How do we figure out the lifespan of an aircraft?
Melinda Laubach-Hock, Director of the Aging Aircraft Lab explains the tests and procedures that are used to determine where and when aircraft will corrode, crack, and more.
Vocabulary: aviation, corrosion, metal fatigue, materials testing, inspection
Next Generation Science Standards: SEP6: Constructing Explanations and Designing Solutions, CCC7: Stability and Change, PS2.A: Forces and Motion, and ETS1.C: Optimizing the Design Solution. Can be used to approach MS-ETS1–3, MS-ETS1–4, HS-PS2–3, and HS-ETS1–3.
An aircraft begins to age the moment it leaves the assembly line. Every takeoff, landing, and minute of turbulence in flight adds extra stress to an airframe. Some problems of aging are easily visible and corrected by routine maintenance, but others can remain hidden away.
Melinda Laubach-Hock, director of the Aging Aircraft Lab at the National Institute for Aviation Research at Wichita State University, describes how her lab first strips away the paint from a sample plane and then disassembles it piece by piece, looking for signs of cracks, corrosion, and metal fatigue. The lab has looked at everything from a Cessna that made regular tourist flights over the Grand Canyon, to a massive KC-135 military refueling craft, and everything in between.
- Engineers routinely establish inspection plans and identify weaknesses in their aircraft designs. Why is the additional testing done at the Aging Aircraft Lab needed? Who uses this information?
- How do you think they test metal fatigue in the lab? Design a protocol you think might work for testing metal fatigue. Do you think that protocol would be the same for all metal equipment on a single plane?
- Why is it important to test every type of plane?
- Melinda and her team are not just visually inspecting planes. Describe why enhanced nondestructive inspection techniques, like the eddy current are important parts of the process. Also, why is it important to the inspection that these techniques are nondestructive?
- The Aging Aircraft Lab works with commercial and military aircraft. Develop two questions about aging aircraft that you think could be investigated by Melinda and her team at the Aging Aircraft lab.
- Melina explains metal fatigue in the interview. Have students investigate material fatigue in a bridge-building challenge. Have a minimum load benchmark for all bridges. Have students design a protocol for testing the fatigue of the materials in their bridges. Are there changes to their designs that might reduce the stress in areas where cracks develop?
- In the spirit of the Aging Aircraft Lab, have your students break it down. Get started with this Spoonful on breaking down clicky pens and then move on to the video below on how we test wear and tear in fabrics. Have students break objects down and then figure out how they would test them for wear.