What airlines are we talking about?
By next year there will be very few, if any L1011s or DC10s in any of the majors' fleets. As Ceilidh said, it's more of the airline's maintenance procedures and standards then anything else.
As you've seen, the L1011 is a favorite among the forum members here. However, it's a well-known that Delta's maintenance of the L1011 lately has not been as good as it was a few years ago since Delta doesn't want to put major time or effort into machines that will be retired in the next few months. I don't know how ATA takes care of their birds, however.
There have been some well-publicized events recently about the DC-10 in the hands of AA, UA, and CO. All are getting rid of them within the next year or so.