Is a 1 hour layover in Amsterdam sufficient?

If this is a single ticket, and the airline is willing to sell it to you with that connection, then any financial risk is theirs. If your transAtlantic flight gets in late, or the airport is crowded, then they will have to put you on their next flight. If your luggage doesn't make the connection, then they will have to compensate you for that somehow. So if you don't mind waiting a bit in Schiphol for the next flight, and waiting a day or two for lost luggage to catch up to you, that's your only risk. I'd probably be willing to take it.

If this is two independent tickets, DON'T DO IT. All the advice in the other answers about the chance of missing the second flight is true, and you would have to pay anything up to a whole new ticket to get yourself to Geneva.

1 hour between connection flights is strongly NOT recommended for many reasons--you can not make sure the first flight will arrive in time, even if it does there are issues could arise from the airport itself.

Assuming your luggage arrives on time and you know Schiphol airport very well and you will directly go from the arrival gate to the departure gate, There are many factors that can cause a late arrival and most of these are out of your hands, some of these reasons would be:

• Late departure. If you depart late, you will arrive late!
• Weather. The best weather analyst still can not predict the weather!
• Air traffic jams. In the busy airports (such as Amsterdam) this is common when pilots are asked to hold position due to jammed skies.
• Airport Gates. Any delay or technical problem in any airplane parked at a gate will cause a chain delays for some time for all airplanes scheduled for that gate.

My advice is to make a better booking even if it will cost more but it will save you from more headache. Unless your both flights are operated by the same airlines/alliance and in one booking then if something happens and you lost your connection flight then its the airlines problem and they will provide accommodation until they provide you with another flight to your final destination.

Amsterdam Schiphol is one of the busiest airports in Europe, and long queues in front of security checks are not unusual -- once I waited around 30 minutes just to get through passport control. Granted, it was a major holiday, but still something to consider.

Apart from that, the airport is quite efficient -- there is only one terminal, and everything is laid out around it. One hour should be enough bar unusual circumstances. For this early hour, I won't be concerned at all. See the airport map with walking distances -- you should be able to go from one end to the other in 20-25 minutes or so.

If you arrive from a Schengen country then you won't be even be subjected to additional security check when you transfer at Amsterdam.

One more thing to consider: KLM managed to delay my baggage 2 out of 3 times I flew through Amsterdam, and all of these were with layovers of similar length as yours. They do have a nice return policy and sent me some vouchers for the inconvenience.

If you have a single ticket, then the airline is liable if you miss your flight/something happens to your luggage. It's not ideal, but I think it's a risk worth taking. From my experience of flying into Schiphol at 6am from across the Atlantic, I was out of the airport within 30 mins - no lines ANYWHERE, incredibly speedy customs (at that time of the morning). The airport isn't too large - you should be able to make it as long as you pay attention to the signs since as it will likely be deserted off staff at that early hour so no one to ask for directions in case you are lost. Good luck!

I did note last time that customs had express lanes for transit passengers, showing outbound flights which would leave soon. If your inbound flight is late, chances are that your outbound flight will be listed there so you can skip the queue.

(Normally 50 minutes should be sufficient)

I personally think that at this early time you should make it. Because Geneva is in Schengen area, you should not be subject to passport control (assuming you are flying from another Shengen country), there is only one terminal so you don't need to change terminals.

For these short layover staff often waits in front of the first plane to help you get to the second place. And even if you miss it, they will rebook you for free.

Having said that, from personal experience, there is really big chance that your luggage is not going to make it. Last time I changed in Amsterdam they lost it both ways, and I was told it happens often if the layover is less than two hours.

I've transited through AMS in the morning (this is usually when the international rush hour starts).

1 hour is very tight, the problem is that even if you were to leave and arrive on time, there are lots of other flights arriving at this window (due to noise abatement and other restrictions, there are very limited number of landing slots available to airlines from 2200-0600, thus the morning rush hour starts from 6 AM); and so the queue to pass immigration for intra-schengen flights can get very long easily taking up the majority of that one hour.

However, AMS staff is very helpful and will move you to a priority lane if you are at risk of missing your flight due to the queue length. Keep and eye and ear out for your flight being called.

The next problem is the weather especially fog. In the winter this can be a problem and cause a chain reaction of delays; so that even if you are at your gate on time, the incoming aircraft is delayed. Not really an issue if you are at your final leg - after all, eventually you'll end up in Geneva the only issue is you'll arrive later.

The problem comes that now the airport is very crowded with people who have missed their connection so everything becomes an issue - finding a place to sit, for example. The bathroom queue. Trying to get a snack will be an issue unless you like to stand and eat.