Originally Posted by
A Squared
A may be "correct", whatever that means, but it's pretty suboptimal. The proposed 3.5 degree descent angle won't work in the described scenario, it would take a 3.77 degree descent angle to descend to the airport, considerably more to "catch the proper vertical path". For reference, a 3.77 degree descent angle is steeper than would be normally permitted for approach design for Cat D and E by the US TERPS and right at the limit for Category C.
Under ICAO PANS-OPS criteria for instrument flight procedure designs for just about everywhere except the US, 3.5° is the max descent angle for Cat C, D & E aircraft, except where they have specific airworthiness &/or ops approvals otherwise. Similarly, 3.72° is the max descent angle for Cat A & B aircraft, except where otherwise authorized.
It's my understanding that the CDFA can actually be interpreted to extend beyond (prior) the FAF - as it is in practice done in the EU now. Like the IATA CANPA, basically if you're in landing config, you're better off to follow the CDFA/CANPA techniques. And as someone else said, these days in any modern aircraft you can use the avionics to help guide you down and the PNF does the dist/alt checks and readouts. Many charts these days provide dist/alt tables for this purpose and they generally extend beyond (prior) the FAF so that by the time you intercept the FAF (even from say 2NM prior) you're already established on the published descent profile for the final.
Re the original question, starting higher than the published descent gradient (and anywhere near max certified descent angle for the acft is not safe - especially if you don't take into account potential hot temp correction issues - even with a 5NM final (worse if the final is shorter, obviously). This is the kind of behaviour (different reasons why) that for example led to the Korean Air unstabilised APCH into SFO a few years back and ultimately a highly undesirable landing (accident). So Option A is really quite suboptimal.
And ultimately if the PIC is not happy, tell the ATC
unable and seek clarification or new instructions.