It should be N5050.03 W00017.57 not E00017.57
The perils of living astride the Greenwich Meridian.
A harmless mistake when entered on a bulletin board, but nearly catastrophic when a E instead of a W was entered into the FMC of a 737 at Heathrow. This 34 nm error caused a complete loss of primary attitude and navigational information. A major disaster was narrowly averted by ATC assisting the crew to return to Heathrow. The report makes very interesting reading
http://www.aaib.gov.uk/sites/aaib/cm...KA%2006-08.pdf
Edited to add that the thing that amazes me most about this incident is the crew noticed the failure immediately after takeoff, but continued their climb into the 1500' cloudbase, instead of remaining VMC and declaring an emergency.