Would be nice if the media could get the story right for once. Personally I think USFS is feeding some of this wrong info, to make tanker contracts more politically palatable.
They were never grounded, no more than AWAC is grounded when UAL cancels its contracts. The tankers can legally fly, there is just no customer, and USFS has actually threated states with reduction in firefighting funding if the states contracted tankers themselves.
There was a news story last week about how the tanker contracts were cancelled last year after inspections found problems. That was very possibly something USFS told them, although its not the case at all. The tankers were cancelled after they were inspected and crews carded. Then USFS said they would very possibly bring them back if Dyncorp looked at them all and approved them, which of course USFS did not after Dyncorp gave its approval.
The airtankers which are the best structurally, are the ones USFS will not bring back on. I think USFS has gotten out of the firefighting business, and its more concerned with media stories, and putting on a good appearance of firefighting efforts.