I don't like flying in summer. That's when the crashes happen the most.
Ms. Couric isn't exactly accurate. Every part of the plane is shielded from lightning except the nosecone weather radar which can't work if it's shielded. Because of this risk, that radar system is isolated (or should be) from the rest of the electrical system which includes lightning arrestors. The average commercial liner gets struck three times a year so it's not a big deal.
What I'm considering right now is the possibility that this is related to the problem that Qantas QF72 had. QF72 was flying from Singapore to Perth and not once, but twice, experienced sudden drops in altitude due to a faulty air data inertial reference unit (ADIRU). That little bugger measures everything about the airplane's attitude and position and sends it off to the flight computer. The ADIRU in the QF72 was faulty, sending jibberish to the flight computer which tried to correct course and attitude based upon that faulty information. The main computer is supposed to see that the ADIRU is fucked and take it offline, relying on backups. Supposedly, this problem was fixed.
What has cropped-up however, is that the ADIRU is only polled of its readings every 1.5 seconds. Should the flight computer see the ADIRU is sending jibberish during a period of any less than 1.5 seconds, then it doesn't know the ADIRU is malfunctioning because the 1.5 second threshold hasn't been reached. That means that the flight computer may make erroneous corrections based on faulty data. The A330, again, flies by wire. The plane flies itself unless overridden and will make radical corrections to the flight path if it deems necessary. While that small window of 1.5 seconds may seem minimal, it may have contributed to the problem with the QF72 flight though this is only a theory on the part of some pilots. Airbus does not consider the ADIRU polling period to be an issue.
Now if all this started suddenly and the pilots were trying to respond to the sudden change in plane direction and attitude because of an ADIRU failure, and given the possible flimsiness of the surface controls while under manual backup control (as seen on AA587), and given the heavy turbulence the plane reported, I wonder if this wasn't a factor.
Talking to pilots, many expressed a concern about fire. When there's a short, as the plane reported, there are sparks and where there are sparks, there's potential for fire. The A330 does have smoke detectors in the passenger cabin, cargo hold, toilets, and cockpit, but nowhere else. Their worry is that a lightning strike could have precipitated a fire that went unnoticed because it was in the fuselage or some other area that goes unmonitored. Because of cabin pressurization, smoke on planes doesn't always act like it does in the normal world and a fire could progress to the point it damages components without the cockpit crew knowing.
Something else too. The global SATCOM system doesn't track commercial planes despite the fact that many are fitted with satellite phone systems. This system is essentially a flying GPS system and while you can't triangulate the position of a plane using SATCOM, the plane already tracks itself. It would take next to nothing in cost or programming to fit the satellite phone systems with a transponder that would keep the plane transmitting its exact position to the satellite system and then on to anywhere else. If this system had been enabled, we'd know where the plane was.
Ms. Couric isn't exactly accurate. Every part of the plane is shielded from lightning except the nosecone weather radar which can't work if it's shielded. Because of this risk, that radar system is isolated (or should be) from the rest of the electrical system which includes lightning arrestors. The average commercial liner gets struck three times a year so it's not a big deal.
What I'm considering right now is the possibility that this is related to the problem that Qantas QF72 had. QF72 was flying from Singapore to Perth and not once, but twice, experienced sudden drops in altitude due to a faulty air data inertial reference unit (ADIRU). That little bugger measures everything about the airplane's attitude and position and sends it off to the flight computer. The ADIRU in the QF72 was faulty, sending jibberish to the flight computer which tried to correct course and attitude based upon that faulty information. The main computer is supposed to see that the ADIRU is fucked and take it offline, relying on backups. Supposedly, this problem was fixed.
What has cropped-up however, is that the ADIRU is only polled of its readings every 1.5 seconds. Should the flight computer see the ADIRU is sending jibberish during a period of any less than 1.5 seconds, then it doesn't know the ADIRU is malfunctioning because the 1.5 second threshold hasn't been reached. That means that the flight computer may make erroneous corrections based on faulty data. The A330, again, flies by wire. The plane flies itself unless overridden and will make radical corrections to the flight path if it deems necessary. While that small window of 1.5 seconds may seem minimal, it may have contributed to the problem with the QF72 flight though this is only a theory on the part of some pilots. Airbus does not consider the ADIRU polling period to be an issue.
Now if all this started suddenly and the pilots were trying to respond to the sudden change in plane direction and attitude because of an ADIRU failure, and given the possible flimsiness of the surface controls while under manual backup control (as seen on AA587), and given the heavy turbulence the plane reported, I wonder if this wasn't a factor.
Talking to pilots, many expressed a concern about fire. When there's a short, as the plane reported, there are sparks and where there are sparks, there's potential for fire. The A330 does have smoke detectors in the passenger cabin, cargo hold, toilets, and cockpit, but nowhere else. Their worry is that a lightning strike could have precipitated a fire that went unnoticed because it was in the fuselage or some other area that goes unmonitored. Because of cabin pressurization, smoke on planes doesn't always act like it does in the normal world and a fire could progress to the point it damages components without the cockpit crew knowing.
Something else too. The global SATCOM system doesn't track commercial planes despite the fact that many are fitted with satellite phone systems. This system is essentially a flying GPS system and while you can't triangulate the position of a plane using SATCOM, the plane already tracks itself. It would take next to nothing in cost or programming to fit the satellite phone systems with a transponder that would keep the plane transmitting its exact position to the satellite system and then on to anywhere else. If this system had been enabled, we'd know where the plane was.
