BHX-DUS
According to LH website EW operate DUS-BHX 3x daily (less at weekend) as it is now with CR9 equipment being used throughout winter 2015/6.
Flybe services looking at timings appear to be operated by ER7 on some flights some on the DH4. The flight that overnights in DUS appears to be operated by a DH4 as it is now. You can check individual flights by filling in dummy booking and looking at the seat plan.
Daza