ATR’s hard landing analysis tool comes in handy

At the end of May, ATR had used its Smart Lander data analysis tool to advise operators whether to ground their aircraft for required landing gear maintenance actions a day after two serious aircraft hard landing incidents. ATR72.

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

These two referrals, which generated a stress analysis of the landing gear parts that ATR immediately transmitted to Safran to determine the need for possible maintenance, enabled ATR to notify aircraft operators within a few hours on whether or not to immobilize their aircraft immediately.

De Laborderie told AIN that until ATR introduced Smart Lander, it took around 10 days for ATR and Safran to analyze flight data recorder (FDR) data produced during the aircraft’s hard landings. ATR 72 and report the results on the required maintenance of the landing gear.

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

In 2018, ATR had decided to create a database of hard landing stress load data on the landing gear to anticipate hard landing events, according to Pascal. ATR began to develop the database by performing simulations of all possible types of hard landings of an ATR aircraft. Each simulation used type certification data that ATR had developed for its aircraft models over thousands of hours of flight and ground and bench testing of each component.

Pascal said that ATR considered five basic types of hard landing: a hard landing on both main gears; landing of the nose gear; a landing on one of the two main gears, subdivided into incidents also involving a skid and incidents not involving a skid; 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, Pascal said. ATR then integrated Safran into the development program so that it could bring its own landing gear design and certification data, common to the ATR 42 and ATR 72, and its extensive experience in the maintenance of ATR landing gear. .

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

ATR initially made the Smart Lander analysis service available only for the ATR 72, mainly because the ATR 72s perform many more flights than the ATR 42s and almost none of the smaller turboprops have ever performed a landing tough in service, said Laborderie.

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

During a hard landing, Smart Lander enables ATR to notify operators within hours whether they should ground the aircraft immediately – wherever it has landed – or whether it can perform a ferry flight back to base main maintenance operator for work on the landing gear, said Pascal. As a third option, for less severe incidents, the ATR could allow the operator to continue to fly the aircraft normally for a given number of flight cycles for approximately one month before carrying out maintenance. required from the landing gear.

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