EH101 crash
 

http://news.bbc.co.uk/hi/english/uk/...000/994041.stm

£45,000,000 lost to the tax payer. Yet another cock up in the introduction to service of this white elephant!! Who in the name of faith allowed this extravagance to enter the fleet.
Never mind, there are 40+ left.............

------------------
TC

To:
Thomas Coupling,

What the Royal Navy bought was a potential for disaster in the EH-101. When the EH-101 was in the design stages I worked as a consultant at Agusta and In my position I worked very closely with Westland. Each company developed a means of compiling a FMEA (Failure Mode Effects Analysis)data base but in the three years I was there they had not developed a means to get the two systems to talk to each other. My position entailed the instruction and supervision of the Italian engineers in the development of the FMEAs. I also had systems responsibilities as well and I too constructed FMEAs. I stressed that they should consider the potential for single point failures that would be catastrophic and down the helicopter. We were about three quarters through the task and the Italian manager had them remove the catastrophic failures from the FMEAs as it was his feeling that there would be no catastrophic failures. I pointed out strongly that the EH-101 was similar in design to the SH3-D/S-61 which Agusta was building and they had suffered catastrophic failures and in some cases, had crashed and burned. Sorry to say, I was overruled. To date, there have been two single point failures that caused loss of life. Both failures had been noted on the original FMEAs.

Another sad point was that the engineering department and the product support department did not talk to each other. This adversarial relationship began in the early days when Agusta was designing the A-109. The respective managers of the engineering and product support had very bad feelings toward each other. Now fast forward to the then present time. Each department had three changes in management and the war was still going on. In my last six months on contract I was assigned by the Director of Agusta to find a means of getting the two departments together. This was imperitive as the product support department needed engineering input to make the manuals. Another point, The product support department because of the isolation from the engineering department and their IBM main frame computer bought an NCR computer that could not talk to the IBM so they (Product Support) had no access to the FMEAs which would be used to construct the troubleshooting instructions in the maintenance manuals. I busted my hump setting up meetings between the two managers, the director and myself.

A lot of good things were said in the meetings but when I left at the end of my contract they were still not talking. The system of communication that was eventually set up was written requests for information sent to engineering. These requests did not go directly from the questionor to the questionee, they went through a filter in the systems engineering department. These two guys would determine if the question was valid or not and if they felt it was not valid it never got to the questionee. The questionor was not told of the rejection and he sat on his butt waiting for an answer.

While all of this was going on, Westland was laying off a major part of their R&M department.

The EH-101 is in certification right now and the FMEAs are crucial in the construction of the safety hazards analysis which is required to gain certification. If the FMEAs don't have catastrophic failures then they will not be accounted for in the safety hazards analysis and another unsafe helicopter will be certificated. Does this ring a bell in the minds of the readers?

As they say, you get what you pay for.

------------------
The Cat

[This message has been edited by Lu Zuckerman (edited 28 October 2000).]

[This message has been edited by Lu Zuckerman (edited 28 October 2000).]

[This message has been edited by Lu Zuckerman (edited 28 October 2000).]

To: Thomas Coupling

Here is another problem on the EH-101 that can be catastrophic but because it is a second order failure it can not be considered in the FMEA but it can be included in the Safety Hazards Analysis but only if the problem has been identified.

Remember in my posting above I stated that by definition there would be no catastrophic failures. So if the transmission would not suffer a lock-up then the situation described below would never happen.

When I was on contract at Agusta one of my responsibilities was the development of FMEAs for the Dynamic System to include the drive train.

The transmission as designed had a shear point in the rotorshaft that when fractured would allow a successful autorotation with full control with the tail rotor still in operation. The fracture would be caused by the lock-up of the main transmission due to a foreign object becoming caught in the gear mesh. That foreign object could be an internal part of the transmission that became dislodged or possibly catastrophically failing due to a manufacturing or maintenance defect.

I questioned the engineering department about how this shearing action would be demonstrated. They said they would look into it. After about eight months or so of waiting I questioned them again. They replied that they would demonstrate it using a modified A-109 gearbox. By the time I left, the test had not been run.

