Airports that do not have very good supply networks like smaller holidays islands; Madeira, Balierics, Caribbean Islands etc etc. Also, places like Toncontin in Honduras.Are those places able to supply fuel for aircraft returning to their bases, or must those aircraft carry sufficient for the return leg?

Might want to check here, where you can click on the countries and then the airports and it will tell you what fuel types they can supply: http://www.airports-worldwide.com/You'll find that most of them can, usually by fuel that is pumped under the ground from large storage tanks to the stands, but some of them use tanker trucks too of course.Sometimes aircraft will take enough fuel to get there and back though, a process known as 'tankering', which is one of the original design goals of the 737, i.e. it was designed to be capable of flying along several short stops to poorly equipped domestic airports whilst carrying enough fuel to do so (a bit like an inter-city bus). That is in fact one of the main reasons why the 737 became a success, and the rival (visually very similar, but poorly endowed with fuel tank capacity) Dassault Breguet Mercure airliner was a flop. Dassault were more used to designing military aircraft, which tend to be capable of mid-air refueling and invariably would fly one, well planned mission rather than several per day back in those days, and they didn't take that into account when designing the Mercure. Thus it was one-nil to Boeing and the 737.Al

AFAIK from the site, WADD has adequate fuel for all traffic currently, but back in 2005 the airport did not meet satisfactory demands and security standards of the ICAO, and was subsequently shunned by the Transportation Security Administration, at least until mid-2007. Dave.