A British Airways Boeing 777-200, registration G-YMMU performing flight BA-245 (dep Aug 30th) from London Heathrow,EN (UK) to Buenos Aires Ezeiza,BA (Argentina), was on approach to Buenos Aires at about 07:30L (10:30Z), but could not continue for a landing due to weather conditions being below minima and entered a hold at 5000 feet. After about 25 minutes in the hold the crew declared "Mayday, we have insufficient fuel to divert!" The aircraft landed safely on Ezeiza Airport's runway 11 at 08:07L (11:07Z) about 12 minutes later.
News: Fog in Buenos Aires on Aug 31st 2012, British Airways B772 has insufficient fuel to divert and other fuel emergencies
Another two flights also had fuel issues and made it down safely.