Which flight controls are considered the secondary group?

The trim tabs and spring tabs are classified as secondary flight controls because they are primarily used to augment the primary control surfaces rather than serve as the main means of controlling the aircraft's attitude and flight path. Secondary flight controls are designed to improve the handling characteristics of the aircraft and reduce pilot workload.

Trim tabs help adjust the neutral position of primary flight controls, allowing the pilot to maintain a desired aircraft attitude without directly applying force to the primary control surfaces. Spring tabs function similarly, providing aerodynamic assistance to the control surfaces by helping reduce control forces. Both types of secondary controls contribute to a smoother and more stable flight experience, but they do not directly control the aircraft's movements in the same way that primary controls such as ailerons, elevators, and the rudder do.

Understanding the distinction between primary and secondary flight controls is essential for comprehending how aircraft stability and maneuverability are managed.