Professional Experience

Additive Manufacturing Feasibility Study for Aircraft Cabin MRO

Duration 4 Months
Team 2 Members
Company Royal Air Maroc - MRO Cabin Workshop
Tools ANSYS Mechanical, CATIA V5, Granta CES, Excel
8
Parts Selected
57
Evaluation Criteria
4
Suppliers Benchmarked
+600%
ROI Over 5 Years
Overview

From Obsolescence to In-House Production

A feasibility study conducted within the MRO Direction of Royal Air Maroc, evaluating whether additive manufacturing (3D printing) could be integrated into aircraft cabin maintenance operations. Certain cosmetic cabin parts face recurring supply constraints, long OEM lead times, part obsolescence, and minimum order quantities disconnected from real consumption. The project followed a full DMAIC approach: from diagnosing the problem with Pareto and Gemba analysis, through technology and material selection, to a structured supplier benchmark and a complete techno-economic evaluation with return on investment.

My Role

Contributions

Co-led the full DMAIC study with my project partner, with personal ownership of the material selection, structural simulation, technical specifications and economic modelling work streams.

Material Selection : Ashby Method

Built a thermoplastic selection funnel in Granta CES Selector, deriving performance indices from thermal and mechanical constraints, narrowing the field to four FDM-compatible, flame-certified candidates before selecting ULTEM™9085 CG.

Flammability & Thermal Qualification

Assessed compliance with UL-94 V-0 and FAR 25.853 / CS-25 Annexe F using TGA degradation data and Stratasys official fire-test results for the certified grade.

Structural Simulation & Taguchi Optimization

Modelled the recurring armrest insert failure in ANSYS Mechanical under passenger and technician load cases, then ran a 40-run parametric Taguchi study to identify and optimise the dominant geometric factor governing structural safety factor.

Technical Specifications (CDC)

Co-authored a 57-criterion functional specification (APTE methodology) across 16 categories, including 7 elimination (NO GO) criteria, used to qualify candidate printer suppliers against Part-145 and FAR/CS 25.853 requirements.

Supplier Benchmark & Decision Matrix

Co-ran a compliance matrix and a weighted multi-criteria decision matrix across four FDM printer suppliers, and modelled a standardised internal cost model to compare print times and unit costs on equal terms.

Economic Model & ROI Analysis

Built the techno-economic model comparing in-house FDM production cost to OEM purchase price across the selected parts, and computed payback period, discounted cash flow and 5-year ROI to support the investment decision.

Methodology

A Full DMAIC Study

The project structure followed the five DMAIC phases, moving from problem diagnosis to a validated, economically justified implementation decision.

Define : Context & Scope

Mapped Royal Air Maroc's MRO organisation and the Cabin Workshop's role within it. Cosmetic and aesthetic cabin parts were identified as a major spend category, exposed to OEM dependency, long procurement cycles and obsolescence risk.

Measure : Gemba & Pareto Analysis

Conducted a Gemba study on the workshop floor combined with AMOS/SAP consumption data. A 5-Whys root-cause analysis traced recurring overstock and stockouts back to a single cause: the absence of an in-house additive manufacturing capability, forcing full reliance on OEM minimum order quantities.

Analyze : Technology & Material Selection

Compared FDM and SLS via a weighted multi-criteria matrix, selected FDM, then built an Ashby material selection funnel down to four flame-certified candidates. A recurring armrest insert failure was modelled and optimised in ANSYS Mechanical using a Taguchi design of experiments.

Improve : Specification & Supplier Selection

Drafted a 57-criterion functional specification, identified four candidate FDM suppliers, scored them on a compliance matrix and a weighted decision matrix, then benchmarked print time and cost on four representative parts using a standardised internal cost model.

Control : Economic Validation

Built a full techno-economic model on eight selected parts comparing in-house FDM cost to OEM purchase price, computing payback period, 5-year discounted cash flow and ROI to validate the investment decision.

Gap between real consumption and OEM minimum order quantity
Gap between real consumption and OEM minimum order quantity
Pareto analysis of annual cosmetic parts consumption
Pareto analysis of annual cosmetic parts consumption
Technical Analysis

Technology, Material & Structural Optimization

FDM was selected over SLS through a weighted comparison, then a two-stage Ashby methodology narrowed the material field before validating structural performance through simulation.

Technology Selection : FDM vs SLS

Criterion Weight FDM SLS
Total operating cost25%52
Average print time25%43
Ease of use in MRO20%52
Part robustness15%43
Surface roughness15%23
Weighted score100%4.15 / 52.52 / 5
Weighted Decision Matrix: FDM vs. SLS

Material Selection : Ashby Method

Using Granta CES Selector, thermoplastics were filtered for FDM process compatibility, UL-94 V-0 flammability, fracture toughness, glass transition temperature and thermal conductivity. The filtering funnel converged on four candidates before a final trade-off between mechanical performance and available FAA/EASA qualification data.

