Royal Navy defends Merlin safety
Guest
Posts: n/a
Royal Navy defends Merlin safety
Human error rather than a design fault caused the crash of a Royal Navy Merlin HM Mk 1 maritime helicopter last October ----- according to naval officers operating the type in Denmark during NATO's Exercise 'Blue Game'.
<font face="Verdana, Arial, Helvetica" size="2">Cdr Will Thomas, Commanding Officer of the Merlin Helicopter Force, told Jane's Defence Weekly that there was "nothing wrong with the aircraft" and that the accident has been attributed to problems with a "single airframe".
Anthony Worner, spokesman for the RN's Naval Air Command, said "the accident was caused by an incorrectly set rotor brake actuator" on the lost aircraft, and that there was "no inherent problem".
A full account of the 27 October accident will be determined later this year when a RN board of inquiry concludes its report. Other naval sources revealed that this investigation was now concentrating on "attributing blame" for the incident after finding the cause.
The RN's public comments come as welcome news for EH 101 manufacturer AgustaWestland, which is understood to have been concerned that waiting until the end of the board of inquiry process could have hampered its chances of winning the 100-aircraft Nordic helicopter contest.
Cdr Thomas, who is the RN's 'type chief' for the Merlin, said the aircraft flew again on 21 December, and that operational evaluation work and training is continuing ahead of the first frontline Merlin unit, 814 Naval Air Squadron, embarking on the carrier HMS Ark Royal in February 2002. "We are flying 200 hours a month and have eight aircraft in 700M Naval Air Squadron [for operation evaluation work]," he said. The RN currently has 14 Merlins at Royal Naval Air Station Culdrose, with the service's last of 44 aircraft to be delivered by late 2002.
"It remains to be seen if we get a replacement aircraft for the one lost in last year's crash, but the RN's buy of 44 Merlins had an element of attrition included in it," said a RN source. "The frontline strength of the service's two frontline Merlin squadrons will not be affected."
According to Cdr Thomas, development work on the aircraft is continuing simultaneously as the Merlin is being prepared for frontline service. "Military aircraft releases [certification of flight activity undertaken at the UK Defence Evaluation and Research Agency's Boscombe Down facility] are taking place continuously," he said. "We are training 814 Sqn's crews and developing standard operating procedures."
Cdr Thomas said Exercise 'Blue Game', which had a multinational littoral warfare theme, was contributing greatly to the Merlin's entry into service, with two aircraft forming part of the RN's 10-helicopter contribution to the exercise. "This is an excellent operating environment," he said. Conducted between 24 April and 11 May, the 'Blue Game' manoeuvres involved around 65 naval vessels drawn from Belgium, Canada, Denmark, France, Germany, the Netherlands, Norway, Poland, Portugal, Spain, the UK and the USA, including 16 assigned to NATO's Standing Force Naval Atlantic and Mine Countermeasures Force North.
Shipborne helicopters also participated in the exercise, along with fixed-wing maritime patrol, fighter and bomber assets from countries, including Denmark, Germany, Norway, the UK and the USA.</font>
Anthony Worner, spokesman for the RN's Naval Air Command, said "the accident was caused by an incorrectly set rotor brake actuator" on the lost aircraft, and that there was "no inherent problem".
A full account of the 27 October accident will be determined later this year when a RN board of inquiry concludes its report. Other naval sources revealed that this investigation was now concentrating on "attributing blame" for the incident after finding the cause.
The RN's public comments come as welcome news for EH 101 manufacturer AgustaWestland, which is understood to have been concerned that waiting until the end of the board of inquiry process could have hampered its chances of winning the 100-aircraft Nordic helicopter contest.
Cdr Thomas, who is the RN's 'type chief' for the Merlin, said the aircraft flew again on 21 December, and that operational evaluation work and training is continuing ahead of the first frontline Merlin unit, 814 Naval Air Squadron, embarking on the carrier HMS Ark Royal in February 2002. "We are flying 200 hours a month and have eight aircraft in 700M Naval Air Squadron [for operation evaluation work]," he said. The RN currently has 14 Merlins at Royal Naval Air Station Culdrose, with the service's last of 44 aircraft to be delivered by late 2002.
"It remains to be seen if we get a replacement aircraft for the one lost in last year's crash, but the RN's buy of 44 Merlins had an element of attrition included in it," said a RN source. "The frontline strength of the service's two frontline Merlin squadrons will not be affected."
According to Cdr Thomas, development work on the aircraft is continuing simultaneously as the Merlin is being prepared for frontline service. "Military aircraft releases [certification of flight activity undertaken at the UK Defence Evaluation and Research Agency's Boscombe Down facility] are taking place continuously," he said. "We are training 814 Sqn's crews and developing standard operating procedures."
