Most informative post Bloggs.
Given the witting or unwitting leak of information in the article (crew duty hours), the commercial limitations of the LHR-PER and the requirements for a very close alternative become clear.
YPPH YCUN 67 nm
YPPH YBLN 109 nm
YPPH YGEL 199 nm
YPPH YPKG 291 nm
Distance range rings from the various aerodromes intersecting at PER.
Source:
Great Circle Mapper