The parking brake is engaged through a deliberate sequence that uses both the toe brakes and a specific handle action. You must apply the toe brakes to create hydraulic brake pressure, then pull and rotate the parking brake handle 90 degrees to lock the system. This combination ensures the brakes are actually applying and will stay applied when parked, because the handle’s 90-degree turn mechanically locks the valve to retain the hydraulic pressure in the brake lines. The other statements miss part of this sequence or describe scenarios that aren’t how this system is designed. One option suggests the handle alone activates the brake, which omits the necessary toe-brake action. The others imply partial operation via an emergency system or a dependence on hydraulic failure, which doesn’t match the described locking action that secures the brakes through the coordinated steps.

The elevator controls pitch by changing the tailplane’s angle of attack and the resulting force on the tail. When the control stick is moved aft, this setup causes the trailing edge of the elevator to move downward. That downward deflection increases the tail’s downward force, rotating the nose downward. So, both the elevator trailing edge and the nose move downward. If the trailing edge moved upward, it would typically produce a nose-up moment, which is why you often hear that nose-up occurs with up elevator deflection.

Redundancy in braking systems means there’s more than one source of hydraulic power. If the primary hydraulic system fails, a secondary (alternate) hydraulic system can still pressurize the brakes, so braking action can continue. Because of this backup capability, the brakes are not necessarily inoperative when the primary system fails. The idea that braking would automatically apply simply due to pressure dropping isn’t how braking works, and there would only be a loss of braking if both hydraulic systems failed.

The main idea is how the PCL UHF/VHF key directs where your transmit signal goes. This two-position control routes the push-to-talk path to the selected radio band. When you push the control upward, the transmit path is connected to the UHF radio, so you transmit on UHF. When you push it downward, the path switches to the VHF radio, so you transmit on VHF. This design gives you quick, unambiguous control over which band you’re using and prevents both radios from transmitting simultaneously. The other possibilities would imply the wrong direction mapping, dual transmission, or no effect, which doesn’t match how the switch operates.