Defiance Healthcare

Aircraft Repair

All actions which have the objective of restoring an item in or to a state in which it can perform its required function.

Repair

Design Approach4 design approaches

Safe Life Design: Design for fixed conservative fixed Life.Fail Safe Design: Design the structure with multiple load paths or presence of redundant structure.Infinite Life Design: Design of Structures for stress below Endurance Limit .Damage Tolerance Design: Design the structure with an assumption of the pre existing damage and provide inspection intervals.Repair of minor damages- small dents, scratches, cracksRepair of corroded areasRepair of PaintSealing RepairMetallic RepairsComposite RepairsClassification Of General Repairs5Reasons for damages FODFatigueMishandlingManufacturing defectDesign- life limited parts, design flaw.Weather conditions. Etc.Damage EvaluationAn evaluation of the damage is necessary to establish the damage category:

- Allowable,

- Repairable,

- Requires manufacturer`s instructions.

MRO- Maintenance, Repair & OverhaulAircraft MRO is the overhaul, repair, inspection or modification of an aircraft or aircraft componentMaintenance includes the installation or removal of a component from an aircraft or aircraft subassembly, but does not include:Elementary work, such as spark plugs, checking cylinder compression, etcServicing, such as refueling, washing windowsAny work done on an aircraft or aircraft component as part of the manufacturing process, prior to issue of a certificate of airworthiness or other certification documentRegulation of MaintenanceJAA - Joint Aviation AuthoritiesJAR - Joint Aviation Requirements JAR-OPS 1 & 3 issued in May 1995JAR-OPS 1 - AeroplanesJAR-OPS 3 - Helicopters

Applicability, i.a.w. JAR-OPS 1 & 3 Subpart A:Civil aeroplanes in commercial air transportationOperators whose principal place of business is in a JAA Member State

9Types of MaintenanceEach airline develops its own program, based on manufacturers planning documents, but includes adjustments for the airlines own operations

Each aircrafts requires different operators and programs

BUT, aircraft of the same number of routine maintenance hours during the program cycle

Maintenance of aircraft usually categorized into Product type (airframe, engine and components)Timing and purpose of work

Then, resulted into 4 categoriesRoutine scheduled maintenanceNon-routine maintenanceRefurbishmentsModifications

MRO- Maintenance, Repair & Overhaul

Routine scheduled maintenanceIncludes airframe and engine checksThe most elementary is visual inspection of the aircraft before flight- walk-around To ensure there are no leaks, missing rivets or cracks

Types of checks-In GradesOvernightA-CheckB-checkC-checkD-Check13Routine scheduled maintenanceOvernight: Operate 1 to 1.5 hrs. inspection (End of working day) to ensure the plane operating in according to OEM s (Original Equipment Manufacturer) minimum list, example installation of telephones and other devices

A-Check: Done after 125flight hours (2-3 weeks)An amplified preflight visual inspection of plane's power plants, avionics and accessories

14Routine scheduled maintenanceB-Check: Done approximately after 175 flight hours (3 to 4 months)An open inspection for preventive maintenance (exterior wash, engine oil)Oils filters are removed and checked, parts are lubricated and carefully examined

Routine scheduled maintenanceC-check: Carried out approximately for every 3000 flight hours (15 months)Incorporates both A and B checks Components are repaired, Flights controls are calibratedMajor internal mechanism are testedOther tests include minor structural inspections, compressor, flight control rigging tests, engine, compressor washes, aircraft appearance maintenance, and post-check flight tests

Routine scheduled maintenanceD-Check: The most intensive, approximately 20, 000 flights hours (6-8 years)Cabin interiors (including seats, galleys, lavatories, cockpit, furnishings, headliners and sidewalls) are removed to enable careful structural inspectionsFlights controls are examined and the fuel system is probed for leaks and cracksThe aircraft is stripped to its shell and rebuilt to return it to its original condition

Routine scheduled maintenanceDone due to unforeseen event such as accident.An example of the first engine damage due to bird ingestion or an airframe dented by a catering truckDone also for an aging aircraft

Non-routine Maintenance Maintenance

JT8D at TAP Maintenance & Engineering Engine Overhaul ShopCFM56-5B and CFM56-5C at TAP Maintenance & Engineering C-Check HangarI must leave this shop in full airworthy condition !TAT and profit margin considerations shall never impair quality !19

Composite Scratch repair-temporaryNon perforating damage repair- permanent

Non perforating damage repair- permanent Extra Plies

Edge Band Delamination Repair

Edge Erosion Repair

Perforating Damage Repair

26HOLD OPEN ROD SUPPORT FITTING REPAIRTheoretical Substantiation

Location of damage

26Thank You