Originally Posted by
henkybaby
That seems not to be the case since the rear exit is open long before the cone is jettisoned. It seems like it has something to do with getting smoke out of the cabin.
What you see in the video is the bottom of the slide that is deployed from the service door on the left side of the aircraft, which is where the small galley is near the back of the aircraft... It is NOT the rear exit. It just appears to look like it because of the angle.
The tail cone is jettisoned from the aircraft to allow the actual rear emergency exit to be opened and the slide or stairs deployed, see here:
Youtube Video
For whatever reason, the actual slide its self was not deployed or failed to deploy.