Be sure to have good HF and once on air be careful not to misrepresent LIMAL and LIMEL. LIMAL was formerly PLATY and is South of the Canaries whereas LIMEL is much further South twixt TITOR and AKDAK. But working the same HF, different native tongues…
Meantime visit
http://www.aidu.mod.uk for a good browse. Two useful strip ERCs are available, namely AT(H)ST1 and AT(H)ST2. Not only do these show ATS routes but also dotted tracks into and out of Ascension.
You can also buy from aidu on an ad hoc basis the CD disk UK Military Aeronautical Planning Document [Unclassified version]. This contains a set of statistical wind/temperature tables useful for the region and also many other parts of the world. Wind is tabulated at 50% significance but interpolation formulae are provided to translate these into 85% significance and other values, most people would go for 85% I guess.
There also used to be an excellent “Yellow Book” or Flight Information Publication, produced regularly by them, quite slim and with useful gems of information, not least being the HF Flightwatch operated by Serco on behalf of the RAF. You call them, they’ll respond, take your position and weather and let you know who is knocking about.
Besides the yellow book there is a thicker AIDU publication called SAAFE that covers the region specifically with all you need to know about aerodromes, facilities, frequencies, ASDAs etc .
I’d advise you that
http://www.ais-asecna.org particularly if you use UG853 in the vicinity of TITOR. where the directionality changes!
To get the mid-atlantic picture ring ASI ops (number in SAAFE) or ring Cable & Wireless on 00 247 6255. They can connect you.
Ascension AB will not take you no matter what you may have heard about agreements for civil traffic. Not only will the authorities imprison you but they’ll impound your aircraft. Just don’t think you can call an hour beforehand or wing it with a lame excuse. It’s a no-no-no.
GOOY the best of the African bunch. GCLP, GVAC civilised and helpful. FHAW very good on HF but no entry as described. SBFN spartan.
Enjoy.