Sunday, December 25, 2011

On-time Arrivals "Improving"

You see the headlines in how well airlines are doing in their on-time arrivals, which happens to be one of the performance measurements by the U.S. Department of Transportation (USDOT). What many passengers don't know is that airlines build a generous margin of safety to insure a high probability of on-time arrivals. For example, a flight from Reagan National Airport to New York LaGuardia takes about 38-45 minutes of wheels-up to wheels-down, but yet the schedule shows 1 hour and 21 minutes for that flight. In this case, the airline built in a margin of safety of 41 minutes for a 40-minute flight. So even if the flight is 30 minutes late in take-off, the airline can boast an "on-time" arrival as the plane is taxiing to the gate with 10 minutes to spare. Sometimes things don't work out so well. Planes arriving well before their "scheduled" arrival may find themselves stopping short of the gate due to the fact that a departing plane has not left the gate that the arriving plane is supposed to occupy. Weather delays and congestion may also mean that a plane may circle around and queue for landing at busy airports such as Chicago O'Hare and New York LaGuardia. Airlines do post the "probability" factor, usually on a scale of 1-10 for the "timeliness" of their flights. The higher the number, the more likely the flight will be on time.