EC225 crash near Bergen, Norway April 2016
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HC, I know you have been out of the game a while but why do you need to monitor the systems on a 175? The hierarchy is such that you never look at the ‘systems’ unless there is a reason to. The master list concept made the 175 a whole lot better than the 225. As for the mechanicals, as you say, only time will tell but it does seem a great deal less frantic than the 225. AH are being extremely cautious with the gearbox. I do hope it is a success in the long run as it is the most quiet, smooth and fast rotary machine I have ever flown. Take it to a FL and it is like a plank wing....apart from the orange suit, underwater breathing apparatus and life jacket...and the constant awareness that it is all about to go wrong...
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The following article from 'Helihub' appears to capture reservations held by a number on PPRune.
"The Final Report is also worrying. The following are the key features that cause most concern:
“the available degree of scientific and technical knowledge meant it was neither foreseeable nor foreseen that a crack in a plant gear could propagate in a sub-layer, and as a result generate very low levels of detectable particles…With knowledge gained from this investigation, Airbus Helicopters has introduced a series of safety measures on the H225. Some of the technology that has been developed is ground-breaking for the helicopter industry. Airbus Helicopters will continue to pursue innovations and improve safety standards through a proactive approach that sees us challenge internally everything we do. Work on a number of potential improvements to the H225 are in progress, and I remain optimistic that this concerted and complex work will yield new advances.”"
"The Final Report is also worrying. The following are the key features that cause most concern:
- There is no way of assuring detection of possible failure of the MGB sufficiently in advance of total failure. There was no spalling detected during the growth in cracks in the planet gears and thus little or no probability of detecting cracks growing before a complete fracture (section 2.4.2.6), the investigation discovering that the oil cooler acted as a particle trap preventing 44% of the debris from reaching the oil filter including the largest particles (section 2.5.7). Airbus have improved the capture of particles in the oil by introducing a new full flow magnetic plug increasing the capture rate from 12% to 50% and strengthened inspection criteria and equipment allowing a more detailed analysis of these particles.
- Airbus Helicopters and the European Aviation Safety Agency (EASA) did not realise the safety potential from the G-REDL accident report (section 2.8.6.2). The G-REDL report was described as a “turning point with respect to the continued airworthiness of the AS 332 L2 and the EC 225 LP helicopters”, the UK’s Air Accident Investigation Branch (‘AAIB’) making safety recommendations clearly relevant to the LN-OJF accident which were not followed through by EASA or Airbus (section 2.1.1.3). In particular, the Final Report of the AIBN (section 3.2.9) found that:
- “Less than 10 % of the second stage planet gears ever reached their intended operational time before being rejected during overhaul inspections or non-scheduled MGB removals due to signs of degradation.
- Airbus Helicopters did not perform systematic examination and analyses of unserviceable and rejected second stage planet gears in order to understand the full nature of any damage and its effect on continued airworthiness.
- Airbus Helicopters did not section and inspect any of the second stage planet gears that were scrapped during overhaul. Therefore, it remains uncertain whether any of these gears had subsurface cracks similar to observations made on LN-OJF.
- The differences between the two planet gear bearing designs had not been previously assessed through in-service statistics and calculations.”
- EASA and Airbus acted precipitately when EASA removed the flight prohibition on the H225 on 7 October 2016, with the investigation ongoing and 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” (section 2.14.2.4).
- The following issues are currently not fully resolved (section 3.2.11):
- 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;
- The capability to detect and interpret metal particles of few mm2 in the MGB oil system to prevent critical failure;
- Why the cracks in the outer race grew subsurface into the gear bulk material and finally resulted in a fatigue fracture while creating limited spalling.
- “Two catastrophic events and the service experience of few second stage planet gears reaching their operating time limit, may suggest that the operational loading environment, on both AS 332 L2 and EC 225 LP, is close to the limit of endurance for the design” (section 2.14.4.1).
“the available degree of scientific and technical knowledge meant it was neither foreseeable nor foreseen that a crack in a plant gear could propagate in a sub-layer, and as a result generate very low levels of detectable particles…With knowledge gained from this investigation, Airbus Helicopters has introduced a series of safety measures on the H225. Some of the technology that has been developed is ground-breaking for the helicopter industry. Airbus Helicopters will continue to pursue innovations and improve safety standards through a proactive approach that sees us challenge internally everything we do. Work on a number of potential improvements to the H225 are in progress, and I remain optimistic that this concerted and complex work will yield new advances.”"
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Greetings from the GOM. Food for thought, though I’ve not read nor heard anyone linking the two Puma characteristics:
1) Makila engines compressor stall regularly. (Normal for all gas turbines, according to Eurocopter/Airbus). After personally experiencing it in the 225 I can testify it is moderately violent and affects the entire drive train and airframe.
2) Components within the gearbox have a history of failing.
Any thoughts on the shock of multiple compressor stalls on MGB components?
1) Makila engines compressor stall regularly. (Normal for all gas turbines, according to Eurocopter/Airbus). After personally experiencing it in the 225 I can testify it is moderately violent and affects the entire drive train and airframe.
