Story ID: 338
ATR’s Hard-Landing Analysis Tool Proving Worthwhile
By: Chris Kjelgaard
Caption: Within its first three months of service the Smart Lander tool allowed ATR to advise operators rapidly of landing gear maintenance needs.
Word Count: 753
By late May ATR had used its Smart Lander data analytics tool to advise operators whether to ground their aircraft for required landing-gear maintenance actions a day after two ATR 72 serious hard-landing incidents.

Although ATR unveiled Smart Lander on May 12, the new hard-landing analysis tool for ATR 72 landing gear had entered service about three months earlier, according to Vincent de Laborderie, ATR’s head of flight technologies. Developed with Safran Landing Systems, which manufactures all ATR landing gear, Smart Lander—promoted by ATR and Safran as “the first of its kind in the aviation industry”—recorded no need for referrals during its first two months, but in the third month ATR referred two incidents using the tool.

Both referrals, which generated stress analysis of landing-gear parts that ATR immediately conveyed to Safran to determine the need for any maintenance, allowed ATR to advise the aircraft operators within hours on whether or not to ground their aircraft immediately.

De Laborderie told AIN that until ATR introduced Smart Lander it took about 10 days for ATR and Safran to analyze the flight data recorder (FDR) data produced during ATR 72 hard landings and report findings on required landing-gear maintenance.

Yoann Pascal, ATR’s head of hydromechanical systems, said ATR began discussing internally in 2015 how it might let operators know far more quickly what they should do with ATR 72s involved in hard landings and how much, if any, maintenance the landing gear parts would need.

By 2018 ATR had decided to create a database of landing-gear hard-landing stress load data to anticipate hard-landing events, according to Pascal. ATR started developing the database by performing simulations of every possible kind of hard landing of an ATR aircraft. Each simulation used the type-certification data ATR had developed for its aircraft models through thousands of hours of flight and ground and bench tests of every component.

Pascal said ATR considered five basic types of hard landing: a hard landing on both main gears; a nose-gear landing; a landing on one of the two main gears, further split into incidents also involving sideslip and incidents not involving sideslip; and a bounced landing.

The simulation process used to create the stress load database did not include incidents in which the aircraft ran off the runway or those covered by other ATR grounding and maintenance procedures, said Pascal. ATR then brought Safran into the development program so that it could provide its own design and certification data for the landing gear—which is common to the ATR 42 and ATR 72—and its massive experience in ATR landing-gear maintenance.

Today the Smart Lander database contains hundreds of thousands of simulated hard landings of ATR aircraft in every possible combination of weight, balance, passenger or cargo payload, and landing-stress load, as well as stress-load data obtained from FDR recordings of all actual hard landings in service and thousands of normal landings, said de Laborderie. Smart Lander uses machine-learning algorithms to compare real-life incidents with the incidents in the database, finding the most similar incidents the database contains—simulated and/or real—and basing its analysis of every landing-gear part on those, said Pascal.

ATR initially has made the Smart Lander analysis service available only for the ATR 72, mainly because ATR 72s perform many more flights than do ATR 42s and the fact almost none of the smaller turboprops have ever made hard landings in service, said Laborderie.

However, he added, ATR has made the Smart Landing tool immediately available for use should any operator incur a hard landing with an ATR 42. ATR also is monitoring closely the flight history of the new ATR 42S STOL version of the aircraft to see if any hard landings occur on any short and/or unprepared runways. It thinks the automatic actuation of the wing spoilers immediately on touchdown should mitigate any potential ATR 42S hard landings, but it will offer Smart Lander if needed.

Upon a hard landing, Smart Lander lets ATR advise operators within hours if they need to ground the aircraft immediately—wherever it has landed—or if it can perform a ferry flight back to the operator’s main maintenance base for the landing-gear work, said Pascal. Under a third option, for less severe incidents, ATR could allow the operator to keep flying the aircraft normally for a given number of flight cycles over approximately a month before performing the required landing-gear maintenance.