Lets go back to the lock-up and fracturing of the rotorshaft. When the transmission seizes it is instantaneous. The drive to the rotor stops for that instant and the rotor being fully articulated will keep on moving on the drag hinges until the dampers are bottomed out. When this happens the inertial load of the rotor transmits its’ energy through the damper body into the fixed rotor head and the stored energy in the rotor system torques the shaft to the point of fracture.

When I left Agusta I went on contract with the Italian Company that built the hydraulic system and the dampers for the EH-101. It was there that I was able to see the design spec for the damper. Among many design requirement was the tensile and compressive loads on the damper. They were +/- 1800 pounds with a 1.5 safety factor. That means the dampers were stressed for 2700 pounds +/-before yielding. I told them about the shearing loads that passed through the dampers and that they were far in excess of 2700 pounds. If the lock-up occurred, the dampers would fail and the lead / lag loads would be unrestrained. At the same time the dampers fractured a very severe compressive and lateral load would be applied to the elastomeric bearings causing them to degrade at the least and at the worst to completely fail, most likely causing the helicopter to crash.

I asked the engineers to notify Agusta to recalculate the loads and initiate a design change. They said no. I asked them why, and this is what they told me. A year previous to that time when this company was awarded the contract to build the hydraulic system for the EH-101, the companies’ engineers detected a major design error in the hydraulic schematic. They brought this to the attention of the Agusta hydraulics group and all hell broke loose. Agusta went mad accusing the engineers of second guessing them and being critical of their work. They said that they didn’t want to go through that again. They said it was Agustas’ problem and if they would eventually discover the design fault then they would issue a new design contract. By the way, the schematic was eventually changed.

This was Italian Machismo at work. There is much more but it deals with methods of internal operation.


------------------
The Cat

------------------
The Cat

[This message has been edited by Lu Zuckerman (edited 30 October 2000).]

[This message has been edited by Lu Zuckerman (edited 30 October 2000).]

Lu...

I'm intrigued by you....

You appear to know your stuff as an aviation engineer by demonstrating significant technical knowledge across the board. However it seems to me that you are only too keen to advertise this prowess when remonstrating about certain manufacturers' products.
Those that spring to mind:
(a)The ubiquitous R22 and R44 issues
(b)The S61 rotor blade issue
(c)Agusta 109 design
(d)EHI with their EH101

Why are you putting yourself in the firing line so often in so public an arena. You must surely be burning your bridges by adversly commenting about these companies. They will never re employ you again!!
Unless of course you are retired now and can afford to 'come out' like this!

Anyway, a technical point for you:
If and when any rotor shaft "disengages" from its main drive in the manner in which you described (re the 101), then the pilot will in actual fact have absolutely NO control over that rotating head, agreed. And if he flares, the rotor will overspeed and the blades will detach...if he bunts, then the rotor speed will decay and stop!!!
How then can a detached rotor head be of any use to the pilot???

I am sure I speak for others on this net, and would be keen to learn more about your professional background and qualifications, if it is not too much of an imposition.

many thanks



------------------
TC

To: Thomas Coupling

First of all, I will be 70 years old in December and Very few Major manufacturers would hire me at that old an age. I am not retired and continue to work. However, the manufacturers of components and appliances that are used on aircraft and any other systems are more than glad to hire me on a consulting basis as they have a very low level of expertise in the areas that I work in. My last few jobs include, working as a RMS consultant on the following systems.

Modification of passenger aircraft to cargo aircraft or to create a combi. I worked on DC-9s, 727s and 737s. My experience on these jobs was restricted to the cargo systems. At the same job I also worked on the upgrade of the KC-135 electronic system and navigation systems.

My next job was working on the Bombardier C-604 and Regional Jet doing Failure Mode Effects Analyses on all of the mechanical systems.

After that I worked a short contract on the F-16 Recon Pod and the Apache electronic package cooling system as well as on the 767-400ER air driven hydraulics package.

After that I worked an 8-month contract for Eli Lilly doing reliability analysis on capital equipment.

The last job was doing RMS work on the cargo handling systems on the A340 and the A3XX.

