What is NOT a stall indication?

The correct answer highlights that a loss of cabin altitude is not a stall indication. Stall indications are typically associated with a loss of lift and control effectiveness due to an aircraft exceeding its critical angle of attack.

Stall indications include devices and phenomena that warn the pilot of an impending loss of controlled flight. The stick pusher is a mechanism designed to automatically push the control yoke forward to reduce the angle of attack and prevent a stall. The stick shaker activates to vibrate the control column, alerting the pilot of an approaching stall. Both of these are direct stall indications and crucial in maintaining safe flight operations.

In contrast, a loss of cabin altitude pertains to changes in pressure within the cabin and is related to the aircraft's pressurization system rather than its aerodynamic performance. This aspect deals more with passenger safety and comfort rather than indications of a stall condition, making it irrelevant to stall awareness. Thus, the identification of loss of cabin altitude as not being a stall indication is appropriate, as it does not serve as a warning of aerodynamic stall.