2) Components within the gearbox have a history of failing.
Any thoughts on the shock of multiple compressor stalls on MGB components?
I still fly in 92s for other purposes. It's a great aircraft and along with the 225 has given us a huge step forward in large rotorcraft safety during the last 14 years but I remain a little suspicious of it. Quite a few ifs and buts in its engineering history though nothing compared to many older types of course. These subjects are so distorted by people happily ignoring hundreds of deaths that have occurred across the history of the helicopter.
These subjects are so distorted by people happily ignoring hundreds of deaths that have occurred across the history of the helicopter.
It is hard to reckon with the findings of the AAIB Report quoted by Mars.
A loss of two Rotor Heads in fairly short succession....does give grounds for pause don't you think?
Before you challenge the above, consider I would be saying the same thing no matter the Type.
Every "new" aircraft will have unforeseen issues no matter how good its designers think they are....the 92 and 225 are alike in that.
The difference being the 225 issues have not been completely sorted to the satisfaction of the AAIB as I read it.
Are they not supposed to be the Subject Matter Experts when it comes to analyzing these kinds of things?
Greetings from the GOM. Food for thought, though I’ve not read nor heard anyone linking the two Puma characteristics:
1) Makila engines compressor stall regularly. (Normal for all gas turbines, according to Eurocopter/Airbus). After personally experiencing it in the 225 I can testify it is moderately violent and affects the entire drive train and airframe.
2) Components within the gearbox have a history of failing.
Any thoughts on the shock of multiple compressor stalls on MGB components?
1) Makila engines compressor stall regularly. (Normal for all gas turbines, according to Eurocopter/Airbus). After personally experiencing it in the 225 I can testify it is moderately violent and affects the entire drive train and airframe.
2) Components within the gearbox have a history of failing.
Any thoughts on the shock of multiple compressor stalls on MGB components?
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I'm retired now so I can look back on a 50-year career in aviation and contemplate what I have learnt about human nature in that time. The saga of the AH and EASA 'shortcomings' in this sad tale has served to underline the fact that justice is inversely proportional to the size/power/money available to the transgressor. If you are lucky enough to have access to any of those 'assets' then 'getting-out-from-under' is a mere formality. The only good thing I have to say about such villainy is that it helps to provide a good plot-line for my next book. Look out for the crooked engineering manager in the next crime thriller at www.geoffnewman.co.uk
Will the Engineering Manager be named Jethro and be Cornish with a sense of humor?
HC, I know you have been out of the game a while but why do you need to monitor the systems on a 175? The hierarchy is such that you never look at the ‘systems’ unless there is a reason to. The master list concept made the 175 a whole lot better than the 225. As for the mechanicals, as you say, only time will tell but it does seem a great deal less frantic than the 225. AH are being extremely cautious with the gearbox. I do hope it is a success in the long run as it is the most quiet, smooth and fast rotary machine I have ever flown. Take it to a FL and it is like a plank wing....apart from the orange suit, underwater breathing apparatus and life jacket...and the constant awareness that it is all about to go wrong...
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SAS - Just remember that the train to Plymouth from Penzance doesn't stop at Camborne on Tuesdays.
As to which of the OEM hierarchy should be painted the 'villain' we need a story-line that creates uncertainty and multiple possible transgressors.
Remember the golden rule of The Peter Principle' (people are promoted to their own level of incompetence) - all employees are required to be 'TEAM PLAYERS' which, when translated into corpoarte reality means that YOU play the game but THEY (management) ram the bat up your a****e.
As to which of the OEM hierarchy should be painted the 'villain' we need a story-line that creates uncertainty and multiple possible transgressors.
Remember the golden rule of The Peter Principle' (people are promoted to their own level of incompetence) - all employees are required to be 'TEAM PLAYERS' which, when translated into corpoarte reality means that YOU play the game but THEY (management) ram the bat up your a****e.
HC....Having a PM looking over your shoulder is nice....not necessary.
The PM can relieve the PF of some of that stress by analyzing and troubleshooting and offering up a plan of action while the PF.....flies the aircraft....right?
We did all this Single Pilot long before "Screens" and automation were heard of and it worked.
Do you reckon Pilots...PM or PF are less capable today because of the very Technological advances and changes in Training/Cockpit Procedures?
Are they really becoming "Children of the Magenta"?
The PM can relieve the PF of some of that stress by analyzing and troubleshooting and offering up a plan of action while the PF.....flies the aircraft....right?
We did all this Single Pilot long before "Screens" and automation were heard of and it worked.
Do you reckon Pilots...PM or PF are less capable today because of the very Technological advances and changes in Training/Cockpit Procedures?
Are they really becoming "Children of the Magenta"?
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That is where I stand, HC. There is no current sign of there being a search for intelligent life in the UK North Sea, so the subject doesn't really come up. However, if I were getting on a helicopter at Dyce or Scatsta tomorrow then I would happily get on the world's most examined rotorcraft, which is the 225. The numbers tell me that is the correct approach..
