Originally Posted by zan5hin

Mileage Monkey gives it the green light, but the oneworld itinerary planner hates the fact I'm not ending in JNB and going through Europe:
JNB-xLHR-LAX-JFK-DFW-YVR-MEX-MIA-JFK-HKG-DEL-NRT-PEK-HKG-AMS//CAI-MAD-HEL-BUD-xLHR-NBO

Originally Posted by Gardyloo

No, not valid. Two entries into Europe. South Africa is not one of the countries that allows a "free" London transit.

Originally Posted by pandaperth

Garydloo is correct. The rules states:
..
<snip>
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So you can either:
enter Europe the first time from one of the listed countries and just transit to another continent - e.g. NBO-xLHR-LAX...
or
enter Euorpe the second time from another continent and transit to one of the listed African countries - e.g. HKG-xLHR-NBO
..
<snip>
..
The rule is that your are allowed to transit Europe, not that you are allowed to transit LHR....