Heathrow saw 6.1 million passengers in May, a 4.7 per cent increase on May 2012.
The average number of passengers on each flight rose to almost 152, equating to a load factor of 74.7 per cent, up 1.1 percentage points.
The average number of seats per aircraft was 202.9, up 3.8 per cent.
The growth in passengers using Heathrow was across most markets.
Transatlantic traffic was up 3.6 per cent, with European short haul passengers up 6.9 per cent.
Operations responded to the emergency landing on May 24th by reopening the runway as quickly as possible and assisting the airlines with looking after their passengers.
“Overall passenger numbers do not appear to have been impacted by the operational disruption, however the average load factor and aircraft size is likely to be higher with passengers on cancelled services rebooked onto later flights,” Heathrow explained in a statement to market earlier.
Heathrow chief executive Colin Matthews said: “May saw another rise in the number of passengers travelling through Heathrow.
“More and more of them are being carried by newer, quieter aircraft which we incentivise to use the airport.”
During the month Heathrow also confirmed the revamped Terminal 2 would open on June 4th next year.