Superior performance is the key to success for any airline, both regional and major. It is an indicator of how well we are performing against our previous metrics, and measures how well we are meeting our business objectives. Within the airline community, we have several metrics that determine the success of our operation, including D:0, A:14, completion, controllable completion, delay code and first flight. Familiarize yourself with the following terms below:

D:0: On-time departure; doors closed and brake released within zero minutes of the scheduled departure time. At ExpressJet, this is recorded electronically via the ACARS system. It is essential that our flights depart on time in order to provide both our customers and major partners with an experience and service they can be proud of. A single late departure can cause negative consequences throughout the remainder of the day including delaying future flights, burning more fuel to make up for lost time, and possibly even causing customers to miss their connecting flights.

A:14: On-time arrival; main passenger or cargo door opened within 14 minutes of scheduled arrival time. The 14-minute “wiggle room” is because variances in the flight path (weather, rough air, etc.) make it difficult to pinpoint the exact time a flight should take. The Department of Transportation (DOT) uses this measure when reporting reliability of airlines.

Completion Factor (CF): Completion of scheduled flights – takeoff to landing. Flights cancel. It happens for a number of reasons – weather, Air Traffic Control (ATC), proactive reductions, maintenance, etc. An airline’s completion measures the percent of scheduled flights that are completed, and does not take into account the reason for flight cancellations.

Controllable Completion Factor (CCF): Completion of scheduled flights – takeoff to landing – but only taking into account those cancellations we have control over. For example, we can control if we have properly staffed a flight with a crew, but we can’t control a flight cancelled due to weather. The controllable completion percentage is always higher than or equal to the completion factor.

Delay code: When a flight doesn’t meet its D:0 or A:14 goals, there needs to be an explanation. Delay codes are input into the ACARS system explaining why a flight was late. Sometimes the gate agent holds the door for a late-arriving passenger, or perhaps catering arrived late. It might be that the flight was delayed on a previous leg and got to the gate late. All of these reasons are reviewed, and steps are taken to make improvements where possible.

First flight: The first flight of the day by an airline. Each airline define it differently (any flight before 6 am, any flight before 11 am that sat for 4 hours, etc.), but there is always a focus on the on-time departure of first flight.

We want to help you make the smart choice for your future by providing you with the information you need to know. If you have any questions about our performance metrics or work rules, visit In the upcoming weeks, we will be bringing you more aviation vocab terms.

Check out the other articles in our Aviation Vocab 101 Series:

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