When should muscle tension be maintained during AGSM?

Maintaining muscle tension during the Anti-G Straining Maneuver (AGSM) is crucial for counteracting the effects of increased G-forces experienced during flight maneuvers. The primary purpose of AGSM is to help maintain blood flow to the brain and prevent G-induced Loss Of Consciousness (GLOC) by increasing intrathoracic pressure, which helps keep blood in the upper body and the brain.

The correct answer emphasizes that muscle tension should be maintained until the aircraft returns to 1 G. This is because reaching 1 G signifies that the pilot has returned to normal gravitational conditions, where the risks associated with high G forces are no longer present. Once the aircraft settles back into a 1 G environment, the need for sustained muscle tension diminishes, allowing for relaxed muscle recovery and decreased fatigue.

Each other option presents a different phase of flight that does not accurately reflect the timing required for muscle tension during AGSM. For instance, maintaining tension until descent is initiated, until cruising altitude is reached, or until landing is complete does not adequately address the need to manage the body's response during periods of increased G forces, which is vital until the normal forces return to baseline.