The One Eleven had an escape chute / tube through the forward freight bay, accessible from the cabin, but on the fateful day in 1963 the hatch would not open due to the air pressure on the outside due to the near vertical flat descent and also possiby due to negative cabin differential.
On later aircraft the hatch was fitted with explosive bolts. ('YDs hatch was blown off in the hangar about 1972 when I was an apprentice at Hurn).
There was also an anti spin/stall recovery parachute assembly ready to be fitted the following week when G-ASHG was due at Hurn for maintenance.
( my father was a flight shed inspector at the time).