Go Back  PPRuNe Forums > Aircrew Forums > Rotorheads
Reload this Page >

EC225 crash near Bergen, Norway April 2016

Rotorheads A haven for helicopter professionals to discuss the things that affect them

EC225 crash near Bergen, Norway April 2016

Old 9th Jul 2018, 07:36
  #1861 (permalink)  
 
Join Date: Aug 2001
Location: Cornwall
Age: 71
Posts: 1,305
As so often the case in helicopter design, the 'weight engineers' have it over the others. I remember a video conference held by Shell Aircraft at LHR with the engineering guys at Sikorsky following a number of issues caused by components with a lack of tolerance to any kind of minor abuse (dent, scratch knock). The chairman invited the Sikorsky Chief Engineer to take a flight bag containing 30kg of metal and "put it back in the airframe". When you trim the margins to 1 x the critical load factor I guess you are the very definition of someone pushing their luck - actually YOUR luck. BTW there was only a chuckle from the three engineers in the US.

G
Geoffersincornwall is offline  
Old 9th Jul 2018, 08:02
  #1862 (permalink)  
 
Join Date: Oct 2006
Location: UK
Posts: 4,599
Epicyclical automatic transmissions installed in automobiles are built up and then inserted into the gearbox. This means that the orbital gear is separate from the gearbox case. The 225 problem is that this gear is integral with the gearbox case so any damage affects the main rotor support structure. A complete redesign where the reduction gearing is separate from, with sufficient room for debris to be ineffective, might be the answer.

You are still going to lose the drive to the main rotor but at least you will have still have some form of control in autorotation as long as you do not shut down the engines.

The gearbox will be bulkier and a bit heavier but it should still be able to fit within the doghouse.
Fareastdriver is offline  
Old 9th Jul 2018, 08:25
  #1863 (permalink)  
 
Join Date: Aug 2001
Location: Cornwall
Age: 71
Posts: 1,305
I believe the MD902 has a design that separates the rotor support from the main gearbox such that the rotor loads are transmitted to the airframe directly and not through the transmission.
G
Geoffersincornwall is offline  
Old 9th Jul 2018, 11:21
  #1864 (permalink)  
 
Join Date: May 2002
Location: "Deplorable but happy as a drunken Monkey!
Age: 71
Posts: 16,313
We have had similar discussions in the past about the difference in MGB design philosophy between the European and American methods.

There is a difference.

The major difference is the “Load Bearing” and damage resistance post internal failure.

Perhaps a qualified Design Engineer could provide us an accurate summary of the differences between the S-92 and 225 gearbox designs?
SASless is offline  
Old 9th Jul 2018, 12:11
  #1865 (permalink)  
 
Join Date: Sep 2007
Location: Birmingham
Posts: 244
Originally Posted by Evil Twin View Post
Only one crash was a 225, the other a 332L2.
True but relevant only to the extent that these are the two models that share the eight planet gear design that has resulted in the two accidents.
Both the lower power/weight 332L2 and later H225 designs have suffered near identical failures resulting in major loss of life.

The flaw remains in both types.

As the AIBN put it ...


"The protective measures in the RTS likely reduce the product’s exposure to unsafe
conditions leading to another catastrophic event."

but ...

"The following issues are currently not fully resolved:
- Data, analyses and tests do not conclusively prove that the planet gears still in
service will not have the potential to develop subsurface and possible
undetectable fatigue cracks from a surface damage."