The above jobs were done in just the last six years.

I have been in the aerospace and aircraft industry since 1955 and before that, I was a chopper and fixed wing mechanic in the US Coast Guard.

Regarding the fracture of the EH-101 rotor shaft. When the fracture of the shaft occurs the remaining part of the shaft will rise up a fraction of an inch and what retains it might be referred to as a Jesus Bearing. The swash plate and control inputs are still functioning, as are the pitchlinks above the swash plate. The pilot still maintains control and, if I remember correctly the tail rotor drive remains intact as it is driven by the functioning part of the shaft and if I remember correctly, at least one hydraulic pump will function. That is, if the rotorhead has not self destructed in the process of breaking the jam.

That’s the way it was designed but I left the program in about 1986 so it might have proven too difficult to incorporate. Besides, I could be suffering from Old timers disease and may be imagining the whole thing..

IT WOULD BE TOO SELF SERVING TO PUT MY CV ON THE INTERNET SO SEND ME YOUR EMAIL ADDRESS AND I'LL SEND YOU A COPY. THAT IS, IF YOU ARE REALLY INTERESTED.


------------------
The Cat

[This message has been edited by Lu Zuckerman (edited 30 October 2000).]

Lu, You is da one.... TC and a few other boy pilots may have been upset with your knowledgable postings but I have rarely read such sense on a forum such as this.
Get those postings flowing, it keeps us young guys on our toes.

4R

To Thomas Coupling:

It would appear that they have now grounded the helicopter, so you needn't worry about more extravagance. By the way, apart from this accident, the only story that seems to be coming out about this helicopter is very positive - why do you think it is a white elephant? Did you see that Air Show programme about it last year?

And since when have TV and the media accurately reported anything that cannot be summed up in 20 second sound bites ?. Most reporters have no technical knowledge and report exactly what the manufacturer or government agency tell them. Or worse they seek expert opinion from someone who has no expertise and treat that as confirmation of the story.

Check out the Military Pilots threads as this is also a topic under discussion on that forum.

------------------
The Cat

I was there when this beast reared its ugly head in the services. Speak to the boys who are involved in this. Ask them about:
(a) Spare parts availability
(b) Reliability
(c) Major software glitches
(d) Running costs!!!!!!!

The tell me this is what the services really need.........

------------------
TC

Further more...from one of the crew who fly the 'beast':
...and no doubt we will buy some more. Quite a few more merlins in fact. Take one horribly complex aircraft with 3 engines that has poor engine out capability, that we didn't, and still don't want, and this will not be the last time. Congrats to the crew...glad you're okay, same to jag boy...good skills on the martin baker letdown.


------------------
TC

I did hear from someone with connections into the dark blue that everyone on the Merlin project down in Cornwall has been told that if they say anything negative about it, their job's on the line.

Only hearsay, but I'd trust the person I heard it from.

------------------
I got bored with "WhoNeedsRunways"

Rotaree

The Merlin has NOT been grounded. Flying has been temporarily suspended!!!. This goes hand in hand with the 'dont say anything negative' warning from the Nr Fairy.
Did you hear the rumour that the whole thing has come unglued after exposure to seawater - just what we need in a maritime helo. Well done Westlands. Whoops, there I go, saying something negative!!

While performing my FMEA analysis on the fuel system of the EH-101 I noted that a fuel tank vent line opening on the fuselage would be under water if the helicopter made a water landing. I initiated a design request to install a float valve similar to that used on a snorkel used by swimmers. In this way, the hydrostatic pressure would close the valve. If such a device were not incorporated, the sea water could be forced into the fuel tank contaminating the fuel and effect engine operation. If the water ingestion were severe enough, it could cause engine surging or possible shutdown. I left the program before any action was taken.

That is, assuming any action was taken.

Check your fuel tank and fuel system schematics to see if this valve or a similar device has been incorporated.

------------------
The Cat

[This message has been edited by Lu Zuckerman (edited 19 November 2000).]

[This message has been edited by Lu Zuckerman (edited 19 November 2000).]

