What if the aircraft was based in Moscow and operated DME-LHR-DME-LHR-DME? Taking into account the time difference I’d say the aircraft could leave Moscow early in the morning and arrive into Heathrow in time for the BD891. Similar situation with the return, leaving Heathrow after the arrival of the BD894. But this is still only a possibility if they announce a double daily service.

But like OneLeft has pointed out, bmi will only operate one flight per day.