Wednesday, November 1, 2006
Helicopter Parts: Playing Their Role
It's said that a helicopter is just a lot of parts flying in close formation. A big part of the industry's new safety initiative is to ensure that they stay in close formation throughout the entire flight.
Last year, the helicopter industry essentially committed itself to reducing the accident rate by 80 percent over the next 10 years. Major emphasis will be placed on operational aspects, the primary cause of most accidents-stop flying into inadvertent IMC, stop controlled flight into terrain, stop flying into buildings, wires, trees and other solid objects.
However, hard looks are also being taken at mechanical failures in flight, caused by the structural failure of a key part within a critical system. David Downey, manager, FAA Rotorcraft Directorate, Aircraft Certification Service, said that the FAA is about to issue a notice of proposed rulemaking on two new rules involving parts. One deals with damage tolerance for composite materials, and the other with damage tolerance for metals. "The FAA has been working with industry for the past seven to eight years on this project. It is now at (FAA) headquarters waiting to be signed out," he said.
Downey said that the manufacturers have already "stepped up" toward meeting the requirements of the new proposal. The ruling will create a higher level of certitude, saying that for a critical structure area, a part has to be able to incur a fault or crack or debonding and not propagate a failure. "The rule basically bumps up the level of safety that we have for both composites and metals," he said.
The NPRM is expected to be issued within the next six to eight months.
More efforts to prevent the failure of parts are improvements within the monitoring of parts during flight. This monitoring can be done through better implementation of equipment, such as health and usage monitoring systems (HUMS), vibration health monitoring (VHM) and engine vibration monitoring (EVM) systems.
A recent study by Shell Oil, in which the company analyzed all the mechanical malfunctions in the off-shore fleet, found that 70 percent of mechanical malfunctions could have been diagnosed prior to failure by the use of HUMS.
Bob Sheffield, representing the International Association of Oil and Gas Producers' Aviation Subcommittee at the European Rotorcraft Forum held last September, said that in order for the offshore industry to meet its air safety goals, "manufacturers must support HUMS/VHM/EVMS and provide affordable solutions for legacy aircraft." He noted that the helicopters in common use today for offshore work are the AS-332 Super Puma, Bell 412 and Sikorsky S-76, "designed to requirements that are now over 25 years old."
However, to be truly effective, the use of parts monitoring devices require massive inputs of data.
"Some, if not most, of the parts failures that we see right now are in large part unpredictable. They include "new failure modes that haven't been seen in the past because of everything from new operating environments to new stresses that are being introduced into the aircraft because they are flying in flight regimes they haven't flown in before," said David Ford, president of Keystone Helicopter.
As a result, efforts are more focused "on trying to identify an incipient failure in time to warn the crew, so they can take action rather than driving more redundancy or a more failsafe design philosophy. One area that is getting a lot of attention is doing that electronically rather than mechanically, so you can add multiple redundancies without adding a lot of weight."
Ford noted that Sikorsky is now putting a HUMS package on its S-92s, and will have it on its S-76D. It will be able to monitor every part on the aircraft, with automatic data linking back to the company.
"Sikorsky is getting huge amounts of data dumped back into their system," he explained. "This data is being constantly analyzed so that they will be able to build a data base and draw conclusions much earlier in the life cycle (of each part) than it has in the past. They will be able to predict wear-out modes and that sort of thing before the problem becomes a fleet wide issue."
He said that the more data that is gathered, which is a function of having more HUMS systems, the more Sikorsky is able to draw correlations between certain failures and data from sweeps of various frequency ranges. "When they see a certain frequency range begin to grow, that's typically indicative that you have a bearing that's wearing or something changing. As they get more information in the data base, they are able to identify that increases within a certain frequency range are indicative of a problem with a part that can be associated with that particular frequency range."
OEM vs. PMA
One area in which safety is becoming less, rather than more, of an issue involves the production of after-market PMA parts. Once forced to wear the mantle of the shoddy, and therefore unsafe, poorly made substitute for the "real thing," the PMA part is now seen as an equal to the OEM produced and approved part.
In a recently released position paper, the Modification and Replacement Parts Association (MARPA) noted that out of some 425,000 PMA parts certified by FAA, only 34 proved to be defective, requiring airworthiness directives (ADs). Of those, only seven involved helicopters.
