Your list please?
ac500u
>>Again, I'm in no way advocating 747's landing before displaced thresholds.<<
So, I'm curious, just which aircraft DO you advocate landing before displaced thresholds? Should there be published lists? Not 747's but C172's , ok. What about ATR72's... too big? How about twin otters?
I believe you're clutching at straws trying to make the case for your friend. The fact is that no matter how many times people do something wrong, its still wrong. So far, I have been unable to find a single definition of Landing Distance Available that includes the area before the displaced threshold. I have found many, many references specifically prohibiting it.
Another question springs to mind. If you do not accept the displaced threshold as the beginning of the surface available for landing, what is your understanding of that point? Exactly where do you think its okay to plan touching down? If the unprepared surface short of the runway looks good to you, can you land there too? Is that also type specific, ie, not 747's but "light" aircraft ok?
Aviation and aviation regulation is full of grey areas. Not everything is as black and white as it should be or, in many cases, as it needs to be. In this case, the majority of posts are against landing before the displaced threshold. Technicalities aside and outside emergency situations, I think there would be very few good reasons for doing so.