相关题目
By the end of 1995，a new soft ground arresting system should reduce potential damage to aircraft overshooting the runways at the New York and New Jersey airports. The new system will be installed at the end of two or three runways at JFK international (1995/1997), one at Newark International (1998), and two at LaGuardia Airport (1996), all falling short of the 1000 ft(350m) overrun required by the Federal Aviation Administration (FAA). In a four-year cooperative agreement, the Port Authority of New York and New Jersey, owners of the region’s three major airports, has agreed to fund up to $4.5 million jointly with the FAA, to complete research, design, installation and monitoring of the concrete based foam blocks, said to bring a four-engined Boeing 747 travelling at 60mph to a full stop in under 600ft (183m). Information gathered during operation of the first block, to be in place at JFK by the end of the year, is intended to be used by the FAA for the preparation of a nationwide standard. The system, designed by ESCO (Engineering Systems Company) has already been suc cessfully tested at the FAA’s Technical Center, but requires further detailed investigation before the design can be finalized. Questions that still need to be answered revolve around the ease of snow removal, maintenance, strength and longevity, and on how to stop animals burrowing into the soft material. These will ultimately determine the composition of the arrester blocks. A full-scale test with an aircraft will be undertaken at the Technical Center in June. The precast foam blocks comprise a mixture of foaming agents bound by cementations material, producing a low density, light weight aerated block with little tensile strength, so that it is easily crushed when overrun by an aircraft, simulating the effect of being bogged down in sand. This deliberate fragility will affect not only the size of the blocks and jointing, but also transportation. For this reason, ESCO will be setting up a precasting factory at JFK for the first installation covering an area of 150 ft (45m) --the width of the runways--by 540ft (165m) in length. 4. will ultimately determine the composition of the arrester blocks.
By the end of 1995，a new soft ground arresting system should reduce potential damage to aircraft overshooting the runways at the New York and New Jersey airports. The new system will be installed at the end of two or three runways at JFK international (1995/1997), one at Newark International (1998), and two at LaGuardia Airport (1996), all falling short of the 1000 ft(350m) overrun required by the Federal Aviation Administration (FAA). In a four-year cooperative agreement, the Port Authority of New York and New Jersey, owners of the region’s three major airports, has agreed to fund up to $4.5 million jointly with the FAA, to complete research, design, installation and monitoring of the concrete based foam blocks, said to bring a four-engined Boeing 747 travelling at 60mph to a full stop in under 600ft (183m). Information gathered during operation of the first block, to be in place at JFK by the end of the year, is intended to be used by the FAA for the preparation of a nationwide standard. The system, designed by ESCO (Engineering Systems Company) has already been suc cessfully tested at the FAA’s Technical Center, but requires further detailed investigation before the design can be finalized. Questions that still need to be answered revolve around the ease of snow removal, maintenance, strength and longevity, and on how to stop animals burrowing into the soft material. These will ultimately determine the composition of the arrester blocks. A full-scale test with an aircraft will be undertaken at the Technical Center in June. The precast foam blocks comprise a mixture of foaming agents bound by cementations material, producing a low density, light weight aerated block with little tensile strength, so that it is easily crushed when overrun by an aircraft, simulating the effect of being bogged down in sand. This deliberate fragility will affect not only the size of the blocks and jointing, but also transportation. For this reason, ESCO will be setting up a precasting factory at JFK for the first installation covering an area of 150 ft (45m) --the width of the runways--by 540ft (165m) in length. 3. Which of the following hasn＇t funded for the development of the new system?
By the end of 1995，a new soft ground arresting system should reduce potential damage to aircraft overshooting the runways at the New York and New Jersey airports. The new system will be installed at the end of two or three runways at JFK international (1995/1997), one at Newark International (1998), and two at LaGuardia Airport (1996), all falling short of the 1000 ft(350m) overrun required by the Federal Aviation Administration (FAA). In a four-year cooperative agreement, the Port Authority of New York and New Jersey, owners of the region’s three major airports, has agreed to fund up to $4.5 million jointly with the FAA, to complete research, design, installation and monitoring of the concrete based foam blocks, said to bring a four-engined Boeing 747 travelling at 60mph to a full stop in under 600ft (183m). Information gathered during operation of the first block, to be in place at JFK by the end of the year, is intended to be used by the FAA for the preparation of a nationwide standard. The system, designed by ESCO (Engineering Systems Company) has already been suc cessfully tested at the FAA’s Technical Center, but requires further detailed investigation before the design can be finalized. Questions that still need to be answered revolve around the ease of snow removal, maintenance, strength and longevity, and on how to stop animals burrowing into the soft material. These will ultimately determine the composition of the arrester blocks. A full-scale test with an aircraft will be undertaken at the Technical Center in June. The precast foam blocks comprise a mixture of foaming agents bound by cementations material, producing a low density, light weight aerated block with little tensile strength, so that it is easily crushed when overrun by an aircraft, simulating the effect of being bogged down in sand. This deliberate fragility will affect not only the size of the blocks and jointing, but also transportation. For this reason, ESCO will be setting up a precasting factory at JFK for the first installation covering an area of 150 ft (45m) --the width of the runways--by 540ft (165m) in length. 2. By the end of 1998, at least how many airports will have installed the new system?
