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Sikorsky S-92: From Design to Operations

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Sikorsky S-92: From Design to Operations

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Old 27th Feb 2003, 21:06
  #141 (permalink)  
 
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Dangermouse, is this the same fabulous EH101 that the Military are struggling to give a full Military Aircraft Release to, the one that has the first dozen Navy Merlins operating on different software fits and individual Release to Service, the same one which is cracking in various places but can't be repaired by anyone but Westlands because it is composite, the one that can't be shut down on sloping ground because of the airframe deformation it causes and the same one we will probably be stuck with in the SAR force - not because it is any good for the job but because the Military have always been forced to support Westlands regardless of the quality of the product?
By the way, since I get the impression you work for WHL - why, since it was a joint venture with Augusta, did Westlands not build the main rotor gearbox? I ask the question because one of the few good Westland products I have seen is the 3 pinion MRGB on the Lynx - it has a clever load sharing ring that allows the full power of a single engine to drive the gearbox in the event of a single engine failure. Wouldn't that have been a good idea on a 3 engine helicopter - the ability to harness the full power from the remaining 2 engines, shame the EH101 can't!
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Old 28th Feb 2003, 16:51
  #142 (permalink)  
 
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Angry

I have got to concede the point to NL and FS, the 101 is not JAR29 certified per se but uses JAR29 as the basis for certification following the FAR29 and BCAR cert in 94, if the comment had read 'It is the only aircraft in its class certified to the latest standard of the rigorous FAA Part 29 requirements', it would have been clearer.

Crab: I dont know where your info comes from but you are confused about aircraft procurement, qualification and RTS.

The spec to which any item is designed is promulgated by the relevant IPT on behalf of the user.

The manufacturer designs and qualifies the aircraft to meet a spec, this is overseen by the relevant IPT (NOT the user). Thus the IPT are the customer and the auditor of the design from a compliance point of view. The IPT are MoD staff and hence not constrained by commercial concerns.

In the case of Merlin WHL have determined that the aircraft is both safe to fly and spec compliant and that info has been given to the IPT after approval by the design staff, airworthiness staff and the Engineering director.

The fuselage distortion on shutdown comment is completely unfounded and we ought to know, if you manage to get a copy of the WHL lims document you will see that as far as we (the designers after all) are concerned the aircraft can land on severe slopes with significant cross winds without trouble, please do not accuse us (yes I work for WHL) of not having the interests of the user at heart, flightsafety is paramount and we would not promulgate a 'release' for a knowingly deficient aircraft.

In the sad case of the UK the IPT have decided that the design Release to service (RTS) which is issued by the ACAS is based on Recommendations from QinetiQ who are now a commercial organisation, every 'fault' they find gives them more work and more profit....(conflict of interest?)

The RTS for both Merlin variants is an agreed incremental approach, between us, the RAF, the IPT and QQ (who have the most to lose by recommending a full MAR quickly, less work etc) and we have generally met our programme dates, ask QQ why they only schedule 12 hrs a month of flying when we achieve 24, thats the delay in MAR production.

Composites are not the same as metal, you have to treat them differently, from your location I guess you are involved in the SK 3A at chivenor, so 21st century technology might appear strange to you.

The initial Merlin deliveries had some teething troubles (as all new A/C do, comments from the early users of Tornado would be interesting) but it was all agreed by the customer (not you, the IPT, any grievances should be directed at them, they audit us and were happy).

As for being unhappy with the 101 as a SAR cab, talk to the canadians about their recent experiences or read Defence Helicopter. If you are happy with the SK and think that a 150 kt cruise with an deliberate icing clearance, 3 FADEC engines, 50 kt cross wind hover capability, properly designed NVG 'glass' cockpit and a cabin you can get a landrover in aren't an improvement you really are deluded.

As to the quality of our products and we are a protected company what is flying at Shawbury, what is flying at Odiham, why is the Apache flying at Middle Wallop instead of letting us do our own A/C (remember Lynx3?). Dont forget August 1986...(400 kph level without compounding ). The Canadians (twice), Portuguese, RAF, RN, MMI, Danish and Japanese can't all be wrong can they?

