Originally Posted by
underfire
I would not hold you breath, there is actually very little actual science in RECAT. RECAT is good for final approach segment, and perhaps the departure recat will come alive again.
The entire RECAT was based on 4 valid wake measurements out of Memphis....What has been known for years is that the wakes dont last as long as they state, and especially in even a light crosswinds, are out of the flightpath in around 20 seconds.
So the 'science' is just closing up the spacing until you have more wake encounters, then they will back it off. It does not take into account still air, or inversion layers, in reality, it is just sticking their finger up somewhere.(this is why they are studying 'acceptable' wake encounters.
Look at LHR. Doesnt everyone think there is a good possiblity of a wake encounter on final, and expect a wake encounter on dep? The reason there are not more serious incidents is that everyone expects it to happen.
Yes, the post was about how severe the wake is from the 787.
The 748 was required to do studies on wake as well as part of cert.
Are you talking about RECAT in the USA, or RECAT-EU which is different? And yes, RECAT-EU is only applied for intermediate and final approach spacing, and departure spacing at LHR. RECAT-EU is certainly based on far more measurements than just 4.
How does an encounter become less serious if the following flight crew expect it?
From most of the main LHR-based airlines we can get access to FDR data, from which one can extrapolate the force of the wake.