All depends on the degree of risk that individual customers/operators/travellers are prepared to accept
birmingham is offline  
Old 9th Jul 2018, 12:35
  #1866 (permalink)  
 
Join Date: Aug 2004
Location: DDA
Posts: 36
Originally Posted by 212man View Post
Where do you see that? I looked and can only see reference to it be one of the options to be looked at and the quickly ruled out as they shown to be correctly mounted at the time of the break up.
Page 143 of the report..
"2.8.6.2 Despite the intentions of the G-REDL test program and the safety measures introduced to improve the chip detection system, the AIBN finds that the actions undertaken by Airbus Helicopters following the G-REDL accident could have been more effective with regards to a possible scenario with limited spalling, assessing the effectiveness of the detection system and reviewing the MGB design features. The AIBN also finds that the oversight of Airbus Helicopters by EASA could have been more effective with regards to implementation of the safety recommendations and the follow-up on the information from the G-REDL accident report. In summary, Airbus Helicopters and EASA did not successfully manage to realise the safety potential from the G-REDL accident report."

and

"2.13.1.3 The AIBN understands EASA’s obligation to follow its procedures as a public administrative body. However, the AIBN had to wait for two to six months before receiving some of the documents from EASA and consequently this influenced the progress of the investigation."

further

"2.14.1.2 Further, it is essential for the AIBN to assess the safety actions already taken following this accident in order to issue relevant safety recommendations. In addition, this investigation has been affected by the grounding of the AS 332 L2 and the EC 225 LP helicopters and the subsequent effort by Airbus Helicopters and the regulators concerning the return to service (RTS) (see Appendix F). During this process, important information related to the return to service was delayed or not disclosed to the AIBN."

and

"2.14.2.3 On 7 October 2016, EASA lifted the flight prohibition based on the RTS actions put in place by Airbus Helicopters. According to EASA, the mandated RTS actions ensured airworthiness was restored at an acceptable level of safety in accordance with Part 21 and EASA procedures. Furthermore, the CARI was developed to make further improvements (see Appendix F to the report).
2.14.2.4 The investigation was ongoing with important aspects still open. The AIBN understands EASA’s role and Airbus Helicopters’ position, but would have expected a more precautionary approach at the time, since the accident involved a critical part in which failure has led to two catastrophic events. The national bans on flying in Norway and UK imposed by the CAAs remained in place."



In this section and paragraphs of the report it becomes pretty clear that more should have been done by both Airbus and EASA.

Last edited by aheoe26104; 9th Jul 2018 at 13:33. Reason: More information
aheoe26104 is offline  
Old 9th Jul 2018, 13:51
  #1867 (permalink)  
 
Join Date: Aug 2004
Location: DDA
Posts: 36


This can go anywhere including finally killing the Puma (of all models..)
aheoe26104 is offline  
Old 9th Jul 2018, 18:10
  #1868 (permalink)  
 
Join Date: Aug 2004
Location: Aberdeen
Age: 63
Posts: 2,012
Originally Posted by 212man View Post
Where do you see that? I looked and can only see reference to it be one of the options to be looked at and the quickly ruled out as they shown to be correctly mounted at the time of the break up.
para 2.11.3.1
Page 149-150.

well perhaps “stick” is an exaggeration, but reading between the lines the smokescreen was noted!
HeliComparator is offline  
Old 9th Jul 2018, 18:50
  #1869 (permalink)  
 
Join Date: Dec 2005
Location: England
Posts: 1,249
The comments on weight saving made me smile. The AW169 has dozens and dozens of titanium screws holding on various panels.
Every time an engineer rounds one out it is going to cost about 30 dollars a steel equivalent is less than dollar.
Seems to be a new AW profit centre AW 139 winglet screws are even worse for price.
AW must have shares in a screw factory.
The number of screws holding purely trim panels is past a joke, try getting access in the baggage bay to the avionics.
ericferret is offline  
Old 10th Jul 2018, 11:03
  #1870 (permalink)  
 
Join Date: Jan 2007
Location: here and there
Age: 62
Posts: 137
ericferret: The S92 is the same majority of the panels are held on by Titanium screws.
twisted wrench is offline  
Old 10th Jul 2018, 11:14
  #1871 (permalink)  
 
Join Date: Sep 2009
Location: UK
Posts: 121
Place all of those titanium screws in a bag and weigh them and then do the same with their steel counterparts and see what the weight difference is....

