On Tuesday, September 24, 2019 at 12:32:32 PM UTC+1, RR wrote:
Steve has mentioned the key here. If you are about to head home, and find yourself saying somthing like the following, "I am 1000 over, my 1000ft reserve" then your reserve is doing you a disservice. It is somewhat of catch 22. You need to be aware of your reserve in case things go south and you fall below it, but the purpose is to keep you from needing to think about it (always have 1000 ft in reserve).

The biggest problem is when things go south. If you are close in, you fall below 0, now you need to subtract from your reserve to figure out your true arrival height. If you use somthing other than 1000 ft it gets harder. So right when you most need clear information you are doing mental math. Bad timing to insert a math problem before you need to make a critical decision. Some (in the admiralty), if not most, know how I know this.

It has been described as setting your watch ahead so you are not late.

I too had flown with a reserve for years, and was worried about switching, but just a few flights and you adjust. And a few more and you realy start to appreciate the fact that you are, for the first time, realy getting the number you want out of your flight computer.

How high will I be when I get there...

RR
Commodore

I think there is merit in having a small reserve of, say, 200 feet to allow for pressure altitude changes during flight, obstructions on the approach etc but to regard that as if it were a zero arrival altitude.

The biggest downside I find of a large reserve height isn't the mental arithmetic. With LXNav or Naviter glide computers it is to remember that it is added to the FAI or record "task arrival height" (1000m below start height). One day I struggled for a climb to make task arrival only to find I was getting there 1000 feet higher than necessary and way above ground.