1 Overview of Composite Material & Process Control Rotorcraft OEM Perspective Mark Chris Associate Technical Fellow Composite Materials & Process Engineering 14 September 2010
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Overview of CompositeMaterial & Process Control Rotorcraft OEM Perspective
Mark ChrisAssociate Technical Fellow
Composite Materials & Process Engineering
14 September 2010
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Overview
Requirements Control of Materials Control of Processes
Methods of Compliance Integrating Extended Supply Chain Raw Material Suppliers OEM fabricated parts Subcontractor/Partner fabricated parts
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Composite Part Fabrication Steps Requiring control
Material Tooling
Layup
CompactionCureComposite Part
Basics
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Requirements Commercial Programs - Code of Federal Regulations (CFRs) Military Programs - DOD System Design Specifications
PER Bell SPI 431...”Bell Helicopter will fully comply with applicable regulations”
14 CFR 21.123 Production under a type certificate: “…establish and maintain an (FAA) approved production inspection system that insures that each product conforms to the type design…”
14 CFR 21.125(b1) Production inspection system, MRB:“Incoming materials used in the finished product must be as specified in the type design data…”
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Requirements 14 CFR 21.165(a) Responsibility of holder: “Maintain the
quality control system in conformity with the data and procedures approved for the production certificate.”
Approved Data and Procedures: Engineering Drawing specifies -
• Materials by the controlling Material Specification.
• Processes by the controlling Process Specification.
• Inspection and acceptance criteria.
Material Specifications14 CFR 29.603(b) Materials must meet approved specifications that ensure their having the strength and other properties assumed in design data.
Design Values14 CFR 29.613(a) Material strength properties must be based on enough tests of material meeting specifications to establish design values on a statistical basis.
Process Specifications14 CFR 29.605(a) The methods of fabrication used must produce consistently sound structures. If a fabrication process (such as gluing, spot welding, or heat-treating) requires close control to reach this objective, the process must be performed according to an approved process specification.
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Start at the base of the building block
approach -(Materials/Coupons)
FAA Material & Process Control WorkshopWichita KS
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Guidance: Advisory Circular AC No. 21-26 Quality Control for the Manufacture of Composite Structures
FAA approved Bell M&P Specifications & Quality Systems follow this Model:
Incoming material acceptance plan - Ensures conformity and uniformity of purchased composite materials to specifications identified in the approved type design.
Supplier laboratory test reports (Certificate of Conformity) -Actual test results that accompany each batch of material received
Purchaser Receiving Inspection - Samples taken on a batch-to-batch basis and tested by end user.
Allowance for reduced testing - After confidence in the quality of products from a particular source has been established by the production approval holder
Methods of Compliance
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Reduced Testing – Source InspectionBell approved Agent or Representative observes all
required supplier quality conformance testing at the source facility:
Mitigates need for duplicate testing at purchaser facilities. Material System specific – Approval noted on QPL Requires Statistical Basis – Historical purchaser and
supplier data analyzed to demonstrate long term stability. Source Inspection Plan – Formalized written process for
data evaluation, training & approval of agents (delegates), audit requirements, audit schedules, inspection work plans/reports and “Authorization to Ship”.
Typically applied to “high volume” material systems/parts. Web based “SMART” system developed by Bell to manage
delegated source inspection process (Materials & Parts).
Methods of Compliance
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Higher levels of the building block -
(Details/Components)
FAA Material & Process Control WorkshopWichita KS
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Inspection of Composite Parts/AssembliesFirst Article Inspection required to demonstrate all
engineering requirements are met: Locks production configuration (materials, processes,
tooling and inspection). Creates baseline conformity data set. Non-destructive & destructive testing (depends on Class)Production Inspection Non-Destructive Inspection (NDI) – Formalized written
inspection procedures and acceptance criteria. General and/or part specific.
Scheduled Destructive Test – Primary Dynamic structures (may be mitigated by advanced NDI capability).
Unscheduled Destructive Test – Significant changes in process, tooling, location of manufacture etc.
Methods of Compliance
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MRB System for Composite Parts/AssembliesMaterial Review Board System required to assess and
disposition all non-conforming materials and parts: Formalized written review and disposition procedures. Specific personnel requirements must be met to be placed
on approved MRB list (Rigorous In-house & Offsite delegation process).
Requires development of corrective and preventative action plans as part of the review/disposition process.
Requires periodic audit of the MRB process to ensure: Awareness of known issue areas Validation/Analytical requirements are met Accuracy of dispositions Standardization of the process
Methods of Compliance
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ATLM
Hydro-abrasive Water Jet5-Axis Machining
Fiber Placement(Unique Fiber Forms)
Opportunities for reduced process variability (automation)
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Integration Challenge - Establish and monitor M&P controls across an extended supply chain. Equivalence of test results between Material Supplier,
OEM and Subcontractors/Partners - mitigate “false positives” (lab-to-lab variation).
Consistent interpretation of Material & Process Specifications.
Consistent Training across the supply chain. Understanding/addressing cultural differences. Managing ECCN and ITAR requirements on materials,
parts and data (International programs).Oversight & scheduled auditing of all the above.
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Rotorcraft Damage “Tolerance”
Bell OH 58D –Kiowa Warrior Operation Iraqi Freedom
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