On 22 October 1916, he was appointed as a probationary flight officer in the Royal Naval Air Service and posted to its headquarters on HMS President.
[4] On 3 January 1917 he was riding in the rear seat of Curtiss JN4 serial number 8820 when it crashlanded at Redcar, tearing off the undercarriage and damaging the propeller.
[8] By the time Pinder left 213 Squadron at the end of August 1918 for an Air Ministry post with the Grand Fleet, his aerial victory score stood at 12.
[11] He was granted a short service commission as a Flying Officer in the RAF on 24 October 1919,[12] though this appointment was later cancelled.
Pinder teamed with Brazilian Lieutenant Aliatar Martins to make this flight in a Macchi M.9 flying boat.
They state that Pinder and Martins landed in the Lagoa dos Esteves, Içara to repair a propeller.
[5] After the drownings, a search party found the seaplane in the lagoon and threatened to kill all the local men in the vicinity because there was suspicion of foul play.
Pinder and Martins were originally buried in the first graves of the local cemetery, but were removed several years later.