On the positive side thanx for the comment on the Lynx MGB, the workshare years ago was decided on by WHL and Agusta (if I recall during our problem period) and they got the MGB, c'est la vie, anyway in the 101 case the MGB is perfectly OK as is, we have OEI CAT A performance at well above MAUM, three engines are better than two, less dead weight to carry around to cope with losing 1/2 your power instead of 1/3, similarly 4 is better than 3! I would be interested in the SK and S92 Cat A performance penalties as a comparison (didn't Flight International say that to achieve CAT A behaviour the S92 loses 1000kg in AUM?)

To sum up, do some research and get yourself a flight at Benson before commenting.

The 101 looks great in USMC colours.....
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Old 28th Feb 2003, 19:28
  #143 (permalink)  

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Thumbs up Yeah, but what if.....?

To: Dangermouse

Check to see if Agusta ever verified that the main transmission can survive a mechanical lockup. If they did, did the demonstration take place using an EH-101 transmission or did they use an A-109 transmission and, did they ever determine the level of damage suffered by the rotorhead when it supplied the necessary energy to break through the lockup. I await your response.

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Old 28th Feb 2003, 20:46
  #144 (permalink)  
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dangermouse,
Thanks for responding to crab, I almost did (but thankfully suppressed the urge!) because each machine has lots to offer. It is up to our customers to decide. As I have posted in the past, I have many friends at Westlands, including several test pilots, and do wish to be able to drink coffee there in the future!

For the record, the Collier press release said, "It is the only aircraft in its class certified to the rigorous FAA Part 29 requirements, incorporating the latest specifications for flaw tolerance, bird strike capability and turbine burst protection. " That statement is quite correct, but the comma does allow one to stop a bit too long, perhaps.

Regarding Cat A, the S-92 is qualified to Cat A at its max gross weight, up to hot high conditions.
 
Old 1st Mar 2003, 10:40
  #145 (permalink)  
 
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to Nick, thanx for that, obviously FI got their facts wrong

To Lu, I havent a clue about that one, is it a certification point?
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Old 1st Mar 2003, 11:07
  #146 (permalink)  
 
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Dangermouse, I see you have used the classic defense of blaming Qinetic and the IPT for the delays bring the Merlin into service, how stupid of me not realise that WHL are completely blameless.
You have rather dodged the issue of cracking in the airframe - yes I know composites are different but when a Sea King cracks (station 290 or the I beams for example) WHL issue a repair schedule so that the military (MASU for example) can repair the airframe themselves. Now your super composite aircraft is cracking, please deny that any work has to be carried out by your firm at extra cost to the military (more work, more profit).
I am sure that the aircraft can be safely landed on severe slopes with significant crosswinds but I suspect your WHL lims document just says it can be done - not that shutting down on slopes will cause the airframe to distort - anyone from 28 Sqn care to comment?
As far as the Canadians go, 2 of our flight are planning to visit Greenwood next month so we will see if they really are as ecstatic as you claim. The Canadians were so desperate to get their politicans to stop fannying about with procurement decisions they would have jumped at the chance of any new helicopter - they didn't exactly have a fly off of different contenders, did they?
I know you will argue that the Danes assessed the aircraft fully before they fdecided to go for it, unlike the RAF who had the SH version forced upon us instead of something useful like more chinooks. As for the landrover in the back, providing you take the windscreen off (particularly excellent thing to do when you are being extracted under fire) you might just squeeze it in but don't pretend this is an SH aircraft, it is just not squaddie proof.
As for being an improvement on the Sea King - I would love more range and more speed as well as better icing clearances but a SAR aircraft has to be first and foremost a stable and effective winching platform where the winch wire doesn't foul the airframe and the downwash doesn't trash the survivor.
Nick had some very well presented arguments about the wisdom of 2 engines v 3 that he gave to the SAR conference last year which WHL really didn't have an answer to but according to your logic the more engines the better - dead weight is carrying around spare engines as a back-up to an engine that is statistically very unlikely to fail!
I did fly in an early EH101 and was particularly amused when my boss asked to see how the ac behaved with the active anti vibration kit to be switched on - it already was.
Try to find someone in the military who is actually pro WHL and it's products and you might go some way to understanding that as much as you soft soap the IPTs and the MOD procurement chain, the guys who actually fly the stuff are not impressed - even if none of it is your fault (yeah right!)
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Old 1st Mar 2003, 15:15
  #147 (permalink)  

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Thumbs up Certification as well as flight safety!!!!

