EASA AD US-2021-09-06
SUPERSEDED BY FAA AD 2025-07-03
Summary
FAA Airworthiness Directive 2021-09-06 is a final rule superseding AD 2019-22-10 and applies to all Boeing 737-600, -700, -700C, -800, -900, and -900ER series airplanes. It addresses cracking issues in the left- and right-hand side outboard chords of frame fittings and failsafe straps near station 663.75. The directive mandates repetitive inspections and repairs to ensure structural integrity and safety.
What Changed
This AD reduces the compliance time for the initial inspection on certain airplanes and shortens the repetitive inspection intervals for all affected models compared to the previous AD 2019-22-10. It also extends the reporting requirement deadline from 3 days to 10 days and clarifies reporting obligations. Additionally, it confirms that installation of certain winglets does not affect compliance and corrects a typographical error in a referenced effective date.
Why It Matters
The updated inspection thresholds and intervals ensure earlier detection and timely repair of structural cracks, enhancing flight safety and preventing potential failures. Operators and maintenance teams must adjust their inspection schedules accordingly to remain compliant and avoid unsafe conditions. The extended reporting timeline reduces administrative burden without compromising safety oversight.
What To Do
Operators of Boeing 737-600 through 900ER series airplanes must comply with the revised inspection intervals and perform detailed inspections for cracking at station 663.75 frame fittings and failsafe straps. Any cracks found must be repaired promptly. Inspection findings must be reported to Boeing within 10 days of the initial inspection. Compliance with this AD is mandatory starting June 8, 2021.
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