Connecting flight Amsterdam to Vienna

KLM has another flight at 11:45 am they can put you on if you miss the 6:50 am you are on now due to flight delays. You can ask for priority immigration check if your flight is leaving in the next 30 minutes.

It is ---- IF -- your plane is on time. A couple of years ago we had an equally short time and missed by about two minutes. Our plane was about twenty minutes late to the gate and we made the mistake of sitting in the far back corner of the plane so it was another 20 minutes or more before we got off the plane. We were re-booked on another flight but it was a couple of hours later. A bit inconvenient but only slightly inconvenient. There are special lanes for people with short connection so don't be afraid to use them. Our hang up was the security line after we had cleared immigration. (You will clear customs in Vienna.) While it was a short line it still took 10 to 20 mins to go through carry-on xray check, body scans, etc. It would be best if you could sit near the exit door on the plane to reduce exit time..

Your flight is the first one that comes up on the Delta website with the 55 minute layover. You may breeze through or you may be delayed. Consider asking the flight crew if it can be arranged for you to exit off the plane early. Find out where your departing gate for Vienna in advance.
Schipohl has an excellent website for all flight details.

To explicitly answer one of your questions, if you have your bag checked through to Vienna on a single "ticket" with two segments from Delta (even if another airline operates the second flight) you will not see, handle, or inspect your bag in Amsterdam. You will exit in Vienna through the (presumably) "Green" nothing to declare line, unless you have something to declare.

Do your best to induce Delta to give you both boarding passes in Atlanta. It may happen without asking.

Thank you all for your suggestions.