A noted case of a PMA part receiving an AD came from the 2003 fatal crash of an MD500D in Hawaii. This was caused by the failure of the Model 250 engine compressor splined adapter couplings manufacturered by Extex. However, the same part is also manufactured by Rolls-Royce and Alcor, both of which had reported failure of the couplings.
"Initially this was looked at strictly as a PMA issue," said Jason Dickstein of the Washington Aviation Group and a lawyer specializing in aviation issues. Then the FAA found that there was a history of the Rolls-Royce part failing, but no one had issued an AD on them. "So they were rushing to an AD on the PMA parts. The difference being that there had been no fatalities in the Rolls-Royce parts failures. But the failure mode had already been identified repeatedly out of Rolls."
Today the safety of PMA parts predominantly has been accepted by the industry, with a major reason being the close collaboration between the FAA and MARPA, according to Downey. MARPA is now six years old, "with a really good and growing relationship between the FAA and MARPA," he said. "MARPA has been very helpful to us, and we've been working closely together on PMA issues."
The Aerospace Industries Association (AIA) also works closely with both industry and FAA "to assist [FAA] in making sure they are applying their process for certification of parts and repairs in a consistent manner, that equal treatment is being given to the OEM and PMA parts, or alternate repairs that are developed, so that they are all certified to the same levels of safety," said Michael Romanowski, AIA's vice president, civil aviation.
"PMA and third-party repair is part of the regulatory structure. It is part of the business environment. We recognize that, and we have members who are involved throughout the spectrum. There is a recognition that there needs to be an assurance of the level of safety," said Romanowski. There has been a lot of attention from the FAA to ensure a level playing field and that as parts and repairs are certified, they are certified to the same standards.
In effect, the battle between OEMs and PMAs has now moved out of the safety arena and into the economic battle ground. Engine manufacturer Pratt & Whitney has, in fact, put a serious crack in the dike by launching Global Material Solutions, a subsidiary created to produce PMA parts for the CFM56-3.While this initially effects only an engine not used by the helicopter industry, it marks the first time an engine manufacturer has moved into the lucrative spare parts market against a competing OEM, in this case CFMI, the consortium of General Electric and SNECMA.
"The image of the PMA has improved dramatically," said Larry Shiembob, president of Extex. "Honeywell even has a PMA office to deal with PMA parts."
Shiembob noted that perhaps the main issue is PMAs overhauling other people's parts, citing an example of using PMA parts at a non-OEM repair facility can save almost $35,000 for the overhaul of a Rolls-Royce 250 engine, "enough to fuel a helicopter for a full year." Of that savings, roughly $13,500 was non-parts related.
The fact that the OEMs are no longer playing the safety card does not mean they have given up. Tactics now range from lawsuits claiming theft of intellectual property to threats of invalidating warranties.
The threat against an operator's warranty was always in the background, "but [the OEMs] are really focusing on this one now," according to Rob Baumann, president of HEICO Group, one of the largest parts suppliers to the industry.
"This [threat] has a lot of problems," he said. "For one thing, they only say it. They never write it down, it is never given in a public forum. One of the OEM's did come and say 'You'll be supported in a different way,' but they didn't come out and say they would invalidate the warranty."
One reason the OEMs will not invalidate a warranty if the operator uses PMA parts is the Magnuson-Moss Warranty Act, Baumann said. This act is actually aimed at the automobile industry and prevents an auto manufacturer from invalidating a car's warranty if the owner puts a generic part in it. "But the reason you'll never see [a helicopter] OEM put in writing that they will invalidate the warranty is because they know it is only a breath of legislation to open it up and say that Magnuson-Moss covers not just the automotive industry, but anything along that line."
A second reason is the commercial consideration, he said. "An operator comes in and says, 'Yes, I put a non-OEM part on my helicopter, and the PMA part had absolutely nothing to do with this failure. You know it and I know it. Now, if you don't support this, I will remember it, and you will pay for it later.' The OEMs know it's not an argument they want to press the customer on if the failure really didn't relate back [to the PMA part]."
Guns and Butter
After decades of essentially flat growth, the worldwide helicopter industry is suddenly being virtually overwhelmed with riches. The growth of industries such as offshore oil and gas exploitation, airborne emergency medical services and electronic news gathering has created an explosion in the civil market, while military programs such as the ARH-70 armed reconnaissance helicopter, UH-145 light utility helicopter, and upgrade programs to the H-1, H-60 and CH-53 are creating requirements for hundreds of helicopters. That's a lot of helicopter parts.
