Plane spotting at Heathrow

[sirwa69]

I have a 9 hour transit in LHR on Thursday and I thought I could keep young master Sirwa amused for a couple of hours watching the planes.
Can someone please let me know if it is still possible to watch from the top of the Queens building or if there is a better spot?

Thanks

[trident3A]

There's been a few threads on this, see this one for starters:
http://www.pprune.org/spectators-balcony-spotters-corner/382608-heathrow-viewing-area.html#post5083767