Time Constraints: Arriving by plane, leaving by train

I doubt it. Remember that you have to check in for the Eurostar 30 minutes before any departure.

You also can't be sure that your plane from the U.S. will arrive on time.

London experts can speak more specifically, but I wouldn't try something as close as that.

Since you are already at the airport, I would fly to Paris, but if you want to take the chunnel train, are you sure you need a private car? The Picadilly line will take you direct From Heathrow to Kings Cross/St Pancras in about an hour at a fraction of the price and you won't have to worry about car traffic. Since your train ticket is only valid for a specific departure, I would feel more comfortable with a four hour buffer.

My advice is fly to Paris on a connecting flight, doing what you propose is fraught with risks, which could cost you a lot of money.

No one knows what time your flight will arrive, but let's assume it arrives on time I would prefer 4 hours. Just take the Tube all the way to Kings Cross and relax at St Pancras.

Three hours does not give you enough of a buffer. If you really don't want to fly on to Paris (the simplest option), I'd spend the night in London and take an early train to Paris the next day. That way you don't have to worry about late flights, traffic, etc. You could get a room at a hotel very close to the St. Pancras station, have some time to walk around/stretch our legs, eat supper and get a good night's rest. As others have indicated, you MUST check in at least 30 min. prior to your Eurostar train's departure (the security there is very much like that at an airport- so it may take more than 30 min.).

Just to add, that due to more stringent security measures, it is advised to check in for the Eurostar one hour before departure time, not 30 minutes, which means for the 18:30 train you should be there by 17:30 and your flight is scheduled to arrive at 15:30. You will never make it in 2 hours. Never. I would want at least 4 and would be happier with 5 hours from the time your plane lands to get to St Pancras for the train. The Heathrow Express would be safer than a private transfer, too, in case of traffic problems. Yes, a long day but an exciting one.

I would never expect to be leaving the airport in less than 90 minutes from touchdown, often 2 hours.

An hour check in at Eurostar.

You'll be fine, as long as you can apparate.

" apparate" ? ?

well they can't use flue powder, can they? No fireplaces at either end.

Nigel, a perfect solution, as aparation will of course mean you arrive a King's Cross platform 9¾, which as everybody knows is just across the road from St. Pancras Eurostar entrance.

Norma, read your Harry Potter.

bruinpi, I agree with everybody else, get a direct flight to Paris, a lot simpler. And clearing customs is the one thing that doesn't take any time, it is all the rest: plane late (could be +/-1 hour), taxiing, getting off the plane, walking through corridors, immigration (1 hour not unusual), getting out of the airport. And at 15:30, a car to St Pancras is likely to be the slowest option, slower than the train.

I am the sole person on this planet who knows nothing about Harry Potter, except what I glean from doing crossword puzzles.

Love the Harry Potter references. Time to read again???

Of course since I didn't pass my O.W.L.S., I don't think I'd be very successful in "apparating" and would probably end up splinching myself in some way, shape or form :)

Brilliant work Nigel!!!!

I want to thank everyone for their input and suggestions. I (meaning my wife and I) have decided to relax upon our arrival and just check into a room for the night before heading out the next morning via train to Paris and then onto Bayeux.

Now I hafta find a room in London near the train stations :)

Thanks everyone!!!!

Last Spring we used Hotel California - interesting place with tiny rooms but within a block of Kings Cross. The lines to checkin for the Eurostar can be very long. We need about an hour and a half to get through check in and security.