AD 2021-12-04 Prompted By A Report That Corrosion Was Found On The Horizontal Flange On The Front Spar Lower Boom

The FAA is adopting a new airworthiness directive (AD) for all Fokker Services B.V. Model F28 Mark 0070 and 0100 airplanes.

This AD was prompted by a report that corrosion was found on the horizontal flange on the front spar lower boom, between the rebate strap and the lower boom, and resulted in bulging. This AD requires doing a detailed visual inspection to detect any bulging, loose, and missing countersunk fastener heads at the left-(LH) and right-hand (RH) outer wing lower skin of the front spar between certain wing stations, and applicable on-condition actions, as specified in a European Union Aviation Safety Agency (EASA), which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products. This AD becomes effective July 9, 2021.

Supplementary Information: EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2021-0014, dated January 13, 2021 (EASA AD 2021-0014) (also referred to as the Mandatory Continuing Airworthiness Information, or the MCAI), to correct an unsafe condition for all Fokker Services B.V. Model F28 Mark 0070 and 0100 airplanes.

This AD was prompted by a report that corrosion was found on the horizontal flange on the front spar lower boom, between the rebate strap and the lower boom, and resulted in bulging. The FAA is issuing this AD to address corrosion on the horizontal flange, which could lead to reduced structural integrity of the wing torsion box structure. See the MCAI for additional background information.

FMI: www.regulations.gov