After engines, landing gear probably get the hardest pounding of any components in aircraft operations. Yet while engine health monitoring has been done for decades, monitoring landing gear health is relatively young. One monitoring company has set out to exploit the opportunity for improving maintenance of these expensive systems.
Flightwatching, now a unit within the Revima Group, has been doing predictive maintenance on several aircraft systems, including engines, APUs, hydraulics, bleed and fuel systems, air probes and landing gear. For the past four years it has worked with landing gear on models such as the Airbus A380 and older ones such as the A300.
“We have been successful on landing gear components such as actuators, proximity sensors and indicators,” explains Flightwatching chief Jean-Philippe Beaujard. His unit provides advanced troubleshooting assistance to airlines and also a remote pre-flight inspection prior to each flight on key items that could lead to a delay or inflight turn-back.
Pre-flight inspections are supported by Flightwatching’s digital checklist application that works on mobile devices. The company sends a new inspection task to maintenance mechanics on the ramp after an alert from remote monitoring. For example, remote monitoring might detect incorrect rigging of a proximity switch that could lead to a problem when retracting landing gear. “We focus on potential component failures that could lead to a cockpit alert or retraction problem after takeoff,” Beaujard explains.
Flightwatching is now evaluating whether existing parameters could also enable it to monitor seal wear.
The Flightwatching exec says his tools have avoided delays and inflight turn-backs with real-time alerts. “Our algorithms scan some key parameters and compute a potential risk that is sent to maintenance control for a pre-flight inspection,” says Beaujard.
Flightwatching has also been working on loads, both hard-landing and more general aircraft loads at landing. It seeks to help airlines quickly spot the parts of the aircraft that need to be inspected after a load alert. Beaujard says aircraft maintenance manuals give very complicated instructions when hard landings occur. Flightwatching can help decode a load case and decide in real time whether an inspection is needed. Essentially, it is interpreting and applying those complicated manual instructions, “very useful for maintenance control.”
The Revima division has also helped airlines troubleshoot a difficult issue involving cockpit landing-gear lever signals. A signal anomaly pointed to further analysis of the digital flight data recorder, or black box. Remote monitoring avoided removal of the data recorder by confirming that the last troubleshooting action had cleared the problem.
Beaujard says the main requirement for airline use of its predictive tools is simply that an airline be willing to investigate the benefits of predictive maintenance for landing gear and provide regular data so that Flightwatching’s predictive algorithms can learn more. Parent Revima already provides flight-hour support for APUs and other components that should reduce costs by predicting potential failures. He would like to see the same sort of agreements for landing gear.