LZ
Hot_LZ is offline  
Old 10th Jul 2018, 14:56
  #1872 (permalink)  
 
Join Date: Sep 2006
Location: Inside the Industry
Posts: 740
From Helihub (Source ERA)

The following statement, issued by Era Group to the US Securities & Exchange Commission (original here), states that Airbus has agreed a $42 Million payout to Era relating to the operators purchase of eleven H225s.

“On July 3, 2018, Era Group Inc. (the “Company”) and Era Helicopters, LLC (together with the Company “Era”), entered into a litigation settlement agreement (the “Settlement Agreement”) with Airbus Helicopters, Inc. and Airbus Helicopters, S.A.S. (together “Airbus”) in the matter of Era Group Inc., and Era Helicopter, LLC v. Airbus Helicopters, Inc., and Airbus Helicopters, S.A.S (the “Action”). The Settlement Agreement settles all claims made by Era against Airbus related to Airbus’ marketing and sale, and Era’s purchase, of eleven H225 model helicopters. Pursuant to the Settlement Agreement, Airbus has agreed to pay Era $42.0 million in cash and provide Era with certain trade account credits that may be used by Era for up to five years. Era has agreed to release Airbus from any and all liabilities, claims, counterclaims, demands, complaints, costs, losses and expenses relating to the Action and to dismiss the Action with prejudice without any party admitting fault.”

Looks like the value that Airbus is prepared to pay for each now useless offshore H225 is about $3.8m (approx 15c - 20c on the $ purchase price for fleet buyers) I expect that this will set the benchmark for other compensation claims from owners of 225s wanting out.

After the AIBN report which is fairly damning, its hard to see how flying the 225 with passengers can be justified. It will be interesting to see if those 225s which have remained in service with the Airbus reduced gearbox overhaul life and FFMP continue in service or are quietly withdrawn.
industry insider is offline  
Old 11th Jul 2018, 08:17
  #1873 (permalink)  
 
Join Date: Sep 2007
Location: Birmingham
Posts: 244
Originally Posted by industry insider View Post
From Helihub (Source ERA)

The following statement, issued by Era Group to the US Securities & Exchange Commission (original here), states that Airbus has agreed a $42 Million payout to Era relating to the operators purchase of eleven H225s.

“On July 3, 2018, Era Group Inc. (the “Company”) and Era Helicopters, LLC (together with the Company “Era”), entered into a litigation settlement agreement (the “Settlement Agreement”) with Airbus Helicopters, Inc. and Airbus Helicopters, S.A.S. (together “Airbus”) in the matter of Era Group Inc., and Era Helicopter, LLC v. Airbus Helicopters, Inc., and Airbus Helicopters, S.A.S (the “Action”). The Settlement Agreement settles all claims made by Era against Airbus related to Airbus’ marketing and sale, and Era’s purchase, of eleven H225 model helicopters. Pursuant to the Settlement Agreement, Airbus has agreed to pay Era $42.0 million in cash and provide Era with certain trade account credits that may be used by Era for up to five years. Era has agreed to release Airbus from any and all liabilities, claims, counterclaims, demands, complaints, costs, losses and expenses relating to the Action and to dismiss the Action with prejudice without any party admitting fault.”

Looks like the value that Airbus is prepared to pay for each now useless offshore H225 is about $3.8m (approx 15c - 20c on the $ purchase price for fleet buyers) I expect that this will set the benchmark for other compensation claims from owners of 225s wanting out.

After the AIBN report which is fairly damning, its hard to see how flying the 225 with passengers can be justified. It will be interesting to see if those 225s which have remained in service with the Airbus reduced gearbox overhaul life and FFMP continue in service or are quietly withdrawn.
It will - the current market conditions must make a complete redesign out of the question - especially given that even the successor airframe has been pushed into the long grass. They still have military/parapublic customers for other Puma types. So I would imagine that they are digesting the report - whose conclusions they have accepted, and are making up their minds how far they can go. If withdrawing the fleet is cheaper than implementing the recommendations then what would you do?
birmingham is offline  
Old 12th Jul 2018, 05:36
  #1874 (permalink)  
 
Join Date: Dec 2006
Location: UK and MALTA
Age: 56
Posts: 1,188
An awful lot of outstanding technology lost due to one critical defect. For those of you who have never flown a 225 this will be lost on you.
DOUBLE BOGEY is offline  
Old 12th Jul 2018, 10:49
  #1875 (permalink)  
 
Join Date: Sep 2006
Location: Inside the Industry
Posts: 740
An awful lot of outstanding technology lost due to one critical defect. For those of you who have never flown a 225 this will be lost on you.
Only the envelope protection and autopilot DB.