By the end of 1995，a new soft ground arresting system should reduce potential damage to aircraft overshooting the runways at the New York and New Jersey airports. The new system will be installed at the end of two or three runways at JFK international (1995/1997), one at Newark International (1998), and two at LaGuardia Airport (1996), all falling short of the 1000 ft(350m) overrun required by the Federal Aviation Administration (FAA). In a four-year cooperative agreement, the Port Authority of New York and New Jersey, owners of the region’s three major airports, has agreed to fund up to $4.5 million jointly with the FAA, to complete research, design, installation and monitoring of the concrete based foam blocks, said to bring a four-engined Boeing 747 travelling at 60mph to a full stop in under 600ft (183m). Information gathered during operation of the first block, to be in place at JFK by the end of the year, is intended to be used by the FAA for the preparation of a nationwide standard. The system, designed by ESCO (Engineering Systems Company) has already been suc cessfully tested at the FAA’s Technical Center, but requires further detailed investigation before the design can be finalized. Questions that still need to be answered revolve around the ease of snow removal, maintenance, strength and longevity, and on how to stop animals burrowing into the soft material. These will ultimately determine the composition of the arrester blocks. A full-scale test with an aircraft will be undertaken at the Technical Center in June. The precast foam blocks comprise a mixture of foaming agents bound by cementations material, producing a low density, light weight aerated block with little tensile strength, so that it is easily crushed when overrun by an aircraft, simulating the effect of being bogged down in sand. This deliberate fragility will affect not only the size of the blocks and jointing, but also transportation. For this reason, ESCO will be setting up a precasting factory at JFK for the first installation covering an area of 150 ft (45m) --the width of the runways--by 540ft (165m) in length. 1.The new soft ground arresting system is designed to .
Radio navigation is used by all commercial pilots, as well as by most other pilots. For this type of navigation, the pilot tunes the radio navigation equipment so as to receive a signal from a ground stationed NAVAID (navigation aid). A needle on the equipment tells the pilot when he is flying on a direct course to or from the station. It also shows when the aircraft drifts off course so that its direction can be corrected. The most common system designed for civil aircraft is called VOR (very-high frequency omni-directional radio beacon). In con junction with the VOR, airlines use another special device called DME (distance measuring equipment). This combined system is known as VOR/DME. A similar system used almost exclusively for military aircraft is called TACAN (tactical air navigation). A combined system, called VORTAC, can be used by both civil and military aircraft. Prior to the evolution of these systems (VOR, TACAN, and VORTAC) the radio compass low- frequency radio receiver in conjunction with the non-directional beacon (NDB) was the mainstay of air naviga tion. The low-frequency radio receiver allows the pilot to home on signals from the radio station. By applying certain procedural steps, the pilot is then able to navigate off of the station. These non-directional radio beacons, however, are subject to disturbances such as fading signals and interference from distant stations during night operations, which can cause the instrument to deviate drastically. There are three transoceanic navigation system commonly used by civilian air transports throughout the world:(1) Inertial Navigation Systems，(2) LORAN (long range navigation)，(3) Decca. Inertial navigation equipment is especially suitable for unaided operation during long flights over water or land areas without adequate radio stations on the ground; its functions naturally complement those of radio navigation systems. The LORAN (long range navigation) system was developed in the United States during World War II to overcome the accuracy limitations of older systems. Several LORAN sys tems cover most of the important trade routes of the world. They are used by marine naviga tors as well as air navigators. The Decca system was developed in Great Britain, also during World War II. It has since come into extensive use in many parts of the world. Decca is like LORAN in principle, the main difference being the type of signals used. Planes which use LORAN or Decca have equipment for receiving special signals, sent out continuously from transmitting stations, to indicate the plane’s exact position.5. is the most suitable title of the passage.
