What does the term Per Diem mean in the context of airline operations?

In the context of airline operations, the term "Per Diem" primarily refers to a daily allowance for meals and other incidental expenses incurred by employees while on duty away from their home base. This allowance is intended to cover the costs of meals, snacks, and sometimes even accommodation when employees, such as flight crew members, are required to stay overnight in a different location for work purposes. The concept is essential in providing fair compensation to employees for additional costs they might face while fulfilling their job responsibilities away from home.

The other options address different aspects of airline operations. Measurement of daily passenger capacity is a crucial operational metric but is unrelated to Per Diem. The exchange rate for flights is relevant to financial transactions involving international travel but does not pertain to employee allowances. Lastly, daily operational hours of the airline discuss the scheduling and logistics of flight operations rather than covering employee expenses. Thus, the correct understanding of Per Diem focuses on the financial support given to employees for daily expenses while they serve on duty away from their usual location.