This time we're making arguments in court, rather than on top of a plane.
Just over a year ago, at the start of 2009, transport secretary Geoff Hoon gave the government's approval for a third runway at Heathrow airport. It would be accompanied, he said, by "the toughest climate change regime for aviation of any country in the world".
Cleaner planes, tougher regulation, green slots for takeoff and landing - the secretary of state was keen to broadcast the runway's green credentials. But it didn't make a lot of sense to me then - and it still doesn't.
Anyway, I'll get to spend a whole lot more time thinking about it this week, because tomorrow I'm off to court to report on a legal challenge to the controversial third runway decision.
Greenpeace is part of a coalition mounting a legal challenge to the government's Heathrow decision. Twelve other groups are also backing the challenge, including local councils, other NGOs, residents' groups - altogether, millions of people are represented.
In front of Lord Justice Carnwath, our lawyers will claim that the consultation the government held over the plans for Heathrow expansion was fundamentally flawed. They'll argue that the decision to expand Heathrow is at odds with the UK's overall climate change targets, and they'll also contend that the government hasn't made good enough plans to ensure there's enough public transport to serve an expanded airport.
It's a trio of challenges to the way the decision was made - and if the ruling goes in our favour on any one of the three points, the government's decision to proceed with the runway will be overturned, which is obviously going to lead to a pretty major rethink in transport policy.
We'll see what happens, but it's sure to be a comprehensive thrashing-through for the issues around the third runway, and I'm lucky enough to get to sit through the whole thing, in order to report back to you all.
Wish me luck... (And look out for updates from the court, or just outside the court, through the week.)