To: Dangermouse

When the EH-101 main transmission was originally designed it incorporated a shear point that would fracture in the event of a sudden stoppage due to something getting into the gear mesh thus allowing a safe autorotation. The energy that is necessary to effect the fracture (shearing) is provided by the inertial energy of the rotor system. During this instantaneous stoppage the blades move forward and transfer their energy through the dampers to the rotorhead and this collective energy causes a reversal of the drive reacting against the stoppage and results in the fracture.

I questioned the Agusta dynamics group as to their demonstrating the ability of the transmission to survive a sudden stoppage. At first they were vague in their response but later stated that they would alter an A-109 transmission for the demonstration. They indicated that they would scale up the results to demonstrate the EH-101s capability of surviving a sudden stoppage. I left the program shortly after that.

My next consulting position was with the company that built the EH-101 hydraulics system, the flight control servos and the dampers. While there, I read the specs for the damper. It indicated that the maximum load on the damper during all areas of flight would not exceed 1800pounds (tensile and compression). Allowing a 1.5 safety margin it would be expected that the damper would start to yield at some point over 2700 pounds (tensile and compression).

Referring to my statement above about the dampers transferring the kinetic energy of the blade the instantaneous load on the damper would far exceed the 2700-pound safety margin causing the structural failure of the dampers. The damper failure can also translate into side loads being imposed on the blade elastomeric bearings resulting in their possible failure.

In any case the pilots would lose control of the helicopter.

So, the question is did Agusta run the test and did they consider the loads on the dampers and would the dampers successfully transfer the loads without failing.

Check the certification requirements to see if the shearing of the shaft is a requirement requiring testing or if the CAA is like the FAA
did they do a computer analysis involving all of the structural loads that apply.

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Old 16th Apr 2003, 00:13
  #148 (permalink)  
 
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Devil

Just stumbled across this topic and being a Merlin operator I would like to have my say.

First, congratulation to Nick and the boys - development to certification a long and expensive process. Well done.

Now to the 'comments' about the Merlin. Despite the obvious experience of many of the members almost everyone forgets that when a new platform enters service there are issues.

These issues only become problems when they cannot be addressed. WHL have addressed all the issues and this has resulted in the RN being able to deploy the aircraft to the front line.

The Cormorant version is the best SAR aircraft in the world today - not my thoughts - the thoughts of the Canadian SAR operatives so what more do you want Crab?

I would like to see the Merlin replace the Sea King in the SAR role - just hope that money sponges aka LMA, are not involved you might see a working spare parts supply line then!!

Every design has aspects not liked by the operators but the S-92 and the EH101 are the best helicopters ever design both in terms of operation and safety.

Having read both the MAR and the RTS it appears that our friends at Boscombe Down are on a job preservation jolly. The cabs could do more if these jokers were not involved!

Keep up the good work Dangermouse and thanks for the opertunity to get on my soap box!!
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Old 16th Apr 2003, 05:09
  #149 (permalink)  

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Thumbs up How safe is safe?

To: ZH844

Every design has aspects not liked by the operators but the S-92 and the EH101 are the best helicopters ever design both in terms of operation and safety.
Based on what Nick Lappos has stated about the design characteristics of the S-92 I would agree with your comment above. However I disagree with the second point of your statement about the safety of the EH-101 Merlin. Westland can only address those elements that they had design responsibility for. Agusta was responsible for the powertrain, the hydraulics system the rotorheads, flight control system and some of the blade design as well as fuselage design for the civil version.

I supervised preparation of the Failure Mode Effects and Criticality Analyses (FMECA) for the Agusta designed elements which, included all of the catastrophic failures that could cause loss of the aircraft. For whatever reason the department manager had all catastrophic failures removed from the FMECAs so they were never considered in the certification for civil usage or, for military applications. As a result, two of these catastrophic failures have manifested themselves on the Merlin and many more will in the future. See my post above regarding gearbox seizure.



Last edited by Lu Zuckerman; 16th Apr 2003 at 09:50.
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Old 1st Jun 2003, 01:45
  #150 (permalink)  
 
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Question

Nick Any progress on the TC/JAA validations?
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Old 1st Jun 2003, 03:41
  #151 (permalink)  
 
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A European validation team on it way to the States next week.
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Old 1st Jun 2003, 04:32
  #152 (permalink)  
 
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zalt and jimL,

The JAA team is coming to statford and West Palm Beach next week to perform the next stage of the JAA certification. We intend to fly the program they request (which should not be too extensive) and then complete the HIRF (High Intensity Radiation Field) tests at Pax River in late summer. This data will be presented to the JAA, and we hope to have certification shortly thereafter.
A complication is the EASA organization start-up, which might create some complexity in the legalisms of JAA certification, but the authorities seem quite dedicated to continuing the process in an orderly manner.

