Which statement is true regarding aircraft manufactured prior to March 1, 1979?

The statement that aircraft manufactured prior to March 1, 1979, operate per aircraft specs or Type Certificate Data Sheet (TCDS) instructions is accurate due to the regulations and standards governing aircraft at that time. Prior to the establishment of specific requirements for Approved Flight Manuals (AFM), many aircraft did not have AFMs and relied on the guidelines and specifications outlined in their TCDS. The TCDS provides critical information regarding the aircraft's operational limits and requirements, which operators had to follow for safe and compliant operation.

In essence, for those older aircraft that did not have an AFM, adherence to the TCDS meant that pilots and operators relied on the specified performance data and limitations described in the TCDS to ensure safety and efficiency in flight operations. This regulatory framework defined how these aircraft should be operated even in the absence of an AFM.