everyone here seems to be assuming that if the three hour rule forces you to return to the gate you will not get where you are going for at least overnight and possibly several days. This just simply isn’t reality.

I *always* find that in IRROPS i get on the very next flight, or at worst the one after that. Sometimes my original flight goes out eventually but i get rebooked on a flight that gets there at the same time or even SOONER than my original flight would have if it had left and arrived on time. I realize my luck wont hold forever but I’m just illustrating that the scenarios assumed here are even LESS likely than my “luck”

on the flip side – if we are on the tarmac for over 3 hours we ARE GUARANTEED to be on the tarmac for over three hours. Personally I’d rather go back to the gate if it is ONE hour. I prefer breathable air, ability to get food/water, ability to find alternate mode of transport (or go home if flying out of my home city), ability to use a real restroom, charge my phone/laptop, or stretch my legs.

additionally arriving 4 hours late doesnt help me any more than cancelling the flight – its just more miserable. Chances are if its 4 hours late I will miss my connecting flight/meeting/wedding/training/conference/party/cruise ship or whatever I may be flying to. So i’d rather the flight get cancelled and go get a hot meal, a cold beer, and a bed to sleep in – assuming its the off chance that i dont get rebooked on the next flight out.

Well, they are in Europe, through somehow some airlines (eg Ryanair) flagrantly violate this.

Perhaps removing the “weather” loophole (and enforcing the regulation) would solve the cancellations problem: Itd be too expensive to cancel.

But I think this is a really helpful and useful measure. Thanks.

The question is, how many flights are being cancelled solely because of the rule? One indicator, as Cranky has shown, is to look at overall cancellation statistics. But that is only part of the picture, and as he admits, inconclusive.

It seems to me that a more effective way to look at this is to compare, month-to-month, the number of flights that left the gate, were delayed for, let’s say two hours or more, and how many of those were cancelled versus those that reached their destinations.

I’ll spare you the monthly data, and provide totals so that this doesn’t turn into an encyclopedia. The following stats are based on my own analysis of BTS data. I downloaded over ten million records of airline performance data to conduct this analysis. I have a fairly extensive track record with these statistics, and I’ve found that the BTS summaries are sometimes wrong, so I always use the raw data.

For the period from October 2008 through April 2009, the most complete data available, the total number of flights with a taxi-out or longest ground time greater than 119 minutes was 7,969.

FYI – Airlines report “longest ground time” when there’s a situation where a flight leaves a gate, returns and is cancelled or leaves a second time. BTS calls them multi-gate departures or operations, at least for the purpose of statistics.

Of those 7,969 flights, 555 were canceled, or 7%. You could conclude that the data show that even after two hours, a passenger had a 93% chance of getting to his or her destination unencumbered by overnight stays and other inconveniences, expenses, etc. On the other hand, 46 of those flights, not counting diversions, sat on the tarmac for a brain-splitting 5 hours or more, and that’s why we’re in this mess in the first place.

If you look at the same data for May 2010, 322 flights had taxi-out or multi-gate ground times of two hours or more. Fifty of those were canceled, or 15% – more than double the pre-rule average. But overall airline on-time performance was also down, so again, one month of data is not enough to draw conclusions one way or the other by proponents or opponents. Only time will tell. But this will be a better indicator, IMO, than trying to figure out how many overall cancellations were due to the rule versus otherwise.

May 2009 had 355 taxi-out or multi-gate ground times of two hours or more, 21 of which were canceled (6% compared to 15% in May 2010).

If you look at the historical data for three-hour taxi-outs and multi-gate ops, the picture is also interesting. For October 2008 through April 2010, there were 839 flights with taxi-out times of three hours or more, and 4 of those were canceled (.4%). During that same period, there were 305 multi-gate operations of 3 hours or more, and 165 of those were canceled. So 309/1143*=27%, meaning that even after three hours, on average passengers had a 73% chance of reaching their destination. Conversely, you also had a .5% chance of sitting on the tarmac for 5 hours or more (46/7969=.005).

* There was one unlucky flight of passengers that fell into both categories.

I could extend this out to 4 and 5 hours, but after that it seems counterproductive. I would hope that even Cranky would realize that there has to be a limit somewhere. The point is that this (above) seems to me to be a better method of measuring the effects and efficacy of the rule, versus looking at cancellations alone. It would be convenient if BTS would provide tables with this data on their website, because all that was a lot of work.

June and July of 2009 combined for a whopping 429 three-hour tarmac delays last year. It should be interesting.

I’m not arguing that this rule isn’t going to increase cancellations – it almost certainly is. But I think there are some confounding factors here. Additionally, it seems like it would be more relevant to compare the cancellation rates since the rule was enacted, rather than the beginning of the year.