Radio navigation is used by all commercial pilots, as well as by most other pilots. For this type of navigation, the pilot tunes the radio navigation equipment so as to receive a signal from a ground stationed NAVAID (navigation aid). A needle on the equipment tells the pilot when he is flying on a direct course to or from the station. It also shows when the aircraft drifts off course so that its direction can be corrected. The most common system designed for civil aircraft is called VOR (very-high frequency omni-directional radio beacon). In con junction with the VOR, airlines use another special device called DME (distance measuring equipment). This combined system is known as VOR/DME. A similar system used almost exclusively for military aircraft is called TACAN (tactical air navigation). A combined system, called VORTAC, can be used by both civil and military aircraft. Prior to the evolution of these systems (VOR, TACAN, and VORTAC) the radio compass low- frequency radio receiver in conjunction with the non-directional beacon (NDB) was the mainstay of air naviga tion. The low-frequency radio receiver allows the pilot to home on signals from the radio station. By applying certain procedural steps, the pilot is then able to navigate off of the station. These non-directional radio beacons, however, are subject to disturbances such as fading signals and interference from distant stations during night operations, which can cause the instrument to deviate drastically. There are three transoceanic navigation system commonly used by civilian air transports throughout the world:(1) Inertial Navigation Systems，(2) LORAN (long range navigation)，(3) Decca. Inertial navigation equipment is especially suitable for unaided operation during long flights over water or land areas without adequate radio stations on the ground; its functions naturally complement those of radio navigation systems. The LORAN (long range navigation) system was developed in the United States during World War II to overcome the accuracy limitations of older systems. Several LORAN sys tems cover most of the important trade routes of the world. They are used by marine naviga tors as well as air navigators. The Decca system was developed in Great Britain, also during World War II. It has since come into extensive use in many parts of the world. Decca is like LORAN in principle, the main difference being the type of signals used. Planes which use LORAN or Decca have equipment for receiving special signals, sent out continuously from transmitting stations, to indicate the plane’s exact position.4. Comparatively speaking, is the earliest system of air navigation.
Radio navigation is used by all commercial pilots, as well as by most other pilots. For this type of navigation, the pilot tunes the radio navigation equipment so as to receive a signal from a ground stationed NAVAID (navigation aid). A needle on the equipment tells the pilot when he is flying on a direct course to or from the station. It also shows when the aircraft drifts off course so that its direction can be corrected. The most common system designed for civil aircraft is called VOR (very-high frequency omni-directional radio beacon). In con junction with the VOR, airlines use another special device called DME (distance measuring equipment). This combined system is known as VOR/DME. A similar system used almost exclusively for military aircraft is called TACAN (tactical air navigation). A combined system, called VORTAC, can be used by both civil and military aircraft. Prior to the evolution of these systems (VOR, TACAN, and VORTAC) the radio compass low- frequency radio receiver in conjunction with the non-directional beacon (NDB) was the mainstay of air naviga tion. The low-frequency radio receiver allows the pilot to home on signals from the radio station. By applying certain procedural steps, the pilot is then able to navigate off of the station. These non-directional radio beacons, however, are subject to disturbances such as fading signals and interference from distant stations during night operations, which can cause the instrument to deviate drastically. There are three transoceanic navigation system commonly used by civilian air transports throughout the world:(1) Inertial Navigation Systems，(2) LORAN (long range navigation)，(3) Decca. Inertial navigation equipment is especially suitable for unaided operation during long flights over water or land areas without adequate radio stations on the ground; its functions naturally complement those of radio navigation systems. The LORAN (long range navigation) system was developed in the United States during World War II to overcome the accuracy limitations of older systems. Several LORAN sys tems cover most of the important trade routes of the world. They are used by marine naviga tors as well as air navigators. The Decca system was developed in Great Britain, also during World War II. It has since come into extensive use in many parts of the world. Decca is like LORAN in principle, the main difference being the type of signals used. Planes which use LORAN or Decca have equipment for receiving special signals, sent out continuously from transmitting stations, to indicate the plane’s exact position.3. is especially suitable for unaided operation during long flights over water or land areas without enough ground stations.
