By U.S. ArmyJune 20, 2017
REDSTONE ARSENAL, Ala. (May 18, 2017) -- You've heard the statistically-backed saying 'flying is safer than driving'. While it's a nice phrase to ease a nervous airline passenger's mind, a pilot can't rely on the odds to keep him or her safe in the air.
There are two parts to a safe flight, the pilot and the mechanical reliability of the aircraft. Pilots put in hundreds of hours of training to perfect their flying skills . To aide in ensuring the aircraft and helicopters carrying Soldiers are mechanically sound, various parts and components are tested at the U.S. Army Redstone Test Center, or RTC, Fatigue Test Laboratory and Material Analysis Laboratory.
Bryan Thompson, senior mechanical engineer at RTC, describes tests the aircraft undergoes at the laboratory to include fatigue and endurance testing.
"The testing helps to ensure parts from new vendors have a fatigue life that's sufficient for use on an aircraft, substantiate new repair methods for components and prove out engineering changes or new designs of components," Thompson said. "This testing helps to improve the safety of the aircraft, reduce the cost of components, and increase the fleet readiness."
Fatigue testing involves applying cyclic loading to a test specimen to understand how it will perform in actual use and how long it will last. Typically the loading involved is higher than seen in actual use to determine if a failure will occur. The testing cycles may go into the millions.
Endurance testing is carried out on items such as bearing and clutches that are sensitive to loading. The test time is equivalent to flight time.
This type of testing involves a variety of equipment and fixtures, including static and dynamic structural load test stands; some made specifically for items to be tested at RTC.
Fatigue and endurance testing is carried out on various structural and load carrying components of the aircraft. Many of these parts are classified as flight critical parts, meaning the loss of the component could lead to aircraft and/or crew loss.
Components are sent to these RTC labs to ensure the manufacturer produced parts to the exact specifications required by the Army. Metrology labs are utilized to painstakingly measure every item. This can help certify multiple vendors and lower prices for the aviation components needed for the aircraft.
Unfortunately, component failures occur during operation, and sometimes result in tragic circumstances. These failures bring aviation components to the RTC laboratory.
Dr. Kevin Minor, materials engineer at RTC, spends many of his days performing analysis on failed Army Aviation Systems components. In environmentally controlled labs, RTC uses very specialized equipment, such as scanning electron microscopes and optical, atomic, and infrared spectrometers, to analyze the failures.
While the fatigue testing works to possibly cause a failure, Minor receives his components after a failure has occurred; sometimes even involving a crash of an aircraft. This testing then becomes a detective case, and possibly part of a criminal investigation, trying to figure out exactly what went wrong.
"The work in these labs is kind of like crime scene investigation for aviation. Our job continuously changes as we can receive small parts such as nuts and bolts or larger parts such as gear boxes and engines and anything in between," said Minor. "Evidence is collected and we get to work. Our job is to find the root cause of the failure and recommend mitigation strategies to prevent similar failures in the future."
The testing done in the labs housed in the Environmental and Components Test Directorate involves significant technical expertise and multi-divisional coordination. Although the work of the Components and Surveillance Test Division never leaves the ground, the testing here helps ensure safety and sustainability in the air.