Hi gums,
'…
how the 'bus got certified with no control feedback …'
The simple answer is that they rewrote the rules. Airbus chose not to use stick force as a cue for speed, instead argued the then novel view that an artificially stabilised and well protected aircraft, available with 'FBW', would provide an equivalent level of safety.
This was no simple task, it took many years of proposals supported by extensive research, simulation and experimental flights; effectively having to re-educate the aviation world (regulators).
The step change to an electrically controlled aircraft with computed protections did not come with past 'baggage' from previous products. The A300 broke into the commercial market, it had three crew until modern avionics, EFIS, digital technology, resulted in the Forward Facing Crew Cockpit (FFCC) -600, thence A310. This change was at the time of great focus on workload and the 2 crew cockpit, where all new aircraft were subject to workload evaluation B737, MD80, F28, BAe146, thus opportunity for radical change.
Copy of Bernhard Ziegler's paper linked below; this is a very thoughtful and far reaching note, which provides the background and much more. Sorry you need to read the pages in reverse, last page first, so concentrate !
https://www.dropbox.com/s/8uzkoc47lmgeo4w/
Bernard Ziegler - much maligned at the time, but time writes history.
Also, many other contributions; including John Wilson (copilot on Comet first flight), with the Advanced Flight Deck simulator (ended up in the Smithsonian in DC).
https://www.dropbox.com/s/dte4j6oade...09410.pdf?dl=0
Some of the gems from Ziegler:-
"…
very careful not to use guidelines which are too broad and subject to too many interpretations, like: 'The man shall be kept in the loop', which is obvious but of no practical use, which is too specific or may prove to be harmful constraints with the evolution of man and machine (at least of his evolution of his culture and habits)."
"
Crews got use to automation much faster, but designers moved forward even faster. A lesson in modesty in front of the immense inventiveness of the human being, and the army experts in human science who are now descending on our community, and should well meditate on this lesson. … as Socrates said, the only thing we know is that we know nothing." - and then the last pages on "Protections
…… ", human reasoning, culture, human machine interface, task, free flight;
… … are you listening Boeing, FAA.