The title of this thread is plain and clear to me.
Required landing distance available. Does inflight requirement exist?
The poster wants to now if such legally binding requirement exists? The answer is NO, there's NO such requirement in the EU OPS. However operator might elect to include such as a requirement in it's relevant documentation. Think logically of it. Why would EASA or FAA bother with TALPA spending time, manpower and money if there was a requirement for RLD in flight? In that case all one needs to do is simply check if RLD is less than LDA and that's it. Why to bother with ALD? In this case we wouldn't be able to complete the landing on quite a number of occasions. RLD is used in the assessment of suitability of airdrome for dispatch purposes at the planning stage and regulator applied their a safety margin for unforeseen circumstances. ALD is relevant after airborne to be able to assess a real landing performance. How else do you wanna know if you'll be able to stop within LDA on a diversion conducting overweight landing for medical emergency with dying pax in the back? Are you not gonna divert coz your RLD isn't equal to LDA but more than ALD? The only problem is, as we're well aware of, it's basically inadequate. To make it somewhat adequate FAA applies 15% margin. However fundamental problem lies with the determination method of ALD. It's nothing but a test pilot landing and doesn't reflect daily business. That's the conclusion, after several overruns, FAA and EASA came to and started to work on a new concept TALPA. Well, nuff of academical BS. I don't disagree with your common sense but regulations are clear. It's also very much a commander's decision regardless of applied margins regs or anything else. If I'm not happy bout the way the situation unfolds it's a no go, no matter what the numbers are saying. Experience sometimes overrules.
