Nicholas Dijkstra tells the story about flying in formation under the Sydney Harbour Bridge.

In May 1942, two US ‘Kittyhawks’ flew under the Sydney Harbour Bridge. Nobody had done that before!

Several Dutch and Dutch East Indies KLM and KNILM pilots were to make a short flight over Sydney for a final check of the aircraft. Some people of the ground staff suggested that it would be nice to come along for the short flight, so at the end close to fifty people were onboard to 5 planes. Then one of the pilots suggested that we could do better than the two US Kittyhawks and all five planes fly in formation under the bridge.

On 14 May 1942, The five aircraft took off and eventually took up formation approaching the bridge from the Sydney Heads. Still in formation we flew under the bridge, pulled up, made a wide turn and then flew in single line again under the bridge and then returned to Kingsford Smith Airport.

After we landed and taxied to the ramp, there was hell to pay! Anybody with authority was there. The authorities did not have much to nail us down with, but we heard later that an order had been issued, forbidding to fly under the bridge and that anyone doing so, would be fined one hundred pounds ($200) for every person aboard.

For the full story see: Visit Sydney Australia

In his book Allies in bind: Australia and the Netherlands East Indies relations during World War Two, Dr. Jack Ford, tells a slightly different story.

KLM/KNILM crews had been serving the South West Pacific Area (SWPA ) Command under General Douglas MacArthur as their remaining transport planes ferried supplies from Brisbane to new US bases in northern Australia. As a protest over their Douglas Dakota and Lodestar aircraft being sold to the US Army, three crews outdid a recent exploit by US P-40 pilots. Before their planes were transferred to Archerfield Qld, the crews flew three KLM/KNILM planes under the Sydney Harbour Bridge on 3 May 1942. Australian authorities were so annoyed by these antics that flying under the Harbour Bridge was prohibited on penalty of a £200 fine”.