Case Analysis and Recommendations
CAUSES OF DELAYS
The primary cause of delays were harsh weather conditions, such as fog, snow, strong northwest winds, etc. Under adverse weather conditions, delays at Logan increased by approximately 7% and the capacity decreased to approximately 78 to 88 operations per hour. The unfavourable weather conditions also resulted in the use of runway configurations which had less than three operational runways. If the northwest winds were severe, only one runway was operational, which caused a further decrease in operations to 40 to 60 operations per hour.
Poor weather conditions also required an increase in separation distances between aircrafts, which further added on to the delays. This was especially a problem for Logan due to their mix of airplanes as 40% of the runway use was by small, non-jet airplanes which had capacities ranging from 9 to 34 passengers. These airplanes flew more slowly and required an even greater distance from larger airplanes. At Logan, if the demand for the runway use came close to capacity, (even under good weather conditions) it resulted in delays. This means overscheduling was another potential problem, even though it had not been a problem for Logan in the past. From 2000 to 2015, there is an estimated increase in annual passengers from 12.4 million to 37.5 million, thus if overscheduling remains prominent at Logan, it could cause even more delays. Boston’s geographical location as the far northern coastal city also resulted in slight delays at Logan. For approximately 90% of passengers, Logan was the point of origination or termination rather than a point of transition to another destination. This meant that flights tended to arrive and depart more uniformly over each hour, rather than in clusters like at transitional hubs. Thus there was very little slack time in the system making it harder to recover from delays.
COSTS AND CONSEQUENCES OF DELAYS
Delays tend to