Do you still have the crew on ground evacuation hatch in the roof of the flight deck on the later B 747 aircraft? Yes I know a crew member would need to leave his seat to operate, and other considerations, but it is quite a big hole. Just offering a discussion point for those better qualified than me to consider.
To answer a few questions...
The cockpit smoke removal on the 400 is essentially a remote lever to open what amounts to a sextant port. The Classics still had the sextant port (Smoke Evacuation Port), which was opened by the FE in order to follow the Cockpit Smoke/Fume Evacuation checklist. The port is only about an inch and a half (38mm) in diameter, and would not depressurize the aircraft.
WRT the overhead escape hatch...
Even depressurized with the packs off and at slow speed, there is such a low pressure area outside that hatch that opening it is next to impossible. We tried, in order to reseat the hatch due to improper closing and a deafening whistle inflight. Getting it open more than 1/2 inch requires superhuman strength that exceeded the strength of a rather large jumpseater. Doing it blind with smoke, and probably having to remove the O2 mask in order to reach the hatch, while removing an assisting crewmember from the seat during an incredibly busy time, isn't a practical matter.
There are no opening windows in the cockpit of a 747.
FWIW, I knew and previously flew with the Captain on that flight. He flew FE and FO with me on the Classics and I gave him IOE when he upgraded to Captain. I enjoyed his company and he always did a great job as a crewmember. RIP and sincere condolences to his family and friends.
Don't ask me for the crew names. Those will be released in due time.
These guys were served a plate of doom. Like Swissair @ Halifax, and short of getting the airplane on the ground immediately at the first sign of fire/smoke, I doubt that anyone could have done better. What is needed on freighters is a main deck fire suppression system. Unfortunately, when the body count gets to a high enough level, that might happen. Personally, I think it's way overdue.