The rest of it was not so special. The fuel system was from 1960s, the engines were old and smokey, the rotor system was nothing really new with no icing clearance etc. All in all, the 175 made it look very old.
industry insider is offline  
Old 12th Jul 2018, 11:30
  #1876 (permalink)  
 
Join Date: Aug 2004
Location: Aberdeen
Age: 63
Posts: 2,012
Originally Posted by industry insider View Post
Only the envelope protection and autopilot DB.

The rest of it was not so special. The fuel system was from 1960s, the engines were old and smokey, the rotor system was nothing really new with no icing clearance etc. All in all, the 175 made it look very old.
Well no, the rotor system was a big improvement over the L2, very smooth at high speed and high weight. The EFIS is still the best IMO - simple but effective. By comparison, that on the S92 and the AW189 look like the scribbling of a child, far too much information, not at all calm, logical and inuitive as the 225 is. The engines became less smokey after a mod to the oil breather system. Rotor de icing was available, just not needed our side of the N Sea.

The 175 May or not be a good helicopter, too soon to know if it has a fatal flaw. And I didn’t like it not having a centre screen, bad HMI because it means that when something goes wrong you have to use one of the screens for system info, which means the PF and PM do not have the same info. How can you be an effective PM if your screens aren’t showing the same as PF?

But unfortunately a helicopter is only as good as its weakest link.
HeliComparator is offline  
Old 12th Jul 2018, 11:55
  #1877 (permalink)  
 
Join Date: May 2002
Location: "Deplorable but happy as a drunken Monkey!
Age: 71
Posts: 16,313
When the “weak link” is Rotor Head retention.....that pretty much kills the deal.....and everyone aboard when that minor flaw occurs.
SASless is offline  
Old 12th Jul 2018, 14:46
  #1878 (permalink)  
 
Join Date: Oct 2006
Location: UK
Posts: 4,599
The only reason that the 225 was smoother than the 332 predecessors was that they put five blades on it. In the early days of the 330 there were concerns over the vibration level. They were at the point of cutting metal for a five bladed head when somebody came up with the idea of the barbeque plate to isolate the rotor vibrations for the fuselage.

From that point on all Pumas from the 330 B to the 332L2 were condemned.
Fareastdriver is offline  
Old 12th Jul 2018, 17:35
  #1879 (permalink)  
 
Join Date: Aug 2004
Location: Aberdeen
Age: 63
Posts: 2,012
Originally Posted by SASless View Post
When the “weak link” is Rotor Head retention.....that pretty much kills the deal.....and everyone aboard when that minor flaw occurs.
If that’s your idea of a minor flaw I would hate to see one of your major flaws!

Although it has to be said that most of the time, the rotor head didn’t fall off. But from an airworthiness point of view it does seem to be a dead duck. Of course we have had a few “pilot error” fatal accidents and near misses on other types that couldn’t have happened on the 225. So the 225 trades a fundamental flaw in helicopters - the pilots! - with another fundamental flaw - the rotor head falling off. From a pilots’ point of view I can see why they wouldn’t like it since most pilots think that a pilot-error fatal accident could never happen to THEM, only to others. But for the passengers, a dispassionate calculation would probably show that the 225 was safer than many other types.
HeliComparator is offline  
Old 21st Jul 2018, 14:01
  #1880 (permalink)  
 
Join Date: Feb 2009
Location: A nice place
Posts: 156
After the improvements how many 225s are flying civilians?
Pablo332 is offline  

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.