little bit extra droop time.
It was never intended for better AEO performance.
Join Date: Aug 2001
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Arcal 76
We use 102% for all take-off and landing including a "vertical cat.B take-off"created from nowhere by our company because the aircraft is to heavy.When you are above 6400 kg all time in Summer, of course it is difficult to comply with a cat.A profile and you become creative.
The three elements of Cat A operation are mass, profile and obstacle environment. If you want to pick just one then make it the mass. If you have to operate above that (Cat B), or use a higher TDP/LDP then use a profile you are familiar with (sim training should condition you to react quickly and correctly if you have an engine failure at a critical moment). Under Cat A a rejected take off should result in no damage to airframe or passengers. It would be reasonable to suggest that experience gained to date (Malaysia) indicates that a reject above a Cat A weight may damage the airframe but the excellent crashworthiness properties built into the 139 will protect the occupants provided the gear is down and the landing is made in a level-ish attitude.
In all of this we must not loose sight of the fact that Cat A is just one element in any risk-assessment process and whether the pilot realises it or not every take-off or landing manoeuvre should be risk assessed. There are many occasions when working offshore or HEMS or even VIP/corporate where you are required to operate to and/or from unfamiliar or challenging (offshore with complex obstacle environment) sites and the risk assessment may place a slow and gentle arrival above any Cat A considerations. Cat A is just one tool in the toolbox.
In the end if you are having to do extraordinary things to get the job done you may just be working a little too close to the edge. Satisfying when you succeed but not what you Safety Manager wants to hear about.
G.
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De Lam
We had this happen on a T/R blade that had 10 hours since new, it was a matter of not removing release ply. It was a definate QA problem at Agusta. On anothe note we rejected about ten glass windshields at the factory (PPG glass) for distortion atound windw edge at factory.
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Cat.B take-off!
Well,I did not wait to read pprune to know what is a cat.A and why we use 102%,guys......amazing 
What I am saying is our company decided to create a cat.B because no profile works as soon as it is hot and heavy (6400 to 6800 kg)
As it is written in our SOP:"the cat B procedure should be utilized if adhering to cat A will compromise the effiency of the flight".
I think it is a statement who tell you where we are.We bought a cat A aircraft,but since we mismanaged the weight,forget the cat A.
When we recieved the aircraft,it was supposed to be an all time Cat A operation until we got to Summer time.....
Same story,over and over again.
What I am saying is our company decided to create a cat.B because no profile works as soon as it is hot and heavy (6400 to 6800 kg)
As it is written in our SOP:"the cat B procedure should be utilized if adhering to cat A will compromise the effiency of the flight".
I think it is a statement who tell you where we are.We bought a cat A aircraft,but since we mismanaged the weight,forget the cat A.
When we recieved the aircraft,it was supposed to be an all time Cat A operation until we got to Summer time.....
Same story,over and over again.
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Arcal 76
Let me understand your situation correctly. Your company buys the best-in-class medium helicopter because it has excellent Cat A performance. Of course your company principle must understand that Cat A is essentially a focus on OEI operations but is an excellent guide to safe AEO operations courtesy of the conservative nature of the WAT curves in this context.
To then accept operations above the Cat A WAT or profiles outside the RFM specifications puts you in that grey area of helicopter operations where a safe outcome is entirely down to the pilots skill and judgement.
The basic tenet of Cat A Ops is that they are predictable. That is why PC1 ops are not possible offshore. That environment involves operations within an unpredictable obstacle environment and we have to consider wind generated turbulence and turbine exhaust heat-pollution as 'obstacles'.
To buy a cat A capable machine like the 139 and then use it Cat B is possible, feasible and practical but it is a bit like saying that because you wear your seat belt whilst driving your car you can drive like a crazy man. Ultimately you will ask your car to do something it is unable to do and then you cannot blame the car when you crash it.
If you elect not to work within the Cat A WAT then be sure you have the skill, be sure you have the judgement, then do not blame the aircraft when you stoof-in. The learning curve in this respect is greased with 'luck' and over the years I have used up my fair share. If I can pass on my experiences to good effect and save you from becoming a statistic then here's a pearl of wisdom.
"Read as many accident reports as you are able and be sure that someone else's misfortune is your free lesson in survival."
G.
To then accept operations above the Cat A WAT or profiles outside the RFM specifications puts you in that grey area of helicopter operations where a safe outcome is entirely down to the pilots skill and judgement.
The basic tenet of Cat A Ops is that they are predictable. That is why PC1 ops are not possible offshore. That environment involves operations within an unpredictable obstacle environment and we have to consider wind generated turbulence and turbine exhaust heat-pollution as 'obstacles'.
To buy a cat A capable machine like the 139 and then use it Cat B is possible, feasible and practical but it is a bit like saying that because you wear your seat belt whilst driving your car you can drive like a crazy man. Ultimately you will ask your car to do something it is unable to do and then you cannot blame the car when you crash it.
If you elect not to work within the Cat A WAT then be sure you have the skill, be sure you have the judgement, then do not blame the aircraft when you stoof-in. The learning curve in this respect is greased with 'luck' and over the years I have used up my fair share. If I can pass on my experiences to good effect and save you from becoming a statistic then here's a pearl of wisdom.
"Read as many accident reports as you are able and be sure that someone else's misfortune is your free lesson in survival."
G.
Jungle performance ? -Royal Thai Army picks AW139 -
The Royal Thai Army Signs A Contract for Two AW139s | AgustaWestland
I wonder how it handles in that environment, say compared to other models used by the Royal Thai Army such as the UH-60 and I think the Thais ordered MI-17 as they reckoned get 3 for a price of a S-70.
I wonder how it handles in that environment, say compared to other models used by the Royal Thai Army such as the UH-60 and I think the Thais ordered MI-17 as they reckoned get 3 for a price of a S-70.
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AW139 SPD/ALT CMD
Can anyone help me better understand what we see on FMS Progress 2/3 page.
At LSK 1L we have SPD/ALT CMD which represent current speed and altitude command.
I'm wondering if changing IAS speed using button we have on cyclic grip and moving alt knob is reflected on FMS Progress 2/3 page at LSK 1L.
Thanks a lot.
Eric
At LSK 1L we have SPD/ALT CMD which represent current speed and altitude command.
I'm wondering if changing IAS speed using button we have on cyclic grip and moving alt knob is reflected on FMS Progress 2/3 page at LSK 1L.
Thanks a lot.
Eric
