hum, by, world's largest airline by turnover and third biggest by traffic volume.

 “The most distinguished aspect of ‘Here’s Where I Belong,’ the new musical that opened at the Billy Rose Theater last night, is the scenery by Ming Cho Lee,” Clive Barnes wrote in reviewing that one-day wonder for The Times in 1968. “But no one ever walked out of a theater humming the scenery.”

Large and big

The European Commission's inquiry into the proposed merger between Air France and KLM is set to be extended by two weeks, a sign that Brussels believes any competition problems will be relatively simple to resolve. If successful, the merger would create the world's largest airline by turnover and third biggest by traffic volume.

hum¹

/hʌm/

verb

gerund or present participle: humming

1. 1.

   make a low, steady continuous sound like that of a bee.

   "the computers hummed"

   Similar:

   purr

   whir

   throb

   vibrate

   murmur

   buzz

   thrum

   drone

   susurrate

   bombinate
2. 2.

   INFORMAL

   be in a state of great activity.

   "the house was humming with preparations for the dance"