Airworthiness Directives; Cessna Aircraft Company Model 172R Airplanes

This amendment adopts a new airworthiness directive (AD) that applies to certain Cessna Aircraft Company Model 172R airplanes. This AD requires modifying the lower forward doorpost bulkhead by installing rivets. This AD is the result of a report from the manufacturer that these rivets were erroneously omitted during manufacture of some of the new production airplanes. The actions specified by this AD are intended to prevent reduced structural rigidity at the forward doorpost bulkhead, which could result in structural cracking and possible loss of control of the airplane.