The nearest alternate for HLE is ASI, 700nm. ERJ 190's can do CPT HLE with ASI as an alternate with about 100 passengers. It doesn't need to make a fuel stop. Even an extended range Avro RJ100 needs to make a fuel stop at Walvis Bay on a CPT HLE route and even then can't carry it's full 100 passengers. It's probably not cost effective to make a stop inbound to St. Helena to increase cargo payload. Any inbound air freight is likely to be light. There is a contract for a once a month maritime cargo ship to supply HLE. The flight from HLE to CPT in the ERJ 190 could carry several 1000 lbs. of cargo as the reserve full requirement is not as great.
Last edited by lolder; 9th Dec 2016 at 13:43.