AOG Recovery & Technical Dispatch
Maintenance, Repair & Overhaul › Line Maintenance · 17 L4 steps · 6 phases · 6 decision gates · Updated 2026-03-19 19:24
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Process Flow Diagram (BPMN)
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L4 Process Steps
| Step | Step Name | Role / Swim Lane | System | Input | Output | KPI | Dec? | Exc? |
|---|---|---|---|---|---|---|---|---|
Phase 1 1.1 |
Receive AOG defect notification | Maintenance Control Centre (MCC) Analyst | SITA ACARS / Electronic Technical Log (ETL) | Pilot-raised defect entry via ETL or ACARS message from flight deck | AOG defect record opened in MRO system with timestamp and station | Defect receipt-to-acknowledgement < 5 minutes | N | N |
| 1.2 | Assess defect against MEL / CDL | Licensed Aircraft Maintenance Engineer (LAME) | AMOS by Swiss AviationSoftware (MEL module) | Defect description, aircraft type/registration, departure time | MEL/CDL applicability decision: relief granted or AOG confirmed | MEL assessment completed < 15 minutes of defect receipt | Y | N |
| 1.3 | Apply MEL relief and replan dispatch | LAME / MCC Operations Controller | AMOS by Swiss AviationSoftware + Amadeus Altéa Operations | MEL relief decision, any associated placard or operational restriction | MEL deferred defect item raised, aircraft re-dispatched with restriction noted in flight release | MEL-cleared aircraft released within 30 minutes of defect; on-time departure recovery ≥ 85% | N | N |
Phase 2 2.1 |
Classify AOG severity and estimate RTA | MCC Duty Manager | AMOS by Swiss AviationSoftware (AOG workflow module) | Confirmed AOG defect record, affected flight schedule, station capability matrix | AOG severity code (AOG-1 / AOG-2 / AOG-3), Return-to-Airworthy (RTA) estimate, passenger impact assessment | AOG classification completed < 10 minutes of MEL decision; RTA estimate accuracy ± 1 hour for 80% of events | N | N |
| 2.2 | Alert station maintenance and mobilise team | MCC Analyst | SITA ACARS / Airline Crew Communication Platform | AOG classification, station engineer roster, aircraft bay location | Station LAME and supporting technicians dispatched to aircraft with tooling kit | First engineer on aircraft within 20 minutes of AOG declaration at main bases; 45 minutes at outstations | N | Y |
| 2.3 | Check local parts availability for likely defect | Station Stores Technician | AMOS (Inventory / Warehouse Management module) | Suspected defect ATA chapter, aircraft type, station warehouse stock snapshot | Parts availability confirmation or shortage flag sent to MCC within 10 minutes | Station first-time fill rate ≥ 60% for top-20 AOG consumable part numbers | Y | N |
Phase 3 3.1 |
Perform initial inspection and fault isolation | LAME | Jeppesen FliteDeck / OEM Fault Isolation Manual (FIM) | Defect description, aircraft built-in test equipment (BITE) readout, fault codes | Confirmed ATA chapter fault code, probable cause, and required corrective action identified | Fault isolated within 45 minutes for 90% of LRU-level defects | N | Y |
| 3.2 | Access AMM / IPC repair procedures | LAME | Boeing Toolbox / Airbus AiRTHM / Trax (document integration) | Confirmed ATA fault code and part number from fault isolation | Approved AMM task card retrieved and printed/displayed for repair execution | Correct AMM revision accessible within 5 minutes; zero deferred task cards performed on superseded revisions | N | N |
| 3.3 | Escalate to OEM engineering support if unresolved | MCC Technical Engineer | Boeing AeroExchange / Airbus AiRTHM OEM AOG Desk portal | Unresolved fault after AMM fault isolation steps exhausted, BITE logs, photos | OEM engineering instruction (TEO/TEM) or disposition issued within agreed SLA | OEM first response < 2 hours (AOG priority); disposition received < 4 hours for 85% of escalations | Y | Y |
Phase 4 4.1 |
Activate AOG desk for emergency parts sourcing | MCC AOG Parts Coordinator | AMOS (Purchasing / AOG Order module) + ILS Partsbase | Required part number(s), quantity, urgency (AOG priority), station and RTA | AOG purchase order raised; parts located at OEM, distributor, or pool inventory | AOG PO raised < 15 minutes of parts shortage confirmation; vendor acknowledgement < 1 hour | N | N |
| 4.2 | Coordinate cross-fleet loan or borrow with partner airline | MCC AOG Parts Coordinator | AMOS (Loan/Borrow module) + direct AOG desk contact | Unmet AOG PO, part number, adjacent airline AOG desk contacts at affected station | Loan agreement confirmed, part released from partner fleet, paperwork (Form 1 / 8130-3) transmitted | Loan agreement confirmed < 2 hours of initial AOG desk activation; traceability documents received before part installation | Y | Y |
| 4.3 | Arrange priority shipment to AOG station | MCC AOG Parts Coordinator | AMOS + DHL / FedEx AOG courier portal | Parts sourced and ready for dispatch, RTA, nearest airport with scheduled freight service | AOG courier shipment booked, AWB number logged in AMOS, ETA confirmed to station | Shipment uplift confirmed < 3 hours of part readiness; ETA accuracy ± 30 minutes for 90% of AOG shipments | N | N |
Phase 5 5.1 |
Execute repair or LRU replacement per AMM | LAME + Avionics / Structures Technician | AMOS (Work Order / Task Card module) | Serviceable part with traceability docs, approved AMM task card, tooling calibration records | Repair or replacement completed; work order in-progress record updated in AMOS | Task execution time within ± 20% of AMM estimated man-hours for 80% of LRU replacements | N | Y |
| 5.2 | Perform functional test and duplicate inspection | LAME (Certifying Engineer) + Independent Inspector | AMOS (Sign-off / Dual-inspection workflow) | Completed repair, applicable AMM functional test procedure, BITE / ground test equipment | Functional test result recorded; duplicate inspection sign-off completed in AMOS | Functional test pass rate ≥ 97% first attempt; zero releases without mandatory duplicate inspection where required by AMM | Y | Y |
| 5.3 | Issue Certificate of Release to Service (CRS) | Certifying LAME (Type-rated, authorisation current) | AMOS by Swiss AviationSoftware (CRS / Tech Log module) | Completed work order, functional test results, duplicate inspection sign-off, airworthiness confirmation | Signed CRS issued in AMOS; aircraft tech log updated; aircraft returned to airworthy state | CRS issued < 30 minutes of functional test pass; zero CRS issued against open critical defects | N | N |
Phase 6 6.1 |
Update tech log, delay code, and disruption report | MCC Duty Manager | AMOS + Amadeus Altéa Operations (Delay/Disruption module) | Closed work order, CRS, actual off-block time vs scheduled | IATA delay code recorded, passenger disruption cost captured, AOG event closed in AMOS | Delay code accuracy ≥ 98% (audited quarterly); disruption report filed within 2 hours of aircraft departure | N | N |
| 6.2 | Trigger reliability review for recurring defect | Reliability Engineer | AMOS (Reliability / Occurrence Reporting module) | AOG event record, defect history for same ATA chapter and aircraft registration | Reliability alert raised if defect recurrence threshold exceeded; engineering investigation initiated | Recurring defect detection rate ≥ 95% within 3 occurrences; RCA report issued within 10 working days | Y | N |
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