Bonjour Gilles,
According to the book "1944 Guerre en Ile de France, vol III", it was a British aircraft that crashed at 1425 hrs on the factory "La Cellophane" at Mantes-la-Ville. It was a Mustang of 19 Sqn RAF flown by Flg Off D F Hart.
The 2nd TAF book confirm that the Mustang III FZ166 of 19 Sqn was lost around 1415 hrs. The cause of loss is listed as "blew up dive bombing barges on Seine."
The pilot, Flg Off Dennis Frederick Hart, is buried in Mantes-la-Ville communal cemetery:
http://www.cwgc.org/find-war-dead/ca...IS%20FREDERICK