On other fronts, we have begun the formal IFR data gathering, and have also begun the de ice program with a tour in the Eglin AFB climatic hangar running right now. We will toss ice at the rotor to help substantiate the patterns on the blades, which will help correlate the airborne data we get next fall. We have every intention of certifying the deice in one season, which requires a flawless deice system, a really bad icing season, and some luck.
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Old 1st Jun 2003, 05:20
  #153 (permalink)  
 
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Chilling thought that Nick!
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Old 2nd Jun 2003, 05:21
  #154 (permalink)  
 
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Question

Nick

Good to hear there is more solid progress!

I'd heard rumours that the JAA were going to have to do a re-familiarisation visit (i.e what they do at the very start of their programme) because the design has changed so much since 1996 and that Sikorsky/FAA haven't supplied any information for two years on the open CRIs.

I know I shouldn't believe what I read in the press, but didn't #3 do trials at McKinley Lab (some place...!) in late 00? Why go back? Config changes or just to add blade deicing to the past test points?
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Old 2nd Jun 2003, 07:40
  #155 (permalink)  
 
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nick: has there been any provisions / hardpoints for the installation for flir and searchlight, if so there approx location . will be installing our new blackhawk nightsun mount next week, will send pix.
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Old 2nd Jun 2003, 08:39
  #156 (permalink)  
 
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S92 windows

Nick, why are the cabin windows so small? Pax like to have something they could climb through if they had to. Most of our 'bears' really don't like the idea of queueing for an emergency exit after ditching! (I know, the chances of an S92 ditching are ziltch - right?)
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Old 2nd Jun 2003, 14:41
  #157 (permalink)  
 
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Rule of thumb - if Nick can get through them they are OK.
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Old 2nd Jun 2003, 15:26
  #158 (permalink)  
 
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S 92 Paris airshow & tour

One for Nick Lappos,
Are you coming over with the S92 for the Paris airshow and subsequent visits to Norsk at Stavanger and Bergen ?. Is the machine going to fly the pond round the top or is it going to be Airtransported the easy way.



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Old 6th Jun 2003, 01:19
  #159 (permalink)  

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Canadian SAR - H-92 v Cormorant

Globe and Mail

Sikorsky attacks rival military copter

Manufacturers shed gloves in fight to replace Canada's aging Sea Kings

By DANIEL LEBLANC
Thursday, June 5, 2003 - Page A4

OTTAWA -- The helicopter war took off yesterday as Sikorsky launched a surprise attack against Team Cormorant's EH-101, and the two companies shed their gloves in the $3-billion race to replace Canada's 40-year-old Sea Kings.

One Cormorant official called it a "pissing contest" as the two manufacturers compared the size and strength of their products, which they hope to sell to the Canadian Forces in coming months.

U.S.-based Sikorsky, which has entered its brand-new H-92 in the race, offered a presentation to The Globe and Mail, stating that its aircraft is faster, stronger, cheaper to maintain and safer.

The Cormorant has long been seen as the Canadian Forces' first choice for a new helicopter, since it has three engines rather than two, and offers more power and size than its competitors. Prime Minister Jean Chrétien has referred to the EH-101 as a Cadillac.

But Sikorsky took a series of shots at the Cormorant, bringing its lobbying campaign to win the contract out into the open. Sikorsky's attacks took Cormorant officials by surprise. They were in meetings with the Department of National Defence all day.

Nick Lappos, project director for Sikorsky's H-92, said his company's aircraft is the best equipment for Canada, even if it has yet to be sold to any military force in the world. Mr. Lappos said the H-92 can carry 1,000 kilograms more than the Cormorant in tough weather conditions:

"Wherever you go, the H-92 carries more than the EH-101."

He added that the Sikorsky's cruising speed of 280 kilometres an hour is faster than the Cormorant's absolute speed limit of 277 km/h and is more fuel-efficient.

Officials from Team Cormorant were outraged, accusing Sikorsky of being hysterical. They said Sikorsky "manipulated" data to try to bring down the Cormorant.

