Technology Essential for Aircraft Maintenance - Essay Example

Technology in Aircraft Maintenance -2 Technological changes are taking place at a rapid rate in all fields especially in the information technology. The tremendous growth of information technology gave a boost to other technologies to grow at a faster rate. Technology in aircraft maintenance also has grown considerably from a push-button, light-up tests for deciding the health of single avionic equipment system to a centralized airplane integrated management system that intervene and collect date from all systems to make sure that all equipments of aircraft are functioning properly, and if anything wrong that will be indicated. It has further developed to become a precious diagnosis tool for aircraft maintenance people. This has helped to save the time for fault location and in turn reduced the effective time aircraft is on ground for maintenance (aviationtoday.com, N.D.). Due to fatigue and corrosion of the airframe structure the effects of aircraft aging increased the likelihood of crash and damages. The sustained safe operations of the commercial aircraft depend on the ability to foresee required changes in the inspection and maintenance procedures to compensate for the aging process. There was a belief that commercial aircraft are designed for endless life with proper maintenance. But this confidence to correctly maintain older aircraft considerably reduced since the failure of the Aloha Airlines 737 fuselage in 1988. The FAA constituted the National Aging Aircraft Research Program (NAARP) to tackle this reduced public belief in the airlines ability to properly maintain the older aircraft. The aim of the plan is to ensure sustained airworthiness of the commercial aircraft through upgrading in equipment, techniques, practices, and procedures in aircraft and engine design, repair, maintenance, and inspection (DTIC, 1991). Aging of commercial aircraft has become a most important issue since a lot of older aircraft attain their design life. Aircraft industry world wide and specially NASA and Federal Aviation Administration have already accomplished important methods to evaluate and monitor the aging aircraft, giving importance to corrosion of material, fatigue damage and nondestructive testing methods. This will help to build up enough and correct scientific knowledge such as the aging issues, and can be considered in the future design process. The capability to know and foresee aging processes can have immediate implications for dealing with existing aircrafts. To understand the response of materials for long time exposure in an aircraft structures service conditions, a basic knowledge of the physical occurrence related with damage and failure has to be developed. This can be done only by experimental materials classification and advancement of the related mathematical and computational models. Appraisal of long-term aging responses of materials and structures by means of testing and analytical methods is not easy, particularly for the multifaceted situation encountered in aircraft service. This may not give a satisfactory result of material performance. Still, the new aircraft has to be designed, and materials and structures assessed over their entire life cycle, it is significant to develop testing and analysis methods, which provide the knowledge of materials and structures performance to help materials selection and structural design decisions. Giving importance to these issues, NASA gave instructions to the National Materials Advisory Board (NMAB) to find out issues related the aging of advanced materials and take evaluation process and analytical methods to characterize the durability of the future materials and structures (Starke, et al, 1996). Aircraft electrical wiring methods are more complex and electrical wires and their related accessories are increasingly significant with regard to aircraft systems that are essential for safe flight. A lot of electric wire failures were reported due to aging of wire. Some of the incidents are known to be contributory factors in some aircraft due to wire failures and related to many other factors. These include: localized heat damage, poor wire insulation, embitterment, rubbing, arcing, faulty or broken connectors. After the fatal accident on 17 July 1996, the awareness and importance of maintaining the integrity of aircraft has increased. This also caused to focus specifically on the aging wiring systems. They included getting data on aging electrical wiring systems through aircraft inspections, going through aircraft service history, reviewing operator’s maintenance standard, practices for electrical wiring and repair training programs. Further, in 2000 Airbus decided to open an electrical installation review program on old A320s, called Electrical Installation Maturity Review (EIMR). The A320 EIMR program consists of wiring inspections of a sample of in-service aircraft to determine the condition of the complete wiring system, and to collect and use data for the purpose off: to verify the wiring system design principle and improve the present electrical design; to verify the material selection; to confirm the performance of the complete electrical wiring installation and to renew if necessary the inspection and repair processes. These inspections not only established the strength of both A300 and A320 electrical system but also gave precious information in respect to technology with regards to certain electrical components, wiring installation and operators’ maintenance practices and also pointed out the need for increased knowledge, among electrical maintenance personnel, of the importance of wiring system. To improve the airworthiness the FAA has launched an important program on aircraft systems aging, to co-ordinate and follow-up the implementation of the improvements related to the design and maintenance of aircraft electrical systems and related documentation and training (Chevant, N.D.). The increased maintenance costs led the airlines industry to look at the concept of preventive maintenance policy. A committee including Federal Aviation Administration (FAA) of USA and airlines was formed to explore planned maintenance policies and progressed through various evaluation and program development such as Maintenance Steering Group-1 (MSG-1) which was further upgraded to MSG-2. The Air Transport Association (ATA) appraised MSG-2 to include further programs in preventive maintenance and this resulted in MSG-3, the Airline/Manufacturers Maintenance Program Planning Document. This is also known as ‘Reliability Centered