Originally Posted by scottishpoet

If your inbound is on time, or even slightly delayed, you will make the flight.

Personally, If this is on one ticket I would have no hesitation. however If this is separate tickets I would not risk the mis connect. This is not down to a fear fo the time window at LHR, more that if the inbound is more than 20 minutes late you would struggle to make the flight from T2.

You can use the airside but to transit from T5 to T2