Born at Ixelles on 23 October 1922, Jacques arrived as a civil refugee in Great Britain on 20 May 1940. He reported to the Belgian Embassy on 27 August 1940 and was sent to Tenby Camp to receive an infantry training. He asked for a transfer to the Air Arm, and was posted to the Belgian Depot on 7 August 1941. He joined the Aircrew Receiving Centre on 29 September 1941 and started his training ( 86A Pilot promotion) at the 5 ITW at Torquay (3 October 1941), followed by 6 EFTS - Sywell (20 December 1941), 22 EFTS - Newmarket (1 May 1942), RAF Cranwell (20 May1942), Infirmary / A Sqn/ Fl 2 - Eastbourne (20 June1942), 58 OTU - Grangemouth (29 September 1942) and was posted to 350 Sqn on 23 December 1942. Transferred to 349 Sqn on 15 June 1943, Jacques was successively posted to 18 APC - Eastchurch (10 May 1944),  57 OTU - Eskett (17 October 1944), 84 GSU - Thruxton,  349 Sqn (November 20, 1944), 83 GSU - Westhampnett (21 December 1944). He returned to 350 Sqn on January 10th, 1945 at Y.32 Ophoven. Jacques Groensteen was killed (MIA) in combat on April 20 1945, whilst flying a sweep in the vicinity of Neuruppin. By that time 350 squadron was operating from B.118 Celle in Germany.

In January 2002, a wreck search led by Mario Schulze of the German group AGFOR resulted in the discovery of the wreckage of Spitfire NH686 in a wood near Malz, Oranienburg. This plane was piloted by the Belgian W/O Jacques "Pichon" Groensteen, who went missing over the Soviet zone on April 20, 1945. Further details reveal that his plane hit some trees and crashed when chasing an FW-190 near to ground level.

The remains of Jacques Groensteen were brought to Belgium on February 5, 2003 to be buried at Evere Cemetery, along with his brother Claude, who lost his life as a navigator in a Mosquito-accident in Canada on September 16, 1944.

(Information kindly provided by Cynrik De Decker, Guy De Win and Daniël Cox)