In the event of smoke in the cockpit, the oxygen diluter setting should be set to what percentage?

When smoke is present in the cockpit, it is crucial for the flight crew to ensure that they have a sufficient supply of pure oxygen to breathe. Setting the oxygen diluter to 100% is the recommended action in this scenario. This setting provides pure oxygen without mixing it with ambient air, which may contain harmful smoke particles or toxic gases.

By using pure oxygen, the flight crew can minimize the risk of suffocation or inhalation of smoke, allowing them to maintain function and address the situation more effectively. This is particularly important since smoke can obscure vision and impair cognitive functions, making it essential to clear the air with pure oxygen to safeguard the crew's health and decision-making ability during a critical incident.