After the Federal Aviation Administration (FAA) issued an Airworthiness Directive (AD) on October 3, 2019, operators of Boeing 737NG aircraft, models 737-600, -700, -700C, -800, -900, and -900ER, were forced to check for cracks on left and right-hand side suspension system, which connects the fuselage with the wings. The system, nicknamed the pickle fork, was designed to safely handle 90,000 flight cycles – the total lifespan of a Boeing 737 NG.