3D scanners for hand luggage
 

I have a couple of questions about the new generation scanners:
1. These new scanners are supposed to facilitate screening of hand luggage People don't need to remove electronic devices or liquids. In some airports, the liquid limit has been removed. The new scanners seem to give a lot of false positives in the UK though. I haven't noticed the same issue in non-UK airports where the new scanners have already been installed. There are huge queues on additional luggage screening in the UK. In Edinburgh, once I was at the airport and noticed that like 2 out of 3 pieces of luggage were waiting for manual screening. There was a huge queue. In Rome, if you have a bottle of wine for example, the new scanner recognises the type of liquid, and the bag goes straight through. In the UK, it gets sent for additional screening. What's the point of having new scanners if you send any bag with a bottle of wine/beer etc for secondary screening? Anything seems to be flagged as suspicious.

2. When it comes to the new scanners, is there a person reviewing images and making a final decision whether to send something for secondary/additional screening (manual check)? This could explain why in the UK there are so many bags that undergo additional screening. It's probably about the instructions given.

I can't directly answer the questions, but I can make a similar observation at the Bremen airport in Germany, which seems to be where both new technology and new people get trained.
It's a good thing that it's a small airport and it's rarely very busy (I don't travel at the busiest times), because it has the slowest security checkpoint of any of the hundreds of airports I've experienced worldwide, and, yes, a high percentage of bags get kicked to the side by the machines for secondary screening. (And then there's the attitude of the security personnel).

[ Whereas, during the height of the early/mid-2000s air terrorism scares, Gatwick had at one point gone to a strict "one hand item per passenger going through security", no matter the airline and class, with the idea of being able to handle the traffic while spending more time looking at every item; this had _just_ been implemented, while I was on a three-week international business trip, so I had no warning, and arrived from Kyiv on my way back to Atlanta via Gatwick with definitely more than one item of hand baggage. I politely asked the security officer who was walking the long queue what to do; he directed me aside, handed me a rather large plastic trash bag, dropped my standard size roll-aboard and my notebook bag into the large plastic trash bag, handed it back, and said "Now you have just one item, sir". And the screeners did not blink an eye. { I don't recall now; I suppose I had already taken the notebook computer itself out for separate screening ... } ]