Read Online Airframe by Michael Crichton - Free Book Online Page A
Authors: Michael Crichton
Tags: Fiction, General, Suspense, Psychological, Romance, Thrillers, Suspense fiction, Espionage, Aircraft accidents, Aircraft accidents - Investigation, Adventure stories; American
Ads: Link
him.
"Optional," Smith said. "It's a customer install. I don't think they put one in. Usually on the N-22
it's in the tail, but I looked, and didn't find one."
Richman turned to Casey; he was looking puzzled again. "I thought they were getting the black boxes."
"We are," Smith said.
"There's a hundred and fifty-two black boxes?"
"Oh hell," Smith said, "they're all over the aircraft. But we're only after the main ones now—the ten or twelve NVMs that count."
"NVMs," Richman repeated.
"You got it," Smith said, and he turned away, bending over the panels.
It was left to Casey to explain. The public perception of an aircraft was that it was a big mechanical device, with pulleys and levers that moved control surfaces up and down. In the midst of this machinery were two magic black boxes, recording events in the flight. These were the black boxes that were always talked about on news programs. The CVR, the cockpit voice recorder, was essentially a very sturdy tape deck; it recorded the last half hour of cockpit conversation on a continuous loop of magnetic tape. Then there was the DFDR, the digital flight data recorder, which stored details of the behavior of the airplane, so that investigators could discover what had happened after an accident
But this image of an aircraft, Casey explained, was inaccurate for a large commercial transport. Commercial jets had very few pulleys and levers—indeed, few mechanical systems of any sort. Nearly everything was hydraulic and electrical. The pilot in the cockpit didn't move the ailerons or flaps by force of muscle. Instead, the arrangement was like power steering on an automobile: when the pilot moved the control stick and pedals, he sent electrical impulses to actuate hydraulic systems, which in turn moved the control surfaces.
The truth was that a commercial airliner was controlled by a network of extraordinarily sophisticated electronics—dozens of computer systems, linked together by hundreds of miles of wiring. There were computers for flight management, for navigation, for communication.
Computers regulated the engines, the control surfaces, the cabin environment.
Each major computer system controlled a whole array of sub-systems. Thus the navigation 41
system ran the ILS for instrument landing; the DME for distance measuring; the ATC for air traffic control; the TCAS for collision avoidance; the GPWS for ground proximity warning.
In this complex electronic environment, it was relatively easy to install a digital flight data recorder. Since all the commands were already electronic, they were simply routed through the DFDR and stored on magnetic media. "A modern DFDR records eighty separate flight parameters every second of the flight."
"Every second? How big is this thing?" Richman said.
"It's right there," Casey said, pointing. Ron was pulling an orange-and-black striped box from the radio rack. It was the size of a large shoe box. He set it on the floor, and replaced it with a new box, for the ferry flight back to Burbank.
Richman bent over, and lifted the DFDR by one stainless-steel handle. "Heavy."
That's the crash-resistant housing," Ron said. "The actual doohickey weighs maybe six ounces."
"And the other boxes? What about them?"
The other boxes existed, Casey said, to facilitate maintenance. Because the electronic systems of the aircraft were so complicated, it was necessary to monitor' the behavior of each system in case of errors, or faults, during flight. Each system tracked its own performance, in what was called Non Volatile Memory. "That's NVM "
They would download eight NVM systems today: the Flight Management Computer, which stored data on the flight plan and the pilot-entered waypoints; the Digital Engine Controller, which managed fuel bum and powerplant; the Digital Air Data Computer, which recorded airspeed, altitude, and overspeed warnings ...
"Okay," Richman said. "I think I get the point."
"None of this would be necessary," Ron Smith said,
"Optional," Smith said. "It's a customer install. I don't think they put one in. Usually on the N-22
it's in the tail, but I looked, and didn't find one."
Richman turned to Casey; he was looking puzzled again. "I thought they were getting the black boxes."
"We are," Smith said.
"There's a hundred and fifty-two black boxes?"
"Oh hell," Smith said, "they're all over the aircraft. But we're only after the main ones now—the ten or twelve NVMs that count."
"NVMs," Richman repeated.
"You got it," Smith said, and he turned away, bending over the panels.
It was left to Casey to explain. The public perception of an aircraft was that it was a big mechanical device, with pulleys and levers that moved control surfaces up and down. In the midst of this machinery were two magic black boxes, recording events in the flight. These were the black boxes that were always talked about on news programs. The CVR, the cockpit voice recorder, was essentially a very sturdy tape deck; it recorded the last half hour of cockpit conversation on a continuous loop of magnetic tape. Then there was the DFDR, the digital flight data recorder, which stored details of the behavior of the airplane, so that investigators could discover what had happened after an accident
But this image of an aircraft, Casey explained, was inaccurate for a large commercial transport. Commercial jets had very few pulleys and levers—indeed, few mechanical systems of any sort. Nearly everything was hydraulic and electrical. The pilot in the cockpit didn't move the ailerons or flaps by force of muscle. Instead, the arrangement was like power steering on an automobile: when the pilot moved the control stick and pedals, he sent electrical impulses to actuate hydraulic systems, which in turn moved the control surfaces.
The truth was that a commercial airliner was controlled by a network of extraordinarily sophisticated electronics—dozens of computer systems, linked together by hundreds of miles of wiring. There were computers for flight management, for navigation, for communication.
Computers regulated the engines, the control surfaces, the cabin environment.
Each major computer system controlled a whole array of sub-systems. Thus the navigation 41
system ran the ILS for instrument landing; the DME for distance measuring; the ATC for air traffic control; the TCAS for collision avoidance; the GPWS for ground proximity warning.
In this complex electronic environment, it was relatively easy to install a digital flight data recorder. Since all the commands were already electronic, they were simply routed through the DFDR and stored on magnetic media. "A modern DFDR records eighty separate flight parameters every second of the flight."
"Every second? How big is this thing?" Richman said.
"It's right there," Casey said, pointing. Ron was pulling an orange-and-black striped box from the radio rack. It was the size of a large shoe box. He set it on the floor, and replaced it with a new box, for the ferry flight back to Burbank.
Richman bent over, and lifted the DFDR by one stainless-steel handle. "Heavy."
That's the crash-resistant housing," Ron said. "The actual doohickey weighs maybe six ounces."
"And the other boxes? What about them?"
The other boxes existed, Casey said, to facilitate maintenance. Because the electronic systems of the aircraft were so complicated, it was necessary to monitor' the behavior of each system in case of errors, or faults, during flight. Each system tracked its own performance, in what was called Non Volatile Memory. "That's NVM "
They would download eight NVM systems today: the Flight Management Computer, which stored data on the flight plan and the pilot-entered waypoints; the Digital Engine Controller, which managed fuel bum and powerplant; the Digital Air Data Computer, which recorded airspeed, altitude, and overspeed warnings ...
"Okay," Richman said. "I think I get the point."
"None of this would be necessary," Ron Smith said,
Similar Books
