The Avro 504 series of planes were
first developed in 1913 as
reconnaissance and bombing aircraft, but Major R. R.
Smith-Barry developed the 504J as a trainer.
The two-seater biplane was a very effective trainer because
the 504 had many of the attributes of single-seater fighter
aircraft, which were difficult for the novice pilot to learn.
The Avro 504 had a skid that was attached to the middle of
its landing gear. This skid projected forward to keep the
aircraft from nosing forward during landing, a necessary safety
feature for many pilot trainees.
These planes continued to be the main trainers for the Royal
Air Force (RAF) into the 1920s. When the Royal Canadian Air
Force (RCAF) came into being in 1920, the Avro 504K and its
successors were made the main-line trainers for the air force
until 1928. Thirty Avro aircraft were sent to Canada as part of
an Imperial gift from Britain after the war.