Landing before the threshold is an off-field landing per definition.
However, I never heard of a single prosecuted case.
UdoR wrote:
Landing before the threshold is an off-field landing per definition.
That’s an interesting interpretation. I would agree if the area is marked as unusable by crosses, but if it is just a displaced threshold how is it not part of the runway? There is a clue in the name 
Not so simple I think… possibly why UdoR wrote:
I never heard of a single prosecuted case.
Landing before the threshold is an off-field landing per definition.
How does that tie out with off-field takeoff? it suddenly become legal? and what does that even mean in country (e.g. UK) where off-field operations and unlicensed runways are permitted?
Landing distance available and touchdown zone (LDA & TDZ) on licenced runways are adjusted for 3deg path with 50ft crossing of thresholds (size of adjustment depends on runway length, width and any obstacles on short final), commercial flying rely on LDA & TDZ and cannot use full runway length
However, for private operations one can use full runway length for takeoff & landing, I am damn 100% sure about this !
At Redhill, I used to takeoff & land on a taxiway when grass was wet, I think when one Chieftan did it on AOC with paying passengers CAA did come around to help
Not sure about the complication of a displaced threshold… but in general:
If you land in before the normal threshold, then it is legally an landing outside of the airport, which in Germany is only permitted with prior explicit permission by the regional authority (w/o it = illegal as Bosco and Udo wrote)
The 450m strip where I learnt did not report anyone, but were always afraid that someone from the authorities or a flying-hostile neighbour COULD report it and create trouble for the pilot AND the operator who had not reported it themselves.
I also believe off-airfield landi gs in CH would require prior permission to avoid being illegal.
Ibra wrote:
Landing distance available and touchdown zone (LDA & TDZ) on licenced runways are adjusted for 3deg path with 50ft crossing of thresholds
No.
LDA is a simple measurement from the threshold (displaced or not) to the other end of the area available for landing. It has nothing to do with approach angles, threshold crossing heights, or touchdown zones. You can land on ‘brick one’ if you want to, and the LDA starts at brick one – not where someone has established that a particular sort of aircraft might tend to touch down.
It is the Landing Distance Required (a calculation) that tends to, according to the aircraft type, assume a 50’ threshold crossing – i.e. the calculation tells you how long an LDA you should need, building in an assumption that you won’t be down on brick one.
The moment you cross the threshold (displaced or not) you’re eating into the LDA, whether you’re down or not.
Ted wrote:
That’s an interesting interpretation.
That’s not an interpretation. That’s German law, actually in force. § 25 (1) third sentence, item 1 LuftVG says that any landing outside published runway is only allowed if the land owner and the authority (Luftamt) agrees. Published runway begins at threshold for landing.
According to § 60 (1) item 4 LuftVG you go to jail for up to two years if you conflict § 25 (1) third sentence, item 1.
That’s not a joke.
However it’s interesting to read that it’s not the same point of view in other countries.
LDA is a simple measurement from the threshold (displaced or not) to the other end of the area available for landing
That is not the definition, I think worth checking plates of licenced runways: distance between threshold to threshold (Google Map) is usually not the published LDA, you may have to look at few certified runways though, these are in licensed and publisted AIP
From ICAO,
Landing Distance. The horizontal distance traversed by the aeroplane by the aeroplane from a point on the approach path at a selected height above the landing surface to the point on the landing surface at which the aeroplane comes to a complete stop (Source: ICAO Annex 8 Part IIIA Paragraph 2.2.3.3. and Part IIIB Sub-part B Paragraph B2.7 e)
From EASA rules,
The ‘landing distance available (LDA)’ means the length of the runway which is declared available by the State of the aerodrome and suitable for the ground run of an aeroplane landing
I am not aware of any NCO rule that prohibits aircraft LDR(50ft) < runway LDA, if anyone has any, I am happy to take it…I am only aware of this for CAT.POL.A.23? even SPO.POL.140 leaves some pilot interpretation
Again, I landed before displaced threshold in UK & France, it’s legal (even landed on taxiways and farms in both countries), I am not sure about Switzerland or Germany though, I would not be surprised it’s banned: they apply commerciale rules to private aircraft anyway…
That’s not an interpretation. That’s German law, actually in force. § 25 (1) third sentence, item 1 LuftVG says that any landing outside published runway is only allowed if the land owner and the authority (Luftamt) agrees. Published runway begins at threshold for landing.
bq.
I am not able to read German, but a reading a translated version of that text, I can’t see how they have defined the runway as you describe.
Specifically that a runway begins at the threshold. I am not arguing what a threshold is or what it is for, nor am I suggesting it’s good practice to land before the threshold.
I can see how they might prosecute you for stupidly low approach. Ie negligence, or fail you for a poor standard of flying, I am sure in the later two cases those regs exist somewhere…
@Ibra that’s wrong I’m afraid. Look again at the definitions you quoted.
Your ICAO definition is one of ‘Landing Distance’ which is not the same thing as Landing Distance Available. Landing Distance, from that definition, is an actual distance achieved in the real world on a single particular occasion, not a published parameter of a runway.
Your EASA definition is of LDA. It is from the threshold to the end of the runway, the threshold being the start of the area declared available and suitable for landing.
LDA is not usually threshold to threshold (assuming displaced thresholds at both ends, even by a small amount) because in each direction the LDA is from one threshold to the end of the runway beyond the other threshold. Unless the other end of the runway features a stopway, which I don’t think forms part of the LDA (but is included in the ASDA).
Displaced threshold at landing end only = LDA is displaced threshold to end of runway.
Displaced threshold at other end only = LDA is threshold to end of runway.
Displaced threshold at both ends = LDA is displaced threshold to end of runway.
No displaced thresholds = LDA is one end of runway to the other (which could also be expressed at threshold to threshold, since the thresholds are at the ends of the runway)
I have looked at some and checked thank you, and I’m happy with my understanding of LDA. I’m afraid I believe you’re incorrect in your understanding, in that you believe LDA is some ‘not measurable on the ground’ parameter that depends on approach angle, threshold height, etc.
LDA is not usually threshold to threshold
I agree on this and I am happy to fly LDR >> LDA and use the whole runway length for my flying, even flare on the grass before the threshold and land before displaced thresholds, as long as they don’t have “X” on them it’s legal
