Underground stations at Heathrow?

Travel Info
I can't seem to find accurate info on the official Underground website, or the Heathrow airport website, so thought maybe people living in London might help me.

I'll be flying in to London in June, arriving at Terminal 4 of Heathrow airport. Is the Underground station there operational? I thought it was closed for work on the new terminal, but was reopened last September. However, if I check the official websites looking for the easiest tube route to my hotel, the underground station at Terminal 4 is never an option. So, is it operational? Can I take the Picadilly Line directly from Terminal 4 or not?

Thanks!

Travel Tips

I haven't ridden out there recently, but I am fairly certain it is indeed open. If it is operational, then you can take the Underground directly from there.

The last time I was at Heathrow the terminal 4 Underground was closed, so I can tell you what you will have to do if for some reason it is closed. There will be buses operating free of charge from terminal 4 to Hatton Cross, the nearest tube station to Heathrow. You can pick up the Picadilly line there. So either way, you shouldn't have a problem getting to your hotel.
Others

Hi There

I was in London late year just before work was finished on the Terminal 4. By the time my holiday had ended (October 2006) it was all done and it was fully operational. Unless they are doing more work it should be fully operational and yes you can take the tube from terminal 4 on the piccidilly line to wherever u need to go.
Thats exactly what I did. The only thing that was different is that I had to take a bus from the aiport to the next closest tube stop due to the work going on at Terminal 4. But like I said it should be all fine and dandy now.

If terminal 4 was still ongoing with construction etc it would say on the official web site as it was on there last year before I flew out.

I hope that helps ;)