To avoid any negative criticism from servicemen can't they impose the official secrets act ?. Or have they removed the more draconian elements that used to curb any public discussions of military matters ?
Lu did each design office have complete control over the systems they were designing ? was there no oversight from the EHI co ordinating team ?.

To: Widgeon


To my recollection,there was a division of design relative to final configuration. I believe Westland completed the Royal Navy Merlin and Agusta completed the Italian Navy version and I believe that Agusta would certify and build the civil version. There was also a division of the design of the structure and dynamics systems and power train as well as the flight controls and auxiliary systems.

I attended several meetings in London at the EHI headquarters and if the meetings between Agusta and Westland were any indication there was at that time minimal oversite on the part of EHI. That may very well have changed as the design and production programs reach a state of maturity.

My duties involved only RMS Engineering as it applied to the design and in the meetings at EHI the Agusta and Westland managers were setting up the program as if the manpower to complete the RMS design input was unlimited.

I got really pissed off and I asked if I could close the door. After doing so, I tore into the two managers telling them that they were committing their respective companies to a level of work that could never be completed. Agusta had four R&M engineers and they had minimal English skills and all of the documentation had to be done using English. Westland was in the perocess of laying off a large part of their staff and, they could never complete the work they were committing themselves to.

As an example, when I worked the Apache program we had almost 36 R&M engineers on staff.

When we returned to Agusta, I got my payback for embarrassing the Agusta manager. He told the personnel including our secretary to not talk to me and it was then that all catastrophic failures were removed from the FMEAs. I sat on my butt for almost a month reading all types of aviation journals and walking out on the flight line and in the production and test areas. It really didn't matter as I earned almost 12K during that period.

------------------
The Cat

Oh yes of course, it's quite normal for helicopters to ditch and expect the engines to behave normally, isn't it? Why not fit supplemental oxygen supplies in case the a/c sinks, at least the engines will still run.

Lu, did you conduct an analysis on the 365N and discover that after an uncontrolled ditching, the blades disintegrated and failed to meet the specification lift requirements? (Taiwan Police force).

What is this? Thank God for those wonderful American Helicopter companies that never get a foot wrong? ( Apart from losing blades in flight, catastrophic gearbox failures and the like).

------------------
Another day in paradise

To: 212 Man

I was not addressing the ditching of the EH-101. This helicopter is configured to make open sea rescues that might require landing in the water. It was under those conditions that I was talking about.

Lets take it one step futher. Supposing the helicopter landed in the water because of a mechanical glitch. Let's assume that the glitch was corrected and the helicopter then lifted off the water to fly back to base or, let's assume the helicopter was retreived in any one of several ways and returned to base. The SOP would be to check the hull for damage and if none was found and the mechanical problem was solved the helicopter would be returned to service.

Water might be found if there was a requirement to strip the sumps on a daily basis but, what if that test were to be made the next day after the helicopter was returned to operation.

I deal in probabilities and possibilities and the way I look at it, is if a water landing was made for whatever reason and the anti backflow device was not installed, the probability and possibility of multiple engine failure is 1.

------------------
The Cat

[This message has been edited by Lu Zuckerman (edited 20 November 2000).]

Lifted from another web-site filled with mirth about this fabulous product. This article comes from that well known aviation publication the Daily Express!
http://www.lineone.net/express/00/11...s/n1020-d.html

What's the story about the owner of that very nice corporate S61N in the UK wanting to buy an EH-101 and Westland refusing to sell him one?

After 15 years of flying around aimlessly, winning contracts that get cancelled and then producing machines that don't seem very capable, you might think they would jump at a high profile corporate sale like that?

Maybe they are too worried about the safety of a high profile billionaire flying in their product?

The vents referenced in the article above are most likely the vents referenced in my post above.

------------------
The Cat

The EH101 was not designed to lift off after a water landing be it from a ditching or a purposeful landing on the water. Once down it stays down. In addition the twin engine capability of this 3 engined hippo is non existent!

