It was just last month that the Department of Transportation (DOT) said not to rush to judgment after seeing more cancellations and slightly fewer 3 hour delays in May. We needed more time, they said. Well apparently the DOT only thinks that’s the case if the numbers don’t 
help their cause. Now that June numbers are out, they’re jumping on them as proof of success. Slow down there, DOT. Your base level look at June numbers is way too superficial and smells simply of politics.
On the surface, things looked much better this year for long ground delays, and really, they were. There were three flights that sat on the runway for more than 3 hours during June 2010. In June 2009, that number was a whopping 278. This year, none sat for more than 4 hours. Last year, it was 42.
So did cancellations spike as a result? A little, but not much. Though the DOT would like you to think that both this year and last saw no change at 1.5 percent of flights canceled, that’s only thanks to rounding. In 2009, it was 1.48 percent. In 2010, it was 1.50 percent. So there was a very slight increase. In fact, three fewer flights were canceled this year but with 6,307 fewer flights operating.
Sounds like a tremendous success, right? Well, it’s good news for some, but it’s important to look at other factors year-over-year to see how we may have ended up in this place.
First, we have to remember that after last summer, the airlines did ramp up their efforts to reduce lengthy ground delays. So some of the reduction should be related to previous efforts and not simply the introduction of this rule. We’ll never know exactly what that is. But we can still dig in and see what happened last June. You’ll notice that the weather was significantly better, despite what many have said.
The Air Travel Consumer Report doesn’t give specifics on the flights that were delayed for three hours, but it does do it for the flights delayed more than 4 hours. So let’s focus on those. There were 42 of those, and most of them occurred during specific events. For example, 13 of them (11 at Dulles) happened in Washington on June 3, 2009. That’s the day that thunderstorms came and sat on top of Dulles from 8p to 10p.
So the weather was bad, but something had to be just as bad this year, right? Nope. In June, there were a couple days with quick passing storms, but the only day that saw sustained thunderstorms over a long period was June 28 when storms sat on Dulles from 145p to 3p, still a much shorter time period, especially when you’re looking at a 3 hour limit.
But the key is the time of day. I looked at flights scheduled on August 12, 2010 as a comparison. Not much should have changed between last year and this year. Between 145p and 3p, there are only 29 flights scheduled to arrive and 15 scheduled to depart. That’s an average of 23.2 arrivals per hour and 12 departures per hour during the time of the storm. Meanwhile, between 8p and 10p, 82 flights are scheduled to arrive and 32 scheduled to depart. Think about that, that’s 41 arrivals per hour or 16 departures. That’s a significant difference.
On top of that, the imbalance of arrivals to departures is huge at night. That’s because a lot of planes come in and stay the night before flying out in the morning. That means that the gates are full at night, so if planes don’t push back to depart on time, then arrivals have nowhere to go. That’s not usually the case during the day. And don’t underestimate the 2 hours of storms this year versus 1.25 hours last year. That’s a huge difference when 3 hours is your cutoff.
There were a couple other events we could look at in June 2009 as well, but I could paint a story for those too. I think the point is clear. Knowing that thunderstorms tend to be the biggest culprit for long ground delays during the summer, June was a luckier weather month in 2010 than it was in 2009.
That being said, even if we had the exact same weather this year, I would bet the performance would still have been better. Simply being more cognizant about the situation would have reduced the number of ground delays, but that’s going to have happened even if this rule didn’t exist.
The bottom line is that the DOT can’t have it both ways. If it wants to just use superficial results to advance its claim, go right ahead. But then don’t tell people who do more in-depth reviews that it’s too early to look at the results. This is a far more complicated issue than either the DOT or the pro-rule people want to admit.
