The U.S. Department of Defense has a unique problem with older aircraft; very expensive replacement parts that often take more than a year to get. A growing number of the millions of parts that make up an aircraft are no longer manufactured or stockpiled. The manufacturer (or whoever now owns the patents) can manufacture needed parts but it takes time (often over a year) and costs a lot more (often several hundred times more) than it should. The price angle became obvious when the military tried to produce some of these parts using the 3-D printers. The military has employed 3-D printing and similar technologies since the late 1990s for quick (often in a few minutes) production of needed replacement part.
These 3-D printers have come a long way since the 1990s and are now used to produce engine components out of high-tech alloys for rocket engines and spacecraft. These industrial grade 3-D printers that produce metal objects are regularly used to create prototype and production parts. This type of manufacturing has brought down the cost of rocket engines because these engines are not produced in large quantities so the higher cost of using a 3-D printer part is not a factor.
But manufacturers don’t have to use this 3-D printer technology to produce rarely needed spare parts for older aircraft. That’s because they make a larger profit by hand making the rarely needed parts the old fashioned way. The manufacturer is guaranteed a certain profit margin on these parts so the more the parts costs to make the more profit they get. Getting Congress to pass a law to deal with this has to get past a horde of defense industry lobbyists and lawyers although in wartime a WERP (War Emergency Replacement Parts) law could be passed to settle the matter, at least until peace, and the old rules returned. WERP would also eliminate having to deal with the mandatory “recertification” for parts (most of them) that are not exposed to high stress or liable to cause major problems if they fail in use. The “recertification process” is often more of a bureaucratic exercise that evolved to protect as many people from responsibility/liability as possible and provide more work for manufacturer and Department of Defense personnel. This is another form of government inefficiency and corruption that hides in the shadows and accounts for why some nations can produce and maintain the same military gear faster and for a lot less money.
Meanwhile, the military has gone through several generations of instant production equipment, including 3-D printers, since the U.S. Army created the first MPH (Mobile Parts Hospital) in 2003. The MPH was created to shorten the development and field testing time for new weapons or equipment components. The first MPH used CAD (Computer Assisted Design) data for parts and new lightweight computer-controlled machine tools to manufacture new parts as needed. MPH was very popular and that led to calls for upgrades. By 2013 MPH added 3-D printers and after that, some users were designing their own new parts and using MPHs to build them for immediate testing. A growing percentage of those new component designs worked and now the army and SOCOM (Special Operations Command) uses MPHs, or just a laptop and a 3-D printer (a mini-MPH) for non-metal parts and a slightly more elaborate rig for metal parts. MPH is typical of how the U.S. military had been adopting new technology, especially since the 1970s. But for military equipment created before that no provision was made in contracts to allow for new technology to produce replacement parts much faster and cheaper.
The key to making this work originally was the availability of computer controlled machine tools, which can take a block of the proper metal and machine it into the desired part. The computer controlled machine tools have been around for decades, but the big breakthrough was the development of CAD software for PCs in the 1980s, which made the process of designing, and then fabricating, a part much faster. The computer controlled machine tools can use the CAD file to automatically create the part. The MPH has a high-speed satellite data link, which enables it to obtain the CAD file for a part. Many CAD files are already stored in the MPH. Often, the MPH staff figure out a way to improve a part, based on the broken parts they see and what the troops tell them.
All these instant parts builder operations tended to be staffed and open 24/7. The demand for critical parts happened round the clock in a combat zone and it was often a matter of life or death to get the part as quickly as possible. This has eliminated many of the “spare parts crises” where large quantities of equipment in a combat zone would be unavailable because a few parts were found to wear out more quickly than anticipated in combat. When that sort of thing happens now the MPH can get parts to the troops quickly while the factory is alerted to produce more and air freight them to the combat zone as soon as they can.
They took another new tool from the 1990s, machines that can create 3-D models from CAD files, and combined it with digital mapping technology. The 3-D model machines were originally developed to produce prototype parts for engineers, to help them in perfecting their designs. The Corps of Engineers adapted the software used in the 3-D model machines so that they could create the 3-D terrain models.
It took the army a decade to develop and deploy a second and third generation of MPH. The 2013 version was actually called Ex Lab (Expeditionary Lab) and was more compact and relied more on 3-D parts builders (3-D printers) and operators trained to help users come up with designs for components that don’t yet exist. It’s often the case that troops discover the need for a new component or improved replacement part for their equipment. In the past, this request often had to go back to the original factory for development and manufacturing. But with the software and equipment available now, as well as satellite data links to factories, it is possible to get this work done quickly in the combat zone. Thus, the new name for what is essentially MPH 3.0.
MPH was developed when the army realized that the easiest and quickest way to get the many rarely requested, but vital, replacement parts to the troops was to manufacture the parts in the combat zone. After September 11, 2001, this led to the construction of a portable parts fabrication system which fit into a standard 8x8x20 foot shipping container. The original version used two containers, but smaller equipment and more powerful computers eventually made it possible to use one container. By 2010, there were four MPH systems in service, two of them in Afghanistan. Since then two more have been built, for under $2 million each. In the first decade of use, MPHs manufactured over 150,000 parts on the spot saving lots of time, shipping expense, and aggravation for troops needing the item. This saved days, or weeks, that it would take to order the part from the manufacturer. The MPH part is usually a lot cheaper (because the air freight and manufacturer markups to pay for maintaining the part in inventory). MPH 2.0 had a 3-D part builder which used metal dust and a laser to build a part. MPHs keep getting more capable 3-D printers. But now the primary obstacle to creating needed parts on the spot is the fine print in the original procurement contract.