Airline passengers gather around a Thomson travel agent's counter after arriving at Manchester Airport, in north-west England, on April 28, 2009, on a flight from Cancun in Mexico. The global airline and travel sectors battened down the hatches Tuesday for a possible swine flu pandemic which could deal another blow to two industries already reeling from the economic crisis. As images of people wearing face masks in public resurrected grim memories of the SARS health scare in 2003, analysts appealed for calm, saying it was too early to speculate on the impact of the new threat.