Cdr Thomas said Exercise 'Blue Game', which had a multinational littoral warfare theme, was contributing greatly to the Merlin's entry into service, with two aircraft forming part of the RN's 10-helicopter contribution to the exercise. "This is an excellent operating environment," he said. Conducted between 24 April and 11 May, the 'Blue Game' manoeuvres involved around 65 naval vessels drawn from Belgium, Canada, Denmark, France, Germany, the Netherlands, Norway, Poland, Portugal, Spain, the UK and the USA, including 16 assigned to NATO's Standing Force Naval Atlantic and Mine Countermeasures Force North.
Shipborne helicopters also participated in the exercise, along with fixed-wing maritime patrol, fighter and bomber assets from countries, including Denmark, Germany, Norway, the UK and the USA.</font>
Guest
Posts: n/a
To: Heliport
The ultimate document that defines the safety and by association the reliability of an aircraft is the Fault Tree Hazard Analysis. The ultimate descriptor of safety is the probability of occurrence of a catastrophic failure that could cause loss of the aircraft and or, death to one or more crewmembers. If you are dealing with a helicopter that is in commercial service the frequency of this occurrence is stated as 1 10 9 operating hours for the fleet of helicopters. To get the frequency of occurrence and the definition of the effects of the failures on the aircraft the FMEA (Failure Modes Effects Analysis) must be prepared. The FMEA by definition must investigate any and all failures even if there is no effect at the system or aircraft level. This includes catastrophic failures as described above.
I do not know if a Safety Hazards Analysis was prepared for the Merlin and all other military derivatives but this analysis was most likely prepared for the commercial variant. However when I supervised the preparation of the FMEAs for the EH-101 I had the analysts include all catastrophic failures in the dynamics and powertrain systems. After several months of involvement in this effort the manager of the R&M group (an Agusta employee) overrode me and told the analysts to remove all references to catastrophic failures. In essence he was saying that the EH-101 was 100% reliable and would never fail catastrophically. This has been proven false on at least two occasions and if the Royal Navy is wrong then it is three occasions. The worst part is that if a Safety Hazard Analysis is performed for commercial certification then there will be no catastrophic failures included in this analysis as well.
The most catastrophic failure that was predicted was the lock-up of the main transmission. It was predicted that the rotorhead would self-destruct in the process of breaking through the lock-up using the kinetic energy of the blades.
------------------
The Cat
The ultimate document that defines the safety and by association the reliability of an aircraft is the Fault Tree Hazard Analysis. The ultimate descriptor of safety is the probability of occurrence of a catastrophic failure that could cause loss of the aircraft and or, death to one or more crewmembers. If you are dealing with a helicopter that is in commercial service the frequency of this occurrence is stated as 1 10 9 operating hours for the fleet of helicopters. To get the frequency of occurrence and the definition of the effects of the failures on the aircraft the FMEA (Failure Modes Effects Analysis) must be prepared. The FMEA by definition must investigate any and all failures even if there is no effect at the system or aircraft level. This includes catastrophic failures as described above.
I do not know if a Safety Hazards Analysis was prepared for the Merlin and all other military derivatives but this analysis was most likely prepared for the commercial variant. However when I supervised the preparation of the FMEAs for the EH-101 I had the analysts include all catastrophic failures in the dynamics and powertrain systems. After several months of involvement in this effort the manager of the R&M group (an Agusta employee) overrode me and told the analysts to remove all references to catastrophic failures. In essence he was saying that the EH-101 was 100% reliable and would never fail catastrophically. This has been proven false on at least two occasions and if the Royal Navy is wrong then it is three occasions. The worst part is that if a Safety Hazard Analysis is performed for commercial certification then there will be no catastrophic failures included in this analysis as well.
The most catastrophic failure that was predicted was the lock-up of the main transmission. It was predicted that the rotorhead would self-destruct in the process of breaking through the lock-up using the kinetic energy of the blades.
------------------
The Cat
Guest
Posts: n/a
To: Jiff
Yes he was. After leaving Agusta he ended up on the European Space Station as Manager of Reliability and Maintainability. He ended up screwing that program over as well.
Other than that, he was a very nice person. He knew a great deal about the specs that govern Reliability, Maintainability and Systems Safety but he totally lacked the understanding of how to implement these programs.
------------------
The Cat
Yes he was. After leaving Agusta he ended up on the European Space Station as Manager of Reliability and Maintainability. He ended up screwing that program over as well.
Other than that, he was a very nice person. He knew a great deal about the specs that govern Reliability, Maintainability and Systems Safety but he totally lacked the understanding of how to implement these programs.
------------------
The Cat
Guest
Posts: n/a
Lu,
I asked the question because I supervised the design of fail safe, redundant control systems for a large theme park operator in Florida. This involved conducting a FMEA on those systems and whenever I highlighted a potential problem the resistance / abuse I received was unbelievable.
