Originally Posted by
industry insider
...Surely Blacksod could have had a simple GPS approach rather than having to use SAR autopilot modes?
The approach they were using was simple, al-be-it for that nasty left turn on to the final course, and it didn't need any automation to fly it safely. All that was needed was to arrive at the IAF (BLKMO) at a height where a constant descent rate of 450ft/min would put you on the final segment (BKSDC) at 200 ft/75kts, and to monitor the radar so that the horizontal navigation made sense with what the GPS was telling you. 3000' at BLKMO would have worked nicely. The numbers can be crunched in your head, it doesn't need an FMS to work it out. And at that height you could still talk to everybody you needed to talk to, with no need to give a landing report whilst still 6+ minutes out.