His flying abilities must have been better then he let on in
interviews as he was selected to be posted to Flying Instructor School at Vulcan Alberta. This led to his posting at No. 9 SFTS at Centralia Ontario. The dual engine Anson was
the aircraft used in training here so after 40 minutes dual training he was on his own. A fellow pilot who he had known from ETS training days joined him on a "Test" flight. Centralia is located near
Lake Huron so Hartshorn and his friend P/O Andy Wakemen flew North up to Sarnia Ontario where they decided that the bridge between Port Huron Michigan and Sarnia would be the target of their
flying skills. Flying under bridge spans was not a recommended practice and could lead to being discharged or death. So they dived under the bridge, only to find that two Lakers were steaming under the bridge
at the same time, leaving them little room to complete the maneuver! Which they managed to do and quickly escape before someone could get the aircrafts registration numbers.
Arriving at the main RCAF depot in Bournemouth he met up with Sgt. Joseph Bachand and a friend, Bachard would also be posted to 419 squadron.
While still with the RCAF he was flying Wellingtons at the OTU, attended Battle school and the HCU to learn to fly the Halifax bomber.
Lt. Hartshorn brought home the aircraft and crew to Middleton St. George without any further damage.
For his actions he was awarded the DFC (immediate). On August 11 1944 he was invested by King George VI and it is believed he is the
only American officer to be invested by the King while in the RCAF. Lt. Hartshorn and crew were again attacked on the night of 29/30 1944
where a flak hit started a fire on one engine. He again managed to bring the aircraft in, this time on three engines. The aircraft survived the war and returned to Canada where it was to be part of Tiger Force.
On October 12 1944 he was posted to the 12th Replacement Control Depot.