January 3rd 2015, Heathrow Airport, London. Low cloud and rain provide ideal conditions to observe wake vortexes and &quot;fluffing&quot; as moisture condenses over the wings of landing aircraft. With the runway visible only at the last minute, several planes had to perform a &quot;go-round&quot;, abandoning their first attempts to land. PICTURED: Water vapour streams from the control surfaces of a Delta  Boeing 767 as it prepares to land on Heathrow Airport's runway 27L.