Lost my dad to Alzheimer's last year. We never went anywhere by air in his last 5 years (partly due to the difficulty of traveling, and partly due directly to the TSA - both he and my mother were disgusted at what the agency was doing and what America had become - she still won't fly to this day).

Based on my experiences - and every case of Alzheimer's is different - it will depend on how far the disease has progressed. In the early stages he was forgetful, but still knew his name. He carried his retired military ID card *everywhere*, so establishing identity was a non-issue. A chat-down might have been problematic. Likewise, having a screener yell at him or order him around might have been problematic.

In the later stages, it would have been a real problem - to the point that he'd get angry and frustrated when he couldn't remember things. The risk of anger, resulting in headlines - either at the checkpoint or on a plane - was enough for us to not even want to travel by air. Period.

My advice, for what it's worth, is to determine the level of cognitive ability and judge whether travel is even advised. If it is, you will be far better off if an escort can travel with her (to explain the process, make sure she gets on the right flight, reassure her in unfamiliar surroundings, and to deal with any airline or TSA issues that might arise). If she displays anger or frustration it's entirely possible that you may run across a full-of-himself screener like the one at IAD that told a passenger (who was rightfully frustrated with checkpoint delays and arbitrary decisions) that "he would not be permitted through the checkpoint unless he were in a good mood".