This normally came from the non technical project manager who's prime objective was schedule and budget. Frequently I was in the position of having to explain why a component could fail rather than the vendor / contractor explaining why it wouldn't, with the project manager vigorously defending the vendor to the point of, the moon is made out of green cheese and I cant afford a budget or schedule hit.
I think I'm fortunate to have completed an apprenticeship in the Royal Navy as an avionics engineer and as a result of this had the balls to argue my point and sometimes manage to get designs modified or changed. Quite Often engineers would back down after heated shouting matches and the design would remain as is (complete with single point and latent failures).
There were many exceptional engineers at this company but from my experience there were very few people who really understood the following terms
Single point failure
Latent failure
fail safe
fault tolerance
redundancy
Are there any similarities within the industries you have experience with? and does any of this apply to the V22 program.
Jiff
I asked the question because I supervised the design of fail safe, redundant control systems for a large theme park operator in Florida. This involved conducting a FMEA on those systems and whenever I highlighted a potential problem the resistance / abuse I received was unbelievable.
This normally came from the non technical project manager who's prime objective was schedule and budget. Frequently I was in the position of having to explain why a component could fail rather than the vendor / contractor explaining why it wouldn't, with the project manager vigorously defending the vendor to the point of, the moon is made out of green cheese and I cant afford a budget or schedule hit.
I think I'm fortunate to have completed an apprenticeship in the Royal Navy as an avionics engineer and as a result of this had the balls to argue my point and sometimes manage to get designs modified or changed. Quite Often engineers would back down after heated shouting matches and the design would remain as is (complete with single point and latent failures).
There were many exceptional engineers at this company but from my experience there were very few people who really understood the following terms
Single point failure
Latent failure
fail safe
fault tolerance
redundancy
Are there any similarities within the industries you have experience with? and does any of this apply to the V22 program.
Jiff
Guest
Posts: n/a
To: Jiff
I have been in the aircraft and aerospace industry for 46 years and I have been involved in Reliability, Maintainability and Systems Safety for the last 33 years. I was fired from Hughes Helicopters because I confronted a design supervisor over the likes of a shear pin in the control system. The mode of failure was for the pin not to shear resulting in the loss of control in one of the control systems. All I asked was that the pin be listed as reliability sensitive which meant that a x be placed in a box on the drawing. I brought it up three times and each time he became more belligerent. I left the meeting and returned to my desk. In the time it took me to walk from the meeting room to my office the decision was made by the chief engineer to have me fired. The management of the product assurance department sucked and besides, they were too weak to fight engineering. Three months later the Army requested the same change and it was done in a flash.
On the V-22 I told the management of the product assurance department that the design of the Prop Rotor was such that it would place a very high demand on the flight control hydraulic system making it less reliable than predicted. After bringing it up three times and being told that it was a Bell problem they cancelled my contract.
Engineers look down on assurance engineers as being numbers crunchers and most of them are. They look at mechanical and electronic systems as mathematical entities that must fit some preconceived equation. Most of them never lifted a wrench or a soldering iron in anger. Many of them have no knowledge of how a piece of equipment is employed or what effects its’ reliability or how things are maintained. Armed with that lack of knowledge and understanding they approach an engineer and tell him that his system is unreliable or unsafe. When asked for proof, the assurance engineer will show the designer his calculations. It is no wonder why assurance engineering is looked upon as a barnacle on the ass of progress.
------------------
The Cat
I have been in the aircraft and aerospace industry for 46 years and I have been involved in Reliability, Maintainability and Systems Safety for the last 33 years. I was fired from Hughes Helicopters because I confronted a design supervisor over the likes of a shear pin in the control system. The mode of failure was for the pin not to shear resulting in the loss of control in one of the control systems. All I asked was that the pin be listed as reliability sensitive which meant that a x be placed in a box on the drawing. I brought it up three times and each time he became more belligerent. I left the meeting and returned to my desk. In the time it took me to walk from the meeting room to my office the decision was made by the chief engineer to have me fired. The management of the product assurance department sucked and besides, they were too weak to fight engineering. Three months later the Army requested the same change and it was done in a flash.
On the V-22 I told the management of the product assurance department that the design of the Prop Rotor was such that it would place a very high demand on the flight control hydraulic system making it less reliable than predicted. After bringing it up three times and being told that it was a Bell problem they cancelled my contract.
Engineers look down on assurance engineers as being numbers crunchers and most of them are. They look at mechanical and electronic systems as mathematical entities that must fit some preconceived equation. Most of them never lifted a wrench or a soldering iron in anger. Many of them have no knowledge of how a piece of equipment is employed or what effects its’ reliability or how things are maintained. Armed with that lack of knowledge and understanding they approach an engineer and tell him that his system is unreliable or unsafe. When asked for proof, the assurance engineer will show the designer his calculations. It is no wonder why assurance engineering is looked upon as a barnacle on the ass of progress.
------------------
The Cat
