Originally Posted by
Eutychus
Does his explanation make sense? Did A340s of that vintage have fuel dumping capacity and would the presence of an urban area make any difference to whether fuel was dumped in this scenario, or was it more a case of wanting to be on the ground in a big hurry and being too busy to bother?
For design reasons beyond this thread it is typical for the previous generation of long-haul quads to have dumping installed. With all engines running, the requirement on climb performance is well satisfied without using it.
Over an urban area or not, with a fire indication on board, landing and safely stopping in any manner that gets you on the ground the fastest is the sole objective.
Imagine rejected take-off at CDG which would cook the brakes as designed. An expedited severely overweight landing due smoke emergency 1 hour later might still take the temperatures above operational limits despite the triple available stopping distance and much lover E(kin), but they are meant to be abused when in need.
Edit: Correct. It's not a failed engine or even decompression that warrants the steepest dive, fire or smoke are.