Add the requirement to provide spares support for the 26,000 helicopters already in the world's civil fleet alone, not counting the world's military fleets, and the question of spare parts suddenly starts to become a bit scary. The question really becomes one of "do the manufacturers build parts for new production helicopters or for product support?"
Sikorsky has already taken the step of sacrificing production capacity to divert some of its parts into the spares arena "so they don't overdrive their headlights," according to Ford. "They could actually build more helicopters if they were willing to sacrifice availability of spare parts, but they have very consciously made a decision to curtail production to ensure that they are not overdriving their venders to the point where they are shorting the spares."
Ford noted that this is an industry-wide problem, but that most OEMs are "starting to get the message and follow suit, although it took a little bit for some of them to get that message."
Eurocopter is using its association with EADS companies such as Airbus to leverage buying power for raw materials, as well as increased emphasis on "supplier tracking and rating," according to Mike Pettay, vice president, logistics support. It also has plans underway to add U.S. suppliers and is working with worldwide suppliers "to add to their capacity by either establishing a presence, or increasing their capacity in the U.S." It has also implemented a new Enterprise Resource System (ERP) "to gain efficiency and increase both productivity and responsiveness," he said. Eurocopter sold 401 civil helicopters in 2005, and recently won the U.S. Army's contract to provide up to 322 UH-145 Light Utility Helicopters.
Even with the OEMs cutting back on production of new helicopters to ensure a steady supply of spares and/or increasing production of parts, there are still spot shortages, Ford said. "Particularly when the part involves some exotic metal where there really are capacity issues and there really isn't enough of the material," he said. The most prominent spot shortages that are currently occurring involve exotic nickel alloy and titanium parts that go into the hot sections of turbine engines. "That's the same raw material that all the engine manufacturers use," he said.
Getting parts directly from the parts OEMs is also difficult, with lead times of from three to nine months, according to Steve Matza, president of Consolidated Aircraft Inc.
"One big problem with the [parts] OEMs is that their accountants won't let them produce the part until there is actually an order on hand," Matza said. "They only build to order. Parts are very expensive, and they do not want costly inventory on the shelves collecting dust when the money could be in the bank collecting interest." Another problem with going directly to the parts OEM is that they occasionally require a company to buy in bulk, 10 or so pieces at once, since they may have to manufacture the part. They may not even have the blueprints to the make the part any more. "We may have to end up calling the helicopter's manufacturer," he said.
However, going to the OEM is not the first choice. "We'll look at ILS or some other parts supply house first," Matza said. He noted that Consolidated belongs to five parts networking companies: ILS, Partsbase, APLS, AirParts and ABD, with "ILS and Partsbase being our first choice for parts search."
Graham Duke, marketing communication manager for Aviall, said that repair stations are getting the parts they need "if they have provisioned correctly, except for circumstances such as production issues or raw material issues. Service level is approximately 90 percent." Aviall is the parent company of ILS, and was recently purchased by Boeing.
Both Aviall and ILS are reporting increases in both parts and services. ILS had a 16 percent increase in subscribers during 2005 over 2004, with searches for parts growing by eight percent while searches for maintenance, repair and overhaul services increased by 26 percent.
ILS also introduced two new software package service earlier this year. Inventory Optimizer is designed to manage the entire sales process, including inventory tracking, negotiating and ordering, while MRO Optimizer is specifically designed for aviation repair facilities to track inventory through the entire repair process.
A unique method of getting parts is through Helicopterparts.com. Run by Rick Seeman in Little Rock, Arkansas, this four-year-old parts provider is a totally computer-based service run similar to E-Bay. The website has two listings, a parts-for-sell listing broken down by manufacturers where the operator can look for a specific part, and a Fast Track locator where the operator can list the part he's looking for and have suppliers contact him directly. There is no charge for listing a part-for-sell or looking for a part-to-buy. The Helicopterparts.Com website also has display ads, which is where the company makes its money.
"Our principle reason for being is the Fast-Track Locator for finding expensive, hard-to-find parts for turbine helicopters, in the shortest amount of time and at the cheapest price," Seeman said. "You click on the appropriate category in the center of the page and fill out the form. Then you go on about your business. We e-mail everyone on earth that we think would be a suspect to have such a part, and they respond directly to you with their price, condition and availability. There is no other place to put an ad to buy or sell parts."