I recall watching Mister Rogers Neighborhood with my children. The show often featured Mister McFeely, the Speedy Delivery man who made same day deliveries long before fax machines. I never could figure this guy out; twitchy, nervous, always chasing the clock, rushing orders through this quiet community; he must have been 89 at the time – or looked it. I always feared my son would turn the show on and see Mister McFeely braced up against a prop stage tree, his heart having burst in his chest, his legs still going a mile a minute; he obviously failed to recognize that the agida was not the three alarm chili he ate for lunch.
I feel we in the industry ignore symptoms of unbridled amazement with technology; we all want the latest and the greatest. Hey, who doesn’t? I’m a little skeptical; I feel the latest may not always be the greatest … well, at least not just yet.
I’m penning a sequel to my novel and had my protagonist talk about the possibility of the 3-D printing of aircraft parts; it was meant to be cutting edge, Mister Spock-type writing, when – lo and behold – someone actually started printing off aircraft parts in real life. Now I have to rewrite chapter three. But, hey, building an air cleaner cover out of ‘printed’ plastic sounds fascinating.
What is 3-D printing?
3-D printing, aka additive manufacturing, is a means of creating a three-dimensional item from a digital ‘blueprint’. The additive process is where an object is built layer-upon-layer until the article is created. It can have functioning internal parts that really work. It uses computer-aided design files, 3-D scanners, blah, blah blah; bottom line: it’s cool times ten.
The National Aeronautics and Space Administration planned to employ 3-D printers in an effort to provide the International Space Station’s inhabitants temporary relief for broken parts. They could transmit 3-D digital drawings of a microwave oven door to use until the next Dragon supply ship brings all the wish list items. Imagine how Apollo Thirteen would have benefited from that technology.
At least two years ago prototype parts were 3-D printed to design whole sections of aircraft, e.g. the empennage, assuring parts fit together as conceived, worked as advertised. Indeed, a cost-effective way to build an aircraft from drawing board to test model before going into full tool and die production mode. Mechanics were no longer burning effigies of design engineers who don’t understand that four foot long rod ends can’t fit inside two foot wide holes.
Technical magazine articles spoke to new techniques being utilized, e.g. selective laser sintering and electron beam melting. These printing procedures upped the ante, raising the quality of 3-D printed parts. Manufacturers employing the newer printers weren’t limited to prototype or design; they can ‘print’ aerospace-quality working parts. Materials including ceramics, thermoplastics, and titanium are well into the experimental range, even culminating into a working miniature jet engine.
How do 3-D printers affect production? Forbes magazine found at least seven ways 3-D printers are upsetting global manufacturing (R. Smith, Forbes, 6/29/2015). In other news, a 55-foot long spar was ‘printed’, its physical integrity matching or exceeding that of the original design, while weighing almost 60 percent less. Imagine using this technology to ‘print’ other primary load-bearing aircraft parts, e.g. elevators, gear struts, or engine mounts. A single engine crop duster would be redesignated as a short takeoff/landing aircraft. Because of lower weights, one could joke that it requires tie downs to avoid floating away. Environmentalists would rejoice in the streets; an aircraft using less fuel, manufactured in half the time. That truly would be: Speedy delivery!
Enter Mister McFeely’s arch enemy
Common Sense; the tortoise to his hare; the con to his pro; Safety, for short. Every time we read the daily aviation news, the headlines report incredible advances in technology. But little is said about discipline. Can this technology be misused by lesser minds that don’t understand – or care about – its limits, weaknesses, or purpose. Can this technology’s power be used inappropriately as well as correctly?
The Wall Street Journal reported airlines, e.g. Delta, are retraining their pilots to recover from certain upsets; the pilots are relearning tribal knowledge lost to digital age technology. Unmanned aerial vehicle operators demand free market rights because of improved technology, yet amateur operators continue to endanger general aviation and commercial airline safety.
I favor entrepreneurship; investments in time and talent must be encouraged. However because we could do a thing, doesn’t mean we should do a thing too quickly. Wisdom takes time. Product and service marketing that promises faster and better must include one more adjective: safer.
Example: the tragic 1979 crash of American 191 in Chicago. In an attempt to reduce manpower and time during engine changes, unauthorized procedures were developed and employed without checking. Faster and better, but not safer.
So what do we understand about 3-D printing? We understand traditional techniques for detecting irregularities, even in most composites; whether using eddy current or dye penetrant, we know what to look for. Can ‘printed’ parts mimic heat treating or sacrificial corrosion? Can they be repaired to original condition or better? What is a ‘printed’ part’s life expectancy and can it replace OEM parts one-for-one? How does it fair in a saltwater environment?
As technology outpaces industry, availability of said expertise becomes more accessible. For instance, I recently bought an LED television for $700 that sold for $5,000 several years ago; availability drove the price down. How long before everyone owns a 3-D printer? How long after that does it become so easy to use? And abuse?
Suspected unapproved parts (SUP) still cause problems, plain and simple. Shysters pushing inferior products to aviators aren’t limited to the USA. Could you be fooled by a SUP just because it has a data plate? How would you know if your fuel pump had printed internal gears? Does AvGas 100 break down 3-D plastic over time?
Truth be told, I worry about 3-D printing being abused and our inability to recognize the abuse. Common sense dictates we proceed with extreme caution, avoiding Speedy Delivery-type decisions. In the meantime, let the Mister McFeelys ride the trolley to Mister Roger’s Neighborhood. We’re in no rush; we’ll get there safely in time.
