Hard landings can be difficult for passengers, cargo and the aircraft itself. Aviation safety practices require airlines to check landing gear before returning the aircraft to service. ATR, the joint venture between Airbus and Leonardo that produces turboprop aircraft, says it has developed AI that can significantly speed up the inspection process and save airlines money.
Bumpy landings usually happen when an aircraft descends faster than the optimal 2 or 3 feet per second. The idea is to gradually lower the plane without making it hover. Pilot error can cause “hard landings,” but pilots often make them on purpose because of wet weather, gusts of wind, or short or crowded runways. Pilots prefer to call these landings ‘firm’.
High force bouncing on the tarmac causes structural stress on landing gear components, which is why manufacturers require follow-up inspections. But defining what constitutes a firm landing and when an aircraft inspection is required is not so simple.
Boeing says accelerations recorded on flight data recorders are an inaccurate indicator of hard landings and that using accelerometers to measure G-forces is unreliable and impractical.
“Boeing believes that pilot judgment and reports describing the landing remain the best source of information for determining whether a hard landing has occurred. Pilots usually land the plane well within the allowable limits and get used to the thrill… . Flight attendants and cabin crews typically report a hard landing when the sink rate approaches 1.20 meters per second. All Boeing model aircraft are designed for a sink rate of 10 feet per second at the maximum designed landing weight and six feet per second at the maximum designed takeoff weight. These values are taken into account in the design of the main landing gear and nose landing gear as well as the wing and fuselage support structure,” said a Boeing 737 technical website.
The hard landing inspection includes a close visual inspection of various structural components to determine if further inspections are warranted. A possible sign of damage is leakage of hydraulic fluid from the shock absorber. A second inspection could involve removing parts of the landing gear.
ATR said last week in partnership with aerospace equipment maker Safran that it has developed “Smart Lander,” a landing gear diagnostic service that uses advanced data analytics to speed up safety determinations. The service relies on machine learning technology based on hundreds of thousands of hard landing simulations to make recommendations for operations about maintenance actions to take based on the hardness of the landing and the load level supported by the landing gear.
Smart Lander helps operators determine whether aircraft should continue commercial operations or be sent to a maintenance base. The process takes less than an hour, compared to more than a week earlier, ATR said.
“Our old process could take 10 to 20 business days. It required analysis from both the ATR Design Office and Safran Landing Systems to decide whether the aircraft was fit to return to service,” said David Brigante, ATR senior vice president of customer support and services, in a press release. “With Smart Lander, we will be able to dramatically reduce our response times, increasing aircraft availability, lowering costs for customers and increasing customer satisfaction, while maintaining the same level of analysis quality.”
Last month, Air Transport Services Group in Wilmington, Ohio, selected Safran Landing Systems to retrofit more than 30 Boeing 767 freighter aircraft operated by its freight forwarding subsidiaries. The move to Safran’s wheels and carbon brakes allows ATSG to operate with a common wheel and brake configuration across its operational fleet of cargo aircraft with carbon brakes, which are lighter than other brake types.
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