By lizabeth Engler Modic | Aerospace manufacturing and design
Supply chains for the aerospace industry have become increasingly complex, challenging manufacturers of military and commercial aircraft to maintain control, consistency, and predictability in the supply of primary assemblies. This includes parts and subassemblies of such major systems such as landing gear, cargo, hydraulics, and structural components as well as smaller components parts sourced from Tier 2 providers.
For large aircraft, small aircraft, and helicopter manufacturers, the time and money spent on subcontracting multiple components of an assembly can be daunting and challenging to manage, especially the complex parts.
In some respects, the supply chain situation has become more problematic in recent years as the aerospace industry has attempted to increase its economies by adopting some of the automotive industry’s more commoditized, cost-driven approaches to purchasing. However, this approach can actually be detrimental to production efficiencies, particularly when it comes to more complex, higher tolerance systems and components.
“When choosing a supplier, we always want to be sure they are going to provide a quality part, and deliver on time, because we design complex, one-of-a-kind parts that must be delivered in time to meet our customer’s schedule,” says Russell Gibbon, director, landing gear and hydraulic systems engineering at Triumph Aerospace Systems in Redmond, Wash.
“If there is a quality problem, we’re in trouble. If they’re late, we’re in trouble. So, we’re always looking for suppliers with a good track record for quality, for consistently meeting schedule commitments, and for having the capabilities for producing the required part using the most efficient technologies,” Gibbon says.
Sourcing necessary capabilities
“When it comes to high-volume, routine build-to-print components, many aerospace manufacturers source them overseas as commodities,” says Randy Brodsky, president of Lakewood, Colo.-based Primus Metals Inc., a Tier 1 and 2 supplier of structural components, kits, and subassemblies to the global aerospace industry. “But when it comes to higher complexity, higher tolerance components, or those that require exotic materials or are produced in lower quantities, then aerospace companies need to seek out U.S. parts manufacturers who have the necessary credentials, production machinery, quality systems, and just-in-time (JIT) delivery capabilities.”
Such was the case with a recent project of Triumph Aerospace Systems – Seattle, a member of Triumph Group.
In producing a complicated landing gear system for a new military helicopter, Triumph was seeking a supplier that could make some critical parts in a limited quantity.
“After canvasing the supply base, we settled on Primus Metals to manufacture a number of the critical and complex parts of the helicopter landing gear system,” Gibbon explains. “Most of the parts were very complex aluminum millings with tight tolerances. All of the parts required delivery within a short time frame to meet our customer commitments.”
Gibbon adds that it was important that Primus could work directly from 3D solid CAD models. “In the old days you had to provide drawings detailing every feature of a part,” he says. “Now we send the supplier a solid model from CAD, and they use that to create the CAM files to machine and then to inspect many features of the part. In terms of getting the parts faster, getting them made to precise tolerances, and shortening lead times, manufacturing direct from a solid model is an important capability.”
Avoiding potential risks
Brodsky, whose company manufactures a broad range of turnkey, integrated sub-systems, and components used within aircraft, says aerospace companies can improve on supply efficiencies by verifying that their suppliers have all the necessary capabilities and credentials.
For example, AS9100 (Rev. C)-certified manufacturers are able to produce the most complex components in-house, and then work exclusively with its National Aerospace and Defense Contractors Accreditation Program (Nadcap) supply chain for part finishing to manage all the burdens that a purchasing agent is normally required to perform through multiple vendors. Final subassembly is commonly handled in-house as well. In many instances, machining experience, equipment capability, capacity, and quality systems will affect a supplier’s ability to deliver on a timely, consistent basis.
“When you’re machining titanium or high-nickel alloys or hard materials, the production floor can’t just run one part right after another,” Brodsky says. “You’ll have a lot of tool wear and deflection, even with the highest quality machinery, so you have to be sure the machinist is able to accurately measure parts, make precise adjustments, or change tooling. It’s just not a load and go.”
Brodsky adds that there are more complex design coming out each year because engineering is evolving exponentially. The demand to find high quality manufacturers continues to become more difficult.
“It can be extremely risky for aircraft manufacturers to assume that a low bid – or perhaps even relying on a traditional supplier – will provide quality parts that require next-generation materials or other complexities,” he says. “In some cases, there can be 1,000 dimensions on a single piece of hardware and tolerances within millionths of an inch. Such requirements are usually outside the capabilities of the ‘commodity’ job shop and customers become complacent about monitoring historical suppliers and continuing to seek the best of the best in the marketplace.”
Other complexities recently introduced include parts with extensive finishes and plating processes, and those that must be heat-treated or undergo destructive testing.
In addition, more and more defense-related companies are requiring that members of their supply chain be International Traffic in Arms Regulations (ITAR) compliant and registered. This is often required for a company involved in the manufacture of goods or services covered under the United States Munitions List (USML), or a component supplier to goods covered under the USML. This, in turn, means that the supplier must be registered with the State Department’s Directorate of Defense Training Controls (DDTC) and maintain rigorous internal processes dictated by ITAR regulations.
This ITAR requirement, in conjunction with the AS9100 certification, removes the aerospace customers’ opportunities to source defense-related parts from offshore manufacturers, and also limits the number of eligible domestic suppliers.
Enhancing management control
The ability of the supplier to provide complete assemblies, subassemblies, kits, and turnkey products can improve an aerospace customer’s management control over its own manufacturing processes.
Such control enhances their abilities to consolidate orders instead of having to facilitate and maintain many supplier relationships to accomplish the same goal. This further reduces the lead times for product delivery as well as drives down supply chain costs.
Yet many suppliers, both domestic and overseas, are unable to manage the supply chain effectively, which is critical for producing turnkey parts and assemblies, Brodsky notes.
“This is important to many aerospace companies because there is a lot of risk involved when their component contractors are using three, four, or five subcontractors to fulfill their commitments, in addition to the customer already using multiple suppliers to fulfill the same program’s demands. Coordinating and ensuring the delivery of all these variables commonly fails.”
Primus Metals deals with premier commercial and military aerospace manufacturers such as UTC, Lockheed Martin, Ball Aerospace, Zodiac Aerospace, Eaton Aerospace, and Triumph Aerospace Systems. Therefore, it is significant that Primus has a robust Nadcap supply chain, which enables the company to produce turnkey parts and assemblies.
“This is very important when there are multiple subcontractors involved,” Brodsky explains. “But it requires additional overhead and strong internal controls, so many of the smaller job shops don’t want to deal with it.”
At the same time, Brodsky estimates that more than 95% of his company’s business has to deal with a significant level of supply chain management. While this can have some effect on the company’s pricing structure, he feels that for most customers, the supplier’s ability to provide reliable quality with on-time delivery is worth far more savings than a few percent of hard costs on the front end.