What's the replacement cost on one of those engines?
ETA: Found these:
# In October 1990, a B-1B (86-0128), from the 384th Bomb Wing, 28th Bomb Squadron, McConnell AFB, while flying in a low level training route in eastern Colorado, lost an entire engine (although the crew was unaware the engine had actually departed the aircraft). It was later determined the engine had suffered catastrophic failure, in which engine blades cut through the engine mounts, causing the engine to detach from the aircraft.
and this little gem
In May 2006, a B-1B (86-0132) from the 7th Bomb Wing, 9th Bomb Squadron, Dyess AFB, Texas, upon recovery from an 11-hour ferry flight to Diego Garcia landed "gear-up". The Air Force investigation concluded that the pilots "forgot to lower the landing gear". A resulting fire was quickly extinguished and the crew escaped through the top hatch unharmed.[38] Four days later the aircraft was raised and its landing gear deployed. The aircraft damage was estimated at nearly $8 million.[39]