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31st MXG innovates through 3D printing

  • Published
  • By Senior Airman Brooke Moeder
  • 31st Fighter Wing Public Affairs

Innovation comes in many shapes and sizes, and the smallest changes can make the biggest differences.

Four sections within the 31st Maintenance Group came together to find a creative solution to a problem with a Display Management Switch (DMS) knob on the F-16 Fighting Falcon’s sidestick, July 2021.

The F-16 sidestick control grip is the pilot’s main interface for flight, avionics and armament systems on the aircraft. Without a functioning DMS knob, they would be unable to fine tune their avionics display and more.

The team kept running into an unnecessary loss of time and money when the DMS knob on the F-16 sidestick broke. The DMS knob is not a supply asset and the only way to source this item is to order an entire DMS switch replacement and swapping out the entire stick. The replacement process for the switch requires removal of the entire sidestick from the aircraft, just to replace a small knob.

“There was an adhesive that we've had on order for about eight months, and getting any kind of item like that over to Italy is a long process,” said U.S. Air Force Master Sgt. Kyle Eilefson, 31 Maintenance Squadron avionics intermediate section chief. “We had full serviceable switches on hand, but if we were to open it up, we would be down for as long until we got the actual adhesive itself.”

The team brainstormed and came up with an inventive idea to save the U.S. Air Force time and money: 3D print the DMS knob.

“The quickest process was to try to use a 3D printer,” said Eilefson. “Each DMS knob costs 10 cents to print.”

Installing this part directly on the aircraft would alleviate the removal of the sidestick, supply processing, back shop maintenance and reinstallation, ultimately turning a $131.90 job into a 10 cent job and saving 30 man-hours per knob replacement.

Before they could start put their idea into motion, team first had to get their plans approved through an equipment specialist. Then came the task of building and testing the prototype to see if they could even use it.

“We had the conversation, to see if it was even possible,” said Eilefson. “You can’t order this singular part from supply, you have to order the entire switch, not just a knob. By 3D printing, we eliminated the necessity to open up the sidestick and we didn't need this adhesive that took us another five months to get.”

All of the coordination to get a usable prototype took a couple of days and eliminated almost a year’s worth of downtime that could have been used on the DMS knob, according to Eilefson.

“The timeline for engineering coordination for a project like this is typically lengthy,” said Tech. Sgt. Adam Rentsch, 31 MXG air force repair enhancement program (AFREP) manager. “There are several steps that must be accomplished before a design will be approved. It was something that we knocked out in days because everyone was synced up and everyone was on board. The whole team was leaning way out farther than they normally would to solve the problem.”

To fabricate the prototype they needed, the avionics section reached out to the 31st MXG AFREP section to see if they had the capability to 3D print the piece. According to Rentsch, this would be the first 3D printed part to go on an F-16 at Aviano Air Base.

U.S. Air Force Staff Sgt. Bryan Hernandez-Navarro, 31st MXG AFREP technician, found the specifications and measurements for the DMS knob using schematic diagrams and quickly got to work creating the prototype.

“We got the engineering diagram,” said Hernandez-Navarro. “The diagram had all the specifications and dimensions for the knob and then it said what kind of plastic we would need. Once I got the specifications, I started to design the prototype using computer aided design software. After that, I began manufacturing the prototypes.”

After the prototypes were printed, a member within the 31st MXG Precision Measurement Equipment Laboratory flight ran stress tests on the prototypes to test its durability.

“We took a force gauge, something you push on it to tell you how much weight you're applying, and we pushed it down on the knob in each direction, and then we put some string around it and pulled it up,” said Senior Airman Jacob Zardiackas, 31 MXG PMEL technician. “We made sure that it would actually hold and it wouldn't break.”

There is a certain amount of force the knob needed to withstand, and Hernandez-Navarro said it wasn’t until the fifth prototype that they had one that passed the test and could be put on the F-16.

Hernandez-Navarro hopes this innovative idea could open doors in the future for the 31st MXG to use more 3D printed parts on fighter generation aircraft. This idea wouldn’t have been executed if it wasn’t for driven Airmen that wanted to make a difference.

“The top line from leadership right now is to accelerate and change,” said Rentsch. “You have four sections that were ready to put that into practice. We were able to use our resources, go outside and solve the problem within a matter of days. We came up with this way to fabricate this part and test it and put it on aircraft with engineering support, so it was a huge team win.”