Aircraft Accidents and 3-D Printing

“3-D printing has popped up on the cutting edge of some surprisingly diverse industries: food healthcare, retail, and now aerospace.” That sentence starts an article I read … three years-ago in Forbes magazine.
One of the issues that came up recently in my Non-destructive Inspection (NDI) class was the dawn of 3-D printing in the aircraft manufacturing world. We were discussing scenarios where NDI principles could be applied in aerospace for finding different structural problems with aircraft, e.g. dye penetrant for cracks in a metal’s surface. This led to the limited number of NDI principles used on composite materials, e.g. tap tests: searching for ply separation by listening for a hollow echo. When I asked the question about new technologies, such as 3-D printing, or Additive Layer Manufacturing (ALM) it caught my students off guard.
3-D printing has made the Science and Technologies documentaries circuits; even sitcoms like The Big Bang Theory have played with it. On the serious side, ALM has been in the news recently, as Airbus adopted a new Titanium printer for manufacturing some components. Smaller aircraft manufacturers have improved on ALM technologies, printing aircraft spars – the load bearing structure for a wing – that are lighter, easier to manufacture and stronger than older technology spars. I wrote an article on this in AMT Magazine a year-ago.
But I digress. In 1992, my airline received some of the first composite intensive airliners. We soon discovered the inconveniences of new technologies when two composite elevators were damaged. There was no procedure – and no one – to fix or replace them, even by the manufacturer. Twenty-five years later, NDI testing for composites have not progressed much further than 1992, while manufacturers design and build practically all composite aircraft.
The aviation industry adopts new technologies because they’re lighter, stronger, less expensive, and, let’s face it, cool. There’s often a rush to implement technologies, that we don’t shake them out properly. Computer-run airliners and new fuel technologies move at light speed; slap a label on it and we’re off. We never pause to ask if we COULD do a thing. Yet history has taught us that we must ask ourselves if we SHOULD do a thing (tip of the hat to Michael Crichton).
How much time has been dedicated to 3-D printing’s integrity? How many materials are used to print with this technology? It’s one thing to print a microwave oven’s door inside the International Space Station; quite another to print an aircraft component that hasn’t been durability tested with extreme temperatures, pressurization, hydraulic fluids, aerodynamic stress loads, and the effects of time. How do we test these 3-D items? How do we assure their continuing integrity? Do they crack, corrode, stress fracture, or just give into age?
If aviation manufacturing does this wrong, it will lead to a whole new age of accidents; one the NTSB and the FAA are quite out of their element to figure out.

2 thoughts on “Aircraft Accidents and 3-D Printing”

    1. Thanks Dana. I recently taught a Non-destructive inspection class and I was assured by someone in FAA Engineering that the FAA was looking into inspection methods for 3-D printing. It will be interesting to see what time periods they come up with for visual and non-destructive inspections.

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