Teoricamente, amanhã expira o “prazo de validade” do “pinger” das caixas pretas. O “pinger” é o sinal ultrassônico que possibilita a sua localização por sonar.
Embora eu tenha lido em alguns lugares que apesar disso o sinal pode continuar ativo por até 60 dias, este blog, o “Unusual Attitude“, comenta que na verdade após os 30 dias a força do sinal cai acentuadamente. Diante dessa realidade, a BEA, autoridade francesa responsável pela busca, teria contratado reforços na forma de um submarino autônomo (não tripulado) da empresa americana C&C Technologies, capaz de operar a 4.500 metros de profundidade. Eis uma nota publicada pela empresa:
“Air France 447 Search Effort: Phase II Fact Sheet
June 24, 2009
C & C Technologies, Inc. (C & C) has received inquiries regarding our discussions with the French BEA on the second phase of the AF447 search effort.
The following information may help minimize communication errors:
1) Pinger Life: Dukane, the AF447 pinger manufacturer, has confirmed that the pingers may only last a day or so longer than the specified thirty days. Unlike regular flashlight batteries that fade out slowly, the battery technology used in the pingers will hold its voltage for the thirty days, and then quickly collapse along with the transmitted signal.
2) Contact by BEA: The French BEA has contacted C & C by phone and e-mail regarding use of C & C’s 4,500 meter (15,000 feet) rated autonomous underwater vehicle (AUV) to perform a sonar search for the flight recorders. C & C has two 250 foot (76 meter) ships near the crash area equipped with state-of-the-art AUV systems. However, the AUVs on those vessels are only rated for 3,000 meters (10,000 feet), and the wreck area approaches 4,500 meters. If the pingers are not found by the end of June, French authorities may ask C & C to send its 4,500 meter rated AUV to Brazil to search the mountainous underwater terrain.
3) Comments Regarding BEA’s Actions: While the first phase of the search for the flight recorders continues, the BEA is making contingency plans for a second phase. Tapping C & C’s world-renowned deepwater AUV search capability indicates the French authorities’ commitment to locate the recorders and solve the mystery. Given the complexity of the situation, the BEA is making all the right moves.
4) AUV Description: Like the unmanned drone aircraft used by the military, AUVs are unmanned, untethered, computer controlled underwater vehicles. C & C’s 4,500 meter rated vehicle is capable of searching large areas while flying at a constant height off the ocean bottom at four knots for two days at a time before returning to the surface to refuel.
The 6 meter (20 foot) cigar shaped vehicle has an acoustic communications link (wireless underwater telemetry system) that can continuously transmit the sonar images to a surface ship in real time. Any debris detected by the AUV can be seen by observers on the ship in real time. The AUV also has a camera, so ambiguous sonar contacts can be quickly identified.
Because there is no cable between the AUV and the ship, the AUV can travel more than twice the speed of ROVs (remotely operated vehicles), which are tethered. C & C’s 4,500 meter rated AUV with mother ship and experienced scientific crew offers the highest possibility of flight recorder location if the current pinger locator effort fails. Pictures and video of the AUV can be found at:! ftp://ftp.cctechnol.com/pub/outgoing/auv.zip
5) C & C’s Background: C & C is the worldwide leader in deepwater AUV operations. The company has performed more deepwater AUV searches than any company in the world, having surveyed enough to encircle the globe four times. C & C’s AUVs are usually used to perform deepwater oilfield surveys worldwide. C & C has 600 employees and operates worldwide.” [grifos meus]
Matéria do Washington Post diz que a NTSB, autoridade norte-americana que investiga acidentes aéreos, está dando uma boa olhada em incidentes recentes envolvendo aviões “computer-centric“, isto é, com controle computadorizado, como os Airbus e o Boeing 777.
Leva água para esse moinho essa descrição de um incidente (não confirmado) que teria acontecido no dia 23, no Japão (também reportado pelo “Unusual Attitude“):
Tuesday 23, 2009 10am en-route HKG to NRT. Entering Nara Japan airspace.
FL390 mostly clear with occasional isolated areas of rain, clouds tops about FL410.
Outside air temperature was -50C TAT -21C (your not supposed to get liquid water at these temps). We did.
As we were following other aircraft along our route. We approached a large area of rain below us. Tilting the weather radar down we could see the heavy rain below, displayed in red. At our altitude the radar indicated green or light precipitation, most likely ice crystals we thought.
Entering the cloud tops we experienced just light to moderate turbulence. (The winds were around 30kts at altitude.) After about 15 sec. we encountered moderate rain. We thought it odd to have rain streaming up the windshield at this altitude and the sound of the plane getting pelted like an aluminum garage door. It got very warm and humid in the cockpit all of a sudden. Five seconds later the Captains, First Officers, and standby airspeed indicators rolled back to 60kts. The auto pilot and auto throttles disengaged. The Master Warning and Master Caution flashed, and the sounds of chirps and clicks letting us know these things were happening.
Jerry S, the Capt. hand flew the plane on the shortest vector out of the rain. The airspeed indicators briefly came back but failed again. The failure lasted for THREE minutes. We flew the recommended 83%N1 power setting. When the airspeed indicators came back. we were within 5 knots of our desired speed. Everything returned to normal except for the computer logic controlling the plane. (We were in alternate law for the rest of the flight.)
We had good conditions for the failure; daylight, we were rested, relatively small area, and light turbulence. I think it could have been much worse. Jerry did a great job flying and staying cool. We did our procedures called dispatch and maintenance on the SAT COM and landed in Narita. That’s it.”
Nesta semana, há expectativa de que a BEA solte um relatório preliminar.
Há um papo nos fóruns de aviação por aí de que, baseado nas características das lesões havidas nos corpos encontrados e no tamanho e estado dos destroços, crescem as apostas na hipótese de que ao invés de se desintegrar no ar o avião tenha caído no mar descontrolado, mas relativamente intacto.