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Old 14th Feb 2017, 11:06
  #157 (permalink)  
bookworm
 
Join Date: Aug 2000
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Again: this wasn't really the aspect I was trying to address in my earliest post, and I wasn't trying to reopen a discussion on this specific accident, only to use it to illustrate my original point.
Noted, and I'm sorry to pick on your post, but I think it illustrates the fundamental misconception in this thread.

After all: if they really could see the airport, how did they come to be victims of CFIT?
Really?! Welcome to the world of "night VFR", where you are required visually to avoid unlit obstacles and terrain at night.

There are two safety aspects to making any approach work where visual means are insufficient:

1) You need to plan to fly a trajectory that is clear of obstacles and terrain, with a margin consistent with the navigational performance of the system you are using. The trajectory also needs to be consistent with the performance of the aircraft.

2) You need to fly that trajectory with commensurate precision.

Approval and publication of an instrument approach procedure are designed to mitigate the risks associated only with aspect 1. You risk CFIT if you deviate significantly from a safe trajectory, whether or not that trajectory is PANS-OPS compliant, approved or published.

Throughout this thread, assertions have been made that, for example, "there are dead bodies and wreckage strewn all over the place" from the use of trajectories that have not gone through the rigours associated with PANS-OPS design, approval and publication. Yet the only accident examples cited are cases where the flight crew failed to fly a safe trajectory (whether published or not) with reasonable precision.
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