In my job, I get to see some amazing military technology: high-speed weapons that penetrate seemingly impregnable defenses and swarming microdrones dispensed from fighter jets. I keep mementos of these wonder weapons in my office. Something unusual just joined their ranks: a latrine panel from a C-5 Supergalaxy cargo plane.

It’s an odd-looking piece of molded plastic, about the size of a toaster, and its job containing wastewater is more necessary than cool. But I keep it in my office because it represents a significant advance in military parts purchasing. Using a 3-D printer, our Air Force engineers made this latrine panel for $300, saving $8,200, compared with the open market prices we once paid through the Defense Logistics Agency.

Though our military is replete with cutting-edge equipment like stealth aircraft and flying emergency rooms, there’s a side of weapons-buying that’s highlighted less often: the maintenance of older systems, like the amazing C-5, which entered service in 1969. It moves the military’s heaviest equipment, including tanks and helicopters, and must be kept war-ready 24-7. This upkeep — “sustainment,” in military parlance — accounts for about 70 percent of a weapon’s total cost of ownership according to Government Accountability Office assessments. For the 52 C-5s the Air Force operates, this amounts to about $620 million per year.

But takeoff-ready airplanes are the delineator between a fight-tonight Air Force and a mere air show. Because the United States requires the former, we’ve borne this expensive side of defense economics for decades. Warplanes like the C-5, the KC-135 aerial re-fueler and the B-52 bomber play indispensable roles in our nation’s defense, but many of these aircraft are considerably older than their pilots. If they were cars, they would be collectors’ items. And, like classic cars, it’s increasingly expensive to keep them running with replacement parts in short supply. Except, unlike cars, our planes are on the front lines every day, not kept in the garage for Sunday drives.

But new manufacturing technology is poised to change this in a way that will streamline maintenance and save federal dollars.

Laws of supply and demand work against our military when it comes to old parts, as antique car enthusiasts well know. You start with the challenge of motivating companies to take our 2-D drawings, create 3-D models, machine prototypes, check myriad military standards (for burning point, melting point and other specifications), then dedicate equipment and people for a small production we probably won’t reorder for many years. Supply (there is none) and demand (it’s essential for us) require us to keep raising the offering price until it motivates a manufacturer — all the way to $8,500 in the case of the C-5 latrine panel. Below that price, manufacturers say it’s just not worth it to reopen production.

Even sticker-shock prices don’t always motivate companies. According to our estimates, more than 10,000 parts requests are delayed or unfilled each year despite our reluctant willingness to pay premium prices defense outsiders should reasonably question. If you’re wondering why it cost the Air Force over $2,600 for a C-5 aft pressure door handle in 2018, it’s because manufacturers did not bid when the price was lower.

We now save both time and money printing them from titanium for $188.

In two short years, 3-D printing has spread across the Air Force. Today, we print thousands of spare aircraft parts from metals and polymers, lowering operating cost by tens of millions while getting planes back to the fight faster. The need is severe: For example, three C-5s are grounded, awaiting exhaust ducts because our purchase offer of more than $430,000 for eight units did not entice a single supplier for months, forcing us to cannibalize parts from the “aircraft boneyard” at Davis-Monthan Air Force Base. When we finally received a bid, the earliest delivery was 34 weeks.

Not surprisingly, we’re working hard to print these exhaust ducts in the future. But certifying safety-critical airplane parts requires PhD-level engineering. Differences from printer to printer can introduce peculiar defects not found in traditional manufacturing. Understanding which minute flaws grow under the stress and strain of flight is the key to safety, and takes time. It’s a driving reason the Air Force is hosting the first Advanced Manufacturing Olympics next summer to build awareness of such challenges and reward solutions.

The chasm between part maker and part user wasn’t always large. Julius Caesar’s army could smith swords, fletch arrows and build bridges thousands of miles from home. As recently as World War II, the United States had sizable numbers of in-house military makers crafting spare parts. It’s hard to imagine the aircraft carrier supplanting the battleship’s supremacy had it not been for aviation machinists and metal smiths who made and repaired aircraft parts far from home.

Advanced manufacturing is bringing back this military’s maker role in the Air Force.

Though we’re already forecasting billions in savings, new initiatives, such as certifying printers instead of the end-state product, should soon allow us to supply even more out-of-stock parts. Our aim is to be able to abstract parts from the printers that make them, allowing consistent replication as printer technology changes. But we don’t want to go it alone. We want the best manufacturing “athletes” to join us this summer and help us end the days of aircraft down awaiting parts. Air forces are meant to fly, after all.