The Southwest Research Institute (SwRI) (San Antonio, Texas, USA) recently received a contract worth up to $300 million to help the U.S. Air Force sustain aircraft landing gear systems.
This 20-year indefinite delivery, indefinite quantity (IDIQ) contract award supports the Air Force’s comprehensive landing gear integrity program, which was formed to incorporate landing gear into the Air Force’s aircraft structural integrity program (ASIP). IDIQs are contract vehicles that fund work tasks over specified periods of time. SwRI was one of three entities selected for this IDIQ.
An aircraft’s landing gear is a complex and vital system, SwRI explains. If the landing gear fails, pilots are often forced to execute what’s known as a “belly landing,” which is dangerous and causes considerable damage to the aircraft at a cost of millions of dollars to repair. These failures are usually a result of material degradation from many years or decades in service, and become more common as the components age.
“Landing gear systems contain hundreds of parts,” says Luciano Smith, principal engineer at SwRI. “Without proper maintenance, parts could fail due to fatigue or stress corrosion cracking.”
SwRI has provided engineering support to the Air Force for decades, with the partnership dating back to aircraft that came into service in the 1960s and 1970s and have since exceeded their design life. SwRI says it has supported sustainment for aircraft subsystems, including propulsion, avionics, electrical, mechanical, electromechanical, and hydraulics technology, in addition to addressing information security and electronics systems problems.
The landing gear program will allow SwRI to bid for work on many Air Force aircraft, including some already supported by previous structural integrity contracts.
“We’re facing a lot of new and exciting challenges,” says David Wieland, manager of SwRI’s aerospace structures section. “We’ll start by creating a 3-D [three-dimensional] solid model of each of the landing gear parts and conducting a static stress analysis. We will also perform data recording to understand the loads seen by the various parts while in use. From there, we’ll do fatigue analyses and risk analyses. Then we’ll measure how the usage affects the life of the landing gear. This will help the Air Force maximize the safety of the landing gear and manage the costs to the fleet.”
Since beginning structural integrity work for the Air Force in the early 1970s, SwRI has developed tools such as NASGRO software—described as a collaboration with NASA that can analyze fracture and fatigue crack growth in structures and mechanical components. The Institute has also developed a flight data recording system to help engineers understand the structural stresses associated with various flight maneuvers.
In addition, SwRI has created specialized inspection probes and nondestructive inspection systems to inspect through bushings without removal, and the SwRI-patented magnetostrictive (MsS) sensors are flying on A-10 aircraft to provide ongoing structural health monitoring.
Source: SwRI, www.swri.org.