What was the earliest plane in push-pull configuration that flew or at least took off?
I have found a plane, that had both a pusher and a tractor propeller, which flew for the first time over Cotroceni airfield, Bucharest, Romania, on June 17, 1910. Likely there are other planes like this that flew before.


Vlaicu I plane during construction


Newspaper article about Aurel Vlaicu's first flight June 17, 1910

Source: A Vlaicu I - Wikipedia