S Atlantic Airfields
Further to my above, several years later and after I had transferred my immediate allegiance, we were contacted at Filton by a consultant for the FCO. His brief was to investigate establishing a tourist industry in FI, St Helena and Tristan da Cunha (bird watching being the main/only attraction). For this you need an air service.
Travelling on the Tri*, he had read an article in the inflight magazine about A400M and wondered whether it could be used for TdC. Apparently there was one place they could build a runway 6000 ft long but it would have a cliff going up at one end and a cliff going down at the other. Volcanoes are not designed with runways in mind. The need was to replace the 4 - 6 monthly ship visits - they could only anchor off-shore and then were limited to individual items of no more than 10 tonnes.
Other snippets were that the nearest airfield was in South Africa, 1700 nms away, and even if they also built an airfield in St Helena that would also be 1700 nms away. Clearly it meant a 4 engine aircraft configured as a combi and really meant either C130, C17 or A400M (in civil variants) but none would be really realistic, probably having to carry round trip fuel not least in case of arriving overhead when the weather then prevented landing. With that in mind C130 could carry about 10 tonnes, A400M 20 and C17 about 30. I showed that A400M could theoretically land and take off at those weights and I guess C130 would, but I do not know about C17.
We exchanged 2 or 3 letters before he went away - I never found out whether he was happy with the results or not - I certainly would not want to run any guaranteed air service on the basis of what I had found out and calculated.