Gorn,
For the YLHR RWY 12 RNAV(GNSS) approach the descent point is 1.7 prior to LHRWF and the angle is 3.49 degrees. Work off your GS and you have a rate of descent that keeps you above the steps.
That is not the way I'd do it. Firstly, the slower your aircraft, the more affected by the H/T wind component on the approach getting quickly to the point where a couple of hundred feet error in your "worked out rate of descent" will either put you into a limiting step or make you miss out because you get to the MApt too high.
Also, flying level until only 7-odd nm to touch is not the ideal way to get stabilised by a reasonable height (~1000ft AGL). I my experience, it is better to start descent earlier from higher. That allows more time to get the descent profile under control.
The simplest and safest way (to do any NPA) is to fly the chart profile, a bit like an ILS. Provided you make each chart profile altitude point eg 5 Mike, 4 Mike 3 Mike you CANNOT hit anything. Even if you are a bit erratic and miss a profile point by 100ft, you are not going to run into anything. If all has turned to worms, it is very easy for PNF/support pilot to call out out "4 Mike 1950!". Instantly, we know where we should be (and hopefully where we are).
Of course, the big spanner in the works doing this is Foxtrot. The distance reference you use changes right in the middle of the approach! When you are doing this type of approach without a graphical display of where you are, the potential for misinterpreting your position increases greatly.
you want to change the whole world wide accepted philosophy about how they are conducted.
That is exactly what I am suggesting, unbelievable as it may seem to you.
a high workload RNAV approach to one of the runways.
I agree. Higher than it needs to be.
Jet A Knight,
So far as Foxtrot is concerned, lots of relevant points, but in this case, even a VOR/DME flown like that would have resulted in a crash.
Except that if it had been a VOR/DME, the PNF would have had a simpler, single distance reference all the way to the runway (as would have the PF) and would therefore have been more likely to work out that something was terribly amiss. Even though the approach was flown fast (perhaps because the PF thought he had already passed Foxtrot and was therefore quite high, poking the nose down?) provided he stayed on or near the altitude profile the aeroplane isn't going to come to grief until he pops out and tries to land too fast.