------------------
TC

To: Thomas Coupling

During the design stage it was considered that the helicopter at some time would intentionally land on the water and take off again. That is why I made the request for the valves in the vent system. By your argument it would be strange that a helicopter capable of flight be allowed to remain on the water if it were ditched for a condition that was repairable while on the water or if the pilots put it on the water to effect a rescue or some other reason.

Under the scenario you stated how do they get the helicopter back to base.

Regarding two engine operation, The Italian Navy like the Royal Navy did not want the helicopter and to top that, they saw no reason to have a third engine.


------------------
The Cat

[This message has been edited by Lu Zuckerman (edited 20 November 2000).]

[This message has been edited by Lu Zuckerman (edited 20 November 2000).]

[This message has been edited by Lu Zuckerman (edited 20 November 2000).]

Lu:

Believe me: SWASHPLATE is still working!!!!!

To: Swashplate

I don't understand the meaning of your message.

------------------
The Cat

I posted this on several other threads:


posted 25 November 2000 13:07
--------------------------------------------------------------------------------
During the design of the EH-101 I brought a potential problem to the attention of the design engineers for the rotorhead and the flight control systems.
The rotor head on the EH-101 uses elastomeric bearings that allow pitch, flap and lead/lag. In the design stage it was not decided which way the bearings were to be installed. The original concept was to install the bearings so that they operated in flight in and about the neutral position which would minimize the stresses in the bearing. The other concept was to install the bearings in the relaxed state while in low pitch thus increasing the stresses when the bearings were in high pitch while in flight. At the time of my involvement they were going with the former as opposed to the latter.

In this situation when the rotor was stopped
and folded along with the tail pylon being folded the hydraulics were still on. With the hydraulics off, the residual torsion in the elastomeric bearings would tend to relax and try to return to the neutral position.
However, with the tail folded these forces would be locked in the system which would place the entire flight control system under a compressive or tensile load ( I can't remember which).

In either case, if the system had to be maintained, requiring a disconnect of the system a control rod could injure the tech and cause a lot of damage to his/her hands and/or face.

I left the program before a final decision had been made. In any case, watch out.


------------------
The Cat

Lu:

Just 'avin a laarrffff mate!!!

Felt this discussion needed lightening up a bit!!

Lu: thanks for your CV...very impressive indeed keep up with the inputs. It would be nice though to hear some good news about some helo design out there!! There must be a success story somewhere!!
My comments regarding the water-borne capabilities of the EH 101 are based on briefings by a MOD company who are now in partnership with an overseas company based in a country famous for its pizzas!!
They declared that the aircraft did not have the lift capability of launching from the sea in anything other than sea state 1 with all systems operating. From experience the S61 I flew onto lakes, 5 times a day many years ago was taped up and assessed watertight even then, it leaked about a half ton of water every minute it remained on the water!! This was when the surface was ripple free!!
The chances of a non existant sea state in any of the envisaged operating areas of the 101, together with the fact that the a/c did not have a 'boat hull' and in addition the possibility of it being there because a system had failed gave rise to their statement that this a/c was not intended to fly away from a sea landing.
Add to that the teaching that a helo should not be flown off the water after a 'surprise' landing due to the inability to confirm the integrity of the tail rotor and sea water ingress to its electrics...reinforced this opinion.

Your other point regarding ..."how is the a/c recovered..."
The same way we always recovered them:
lifting gear onto a support vessel's deck, or towing ashore (if nearby)but this invariably led to the loss of the craft due to swamping!! Good to watch though!!

Take care..

------------------
TC

To: Thomas Coupling

Roger that.

------------------
The Cat

T-C (et al):
Don't you see this as an example of the K.I.S.S. arguement. - Simplification of systems. Less is more. Too many chefs (engines) spoils the broth. One reliable engine is better than two unreliable etc

(BTW the military capability of 225! R44's has got to be superior to 1 EH101, and you can keep 225 R44 flying with 12 ground people! Ok so for the military lets build in some redundancy and call it 100 people! how many ground people to maintain 1 EH101?)

I heard a rumour today (and this is still a rumour network) that a rotor brake fire caused the ditching. Something sticks in the back of my mind that an automatic r/b coming on if flight caused another accident.
Can anyone enlighten me?

