Originally Posted by
Winemaker
Since I'm being pedantic, I'll also point out that a falling object in the atmosphere will reach some terminal velocity, determined by its drag characteristics; for a sky diver it's about 120 mph. I seriously doubt any dropped object in the atmosphere will go supersonic.
Just to bring this sub-forum back to its roots and noting that many of us have dropped stuff from altitude, we can categorically assert that stores can go supersonic with ease when dropped from the high block on a level delivery profile. If not effectively mitigated this can be rather problematic for guided bombs as their control surfaces tend not to work (in a rather dramatic way) when Ernst Mach comes-a-knocking.
With the reference to parachuting one should express some sympathy for those whose job entails leaving an aircraft at altitude that flies at an IAS with a parachute that effectively, at opening, respects TAS. Even with an aircraft that can drop safely from (for example) 135kts from the 30-block, with the relative comfort of a static-line delivery, will find themselves at 0.4~0.5M as the canopy inflates. All that energy from the rapid deceleration is taken by the crotch straps. When you have to drop with a delayed canopy, higher, faster and with large amounts of equipment, the careful packing of manhood is as much of a priority as the chutes.