Action
Final rule.
Summary
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 727 airplanes. This AD was prompted by reports of cracks on the elevator rear spar stiffener assembly. This AD requires repetitive detailed inspections for cracking of the elevator rear spar stiffener assembly, and corrective actions if necessary. We are issuing this AD to detect and correct cracking of the elevator rear spar stiffener assembly, which could adversely affect elevator structural stiffness, which could lead to elevator vibration and possible interference with the tab control rod. These conditions could result in flutter and consequent loss of control of the airplane.