航空维修概论AirportsSafety : the top priorityMoving people and goods can be risky.To meet the specific needs of aircraft maintenance we have been designing access equipment for operations such as stripping and painting.platformsIndependent access platformssuspended to hangar roofs viaoverhead cranes. Vertical, horizontaland slewing movements authorise fullaccess to any part of the aircraft.Static and mobile work platforms,suspended from roof or floor mountedfor heavy maintenance operations.Aicraft maintenance hangars andaircraft engine-workshops.RepairsFor repairs, Comtek often acts on the customer's behalf to provide the manufacturer with the repair schemes that win quick approval for implementation by our expert technicians. Designed for durability, Comtek's repairs not only restore structural strength but in many cases actually improve the in-service performance of the part and reduce life cycle costs.Comtek combines practical experience and technological innovation to provide airlines around the world with the highest quality repair and overhaul services available anywhere. Incoming parts are assessed for damage by professional project engineers, who submit a firm fixed price quotation and completion date in writing for your approval before work begins. If you prefer, mobile repair teams using the latest in portable equipment are available to work on-site at your facility.Mobile Repair TeamsQuick TurnaroundFirm Fixed PricingPrimary or Secondary Structure24 Hour AOG SupportFree Engineering SupportStandard turnaround time is 3-4 weeks, but our service is designed to flexibly respond to urgent requests. You're kept fully informed at all times of the status of your repair, so you will never have any unpleasant surprises - that's what we mean by our service pledge to provide you with "Worry Free Composites Support!"For damage outside SRM limits, we engineer new repairs using the same design and analysis software employed by the aircraft manufacturers, supported by structural test data generated in our own laboratory. We often apply the latest in materials and process technology to create a unique, cost-effective repair - so before you order a new part, call us first!Scheduling ofAircraft HeavyMaintenanceOverviewAircraftrequire regularinspection and maintenance, based on calendar age, hours flown, and cycles of takeoff-landing. Engines, landing gear, and other major systems have limits on their life in service before overhaul. There is a stream of modificationscoming from the manufacturers. All this work needs to be packaged up into a series of maintenance checks, cycling through work that can be done in a single shift without a hangar, to a work package requiring several weeks in a hangar. Efficient packaging and scheduling of this work plays an important part in maximising the availability of the fleet for flying.The planner is faced with a mixture of work which can be planned well in advance, changing out the landing gear, and work which needs to be squeezed in as soon as possible, the manufacturer has advised of the wrong type of O-ring in a pump. A tool to assist in preparing schedules has to be fast, efficient in its long range planning, flexible to handle the ad hoc work, and complete in its handling of all of the work to be scheduled.As much as possible of the workings of the scheduler should be able to be modified by the planners, rather than computer programmers. The inputs, operation, and outputs of the scheduler need to be auditable, to ensure that no airworthiness regulations are breached. The more transparent and intuitive the method used, the more confidence and reliance planners will have in using it.A "black box" approach to aircraft maintenance scheduling would have problems of modifiability, auditability and reliability. OASIS is not just a "white box", where the planners can see the workings inside. To a large extent, the planners build the workings of the scheduling machine, and assume responsibility for the quality of the schedules produced.OASIS is built on top of Orion, a knowledge-based system, and uses a knowledge network to create and schedule Limit based maintenance events as well as independent events. The OASIS scheduler will attempt to place the Limit based events as close to their limits as possible whilst ensuring that they do not use more than the available resources at any point in time. Hints within the network will attempt to book resources initially back from the hard limit by a planning pad, but eat up the planning pad if there is no alternative. The resources being booked can be Facilities such as Hangars or Human resources, or consumable spares, perhaps with refurbishment requirements like undercarriage, with the refurbishment process built into the model.Specification of Maintenance ChecksThe planner prepares descriptions of the resource use and internal constraints for the various maintenance checks for various sorts of aircraft. These descriptions are expanded into lines of maintenance for individual aircraft, taking into account the particular aircraft history and projected flying time. The planner can prepare check descriptions that are time stamped and are used only before or after a particular date, or can prepare a detailed description that applies only to a particular check for one particular aircraft. The knowledge network is built out of these descriptions, and the knowledge network is usedto create the schedule, so the planner has full control of whatgoes into creating the schedule.Representation Of Multiple BasesWhere a maintenance check can occur at several bases, the resource availability can be pooled, or by using a positive tonegative range for Resource Intensity, bases can trade availability among themselves, thecalculations for doing so all embedded in thenetwork.Swallowing Of ActivitiesA larger check, brought forward, should swallow any minor checks within range. This is easily accomplished by making the duration of the smaller check include zero as a possibility, and if a larger check comes close enough, forcing the duration of the smaller check to zero. Additional modelling allows some particular work in the smaller check to move to the larger one, while other work, which would also occur in the larger check, disappears.Piggybacking Of EventsYou will sometimes want to attach some packet of work to one of the checks that must occur on the plane, but may be unsure as to which check it should be. The starting dates of the checks are tentative, and there may be constraints on the event to be piggybacked which conflict with parts of those ranges. You can build logic into the network so the appropriate check will be chosen after the starting dates are known to moreaccuracy.The Knowledge ModellingApproachModelling the knowledge aboutthe application directly leads tothe construction of the"scheduling machine". Most ofthe logic in the model isgenerated by planners, as theydescribe the various checks tobe carried out, in terms ofactivities and resource use andinterrelation with other checks.This information is combinedwith plane histories and expected flying time to create the network model. There is no complex algorithm to build, because the scheduling method is non-algorithmic - the interaction of the elements of the model lead to the solution of the scheduling problem, and the planners assembled those elements. The model can be assembled quickly, and changed quickly in response to variations in work practices or fleet makeup.。
