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AOG structural repair, step-by-step. Operator actions, field controls, and audit-ready RTS under FAA/EASA Part 145.
Structural Aircraft On Ground (AOG) repair is a controlled, field-executed maintenance process performed under approved data—typically defined by the Structural Repair Manual (SRM), OEM engineering, or DER-approved solutions—to restore airworthiness without repositioning the aircraft, while maintaining full Part 145 compliance and traceability.
A Structural Repair Manual (SRM) is an OEM-issued technical document that defines approved repair methods, damage limits, and allowable procedures to restore aircraft structural integrity while maintaining airworthiness.
The SRM specifies:
For operators and MRO teams, the SRM is the primary source of approved data used to determine whether damage can be repaired and how that repair must be executed.
If damage falls within SRM limits, repair can proceed using predefined methods.
If it falls outside SRM limits, alternative approval paths—such as OEM engineering or DER—are required.
Structural repair follows a clear hierarchy of approved data:
This decision pathway directly affects:
Aircraft on Ground (AOG) events spike for different reasons across the year.
In spring, migrating wildlife increases bird-strike risk, often requiring inspection and structural repair before dispatch.
In summer, thunderstorms introduce hail, lightning, turbulence, and icing exposure—affecting radomes, nacelle inlets, and leading edges.
In winter, de-icing operations and contamination increase inspection findings that delay return to service.
Year-round, ground support equipment (GSE) contact remains a major driver of structural damage.
For a deeper understanding of how structural damage is identified before repair decisions, see: What Is Aircraft Structural Damage: Causes, Types, and How It Is Inspected
This playbook shows how operators and mobile structural teams work as one: what to do before arrival, how to control field variables, and which compliance guardrails ensure a defensible Return-to-Service (RTS).
Include operational constraints:
Composite repairs require:
Metallic repairs require:
These are mandatory elements of Part 145 traceability.
See how traceability supports compliant release: Structural Repair Traceability in Part 145 Repair Stations
Field teams adapt:
Without altering the approved repair scheme.
If facility-dependent steps (e.g., autoclave) are required, a split workflow must be planned.
NDT selection is damage-driven:
Performed under recognized standards (e.g., EN4179 / NAS410).
The decision is not “can we repair it?” but:
“Can we repair it faster, safely, and compliantly on-site vs repositioning?”
Typical damage:
Why on-site works:
Typical damage:
Why on-site works:
Typical damage:
Why on-site works:
Choose on-site when:
Choose repositioning when:
Always document:
This becomes part of the audit trail.
SRM / OEM / DER approval must exist before work begins
To understand how SRM fits within repair classification: What Is Aircraft Structural Repair? A Guide to Major vs. Minor Alterations (and Repairs)
Must comply with:
Return-to-service via:
Mobilize → Scope → Execute → Validate → Release
Key insight:
Reducing non-productive time (logistics, access, environment) has greater impact than reducing repair execution time.
Output of a compliant AOG repair:
A complete, traceable documentation package that proves the repair meets engineering, regulatory, and airworthiness requirements at the moment of return-to-service.
Structural AOG repair operates within a broader MRO system that integrates:
See how this is structured at service level: MRO Services
For how execution, logistics, and engineering are coordinated at scale: Repair Management
When damage exceeds standard limits, compliant alternatives are enabled through: DER Repairs
The SRM defines approved repair methods and damage limits established by the aircraft manufacturer to restore structural integrity while maintaining airworthiness.
No. If damage exceeds SRM limits, repair requires OEM engineering or DER-approved data.
Structural AOG events are inevitable.
Delays are not.
Pre-stage:
A structured AOG repair program turns disruption into controlled execution—delivering compliant, airworthy, and predictable return-to-service.
