In just one week (April 29), a new Dept. of Transportation (DOT) rule takes effect, that limits the time people have to sit on a plane – on the tarmac – to just 3-hours.

As soon as word of the rule was first made public, there was an immediate crush of carriers requesting that the rule be waived in some of their cases. Well, now we know the answer to those requests:

No.

As activist Transportation Secretary Ray LaHood put it, “Passengers on flights delayed on the tarmac have a right to know they will not be held aboard a plane indefinitely. This is an important consumer protection, and we believe it should take effect as planned.”

As noted, earlier this year, JetBlue, Delta, American and other sought waivers and/or exemptions to the rule because of various situations at airports they fly to - especially at JFK because its main runway is under construction. The carriers said, without those exemptions, they’d have to cancel flights to avoid breaking the rule (and frankly, to avoid the hefty fines – $27,500 per passenger).

But the DOT says, airlines can minimize delays by rerouting and/or rescheduling flights.

Ball’s in your court, airlines.