In article , B25flyer
wrote:

Everyone might be surprised at what shows up next fire season. Rumor has it
that a 747 program is in the works as a retardent bomber. Seems that a certain
company, with some older 747s, based in a smaller town in Oregon is looking
into making it happen.

747 and DC10 are interesting 'lab' projects, but I doubt if they would
be efficient. From what I understand about fire bombing, you have to
get down on top it and release. Some of the worst turbulence
imaginable.
I doubt the airliner's design was speced for that many constant g's.
Also, their minimum speed would be too high and maneuverability is too
limited.