If I arrive at Heathrow 9:00 can I make it to Gatwick in time for a noon departure ?
I have never been around London and want to know if it is possible.
thanks

If you search above there have been a lot of threads on this with a multitude of answers from people much more expert than I.

I think where most of them would come out is - it depends on:

If your incoming flight is on time (you can check on past records of this) - if it's late you're in big trouble

Time of day/day of week - will affect your transit time to Gatwick

Maybe - a big maybe!

You will be walking out the front door of Heathrow just about the moment you should be walking in the front door of Gatwick.

I wouldn't try it with non-changeable/refundable tickets.

It's certainly possible but it's not a connection I'd willingly pick if I had another option.

Four hours between flights is the minimum time I'm comfortable with for a Xfer from Heathrow to Gatwick. That's almost always more than enough time but on more than a couple of occasions it's been a very close call, within 15 minutes of not boarding.

British Airways says on their website that 3 hours is the minimum connection time. I'd try that IF the flights were both BA and booked together (that way, if you miss the Gatwick flight, the airline must assist you).