Action
Final rule.
Summary
We are superseding Airworthiness Directive (AD) 2012-11-15 for all BAE Systems (Operations) Limited Model 4101 airplanes. AD 2012-11- 15 required a one-time detailed inspection for cracks, corrosion, and other defects of the rear face of the wing rear spar, and repair if necessary. This new AD requires repetitive detailed inspections, and repair if necessary. This AD was prompted by new reports of cracking found in the wing rear spar and technical analysis results, which confirmed that the crack initiation and propagation are due to fatigue, with no indication of any other crack initiation mechanism (e.g., stress corrosion). We are issuing this AD to address the unsafe condition on these products.