A few weeks and several thousand miles apart, two fatal accidents make me ask the following question: Do computers have common sense?
As far as this scribbler knows, the answer is: NO!
Just before going into total silence, the computers aboard Air France’s flight 447 sent a series of messages indicating systems problems. Though still a matter of speculation, a pitot tube might have malfunctioned and precipitated a fatal chain of events.
Yesterday a DC Metro train crashed into another train killing and injuring people. Computers aboard the DC trains are supposed to prevent this from happening.
Many years ago when computers were restricted to large buildings in rooms with lots of no smoking signs, I flew old Curtis C-46 cargo planes. These cigar shaped monsters were primitive even for those days. They had two pitot tubes that fed speed and altitude info to two independent sets of instruments, one for each pilot.
I was a young copilot with less than a thousand hours total flying time when the captain asked me what was my indicated airspeed. My instrument indicated 135 knots, which was normal. His showed 110 and was slowly going down. We were flying through nasty icing conditions. The weather reported by all airports within our reach was dismal.
“You fly this heifer,” the captain said.
I was not in the least happy with this. That the weather reported at our destination was ceiling 200 feet, visibility one quarter of a mile didn’t bother me. Our windscreen was covered with ice and we couldn’t see outside.
I maneuvered the plane, got all the needles centered and began an ILS approach. I did everything the way I was taught during training. Our chief pilot demanded that we’d be capable of doing a prohibited zero-zero landing. It could save your life, he insisted.
That night, I didn’t know we were on the ground until the tail wheel touched the snow covered runway.
Many years later when flying the Boeing 707, I was having drinks with a 747 KLM captain. I was amazed to hear that their company rules prohibited pilots from making a manual approach when the ceiling was less than 1500 feet. He was quite happy with the rule as he thought the computer driven autopilot did a much better job than a human could.
My approach to flying was that of a concert violinist, you’ve got to practice, practice, practice. Having all the bells and whistles was great. I was too polite to remind the Dutch pilot that systems fail. Every day.
A good example of the unthinkable was the U.S. Airways flight 1549 simultaneous failure of both engines. Captain Sullenberger had to rely on his training, experience and skill to bring plane and passengers to relative safety.
It is too early to jump to conclusions on what happened on the DC Red Line. I suspect that over reliance on computers has a lot to do with this disaster.