Airborne_Again wrote:
In Annex 14, ICAO says that the LDA is “The length of runway which is declared available for the ground run of an aeroplane landing.” It also makes clear that the LDA is the distance from the threshold to the far end of the runway. (So any displaced threshold at the far end is disregarded, as are any stopway or clearway at the far end.)
Right, so the Landing Run Required in the a/c spec needs to match the LDA of the airport. Thanks!
BerlinFlyer wrote:
In Germany, it’s definitely an off airport landing
You mean “Aussenlandung” in German?
While the meaning is clear, the expression “off airport” sounds like a bit of an exaggeration… While that part is not considered part of the LDA and therefore the runway, these parts of concretes definitely are part of the airport 
arj1 wrote:
So that is a point over which an aircraft can commence landing, so it is not a landing run available…
I didn’t say it was a landing run available. What I said was that it’s a simple measurement on the ground, from the threshold (displaced or not) to the other end of the runway. It doesn’t involve any assumptions regarding the approach, though the location of the threshold (which obviously affects the measurement) will be placed with regard to the approach.
The conventional assumption, for performance calculations, is that one crosses the threshold at 50’. But you don’t have to – you can land on brick one if you wish.
arj1 wrote:
AFAIK displaced threshold means there are obstacles which (if they are avoided AND the designated angle is followed) prevent the aircraft from reaching the area before it. If you fly a smaller plane and/or steeper angle then should be OK.
A displaced threshold is simply one where it’s located such that runway behind it is available for aircraft taking off (and so counts towards the TORA and ASDA) but not for aircraft landing (so doesn’t count towards the LDA). Why it’s displaced isn’t relevant to the numbers, though it’s usually obstacle clearance.
arj1 wrote:
Right, so the Landing Run Required in the a/c spec needs to match the LDA of the airport. Thanks!
That’s not at all what the ICAO document says! It is only a definition of LDA which incidentally makes clear that nothing bad will happen to the aircraft or runway if you touch down at the beginning of the LDA (i.e. the landing threshold).
How the LDA relates do the landing distance or landing run requirements is another question entirely.
Airborne_Again wrote:
How the LDA relates do the landing distance or landing run requirements is another question entirely.
Precisely!
As a matter of interest, if the runway/tarmac or grass before the displaced threshold, had say a pothole or sticky mud, would/should it be notamed as it is not part of the official LDA?
gallois wrote:
As a matter of interest, if the runway/tarmac or grass before the displaced threshold, had say a pothole or sticky mud, would/should it be notamed as it is not part of the official LDA?
Is not a part? What about landing in the other direction?
If landing in the other direction would it necessarily be a part of the LDA?
My question still is would it be notamed?
gallois wrote:
If landing in the other direction would it necessarily be a part of the LDA?
True! It can be just “something” or “not part of licensed aerodrome” (c) Elstree.
gallois wrote:
My question still is would it be notamed?
If it is a part of aerodrome, I expect it to be NOTAMed – if I can use it one way or the other (authorised use), I want to know the condition.
