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EC 175

Old 24th Apr 2021, 00:23
  #261 (permalink)  
 
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Originally Posted by ApolloHeli View Post
Seems a bit contradictory to me...
Iím slightly surprised that Airbus didnít initially claim they had found the required grease, still in a toolbox.....
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Old 25th Apr 2021, 23:13
  #262 (permalink)  
 
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The report provides a bit more context https://www.gov.uk/aaib-reports/aaib...-ec175b-g-emeb

Since the LAGB had successfully run on a test cell for 12 hours without any deterioration detected in the alternator pinion bearings, with a 10 kVA alternator installed, it is likely that the installation of the 10 kVA alternator by the operator directly influenced the F1 bearing failure that occurred after 18 minutes of the post-maintenance ground run.

Examination of the failed F1 bearing and alternator pinion revealed that they had been subjected to a compressive axial load during the ground run. This axial load was greater than the ability of the F1 roller bearing to withstand it, leading to the bearing overheating and causing the PEEK bearing cage to melt, which was then extruded from the bearing. The overheating also caused significant wear of the bearing rollers, releasing bearing debris into the MGB oil system and causing discolouration of the MGB oil.

Testing conducted by the manufacturer showed that an excessive quantity of grease within the alternator shaft link cavity can create a significant compressive axial load on the alternator pinion when the alternator is clamped to the LAGB. This is due to compression of the excess grease and air within the sealed shaft link cavity acting as a hydraulic piston. This loading case was unintended and had not been anticipated when the LAGB components and associated AMM maintenance procedures were developed.

The method of attaching the alternator to the LAGB used by the operatorís LAE meant that the compression of the grease and air within the shaft link cavity was up to four times greater than would have been the case if the method specified in the AMM had been followed.

The manufacturer stated that the reason for filling the alternator pinion cavity with sufficient grease to cause it to overflow was to ensure that grease remained within the alternator pinion splined area during the in-service period between overhauls, to ensure lubrication of the splines.

This large quantity of grease, combined with the sealed design of the alternator shaft link cavity once the alternator driveshaft was inserted, created a latent condition in which an unwanted axial load could be introduced into the alternator pinion and F1 roller bearing..

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Old 26th Apr 2021, 00:02
  #263 (permalink)  
 
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It’s disappointing that the OEMs are still producing machines that are vulnerable to common maintenance procedures. (Ti studs that need lube, a prayer, and calming music played while torquing. Over greasing causing catastrophic failure.)

It’s the equivalent of having a door handle that snaps off if you try turning it the wrong way. (And mentioning it once during the type endorsement.)
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Old 26th Apr 2021, 03:54
  #264 (permalink)  
 
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unfounded hatred is not helping anyone.
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Old 26th Apr 2021, 06:39
  #265 (permalink)  
 
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Originally Posted by Mee3 View Post
unfounded hatred is not helping anyone.
Not sure this is aimed at me.

There is nothing unfounded about Ti Studs failing or catastrophic gearbox failures.
Nothing trivial about the multiple fatalities from both either.

But we are drifting off topic - this one failed on the ground, and it sounds like a tiny design change (vent) or specific, non intuitive, maintenance instructions will be a permanent solution.
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Old 27th Apr 2021, 07:00
  #266 (permalink)  
 
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G-EMEB?

Apparently, it had another incident offshore recently and while wheeling to one side of the deck to let another machine arrive with a maintenance crew the RH Main gear went through the deck.

Picture links on Helihub.
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Old 27th Apr 2021, 18:19
  #267 (permalink)  
 
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From the AAIB report.
The helicopter was undergoing scheduled maintenance to replace the main gear box (MGB), which had reached its overhaul life of 800 flying hours.
Did we just go back 50 years in time?
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Old 28th Apr 2021, 09:00
  #268 (permalink)  
 
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And there are some that donít even make it that far...

LZ
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Old 28th Apr 2021, 11:57
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Cyclic

Did we just go back 50 years in time?
Further than that I think. Airbus previously EC previously Aťrospatiale don't have a great history building quality MGBs which are durable and long lasting.
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Old 28th Apr 2021, 20:39
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I recall the short TBOH was already rumored just after EC225 disaster in Norway.
I did not believed it then because NHV was also operating 1 or 2 EC175 in Ghana at that moment.
It was then also rumored that Airbus had at least 1 dedicated mechanic stationed at NHV (Den Helder) but makes sense now.

