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3D Printed Airliner Parts Face Regulatory Headwinds (wsj.com)
Some aerospace suppliers are eager to start using 3-D printing technology to turn out large, high-volume structural parts for jetliners, but U.S. safety regulators are taking a go-slow approach toward approving such production. From a report: Three-dimensional printing is a darling of the aerospace industry because it is relatively inexpensive compared with more-prevalent ways of making components. A series of announcements at the Paris Air Show expected in coming days illustrates the immense promise of airliner parts manufactured by 3-D printers -- as well as the formidable regulatory challenges confronting their widespread acceptance (alternative source). On Tuesday, officials of Norsk Titanium AS, a closely held Norwegian company that has developed a novel 3-D printing approach, will unveil a broad partnership with Spirit AeroSystems, a major subcontractor for Boeing and other industry players. Under the arrangement, Spirit sees the potential of eventually using Norsk's technology to produce thousands of different parts at 30% lower cost than traditional milling methods. However, before that can happen, the Federal Aviation Administration has to approve the overall process and certify that the cutting-edge, plasma-deposition technology is reliable enough to ensure identical strength and other properties from batch to batch. FAA officials have said they are moving cautiously, because they want to fully understand the unique technical issues.
This is one area where you REALLY want to make sure you get it right.
Casting and milling are well understood. They have been used since the age of steam. Identifying defects in traditionally machined parts works so well that aircraft rarely have problems related to the manufacture of metal parts.
In a 3D printed part every one of the thousands of layers is a potential failure point. To date there is no reliable way to find a single weld failure in all those thousands of layers. Once 3D printed parts have a decade of successful use in cars then will be the time to use them in aircraft.
Stop calling it 3d-printing. This is just a variation of sintering techniques that have been used for decades in the aerospace industry. While this particular method of laser sintering may be novel and require the FAA to study it before approving, sintering is a well understood metallurgical process. Given the high heat required for the process, no one is going to be home printing machine parts in their basement any time soon.
... that are rushed to market ...
Nothing is being "rushed to market". 3D printed structural parts have been in use for more than a decade, including in military aircraft. It is proven technology.
That Plasma Deposition and Laser Sintering hava BOTH been previously proven to produce parts up to 3x physically stronger then their standard manufacturing method counterparts, Can be made ALL ONE PIECE (even with some moving internal parts), and have so far been stress tested to provide up to 10x the standard service life of the same old-school manufactured part, This might be a bit of bureaucracy.... IMO There is "Testing" and there us using RED-TAPE to stifle innovation. Guess which one this is?
For many classic industrial processes, we select a statistically meaningful units and test them to destruction. If the FAA is trying to fit these "one off" parts into that sort of algorithm the problem should be obvious. Each part is a "one off" and statistical reasoning about batches produced the same way don't (necessarily) apply.
For example, perhaps the Argon supplier accidentally left in some impurities (or worse, the original testing was WITH impurities which happened to help; and the new supply is actually pure ... that sort of thing has happened in the past, and it's hell to debug!).
Oddly enough, nobody has pointed out that the FAA already has experience certifying 3D printed parts for flight, and in a flight regime far more rigorous than aircraft. SpaceX has already flown Falcon 9s with 3D printed engine parts, with the FAA's knowledge and approval.
If the FAA's rocket division would just talk to the aircraft division, the certifying process might go a little faster.
Yes, it is time consuming, but it has ALREADY BEEN DONE. These parts have been thoroughly tested, have already been used in military aircraft, and have a good track record.
Military aircraft are maintained differently than civilian aircraft. They are also designed and utilized differently. Milspec is not the end-all-be-all standard of quality many imagine it to be.
You are implying that the FAA is saying "We would like you to do more testing of X, Y, and Z for issues A, B and C", when what they are actually saying is "I am retiring in two years, and I don't want to make any decision that might jeopardize my pension."
And your evidence for this is what exactly? Do you have anything besides run of the mill cynicism to back up your claim? And exactly how do you figure that any decision by an FAA official would in any way endanger their pension?