Well, thanks for all the responses. The reason I asked seemed logical to me, but you didn't have enough information so, of course, you wondered why the heck I wanted to know. Here's why:

We live five hours from DFW. We have to drive to Dallas and are going to check into a hotel in downtown Dallas (it's a long story) and then take a town car from downtown Dallas to DFW to pick M-i-L up. We had to give the car service her flight info, and since we're paying an hourly rate, we didn't want to have the town car just sitting there with the "meter" ticking, as it were. That's why we don't want to be too early. The reason we don't want to arrive too late is that she doesn't speak English (and is not from Germany, but a small town in Austria.)

The reason I asked if it was the same aircraft is that from my checking on aa.com, there is one nonstop filght to FRA and from FRA to DFW per day. I thought, perhaps, that American had built in extra time into their schedule, as they tend to do sometimes so that it might be possible, IF, and I say IF, AA 71 and AA70 were the same aircraft that might have meant that AA 71 would really arrive earlier than 2:30. (they same way that aa.com shows flights between AUS and DFW as 1 hour 5 minutes, when they usually take much less time depending on air traffic, weather conditions, etc. etc.) Now I know they are not the same aircraft thanks to your information.

But, thanks, again for all the help.