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Your casting supplier just quoted a lead time that breaks your schedule, or your foundry is the single point of failure on the critical path. Metal additive manufacturing can remove that dependency, but only if the part is qualified properly. Set Boundaries manages additive manufacturing as a program: part selection, qualification, supplier readiness and the move into production.
Why are aerospace programs turning to additive manufacturing?
Three reasons dominate. Lead time: castings and forgings can take many months, especially where tooling is needed or foundry capacity is scarce, while additive parts need no hard tooling. Supply chain resilience: a qualified additive alternative gives a program a second route when a single foundry is constrained. And design freedom: additive processes can produce geometries that are difficult or impossible to cast or machine, consolidating assemblies and reducing weight. Of the three, lead time is often the one that makes the business case on programs under schedule pressure.
Which parts are good candidates?
| Factor | Favors additive | Favors traditional methods |
|---|---|---|
| Volume | Low to moderate quantities | High, stable volumes |
| Lead time pressure | Long casting or tooling lead times on the critical path | Short, reliable supply |
| Geometry | Complex internal features, consolidated assemblies | Simple shapes that machine or cast easily |
| Size | Fits within available build volumes | Very large parts |
| Criticality | Non-critical or well-understood loading, easier qualification | Highly critical parts with limited schedule for qualification |
| Material | Alloys with established additive processes and data | Alloys without mature additive processing |
What does qualification involve?
Qualification builds confidence at three levels. Material: the powder or wire feedstock and the resulting material properties, including their variability. Process: the specific machine, parameters, build orientation, post-processing such as heat treatment and machining, and the controls that keep them consistent. Part: evidence that this part, built this way, meets its requirements, typically through inspection, testing and first article inspection. The depth of evidence scales with the part's criticality, and the customer usually defines what it will accept.
How is an additive program run?
- Select and screen candidate parts against the factors above, with engineering and the customer.
- Define the qualification requirements with the customer, including standards and acceptance criteria.
- Choose and assess the additive supplier, including machine capability, process control and quality system.
- Design for the process, adapting the part to additive manufacturing where the change is allowed.
- Build, test and inspect qualification articles, including any destructive testing required.
- Complete first article and approvals, including configuration and drawing changes.
- Transition to production with a controlled, capable process and monitoring in place.
Each step belongs in the program's integrated master schedule with realistic durations, because qualification is where additive programs most often lose their schedule advantage.
Which additive processes are used for aerospace metal parts?
| Process | How it works | Typical use |
|---|---|---|
| Laser powder bed fusion | A laser melts thin layers of metal powder | Detailed parts with fine features and good surface finish; the most widely used metal process |
| Electron beam powder bed fusion | An electron beam melts powder in a vacuum | Certain titanium and high-temperature alloy parts |
| Directed energy deposition | A laser, electron beam or arc melts wire or powder as it is deposited | Larger parts, near-net shapes and repair of existing components |
| Binder jetting | A binder joins powder, followed by sintering | Higher-volume parts where its material properties are acceptable |
The process choice affects achievable geometry, surface finish, material properties, qualification evidence and cost, so it is made with the part's requirements and the customer's acceptance in view.
How is quality controlled in additive production?
Through control of every input and step, because the material is created as the part is built. That includes managing powder or wire feedstock and its reuse, locking machine and process parameters, building witness specimens alongside parts for testing, monitoring builds where the equipment allows, controlling post-processing, and inspecting parts with methods suited to internal features, often including computed tomography. A frozen, documented process is what lets a qualified part be reproduced consistently in production.
What should the business case include?
Schedule, cost and risk, side by side with the traditional route: the lead time avoided, the cost of qualification and any design changes, the unit cost at the expected volume, the reduction in supply chain risk from a second route, and the risk that qualification takes longer than planned. On programs where a casting is on the critical path, the schedule benefit usually dominates, and it should be valued in the program's own terms: the milestone it protects.
Can additive manufacturing repair parts as well as make them?
Yes. Directed energy deposition in particular can add material to worn or damaged components, which are then machined back to shape. For high-value parts with long replacement lead times, a qualified repair can return hardware to service far faster than waiting for a new part. As with new parts, the repair process needs qualification and customer approval, and the repaired part must be inspected to the same requirements as the original. On sustainment programs, repair is often where additive delivers value first, because the business case is immediate and easy to measure.
What experience does Set Boundaries bring?
Holly identified castings as the constraint on a mission-critical airframe-mounted component program, proposed additive manufacturing as the answer, and secured funding and resources to build the capability. That means practical experience of the program side of additive: making the business case, building a qualification approach with customers and airworthiness organizations, and turning month-long casting waits into design changes measured in weeks, rather than only knowledge of the technology.
What goes wrong most often?
Qualification underestimated. The part is printed quickly and then waits months for evidence nobody planned. The wrong part chosen. A highly critical part is picked first, making qualification slow and expensive, when a less critical part would have proven the approach. Post-processing ignored. Heat treatment, machining and surface finishing are part of the process and part of the lead time. Configuration not updated. Drawings, specifications and approvals must change to allow the new process. Supplier capacity assumed. Additive suppliers have queues too.
The main lesson is that qualification strategy decides whether a printed part ever flies. On that program, the approach agreed with the aerospace customers and airworthiness organizations involved was to gather qualification data on the traditionally cast part, then generate equivalent data on additive-manufactured hardware for an apples-to-apples comparison, against frozen material processes and comparable material-property data. A program considering it for the first time should start with the constraint it is solving, such as long casting lead times, and agree the qualification path with the customer before committing hardware.