Airbus support must have improved apparently.
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Old 27th Sep 2021, 23:27
  #271 (permalink)  
 
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There is a very interesting little snippet in the Helihub article today about the CHC/Babcock transaction. https://helihub.com/2021/09/27/compe...on-of-babcock/

Of the UK fleet, one AW139 has been stored for 8 months and one H175 was recently ferried to Airbus for corrosion remedial works which will likely see it out of service for 12 months. Additionally one S92 is still being worked on after suffering a nose wheel collapse in June, and the total includes another S92 pulled out of storage on 10th September. Read more at https://helihub.com/2021/09/27/compe...on-of-babcock/
12 months of corrosion remedial work provides for an enormous workscope, and if the activities are limited to airframe corrosion remediation, there must be virtually nothing left unaffected on this airframe at this stage. Does anyone have any additional insight into what is happening with this machine, or the background to how an almost new helicopter could require such extensive action if it hadn't been ditched in the sea?

Anyone?
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Old 28th Sep 2021, 03:52
  #272 (permalink)  
 
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Originally Posted by Cyclic Hotline View Post
There is a very interesting little snippet in the Helihub article today about the CHC/Babcock transaction. https://helihub.com/2021/09/27/compe...on-of-babcock/



12 months of corrosion remedial work provides for an enormous workscope, and if the activities are limited to airframe corrosion remediation, there must be virtually nothing left unaffected on this airframe at this stage. Does anyone have any additional insight into what is happening with this machine, or the background to how an almost new helicopter could require such extensive action if it hadn't been ditched in the sea?

Anyone?
As far as I know, this is an earlier machine that was built without the correct corrosion protection applied. The corrosion that resulted was kept in check and repaired as and when but was always planned to go back for remedial work including the maturity mods. It's an ongoing thing with another 175 having returned from Spain earlier this year.
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Old 28th Sep 2021, 11:45
  #273 (permalink)  
 
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Originally Posted by Cyclic Hotline View Post
There is a very interesting little snippet in the Helihub article today about the CHC/Babcock transaction. https://helihub.com/2021/09/27/compe...on-of-babcock/



12 months of corrosion remedial work provides for an enormous workscope, and if the activities are limited to airframe corrosion remediation, there must be virtually nothing left unaffected on this airframe at this stage. Does anyone have any additional insight into what is happening with this machine, or the background to how an almost new helicopter could require such extensive action if it hadn't been ditched in the sea?

Anyone?
I don't think you were alone in spotting that! Interestingly, I saw the ferry flight photos on Linkedin but didn't know the purpose
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Old 28th Sep 2021, 11:54
  #274 (permalink)  
 
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If those are early build then most probably a warranty. Some of the those had bad application of surface protection and need redo.
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Old 28th Sep 2021, 12:04
  #275 (permalink)  
 
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Originally Posted by Mee3 View Post
If those are early build then most probably a warranty. Some of the those had bad application of surface protection and need redo.
I guess they (AH) are a bit new to the offshore/Marine environment, so learning as they go........
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Old 28th Sep 2021, 14:16
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Originally Posted by 212man View Post
I guess they (AH) are a bit new to the offshore/Marine environment, so learning as they go........
that's not the reason. but cant say more.
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Old 28th Sep 2021, 14:29
  #277 (permalink)  
 
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Damn Chinese aircraft
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Old 28th Sep 2021, 19:54
  #278 (permalink)  
 
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Originally Posted by Cyclic Hotline View Post
There is a very interesting little snippet in the Helihub article today about the CHC/Babcock transaction. https://helihub.com/2021/09/27/compe...on-of-babcock/

12 months of corrosion remedial work provides for an enormous workscope, and if the activities are limited to airframe corrosion remediation, there must be virtually nothing left unaffected on this airframe at this stage. Does anyone have any additional insight into what is happening with this machine, or the background to how an almost new helicopter could require such extensive action if it hadn't been ditched in the sea?

Anyone?
The first three H175s delivered to Babcock did not have the necessary corrosion protection applied during the build process. All three machines were scheduled to go to Albacete in Spain to have remedial works carried out by Airbus, which takes approx 12 months. MCSE was the first to be completed. I believe MCSG has recently arrived in Albacete for the same treatment.
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Old 29th Sep 2021, 11:42
  #279 (permalink)  
 
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The first three H175s delivered to Babcock did not have the necessary corrosion protection applied during the build process. All three machines were scheduled to go to Albacete in Spain to have remedial works carried out by Airbus, which takes approx 12 months. MCSE was the first to be completed. I believe MCSG has recently arrived in Albacete for the same treatment.
I hope Airbus is supplying Babcock (CHC) with a free backup aircraft to compensate for 3 cumulative aircraft years of downtime?
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Old 30th Sep 2021, 10:02
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Originally Posted by industry insider View Post
I hope Airbus is supplying Babcock (CHC) with a free backup aircraft to compensate for 3 cumulative aircraft years of downtime?
They are. It was known this was going to be needed, and was planned for. Must be costing Airbus a pretty penny though.
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