The thread on the miltary board relates to the loss of the first Italian prototype that suffered a fatal accident after a rotor brake fire caused the primary flight controls to fail ( some talk of composite control rods ).
The story is that the rerofit to prevent recurrance of this was incorrectly installed on the latest accident aircraft and was found defective on others of the fleet. I think a lot of Canadian Miltary pilots might be thanking Chretien for his prevarication now. The Canadian miltary would have been "proving" their first aircraft by now if it had not been for the liberals delay of the program.

Thomas Coupling, could you please tell me how you can say that the EH 101 twin engine capabilities are non existant? Is this fact based ?

[This message has been edited by Pat Gerard (edited 29 November 2000).]

101 robbies for 1 Merlin , interesting concept . Only problem ( opportunity) is finding 101 pilots. ( but as this is the pilots network i guess that is a benefit).
I think the r22 might be a bit shy on range and the autohover and load carrying ability may be a problem. What we need is a side by side comparison . I have now doubt that 101 robbies would be cheaper than one Merlin even if you chucked them out when they reach TBO.

So here we go then, another piece of kit for the Forces that now they decide that don't want........! Take the lid off boys and look in side, you might just learn a thing or two about the future of helicopters.

Being very close to the operational side of this aircraft I believe the only area for concern is the prime contractor Lockheed. They are a complete bunch of idiots and could organise a helicopter program if their professional lives depended on it!!

We have told industry many times about the problems with the Merlin and assumed that the prime contractor would do something about but we were wrong. Talking to contacts in EHI it appears that the information flowed back to the experts at Westlands is highly censored and all the major problems are being stored up until the MoD give LMA some more money to fix them!!!

Why don't LMA walk away from the contract and let us deal with Westland direct? Since the crash Westlands have bent over backwards to help with the investigation, LMA have been no where to be seen, thanks chaps you take all the money and let Westlands take all the crap!!

On the subject of engines, more the better I say!!

If I am correct Lockheed Martin was awarded the contract to design and integrate the electronics suite for the Merlin. IBM had a similar contract with Sikorsky but neither company had anything to do with the design of the helicopters. They are the program managers but should not have much say so relative to airframe problems. But then, I started this post by saying if I am correct.

As far as getting a lot of crap, Westland by virtue of the consortium contract with Agusta was responsible for the Merlin and Agusta was responsible for the Italian Navy version as well as any civilian derivitives But the crap should be shared, as Agusta, designed the system.

As I stated in several posts above the rotorbrake failure among many others was predicted to happen but all references to catastrophic failures were removed from the FMEAs.

------------------
The Cat

[This message has been edited by Lu Zuckerman (edited 29 November 2000).]

Lu, I believe that you are correct but one rumour that I have heard is that the crash was cause by some incompatible software being fitted to the aircraft becuase LMA hadn't paid for the up to date kit. Is this not a programme management issue?

What parts of the electronics suite or system did LMA design? Was it the Flight Management System?

To: Chin Chin

When I worked on the program Lockheed had not merged with Martin and not being directly connected with the electronics system or, supporting software I can't say.

Regarding my comment above I would now say that Lockheed Martin is responsible for the problem assuming what you indicated is proved to be correct.

------------------
The Cat

Lu, let's talk rotor brake.

Did you have any involment in it's design or FMEA during your time at Agusta?

I assume that the design on the Merlin takes some electronic form not the machanical type we had on the Junglies?

To: Chin Chin

As a consultant, I supervised the preparation of the FMEAs. My main function in preparing the FMEAs was on the dynamic system and the power train. However I did not work on the front gear box.

The individual that worked on the front gear box identified several potential problems relating to circuitry defects and internal leakage both of which would cause the application of the rotor brake in flight. Jacking that failure up a notch or two it was apparent that they were catastrophic failures. In my investigation of the potential problems I determined that it was possible for the brake to come on hard and as a result the two thin walled drive shafts would be severely damaged enough to separate losing all of the services on the front gear box as well as causing a significant overheat condition. Those catastrophic failures among all of the others were eliminated from the FMEAs on the whim of the department manager.

------------------
The Cat