A few last minute London questions

Please don't call it the tube blue line. No one will know what you are talking about. It's called the Piccadilly Line.

None of the tube lines go by their color. They are referred to by their name.--Piccadilly line, Central Line, District Line, etc.

1) Yes
2) Yes
3) Yes but I would book 2 hours before. I suspect that accurate timings are not necessary
4) There are no strikes planned and unions must give at least 14 days notice by law. If you're coming over Thanksgiving that limit will soon be reached
5) No idea
6) There is work planned on the Piccadilly line on the first two weekends in December but nothing that will affect services between Knightsbridge and Heathrow
7) I would not book the London Eye until you get here, if at all. There is no way that you can get an accurate weather forecast until at least 48 hours before. In any case there are other free viewpoints available if you like.
Following on from Frank's comment calling a line the blue line is very confusing - the Piccadilly line is dark blue and the one you want from Heathrow, but there is also the Victoria line, which is light blue.

Thank you both for your input. I suppose I'd better get to learning the proper names for the lines rather than the colors. :)

Correct re Eiffel Tower lights.

You don’t say when your trip is but be aware TfL are still having some Oyster card problems after a cyber attack that might not be resolved depending on when you arrive

https://www.theguardian.com/uk-news/2024/nov/04/tfl-reopens-some-oyster-card-applications-after-cyber-attack

I wasn't aware of the situation you mentioned Bill. I'll be in London from December 2-8 (it's a quick trip since my family can't be away long). From the article, it sounds like I'd better keep an eye on the issue, but hopefully it won't be a problem for me.

Re- the Half price Oyster. You buy a normal Oyster Card and then get a staff member on the gateline to add the Half price discount using the staff functions at a Ticket Machine.
It is called Young Visitor Discount and is valid for 14 days.

I want to be sure I understand when/how to book security time slots for leaving Heathrow. If my flight leaves at 11am, for instance, I would normally try to be at the airport by 8am. Is that the time I want to book the security passes? The site makes it look like I'd put in 11am, but that can't be right since that's when the flight is leaving. Does that make sense?

Johnew52, is there a reason you recommend 2 hours before rather than 3? I've only flown out of Heathrow once and don't remember security being terribly long, but that was years ago. Reserving time slots is a good idea, isn't it?

I'd rather be too early over being too late. Thank you!

The 2 hours I stated was based on you getting to the airport 3 hours before but needing to check in and drop bags, where there may well be a queue at that time of day. If you are not checking bags then maybe a bit earlier.

In any event, I am sure that you don't need to give an exact time. I would still say book for 9am.

Ah, that makes sense, thank you!

I was in London early November. No issues with using Oyster card on November 6th or November 14th

2) It's my understanding that an 8 year old does not have to pay for tube/buses, because they go through with an adult but an 11 year old does. I believe we can get a half price oyster card at the airport for this age. Is that correct? The adults will tap phones or credit cards in and out when using tube/bus.

When you travel with the 8 year old, look for the accessible gate (the wider one with a wheelchair/luggage symbol). This gate stays open longer after tapping your card which allows both you and your child to get through.

6) I have a note from several months ago that there will be work on the tube blue line in early December, so when returning to the airport I'll need to take a different line, but I can't find specifics now. Can anyone confirm this information or tell me where I can verify it?

You can check upcoming planned maintenance work for the tube here:
https://tfl.gov.uk/status-updates/major-works-and-events?intcmp=25505