Announced in January, the rules increased flight crews' weekly rest periods to 48 hours from 36 and cut pilots' night flight duty times to a maximum of 10 hours from 13
The MiG was on an air patrol when it dropped off the radar in eastern Romania between the villages of Cogealac and Gura Dobrogei.
The pilot of the IAR 330-Puma helicopter sent to find him had reported unfavourable weather and had been called back to base before it too crashed, the ministry said.
Romania, a European Union and NATO member, plans to phase out its MiG planes and is flying F-16s.