Visiting Windsor and Windsor Castle

Heathrow can be very unpredictable, I have had times when getting to the gate was quick and times where the security line alone was a couple of hours. My advice, check online to make sure Windsor Castle is even open--when we were there in 2013 (and we went a little out of our way) it was closed for a state visit. My fault for not checking!

I was in Windsor just afew wks ago. The line for entry is very long for those without prepurchase tix. We were able to buy ours at Heathrow, so it worked well for us. If u prefer not to chance it, just walk around Windsor and to Eton College just down the hill. There are parks and the thames at Windsor thT is nice just to see and enjoy with perhaps a riverside cafe and beverage. Perhaps it is best to decide once u arrive in Heathrow if u have time for W. Castle. Yes it is beautiful but to see it casually would take 1.5 hrs without any wait lines.

How have you reached your timings? They appear to be very tight and take no account of potential delays. How are you intending to travel to and from Windsor Castle? What terminal are you flying from? How long have you factored for immigration? Have you accounted for traffic? What about the security lines when returning to Heathrow? Have you considered how far your departure gate is from security? Will you need to walk a distance or even take the shuttle?

Your landing may be scheduled to land at 13:20 however the flight might be delayed or there may be significant taxiing time to the stand or even having to get a bus to the terminal which could add 30+ minutes. Then there's the walk to immigration and then immigration itself which probably would take an hour or more. Realistically you're unlikely to be leaving Heathrow until after 15:00 and factoring in getting a taxi, dealing with Heathrow traffic and potentially the horrendous M25 (if the driver opts for that route) then there is every likelihood that you'll miss the last entrance time.

For me your timings are far too concise and optimistic. Personally I like to add an hours buffer to the recommended airport times to cover potential delays and unforeseen events, it makes for far less stressful travel. If it was me, I'd be staying in the airport. If you don't have lounge access I would recommend buying it and just while away those few intervening hours taking advantage of the food and alcohol whilst reading, browsing the internet etc.

I've travelled through Heathrow twice in the last few weeks as a transfer passenger. One time was extremely smooth, the other was not. I don't think you can count on your timings working.

My experience: Flight from US to Heathrow was on time, but were placed in a landing pattern that circled for about an extra 25 minutes until we were allowed to land. We landed at a bus gate. That meant we walked down stairs from the plane to waiting buses. These took about another 5 minutes to drive us to the terminal. Another 5 minute walk until we got to a decision point " arrivals or transfers". We took transfers and waited in a line for immigration. ( 30 minutes) Then, it was time to go through security again (30 minutes). Then you have to figure out where your next flight is leaving and get to that location.

That was how long it takes when everything goes well. Add a delayed flight, many flights arriving at once or??? It isn't that your plan isn't doable on paper, but it simply may not be doable in reality.

Hello, I go to London pretty regularly and have almost always experienced delays getting thru immigration, etc.

I would also consider traffic delays between 3-6 pm.

I truly understand the "wanting" of going to Windsor, but you might be cutting it too close on your timing. Security to get back can take 45 - 90 minutes. Good luck.