Hello all.
I've made a foolhardy mistake of booking separate tickets to "connect" at Heathrow. The question is: can I make my flight?
1. Flying into Heathrow Terminal 3 on Saturday with arrival time of 8:20 AM.
2. Flying out of Terminal 3 at 12 PM.
3. Again, separately purchased tickets.
4. Hand baggage only

Will I likely make my flight? Also, if I am not reclaiming baggage can I just stay "airside" because it's the same terminal?

If your incoming flight is on time or not too much later, you'll easily make it. If you haven't stepped off the plane by 10:20 you have to start to hustle, and by 11Am you have cause for worry but can still make it. Good luck.

You will have to go through security (Everyone connecting at LHR has to go through security even if they stay airside) but if your flight is on time you will be fine.

If your incoming flight is delayed all bets are off.

Okay. But I do not have to go out (customs, passport control) and come back into the "airside", correct? I can just follow the connections signs and go thru security and be on my way?

Go to the LHR website (http://www.heathrow.com/) and click on the "Connections" link on the left hand side of the Home Page - enter you inbound and out bound flight data and you get step by step instructions and time estimates for making that connection. Answers to all your questions can be found there.

Will you have a boarding pass in hand for the second flight? What airlines are involved?

Yes I plan on checking in online and having a boarding pass in hand. Flying in British Airways and flying out Virgin Atlantic. Wanted to know if I was allowed to go through connections even though technically these are separate tickets and not one itinerary?

If you have your boarding pass for your connecting flight it makes no difference if you have separate tickets or booked as one ticket. Connecting is the same.

Just happened to me - my hopes for staying in the secure area while connecting were dashed...

Unlike other airports (LAX for example), Heathrow lets you stay "airside" in what used to be called "Transit" as far as passports are concerned - you don't have to confront an immigration official while "connecting".

But just when you think you're also staying "airside" as far as security goes, you are funneled to the connecting terminal to a spot where people join who are coming from the outside, and you have to go through the (TSA-style) security checks again. So empty your pockets while you're being funneled...

Just double check you do arrive at T-3. Some BA flights do use T-3 but the majority use T-5.

>>But I do not have to go out (customs, passport control) and come back into the "airside", correct?<<

Correct -- but security can take quite a while unless you have priority.

So there really are no benefits to staying "airside" at heathrow. Oh blimey.

To get specific the flights are BA 853 and VS 21. As far as my research goes they are both at terminal 3.

>>So there really are no benefits to staying "airside" at heathrow. Oh blimey.<<

Yes -- a huge benefit. You'll avoid the sometimes VERY long immigration queues. (Customs is a non-issue)

Immigration queues are absolutely no joke and can seriously mess up connecting flights if the incoming one is late. My rule with air travel, until you are waiting to board, hustle up and don't look back. Best of luck on your trip!

You can easily make that flight, should not be an issue I think...