1 hour 10 min layover in Frankfurt - Long enough? NEED OPINIONS

That is a short layover, but if Lufthansa allowed you to book this, and you miss the connection, I think they are responsible for getting you to Barcelona on some other flight.

If the flight to Barcelona is in the same terminal and you don't have to go through a slow security line, it should be OK. You won't have to go through immigration/customs until you get to Barcelona.

Correction. You are entering the Schengen zone in Frankfurt, and you will have to go through "immigration" (passport control). That should not take too long, they just look at your passport and stamp it - unless 300 Americans arrive at the same time. Then there could be a lengthy line. If your bags are checked through to Barcelona, you won't see them, or have to go through customs, until Spain.

A bigger concern is the possibility of arriving late. I've been on 8 trans-Atlantic flights in the last 10 years; three have been an hour late.

I would also say, it's a bit tight but definitely doable. If you are on one ticket, you are protected. LH has to put you on the next available flight if you miss your connection. I once made a 45 minutes connection in FRA which due to a delay was reduced to 30 minutes, and involved going through passport control Schengen to non-Schengen. I didn't run, just walked briskly! Still arrived while the plane was boarding with 10 minutes to spare.

You'll also have to go through at least one security check. We had to go through 2 last summer, with 2 kids in tow. We had a little less than an hour to make our connection, we made it, but just barely.

My own experience is that the flights going to Frankfurt from the US often arrive early. My last one arrived an hour early. Depends on the trade winds and what airport you are flying from.

My advice is to look at the Arrivals on the Frankfurt Airport website to see if your flight usually arrives on time or not each day over a period of time. See what the average is. Late, on time or early.

"Correction. You are entering the Schengen zone in Frankfurt, and you will have to go through "immigration" (passport control)."

You are right. I forgot it was Frankfurt. Last time I changed planes was at Heathrow, so there was no passport check because my destination was Athens, and the UK, although a member of the EU, is not in the Schengen Zone.