The unknowns from Monday:
38853B (France, again with no flight id, is it possible, that this is an hex for Airbus test registration?)
3C48A7 (Germany, no flight id, no further information)
3C6421 (Germany, flight id: CFG674, CFG: Condor Flugdienst)
3D0651 (Germany, no flight id, airframes: D-EAQJ A210 Aquila A-210 AT01 Koelner Klub fuer Luftsport AT01-231 confirmed by fleet list:
http://www.kkfl.de/index.php/unsere-flotte/aquila-a210-d-eaqj )
3D1749 (Germany, flight id: DEHBL, airframes: D-EHBL C172 Reims Aviation F172G Skyhawk AC:? formerly with Aerowest Flugcenter GmbH* 0194 *But no sightings after 2005 and not in their fleet list any-more)
3D3789 (Germany, no flight id, airframes: D-ETGZ, no further information)
3D3868 (Germany, flight id: DETPO, still no further information)
3DA370 (Germany, flight id: DGIDK, D-GIDK P68 Vulcanair P68C DIKO Fly & Charter GmbH CN:? Mk1EB:
http://eastwings.blogspot.de/2012/04/vulcanair-p68c-diko-fly-charter-gmbh-d.html )
3ECC4B (Germany, flight id: DKSID, no further information)
3ED1CE (Germany, again with flight id DKUKK)
3FEB95 (Germany, flight id: DMRZA, still no further information)
3FEB97 (Germany, flight id: DMCZZ, no further information)
3FED67 (Germany, flight id: DMRIS, no further information)
3FF0AB (Germany, flight id: DMMZA, D-MMZA FK9 B & F Speyer FK-9 Mk.3 Luftfahrtverein Mainz e.V. CN:? confirmed by fleet list:
http://www.lfv-mainz.com/uls/ )
3FF0D2 (Germany, flight id: DMBKM, no further information)
3FF102 (Germany again with flight id: DMJSA)
3FF131 (Germany, flight id: DMMZB, no further information)
400588 (UK, no flight id, no further information)
44D8B7 (Belgium, flight id: BEL61J, decoding error of 44D8B3)
47831A (Norway, no flight id, no further information)
484182 (Netherlands, flight id: TRA6412, decoding error of 4841D6)
4A4A16 (Romania, no flight id, no further information)
4B8658 (Turkey, flight id: PGT502, decoding error of 4B8650)
4CA25D (Ireland, no flight id, again decoding error of 4CA259)
506E5E (Slovenia, today without flight id)
AE2FFE (USA, flight id: S153, no further information)
That's all from Monday. All these unknown airframes on one day, must be a new record.
Have a nice Day!