Larry McWha of Team Cormorant said his company's craft is as fast as the H-92 and a lot more powerful than Sikorsky's numbers show. He said that Sikorsky took numbers from a variety of sources, relating to different variants of the Cormorant, to make their own H-92 aircraft look better.

"I'm not going to call them [Sikorsky] liars, but they have obviously taken some numbers wherever it was convenient."

Team Cormorant officials also made reference to a government document dated July, 2001, stating that Sikorsky was not capable of meeting the draft requirements for the Canadian Forces at the time. The document said that in hot weather, Sikorsky faced a "performance shortfall" of 1,000 kg in lift capability.

The other competitor in the race is the European NH-90, built by the French-led consortium NHIndustries. Officials from that aircraft manufacturer told The Globe last month that their helicopter meets all of Canada's requirements at the best price.

The contract to replace the Sea Kings will be awarded to the bidder that meets all the Forces' requirements, at lowest cost.

Team Cormorant has been arguing for a process whereby the contract can go to a higher bidder if its product is markedly better.
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Old 6th Jun 2003, 04:31
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I think Peter O'Neil's article (below) was closer to the mark. Hard to believe, but he received the same brief as Daniel Leblanc, who wrote the more sensational article above.

Chopper bidder's tactics anger rivals, DND
AgustaWestland alleges Defence has watered down requirements
The Ottawa Citizen
Thu 05 June 2003
Page: A5
Section: News
Byline: Peter O'Neil and Mike Blanchfield
Source: The Ottawa Citizen; with files from CanWest News Service

A European firm's aggressive campaign against the federal government's maritime helicopter procurement process has triggered an angry backlash by two competitors as well as the Defence Department.

They are ganging up on AgustaWestland, the Anglo-Italian consortium and manufacturer of the EH-101 aircraft that won a huge Canadian helicopter contract in the early 1990s and then had that contract cancelled in 1993 by Prime Minister Jean Chretien.

AgustaWestland has been alleging that the Defence Department is watering down its requirements to ensure that a cheaper, inferior, and less safe aircraft -- in other words, any chopper but the EH-101, now called the Cormorant -- wins the competition for the $3-billion contract.

The Department of National Defence is taking the unprecedented step of calling together security experts and reporters to briefings this week in an attempt to combat the anti-government spin that has clouded the Sea King replacement.

Department spokesman Jeremy Sales said there are "misconceptions" about the 1999 Statement of Requirements and subsequent specifications on the new helicopter, specifications that AgustaWestland has alleged have been reduced to help competitors of the Cormorant.

Sikorsky Aircraft Corp. spokesman Nick Lappos ridiculed any suggestion that Sikorsky is marketing an unsafe and inadequate helicopter.

He also accused AgustaWestland of misleading Canadians by asserting that the Cormorant, which has three engines, could survive the failure of a single engine while hovering, whereas its competition's two-engine choppers couldn't.

An AgustaWestland advertisement this week said the federal government is willing "to purchase an aircraft that will ditch and sink to the bottom of the ocean if an engine fails while hovering providing it is $1 cheaper than one that will not do that. Saving $1 to lose 10s of millions is strange economics."

"We believe the H-92 is the safest helicopter that's ever been conceived," Mr. Lappos said by telephone conference call during a slide presentation offered to several journalists yesterday.

"I'm absolutely amazed. It is disappointing to find people who will assert, for example, that they are immune to an engine failure when their own flight manual states otherwise."

The Sikorsky briefing cited U.S. army data suggesting an engine failure during missions is extremely rare in any event, with one occurring in a 20-aircraft fleet every 25 years.

Another Sikorsky official, however, endorsed Agusta-Westland's allegation that the Chretien government is diluting its requirements, though to assist another competitor, NH Industries, rather than Sikorsky or AgustaWestland.

"I'd have to say right now that there's a lot of rumour out there right now that they've dropped the bar significantly, and we've certainly questioned the latest release of the specifications," said Lloyd Noseworthy, Sikorsky's regional director of business development in Canada.

Olivier Francou, the Canadian sales director of NH Industries, said his consortium is growing weary of the media campaign mounted by AgustaWestland to discredit the Sea King replacement process, while promoting its own helicopter.

All the helicopters in the U.S. navy are twin-engine, he added.

NH Industries -- a consortium of French, Italian, Dutch and German aerospace companies -- developed its prototype for the NH-90 in the early 1990s as part of a NATO working group.

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