How did the additive work start?
With a schedule problem, not a technology. On a mission-critical airframe-mounted component program at a Tier 1 supplier, Holly identified castings as a major schedule and supply-chain constraint. Every design change that needed a new casting started a clock the program did not control: tooling had to be made, foundry lead times ran to at least 18 weeks, and defects and rejections could restart the wait. On development hardware, where design changes are expected, each iteration was measured in months.
She proposed additive manufacturing as the way out and put the case to company leadership in program terms: the schedule the castings were costing, the supply-chain exposure of depending on them, and what a qualified alternative would change. Leadership provided funding and resources to develop the capability.
How was qualification approached?
The printing was never the hard part; acceptance was. Rather than argue for printed hardware on its own merits, the approach agreed with foreign aerospace customers and airworthiness organizations was comparative. First obtain qualification data on the traditionally cast part, then generate equivalent data on the additive-manufactured hardware, so the customer and the airworthiness organization could compare like with like. The technical team developed frozen material processes and comparable material-property data, because a comparison only means something when the process that produced the parts is fixed and documented.
Framing qualification this way does two things for a program. It gives the customer a decision it can make on evidence it already trusts, and it turns an open-ended research question into a defined set of builds and tests that can be scheduled, resourced and tracked like any other work on the critical path.
What did it change, and what does it mean for your program?
Design changes could be made in weeks rather than waiting months for new castings, and the business gained a U.S.-based manufacturing solution to a supply-chain constraint.
For a client considering the same move, we apply the method we use on any program. The constraint is established first, in days and dollars against the milestones it threatens. The qualification approach is agreed with the customer, and where relevant the airworthiness organization, before hardware is committed, and recorded in the Project Charter as part of what done means. Qualification builds, tests and approvals go into the integrated Microsoft Project schedule with owners and realistic durations, and are reviewed with the program's other risks and opportunities every month. Customers see progress at least weekly. If additive later becomes a production route, the move is planned as deliberately as any other manufacturing transition.
How does Set Boundaries help?
Set Boundaries runs additive manufacturing work as a program: screening candidate parts, defining qualification with the customer, selecting and managing additive suppliers, scheduling qualification realistically and carrying parts through first article and into production. It is also a recovery tool when a casting is the constraint on a late program, as described in supplier recovery.
If a long-lead casting is holding your program hostage, schedule a call.
Related guides
- Supplier recovery on aerospace programs
- Transitioning a program to production
- First article inspection under AS9102
- AS9145 APQP and PPAP
References
- ISO/ASTM 52900, Additive manufacturing: General principles, fundamentals and vocabulary.
- SAE International, AMS7000 series specifications for additive manufacturing materials and processes.
- NASA, NASA-STD-6030, Additive Manufacturing Requirements for Spaceflight Systems.
- SAE International, AS9102, Aerospace First Article Inspection Requirement.
Questions
Common questions
Can additive manufacturing replace castings on aerospace parts?
Sometimes. Metal additive manufacturing can produce parts that were traditionally cast, often without the long tooling and foundry lead times. Whether it is right depends on the part's material, size, loads, surface and inspection requirements, and on whether the customer will accept the change. Where it fits, it can remove a long-lead dependency from a program's critical path.
How long does it take to qualify an additively manufactured part?
It depends on the part's criticality and the customer's requirements. Qualification typically covers the material, the machine and process parameters, and the part itself, including testing and first article inspection, and it may need customer approval. Non-critical parts can move relatively quickly; flight-critical parts require substantially more evidence. Planning qualification as a project, with its own schedule, is essential.
What standards apply to metal additive manufacturing in aerospace?
This is the question that catches programs out, because the honest answer is that there is no standard you can comply with to make an additive flight part acceptable. There is published material on terminology and process families, and there are company specifications, but nothing that a customer will accept as proof on its own. Acceptance is negotiated with the customer and the airworthiness authority, case by case, against the specific part and the specific process. Anyone who tells you there is a standard to certify to has not taken a flight-critical additive part through qualification. Plan it as a negotiation with an evidence package behind it, not as a compliance exercise.
Is additive manufacturing cheaper than casting?
Usually not, and anyone evaluating it on part price is asking the wrong question. For high-volume simple parts, casting wins on unit cost and will keep winning. Additive uses less material and produces less waste, which is worth having and which everyone in the industry already knows. The reason it gets funded is schedule: removing a long foundry lead time from the critical path is frequently worth more than the entire part-price difference, and that is the number the business case should be built on.
What is the biggest risk in an additive manufacturing program?
Underestimating qualification. Printing a good-looking part is the easy step. Proving that the material properties, process control, inspection and part performance meet aerospace requirements, consistently and on the production machine, takes planning, testing and time. Programs that treat qualification as an afterthought find their schedule advantage disappears.
Has Holly Dekle worked on additive manufacturing programs?
Yes. Holly led the effort to replace long-lead castings on a mission-critical airframe-mounted component with additive-manufactured hardware, including the qualification approach agreed with the aerospace customers and airworthiness organizations involved. That experience of moving a part from a cast baseline to an additive one, through the practical realities of qualification and production, is what Set Boundaries brings to additive programs.
Have a question that is not here? Ask Holly on a short call