Property PEKK-A ULTEM™9085 CG ULTEM™AM9085F Antero 840CN03
Fracture toughness K₁c (MPa·m¹ᐟ²)5.653.943.903.14
Glass transition Tg (°C)160177177158
Global performance index W*3.22×10⁻³3.03×10⁻³3.20×10⁻³2.94×10⁻³
NCAMP qualification (Fortus 450/900mc)—Qualified—Qualified
Properties and Performance Indices of the Four Candidate Materials

ULTEM™9085 CG was retained: it combines a strong global performance index with an existing NCAM qualified allowables database on the target machine, removing the need to build a proprietary mechanical test dataset from scratch, and considerably shortening the certification path.

Vertical flammability test results by print direction for ULTEM 9085
Vertical flammability test results by print direction for ULTEM 9085

Case Study : Armrest Insert Failure

A recurring in-service failure of the armrest insert was reproduced numerically: static structural simulation under passenger and technician load cases showed the equivalent von Mises stress exceeding the material's yield strength at several stress-concentration zones, confirming the field failure mode and motivating a geometric redesign.

Total deformation of the armrest insert under passenger load
Total deformation of the armrest insert under passenger load
Von Mises equivalent stress on the armrest insert
Von Mises equivalent stress on the armrest insert

Geometry Optimization : Taguchi Design of Experiments

Two fillet radii (F₁, F₂) were parametrised in ANSYS Workbench and swept across 40 design points. A Taguchi signal-to-noise analysis isolated the relative contribution of each factor to the resulting safety factor.

Factor Range (dB) Contribution Optimal Level
F₁ : Lower fillet radius0.52213.3%0.8 mm
F₂ : Upper fillet radius3.39986.7%2.0 mm
Total3.921100%—
Taguchi Analysis: Relative Contribution of the Factors

F₂ (the upper fillet radius) governs 86.7% of the structural response. The optimised geometry raised the safety factor from below 1 (structural failure) to 1.60, eliminating the field failure mode identified in the case study.

Benchmark & Decision

Supplier Selection

Four FDM printer suppliers were evaluated against the 57 criterion specification, then scored on a weighted multi-criteria decision matrix and an internal, standardised cost model.

Supplier Compliance Rate NO-GO Failures Decision Score (/100)
Sara-Tech Africa (Fortus 450mc)93%0 / Retained88
3DZ-SPA (Markforged FX20)75%2 / Eliminated65
Roboze SpA (500 MR)68%0 / Retained63
Graphics Industries (Intamsys 610 HT)63%3 / Eliminated60
Summary of Overall Compliance Scores
Weighted score comparison of the four candidate suppliers
Weighted score comparison of the four candidate suppliers
Print time comparison across suppliers for the benchmark parts
Print time comparison across suppliers for the benchmark parts

Selected Solution

Sara-Tech Africa-Stratasys Fortus 450mc was retained: zero elimination criteria failures, the highest compliance rate, the shortest print times of the benchmark, and direct access to an NCAMP qualified materials database, significantly de-risking the certification path.

Results

Economic Validation

A techno-economic model was built across eight selected cabin parts, comparing the in-house FDM cost of revenue to the equivalent OEM purchase price. Figures below are presented in rounded / relative form.

~4M MAD
Total Investment
~8 Months
Payback Period
>90%
Avg. Unit Cost Reduction vs OEM
+600%
ROI Over 5 Years
Cumulative net cash flow projection over 5 years
Cumulative net cash flow projection over 5 years

Beyond the eight-part study scope, extending the same production model to the full cosmetic parts catalogue (roughly 100 references) would reduce the payback period to under a month, reinforcing the strategic case for in-house additive manufacturing at RAM's Cabin Workshop.

Conclusions

Conclusions and Perspectives

Key Achievement

Delivered a complete, defensible feasibility case for additive manufacturing at Royal Air Maroc's Cabin Workshop, spanning root cause diagnosis, technology and material selection, structural validation, supplier benchmarking and economic justification, resulting in a validated decision to implement a Stratasys Fortus 450mc via Sara-Tech Africa.

Future Perspectives

Catalogue Expansion

Extend the eligible parts portfolio beyond the initial 8 parts scope to the full cosmetic parts catalogue, further improving payback and fleet wide part availability.

Digital Parts Library

Build a digital library of qualified 3D models for recurring cabin parts, streamlining future additive production and reducing reverse engineering effort.

Certification Extension

Pursue qualification pathways for higher value added, more structurally demanding applications beyond cosmetic cabin parts.

Metrology Integration

Introduce 3D metrology scanning to automate complex-geometry capture, replacing conventional measurement tools currently used for part reverse-engineering.

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