Airworthiness Directives; Boeing Model 737-100, -200, and -200C Series Airplanes

The FAA is superseding an existing airworthiness directive (AD), which applies to certain Boeing Model 737 series airplanes. That AD currently requires inspection of the elevator tab inboard hinge support structure to detect fatigue cracking and corrective action if necessary. That AD also provides an optional terminating action. This new AD adds airplanes to the applicability and requires new repetitive inspections. For airplanes having elevators with laminated rear spars, this new AD requires repetitive inspections for interlaminar corrosion, delamination, or disbonding in the rear spar, repetitive inspections for cracking in the spar web, and repair including related investigative/corrective actions if necessary. For airplanes having elevators with solid rear spars, this new AD requires repetitive inspections for cracking in the spar web and repair including related investigative/corrective actions if necessary. This AD results from reports of cracks in the elevator rear spar web at the tab hinge bracket locations. We are issuing this AD to detect and correct cracking, corrosion, interlaminar corrosion, delamination, and disbonding in the elevator rear spar, which may reduce elevator stiffness and lead to in-flight vibration. In-flight vibration may lead to elevator and horizontal stabilizer damage and reduced controllability of the airplane.