Aircraft Maintenance

Pneumatic tools are to aircraft technicians as scalpels are to surgeons: They are essential ‘tools of the trade’. Yet despite this fact, some technicians either neglect or mishandle their air tools. It can be something as small as using the same compressed air supply to drive paint guns and air impact wrenches; risking lubricating oil leaching into the paint and ruining the next 737 refinishing job. Or it can be as big as tossing precision pneumatic tools around like baseballs, with the concrete shop floor serving as backstop.

Of course, the aviation industry isn’t the only one where pneumatic tool abuse occurs. “Having a pin put in my broken hand, my orthopaedic surgeon asked his nurse to turn on the nitrogen tank used to operate his air drill,” recalls Karl Matis. He is vice president of HECAT Inc., known in the aviation business for its HECAT pneumatic heat exchanger flushing equipment. “Thinking she was opening the bottle, she cranked up the pressure regulator,” Matis says. “When the drill did not work, the doctor jumped up and opened the bottle himself. When he pulled the trigger, the drill immediately screamed with rpm and disintegrated scattering shrapnel everywhere. Luckily no one was injured by debris.”

Back to aviation: What constitutes the proper care and feeding of pneumatic tools? Here’s some answers that will keep your air tools humming along for years to come.

Handle with Respect
Pneumatic tools are meant to be used repeatedly in harsh environments. This is why pneumatic tool manufacturers build their products out of hardened metals, with enough resilience and toughness to keep working day in, day out.

This said, even the toughest air tool has its breaking point, warns Jay Johnson, Mac Tools’ product manager for power tools. Sometimes breakage occurs because a tool is being asked to do too much. Other times, a properly used tool will fail due to years of wear and tear.

“The most common things that break or get damaged on ratchets and impact wrenches are anvils,” Johnson tells AMT. “Anvils often wear out and simply need to be replaced when they break. They’re always under heavy torque, which leads to steel fatigue.

“Gears get damaged on tools like drills, grinders, and ratchets when the user puts too much load on the tool,” he adds. “Pressing too hard on a grinder or hand tightening a fastener with a ratchet after the ratchet torque has maxed out puts a lot of stress on the gears.”