Heathrow Terminal 5

T5 seems to have been somewhat less affected by airport staffing issues, possibly because it remained in use throughout as airlines were moved in, although bag handling is slower. Of course as always anything can happen on any given day.

They may not have the staffing issues as much as other terminals, but it’s still large with a lot of people going through. I was there in the 15th and checking a bag wasn’t terrible, but I was three hours before a 2pm flight. Then the security people told us to move from one security line to the other to deal with crowding, which meant a walk to the other side of the terminal. Not too bad but it was still busy and took time. And when going from the main terminal to the outer gates, a tram is a available but wasn’t working so everyone had to walk. They only posted the gates about an hour before the flight, so with an international flight, there isn’t a ton of time to get out there before boarding. Staff acknowledged the issue for people trying to get to the plane but plan accordingly and take the three hour rule seriously. If you want time to shop, allow for more time.

We got there at least 3 hours early. Took a long time at security. Not as long to check in the luggage. No gate notification for awhile. Got the gate notification and had to get on the tram. It sat there for awhile and people started getting off because it did not move. Then it came to life and people started running to get back on it. Then long walk the gate. Got there maybe 20 minutes before scheduled departure. Then we had an hour delay.

I went through T5 today. I wrote a report on the thread you mention.

Get there early. The security lines were a nightmare. I had Fast Track security and it took over a half hour. Try to get your boarding pass before you get to the airport or that's another line you have to stand in. The same for checked luggage.

I only had carry on bags, had my boarding pass before I got to the airport an had access to Fast Track security. It still too over 45 minutes to get through.

If you think security is bad in T5 you haven't experienced it in T3 where the queue starts outside the building much of the time.

Here is the thread in which Frank wrote his detailed experience about departing out of T5 (the thread mentioned in the OP's original post) - keep scrolling to 6/29 to find Frank's recent post

https://community.ricksteves.com/travel-forum/england/heathrow-was-abominable

Lots of factors as to why queues may or may not be long. In general for long haul flights the advice is to arrive at the airport three hours before your flight. This is to allow for check-in, dropping any luggage, and security. Anything you can do before your flight to make things easier (like getting boarding pass, etc) is always a help.

I will tell you one stupid thing they were doing at T5 security.

After putting your bags, liquids, electornics, coats, belts, stuff in pockets, etc. into bins we had to line up to go through the metal detector. The older women in front of me kept setting off the machine. So the security guy told her to take off her belt and shoes and put them through the machine. She doesn't understand but finally gets it. She sees a chair and sits down to tke of her shoes. No, she has to go out and put the stuff in a bin. She goes back out and starts talking to her husband about all of this. Meanwhile, the security guy wouldn't let anyone else walk through the machine until she was back. I'm not exaggerating....he waited five minutes before anyone could walk through the machine. By that time, there was a line of people waiting and it backed up enough so no one could put their stuff in the bins. Ridiculous.

For anyone else who might be as remotely paranoid as I was about this, I wanted to report back that we just cleared security at terminal 5 after arriving at the airport WAY too early - had to wait an hour for the bag drop to open up but once it did we got boarding passes, checked our bags, and cleared a rapidly moving security line in less than 20 minutes. Honestly, it was no big deal - a very efficient process from start to finish.