Hard landings can be difficult on passengers, cargo and the aircraft itself. Aviation safety practices require airlines need to check the landing gear before the plane returns to service. ATR, the Airbus-Leonardo joint venture that manufactures turboprop aircraft, says it has developed AI that can significantly speed up the inspection process and save airlines money.
Bumpy landings typically happen when an aircraft descends at a faster rate than the optimal 2 or 3 feet per second. The idea is to gradually lower the plane without letting it float. Pilot error can cause “hard landings,” but pilots frequently make them on purpose because of wet weather conditions, wind gusts, or short or busy runways. Pilots prefer to call these landings “firm.”
Bouncing on the tarmac with high force causes structural stress on landing gear components, which is why manufacturers call for follow-up inspections. But defining what constitutes a firm landing and when an aircraft inspection is required isn’t 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 pilot judgment and reports describing the landing remain the best source of information for ascertaining if a hard landing has occurred. Pilots ordinarily land the airplane well within the allowable limits and become accustomed to the sensation … . Airplane flight and cabin staff typically report a hard landing when sink rates approach 4 feet per second. All Boeing model airplanes have been designed for a 10 feet per second sink rate at the maximum designed landing weight and six feet per second at the maximum designed takeoff weight. These values are considered when designing both the main landing gear and nose landing gear assemblies as well as the wing and fuselage support structure,” states an explanation on a Boeing 737 technical website.
The hard landing inspection involves a close visual inspection of various structural components to determine if further inspections are warranted. One possible sign of damage is leakage of hydraulic fluid from the shock strut. A second inspection could involve removing parts of the landing gear.
ATR, in conjunction with aviation equipment maker Safran, said last week it has developed “Smart Lander,” a landing gear diagnostics service that uses sophisticated data analysis to make safety determinations faster. The service relies on machine learning technology based on hundreds of thousands of hard landing simulations to issue recommendations to operations on the maintenance actions to be taken according to the hardness of the landing and the load level sustained by the landing gear.
Smart Lander helps operators determine whether aircraft can be permitted to continue commercial operations or need to be sent to a maintenance base. The process takes less than an hour, compared to more than a week previously, ATR said.
“Our former process could take up to 10 to 20 working days. It required analyses 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 customer support and services, in a news release. “With Smart Lander, we will be able to massively reduce our response times, therefore boosting aircraft availability, reducing costs for customers and enhancing customer satisfaction, while maintaining the same level of analysis quality.”
Last month, Air Transport Services Group in Wilmington, Ohio, selected Safran Landing Systems for the retrofit of more than 30 Boeing 767 freighters operated by its subsidiary cargo airlines. The transition to Safran’s wheels and carbon brakes allows ATSG to operate with a common wheel and brake configuration across its operating fleet of freighter aircraft with carbon brakes, which are lighter than other brake types.