Originally when the current analysis was performed it was assumed that Delta's unusually high Pilot to Aircraft ratio was a result of higher aircraft usage and a larger percent of extended range flying compared to peer airlines. However, as the site has looked into this further, it is possible that Delta may be overstaffed.
Comparing Delta to other competitors such as United and American supports the possibility of their overstaffed condition. American has a Pilot to Aircraft Ratio of 13.9 with 37.3% of their fleet possibly needing extended range crews and United has a ratio of 15.6 with 43.8% of their fleet possibly needing extended range crews. In comparison Delta currently has a ratio of 16.1 with 45.1% of their fleet possibly needing extended range crews.
One of the factors that can change how these percentages effect Pilot/Aircraft Ratio's are the number of aircraft that require full relief crews verse aircraft that require only a relief pilot. Out of the percentages United actually has the highest with 98 aircraft (Boeing 747 and 777) that would likely need full relief crews compared to Delta's 34(Boeing 747 and 777). Interestingly, if you include the Airbus's and 767 400's that could possibly need full crews (16 additional for United and 54 additional for Delta) it closes the gap some. It is still more likely the 747's and 777 would need full replacement crews than the 767 400 and Airbus A330. This produced the reasoning to assume 15 pilots per aircraft was a more efficient staffing level. When compared to 16.1 this may not seem like much but when run through the numbers it has a large effect on hiring.
The following link shows the numbers that reflect the Delta Airline Pilot hiring Demand with the assumption that 15 pilots per aircraft is standard. To do this the numbers were computed in the websites model by adjusting Delta's total number of Pilots to "Needed Pilots" and showing the remaining 846 as excess that would be worked through as Delta pulled on the 717's, which explains why the charts start in the negative. The best way to use the chart is to see when with this new ratio Delta has to pull off the street verse increasing their own efficiency with the pilots they currently have. To Delta's managements credit, if this is analysis is correct, they have not furloughed any pilots but may be opting to gradually increase efficiency.
Originally this idea that Delta might be overstaffed was dismissed due to them hiring off the street a significant amount just in the last two years, back when their staffing looked much the same as it does now. One possible hypothesis could be tied to needed pilots to fill the training gap, as pilots played musical chairs during the final transition in the merge. The training gap reflects the number of pilots needed to make up for the large number of pilots spending time in the Training Center as the Domino effect of pilot transfers played out. However, with most of the growth in Delta's short term future occurring at the bottom of the Seniority List due to the introduction of the 717 there won't be the amount of musical chairs occurring as we might have seen with senior pilots retiring.