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True HC but having done plenty of emergencies in the sim, it has never been an issue. You can display so much more on the PFD that the PM is really at no disadvantage when it comes to monitoring the PF. The systems are a great deal simpler than the 225 as well, so time spent diagnosing is much reduced and it does a lot more for you. If you thought the 225 was smooth then the 175 is like wafting along on a magic carpet! You don’t go deaf after a double either...
HC....Having a PM looking over your shoulder is nice....not necessary.
The PM can relieve the PF of some of that stress by analyzing and troubleshooting and offering up a plan of action while the PF.....flies the aircraft....right?
We did all this Single Pilot long before "Screens" and automation were heard of and it worked.
Do you reckon Pilots...PM or PF are less capable today because of the very Technological advances and changes in Training/Cockpit Procedures?
Are they really becoming "Children of the Magenta"?
The PM can relieve the PF of some of that stress by analyzing and troubleshooting and offering up a plan of action while the PF.....flies the aircraft....right?
We did all this Single Pilot long before "Screens" and automation were heard of and it worked.
Do you reckon Pilots...PM or PF are less capable today because of the very Technological advances and changes in Training/Cockpit Procedures?
Are they really becoming "Children of the Magenta"?
Anyway the point of multi-crew is to improve safety. Most people think it does, although I realise that not all do. Single Pilot can be fairly safe. Multi pilot can be safer. It's just a matter of degree. However the benefits of multipilot only occur if the crew operate together well (I think someone once said it was called CRM) and the chap not in charge is empowered to make interventions. Also, during critical phases of flight, it helps if the other chap can see the same "picture" as the pilot - it's hard to monitor someone if you can't see what they can see. Therefore if you are going to design a new helicopter to be as safe as can be (and bearing in mind that the humans are probably the least reliable bit) why not maximise the crew's ability to work together by giving them the same information - even and especially when things are going up the creek?
PM and PF are not becoming less capable these days, it's just that the skill set is changing. Less importance is now placed on the captains ability to shout orders and ensure everyone knows he is the boss, less importance on the copilot doing a good impression of a quivering subservient wreck, and more importance on working together to ensure a good outcome. Scary, isn't it!
True HC but having done plenty of emergencies in the sim, it has never been an issue. You can display so much more on the PFD that the PM is really at no disadvantage when it comes to monitoring the PF. The systems are a great deal simpler than the 225 as well, so time spent diagnosing is much reduced and it does a lot more for you. If you thought the 225 was smooth then the 175 is like wafting along on a magic carpet! You don’t go deaf after a double either...
HC,
Nice Rant....but you have some facts out of whack.
I am familiar with single pilot IFR in several kinds of aircraft....fixed and rotary.
Yes lots of VFR/VMC but enough VFR/IMC and IFR/IMC to know of what I speak.
I don't suppose in your modern world....one can lean over towards the other pilots side and monitor events on his side of the cab....or is that not allowed these days?
When you were instructing....did you demonstrate maneuvers using your instruments or the Student's?
During an Instrument Approach....what critical information is not displayed on the on the Non-Handling Pilot's side that cannot be seen on all of the other sources?
Are you, as usual, trying to make a Mountain here?
I would be far more concerned about hidden screens....that layered as malfunctions occur and you have to work your way down through the stack because the system does not present the most critical failure ahead of all of the others.
The lack of a Screen surely has nothing to do with CRM.....or do you wish to explain how you took that road off the Roundabout?
Nice Rant....but you have some facts out of whack.
I am familiar with single pilot IFR in several kinds of aircraft....fixed and rotary.
Yes lots of VFR/VMC but enough VFR/IMC and IFR/IMC to know of what I speak.
I don't suppose in your modern world....one can lean over towards the other pilots side and monitor events on his side of the cab....or is that not allowed these days?
When you were instructing....did you demonstrate maneuvers using your instruments or the Student's?
During an Instrument Approach....what critical information is not displayed on the on the Non-Handling Pilot's side that cannot be seen on all of the other sources?
Are you, as usual, trying to make a Mountain here?
I would be far more concerned about hidden screens....that layered as malfunctions occur and you have to work your way down through the stack because the system does not present the most critical failure ahead of all of the others.
The lack of a Screen surely has nothing to do with CRM.....or do you wish to explain how you took that road off the Roundabout?
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HC, as the first UK operator of the type we are still learning but my experience during some fairly involved LOFT scenarios doesn’t show that using 4 screens instead of 5 is a disadvantage. We will have to agree to disagree! Still a brilliant machine which is even safer to fly in terms of the flight envelope protections than the 225.
I don't suppose in your modern world....one can lean over towards the other pilots side and monitor events on his side of the cab....or is that not allowed these days?
When you were instructing....did you demonstrate maneuvers using your instruments or the Student's?
During an Instrument Approach....what critical information is not displayed on the on the Non-Handling Pilot's side that cannot be seen on all of the other sources?
FND - Flight Nav Display,
VMD - Vehicle Management Display
;-)