First let me add my relief to those who had shared my concern about our friends from Brazil. While any loss of life is tragic, it is some consolation that we will mourn the loss in a less personal fashion. Our prayers and condolences are, nonetheless, with those who have suffered enormously.
It may or may not turn out to be an issue, but several of us were looking into the crash unofficially at the NASA Aviation Safety Reporting System where I work as an analyst. Apparently, the very short runway at the downtown airport had recently been resurfaced. Only 6500' +/- in overall length, it is shortened at either end by a "displaced" threshold which limits the available runway for landing to around 6000'. This is pretty much at the lower end of acceptable runway for any transport category aircraft such as the A320.
When the runway was resurfaced it was reportedly not immediately "grooved", a process that literally cuts grooves across the runway surface every inch or so to allow rapid runoff of water. This grooving allows flight crews to consider the surface as "dry" even when rain is falling because the water runoff prevents hydroplaning, a phenomenon where the tires of the aircraft never actually touch the runway surface but, instead, "plane" on a film of water. Hydroplaning may result in little or no braking capability and was a likely reason the pilots aborted the landing after touchdown and attempted to take off again. They were running out of runway and not slowing down.
What was of interest to us at ASRS was the fact that the current "published airport pages" show the runway as "grooved". Almost certainly, there were airport NOTAMS (notices to airmen) clarifying the fact that, due to the resurface, the grooved runway designation was invalid until such and such a date, generally "ufn", until further notice. Unfortunately, NOTAMS are published in the most generic fonts with no attempt to emphasize really, really important stuff from just "sorta" important stuff. The can also be voluminous in quantity, making a complete review a demanding task. They are also published in a very arcane format with lots of contractions which makes easy and quick understanding of their nature difficult at times.
Every transport category aircraft must make a performance evaluation for every takeoff and landing to assure adequate performance (going or stopping)is available at the aircraft's weight, airport altitude and temperature (plus a variety of other considerations). When a runway is grooved they can legally (and safely) take off and/or land at a greater weight in wet conditions because the grooves allow the same braking action as a dry runway.
It is almost certain that the weight of the aircraft with 170+ pax and crew aboard and the likely fuel for a diversion to another airport was at the maximum for such a short runway. If, for whatever reason, the flight crew and dispatchers failed to take notice of the ungrooved nature of the runway and, instead, relied on the only periodically revised airport pages, they might have miscalculated their maximum allowable landing weight.
It is distressing to be aware that only a few miles to the northeast of the downtown airport is Sao Paulo's international airport with runways fully twice as long. Given the inclement conditions and the short runway at their destination it seems likely the pilots would have considered a diversion had they been fully aware of the compromised nature of the runway surface.
A disclaimer: all of the above is speculation based solely on media reports and a review of the current airport charts. It is entirely possible that the crew was aware of the ungrooved runway, had performed all appropriate performance analysis and were, sadly, the victims of circumstances ... primarily the occurrence of hydroplaning on a runway for which their was no margin for error.
Ted
Topic: Airplane crash in Brazil (Read 2654 times)