Radio navigation is used by all commercial pilots, as well as by most other pilots. For this type of navigation, the pilot tunes the radio navigation equipment so as to receive a signal from a ground stationed NAVAID (navigation aid). A needle on the equipment tells the pilot when he is flying on a direct course to or from the station. It also shows when the aircraft drifts off course so that its direction can be corrected. The most common system designed for civil aircraft is called VOR (very-high frequency omni-directional radio beacon). In con junction with the VOR, airlines use another special device called DME (distance measuring equipment). This combined system is known as VOR/DME. A similar system used almost exclusively for military aircraft is called TACAN (tactical air navigation). A combined system, called VORTAC, can be used by both civil and military aircraft. Prior to the evolution of these systems (VOR, TACAN, and VORTAC) the radio compass low- frequency radio receiver in conjunction with the non-directional beacon (NDB) was the mainstay of air naviga tion. The low-frequency radio receiver allows the pilot to home on signals from the radio station. By applying certain procedural steps, the pilot is then able to navigate off of the station. These non-directional radio beacons, however, are subject to disturbances such as fading signals and interference from distant stations during night operations, which can cause the instrument to deviate drastically. There are three transoceanic navigation system commonly used by civilian air transports throughout the world:(1) Inertial Navigation Systems，(2) LORAN (long range navigation)，(3) Decca. Inertial navigation equipment is especially suitable for unaided operation during long flights over water or land areas without adequate radio stations on the ground; its functions naturally complement those of radio navigation systems. The LORAN (long range navigation) system was developed in the United States during World War II to overcome the accuracy limitations of older systems. Several LORAN sys tems cover most of the important trade routes of the world. They are used by marine naviga tors as well as air navigators. The Decca system was developed in Great Britain, also during World War II. It has since come into extensive use in many parts of the world. Decca is like LORAN in principle, the main difference being the type of signals used. Planes which use LORAN or Decca have equipment for receiving special signals, sent out continuously from transmitting stations, to indicate the plane’s exact position.2. According to the passage, the most common system for military aircraft is .
Radio navigation is used by all commercial pilots, as well as by most other pilots. For this type of navigation, the pilot tunes the radio navigation equipment so as to receive a signal from a ground stationed NAVAID (navigation aid). A needle on the equipment tells the pilot when he is flying on a direct course to or from the station. It also shows when the aircraft drifts off course so that its direction can be corrected. The most common system designed for civil aircraft is called VOR (very-high frequency omni-directional radio beacon). In con junction with the VOR, airlines use another special device called DME (distance measuring equipment). This combined system is known as VOR/DME. A similar system used almost exclusively for military aircraft is called TACAN (tactical air navigation). A combined system, called VORTAC, can be used by both civil and military aircraft. Prior to the evolution of these systems (VOR, TACAN, and VORTAC) the radio compass low- frequency radio receiver in conjunction with the non-directional beacon (NDB) was the mainstay of air naviga tion. The low-frequency radio receiver allows the pilot to home on signals from the radio station. By applying certain procedural steps, the pilot is then able to navigate off of the station. These non-directional radio beacons, however, are subject to disturbances such as fading signals and interference from distant stations during night operations, which can cause the instrument to deviate drastically. There are three transoceanic navigation system commonly used by civilian air transports throughout the world:(1) Inertial Navigation Systems，(2) LORAN (long range navigation)，(3) Decca. Inertial navigation equipment is especially suitable for unaided operation during long flights over water or land areas without adequate radio stations on the ground; its functions naturally complement those of radio navigation systems. The LORAN (long range navigation) system was developed in the United States during World War II to overcome the accuracy limitations of older systems. Several LORAN sys tems cover most of the important trade routes of the world. They are used by marine naviga tors as well as air navigators. The Decca system was developed in Great Britain, also during World War II. It has since come into extensive use in many parts of the world. Decca is like LORAN in principle, the main difference being the type of signals used. Planes which use LORAN or Decca have equipment for receiving special signals, sent out continuously from transmitting stations, to indicate the plane’s exact position.1. According to the passage, the most common system for civil aircraft is .
American Airlines Flight 11, operated by a Boeing 767-223ER (N334AA) on the morning of September 11, 2001, departed runway 4R at Logan International Airport in Boston, Massachusetts for the 5+ hour flight to Los Angeles, California at 7:59 am local time. On board the aircraft were 81 passengers (including five hijackers), nine flight attendants, and the two pilots. Shortly after its departure, Flight 11 disappeared from FAA radar screens, and ceased responding to radio calls from air traffic controllers. At 8:24 am, the Captain of another aircraft on the air traffic control frequency, United Airlines Flight 175, reported that We heard a suspicious transmission on out departure from BOS, sounds like someone keyed the mike and said everyone stay in your seats. Less than ninety seconds later, UA 175 would suffer the same fate. At 8:45 am, Flight 11’s aircraft was flown into the side of the North 110-floor tower-between the 80th and 90th floors-of the World Trade Center Plaza in New York City＇s financial district. The aircraft impacted the tower at an estimated 350 knots. This fact, combined with the large amount of burning jet fuel, led to severe structural damage within the tower, which caused its eventual collapse some 104 minutes later at 10:29 am local time.5. Where did American Airlines Flight 11 impact with the tower?
