PPRuNe Forums - View Single Post - Landing distance available
View Single Post
Old 21st Oct 2012, 11:03
  #20 (permalink)  
ft
 
Join Date: Oct 2000
Location: N. Europe
Posts: 436
Likes: 0
Received 0 Likes on 0 Posts
'Not all the GS antennas and PAPI are located exactly 305 m beyond the THR
No, but regardless of where they are situated, they are required to deliver you on the correct glide slope to a point 15 to 18 m above the threshold (some caveats apply, but that's the gist of it).

If they do that, they can be located in the next county. It won't matter, if they are within specs you'll be at your 15-18 m. Conveniently, this corresponds nicely to the certification specifications used to calculate the published LDR. The additional three meters from 15 m will mean all of 58 additional meters of runway consumed before touchdown.

9.G,
which documents are you referring to in addition to CS25.125 regarding what you can do during certification tests? I read CS25.125 a lot more conservatively regarding how 'creative' you can be. "The landings must be made without excessive vertical acceleration,[...]", "The landings may not require exceptional piloting skill or alertness.", "The brakes may not be used so as to cause excessive wear of brakes or tyres[...]. Interestingly, I can't find a specification of the glide slope angle for certification in CS 25, only in CS 23...

You're talking about "ALD"? That's a creature I'm not familiar with. Clarification?

Has anyone found a definition for "distance beyond the G/S"? Is it beyond the GP mast, beyond point R... for starters? If there's no definition, the figure is utterly useless IMNSHO. The two definitions I mentioned can differ significantly, and you could probably invent a fair few more.
ft is offline