Originally Posted by
Miken100
One curiosity for me that hasn't been discussed is that 20 mins into the flight would mean they were well enroute (assuming the OP meant 20mins from t/o) and with the compromise to safety being speculated why they didn't go to East Midlands or Manchester - would that not have been a quicker way to get on the ground than returning to LHR? This suggests to me that whilst the crew were concerned it wasn't a critical/'Mayday' incident....
To be honest, from that sort of position it would probably take 20 minutes to land at any of the airports that you mention, due to the time required to prepare for the approach and physically fly it. Going back to LHR may not have been quicker but as they had just departed from there (and were therefore familiar with the conditions etc) as well as obviously being familiar with LHR approaches/Missed Approach Procedures, then as a "known" quantity it's a safer bet overall.