Maintenance’ (RCM) (maint2k.com, N.D.). Reliability-Centered Maintenance (RCM) can be seen as of reactive, time-based, condition-based, and proactive maintenance practices. This major maintenance approaches, rather than being applied separately, is included to take benefit of their individual strengths in order to exploit capability and equipment reliability while reducing life-cycle costs. RCM includes reactive, time-based, condition-based, and proactive tasks. Further, a user should know system limitations and facility coverage’s, equipment tasks, functional failures, and failure modes, all of which are vital parts of the RCM program (Pride, 2007). The RCM technology came up in the late 1960s and early 1970s. The research work on the subject was done by United Airlines in the 1970s to support the development and licensing of the Boeing 747. The important characteristics of RCM are: focus on the maintenance of the assigned activity of system; identification of specific functional failure: prioritizing the failures; identifying the effective preventive maintenance task in a cost effective way. Even though the main objectives of RCM are to reduce the costs related to system breakdown and downtime, there are various other tangible benefits associated with RCM program (the-saudi.net, N.D). The emergence of Centralized Maintenance Computers in late 1988s and early 1990s made major difference in the maintenance field. It receives health status data’s from most airplane systems, combine these results to decide the source of fault, and correlate the source or fault to the technician for applicable maintenance procedure. The CMC can display these results on the Multifunction Control Display Unit (MCDU) or link these results to ground stations while in flight to support maintenance management. The CMC also provides an integrated user interface to perform ground tests on all connected member systems. As an enhancement to CMC design, Boeing and Honeywell introduced the next generation CMC, as a part of integrated avionic suite on the 777 aircraft in 1995. Unlike the previous CMC design Boeing 777 CMC engaged a model based method, in which cause-effect interaction and fault propagation paths were captured in a loadable database, using ground based tools. This technique reduced the effort required to customize the CMC for the specific aircraft (Bird, et al, 2005). The development of Vehicle Health Management (VHM) in the field of commercial aviation has grown through many generations and different types of aircrafts. The health management system consists mainly of: fault discovery and separation; best sensor quality and placement guidelines; standard built-in-test designs and practices; fault coverage percentage or fault separation correctness percentage; confirmation and validation plans and measures; fault representation guidelines, and interface principles between subsystems and central maintenance systems. Organization and incorporation of these methods are the successful vehicle health management. The growth of health management systems shows the progress of avionics architectures. From the B727 to the B777, health systems have supported mechanical/analog, digital, federated and modular avionics. The main difference between the earlier and present maintenance systems was regarding the storage of fault data which depended on the individual member systems LRU/LRM (line replaceable module). In case of the CMCF, it uses local fault storage to store the data, which make easy for the fault reporting interface for the participating systems. The CMCF recovery of fault data is all contained within the CMCF itself. The CMCF was built upon earlier Honeywell maintenance methods which added maintenance message text to maintenance message codes. The goal is to provide maintenance information in clear English text that is usable by the maintenance technician, rather than having a coded message that requires translation (aviationtoday.com, N.D.). The future trend in the field of commercial aviation moves ahead with new technologies continue to be added and explored. Without looking back, they are moved by the need to bring value to the customer. Numbers of the innovations are based on the present day technologies, for example wireless and internet accessibility, combined together in new ways to offer value added service to customers. In this regard Honeywell is understood well that progresses such as these will support commercial aviation accomplish vital achievements in flight safety, dispatch availability and cost of ownership. As explained earlier technology in aircraft maintenance systems for commercial aviation have undergone major development since the beginning of simple BIT tests in the early 1980s. This progress continues with technology advances in IVHM and process advancement such as Sense & Respond. In short, IVHM technologies are going to play a major role of next generation spacecraft vehicle in support of the vehicle automation, mission planning and execution (Bird, et al, 2005). References aviationtoday.com, (N.D.) 727 to 787: Evolution of Aircraft Maintenance Systems, Avionics magazine, Special Report. Retrieved on 15 March 2007 from http://www.aviationtoday.com/Assets/Honeywellsmall.pdf Bird, G., Christensen, M., Lutz, D. and Scandura, P.A. (2005) Use of Integrated Vehicle Health Management in the Field of Commercial Aviation Management. First International Forum on Integrated System Health Engineering and Management in Aerospace, November 2005. Retrieved on 15 March 2007 from http://ase.arc.nasa.gov/projects/ishem/Papers/Scandura_Aviation.pdf Chevant, D. (N.D.) Aging aircraft electrical systems investigation. Retrieved on 22 March 2007 from http://www.content.airbusworld.com/SITES/Customer_services/html/acrobat/fast_34_p2_10_aging.pdf DTIC, (1991) Program Plan - National Aging Aircraft Research Program, Retrieved on 22 March 2007 from http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA242891 maint2k.com, (N.D.) What is Reliability Centred Maintenance? Retrieved on 15 March 2007 from http://www.maint2k.com/what-is-rcm.html Pride, A. (2007). Reliability-Centered Maintenance (RCM) National Institute of Building Sciences. Retrieved on 15 March 2007 from http://www.wbdg.org/design/rcm.php Starke, E.A. et al, (1996) Accelerated Aging of Materials and Structures: The Effects of Long-Term Elevated-Temperature Exposure, National Materials Advisory Board, National Academy Press, Washington, D.C. -the-saudi.net, (N.D) Reliability-Centred Maintenance. Retrieved on 15 March 2007 from http://www.the-saudi.net/kg/tools/rcm.htm Read More