Revamping the decades-old aircraft APU Training Aid
The RSO is committed to finding new ways advanced manufacturing can be used to enhance sustainment of the fleet. The ongoing automation of traditional manufacturing and industrial practices within the U.S. Air Force means that large cost-saving measures can appear in previously unimaginable ways. A prime example can be found in the ways we update necessary equipment used to train the fleet engineers and maintainers to maintain mission readiness of warfighters.
As any fleet ages, many tools used to train maintainers age as well, and can be rendered obsolete if not properly updated and replaced. This was the case with the E-8C JSTARS Aircraft Auxiliary Power Unit (APU) Training Aid, a wooden, full-sized mock-up of the unit, until the Field Training Detachment (FTD) and the JSTARS Program Office (PO) office saw a unique opportunity in additive manufacturing.
The Joint Surveillance Target Attack Radar System, or JSTARS, is an airborne battle management, command and control, intelligence, surveillance, and reconnaissance platform, and its primary mission is to provide theater ground and air commanders with ground surveillance to support targeting and attack operations. JSTARS were originally manufactured by Boeing as 707-300s in the 1960s, making the aircraft a great candidate for AM sustainment efforts.
Each JSTARS aircraft is equipped with a powerful on-board auxiliary power unit (APU), which provides the electric power to start the main aircraft engines and systems on the ground and, if necessary, in flight. This makes landing in more remote locations possible, and allows the USAF to involve less personnel in the launch. The APU on each flight mission has a sole operator, a flight engineer who must be well-trained on the mechanics of the APU components and repair.
Across the entire USAF, this integral training is conducted by one USAF instructor, Technical Sergeant (TSgt) Daniel Spear, out of 373rd TRS Detachment 6 at Robins Air Force Base (AFB). When TSgt Spear took over the program 8 years ago, the training apparatus was in a state of disrepair.
“It was in shambles,” Spear lamented. “It was made of wood and was 20 to 30 years old; something new would break all the time. All the holes for drilling were completely stripped.” TSgt Spear’s hands-on training course at Robins AFB is the only location the necessary training occurs, and on average, 23 flight engineers complete the 9 day course annually.
There was no traditional repair available for the decades-old aircraft APU Training Aid, and to replace the unit would have cost the USAF anywhere from $150,000 for a new mock-up to $1.2 million for an actual APU. In the interest of sustaining the fleet, a more cost-effective solution had to be found.
When he arrived at the ATTC, TSgt Spear brought with him a growing interest in repairing aging components with additive manufacturing. Cody Sargent, E-8 JSTARS Mechanical Systems Engineer, was familiar with the RSO’s efforts to utilize AM technology from his work with the C-5 program office and USAF Metals Technology Office. Through their combined efforts, twenty-one sub-components to the JSTARS APU mock training aid have been developed using HandiScan Black 3D scanning technology to design for additive manufacturing. This combination of technologies allowed the JSTARS Program Office to undertake a complete overhaul of the training aid, and design printable parts that ensure it can be quickly and easily repaired for decades to come, easily training hundreds more USAF JSTARS flight engineers.
As of August 2020, all of the 21 intended parts have been printed in Acrylonitrile butadiene styrene, or ABS, a common thermoplastic polymer material. The entire mock APU training aid, outside of the sturdy wooden core, has been replaced with updated ABS parts that better represent the actual APU the flight engineers will be working on in the field. This makes the JSTARS APU training aid another clear example of the efforts the RSO is making to advance additive manufacturing within the USAF, paving the way for future manufacturing innovations in a new ecosystem.