Sikorsky has developed a specification outlining the use of three casting technologies: simulation, additive manufacturing of the mold and low pressure casting. This specification has been used in the past on new development projects with positive results, reducing lead times and number of pours to produce a useable part. When the S-92 program needed to develop a second source for a casting, they worked with Magellan Aerospace to implement the specification. The project proceeded on time with all castings able to be used. Some elements of the specification were modified to work with a legacy part design, including the use of statistical process controls to reduce variability in crucible pouring.
Sustainment is the most important part of the aircraft life cycle. After a production program ends there are decades of work to support the aircraft that are flying in the fleet. The average aircraft age of the B-52 is 55 years old as of today. With a decommission estimate of 2040, the fleet's age could hit 90 years of sustainment of a given aircraft. These aircraft require both planned and unplanned maintenance, which requires the original equipment manufacturer (OEM) to supply spare parts. When the required spare parts are not available, it can result in aircraft on ground (AOG) events and missions unable to be flown. During production, an OEM's suppliers have a steady cadence of part orders which results in a steady flow of parts through their facility. Over the lifecycle of sustainment, part orders are more likely to come in smaller quantities and at unpredictable intervals. This results in suppliers needing to start and stop their production lines for these parts, or the need to inventory parts, which creates several challenges. It is not easy to restart a production line. For some parts there is still the element of tacit knowledge that is essential to manufacturing the parts. If there is a break in production, the tacit knowledge can be lost causing a long process to restart production, resulting in increased scrap and longer than normal lead times. Breaks in the production flow also result in suppliers focusing their resources on other projects, so capacity is not guaranteed when a sustainment order is needed. Further, because many sustainment parts were designed decades ago using manufacturing processes that were most robust during that time period, many advanced technologies for manufacturing are not applied to sustainment parts. As time goes on, parts with multiple sources become parts with sole sources or worse, they become obsolete. Options for procurement become limited, often requiring protracted negotiations and requiring the OEM to accept long lead times, unit cost increases, requests to reimburse the supplier for non-recurring expenses (NRE) to re-start the line, and/or large minimum buy quantities. If parts have become obsolete, then efforts are typically initiated to qualify a new supplier to build the parts as originally designed or to qualify a replacement part that is very similar to the original. This can be an effective approach for some parts and suppliers, but it is a time consuming and costly strategy that can still be ineffective in the end. Using the advanced technologies that have been developed since their original design are a much more effective, responsive, and flexible approach to addressing these supply challenges.
Integration of advanced technologies in the casting commodity through digital transformation efforts is essential to future success of rotorcraft transmission castings. This paper reviews the advanced technologies that have been integrated into the casting process for transmission housings. The transformation in casting designs, solidification modeling, mold fabrication, casting techniques, thermal and mechanical post processing, inspection, and quality management are all impacted by new technologies and driven by the continued digital thread in the manufacturing process. The casting manufacturing process is 6000 years old, but the complexity of aircraft requirements and part designs has outpaced capability of standardized casting processes. Digital transformation driven technologies create repeatable processes that reduce production scrap and development lead times.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.