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Delta Air Lines Flight 173
Delta Air Lines Flight 723 was a Douglas DC-9 twin-engine jetliner, operating as a scheduled domestic passenger flight from Burlington, Vermont to Logan International Airport in Boston, Massachusetts, with an intermediate stop in Manchester, New Hampshire. On July 31, 1973 at 11:08 AM, while on an instrument landing system (ILS) instrument approach into Logan in low clouds and fog, the aircraft descended below the glidepath, struck a seawall and crashed, killing all 89 occupants; two people initially survived, but later died of their injuries. Aircraft and crew The DC-9-31, registration serial number 47075, was manufactured in September 1967 and had 14,639 flight hours at the time of the accident. The jetliner was one of the aircraft that Delta Air Lines acquired in their 1972 merger with Northeast Airlines, to whom the aircraft was originally delivered. The flight crew consisted of Captain John Streil (49) and First Officer Sidney Burrill (31). Captain Streil, a highly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Controlled Flight Into Terrain
In aviation, a controlled flight into terrain (CFIT; usually ) is an accident in which an airworthy aircraft, under pilot control, is unintentionally flown into the ground, a mountain, a body of water or an obstacle. In a typical CFIT scenario, the crew is unaware of the impending disaster until it is too late. The term was coined by engineers at Boeing in the late 1970s. Accidents where the aircraft is out of control at the time of impact, because of mechanical failure or pilot error, are not considered CFIT (they are known as ''uncontrolled flight into terrain'' or ''UFIT''), nor are incidents resulting from the deliberate action of the person at the controls, such as acts of terrorism or suicide by pilot. According to Boeing in 1997, CFIT was a leading cause of airplane accidents involving the loss of life, causing over 9,000 deaths since the beginning of the commercial jet aircraft. CFIT was identified as a cause of 25% of USAF Class A mishaps between 1993 and 2002. Accord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northeast Airlines
Northeast Airlines was an American airline based in Boston, Massachusetts that chiefly operated in the northeastern United States, and later to Canada, Florida, the Bahamas, Los Angeles and other cities. It was acquired by and merged into Delta Air Lines in August 1972. History The airline began as Boston-Maine Airways, founded as a Pan Am contract carrier on July 20, 1931, by the Boston and Maine Railroad and Maine Central Railroad, flying from Boston to Bangor via Portland. It flew only sporadically until August 11, 1933, when National Airways began to operate its flights under contract. National also operated Central Vermont Airways, a subsidiary of the Central Vermont Railway, and the two carriers together had a network across New England to New Hampshire, Vermont, and Montreal. Amelia Earhart and Eugene Vidal were among the co-founders of National, and Earhart was a prominent salesperson for the airline in its early years. National initially operated Stinson Airli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cockpit Voice Recorder
A flight recorder is an electronic recording device placed in an aircraft for the purpose of facilitating the investigation of aviation accidents and incidents. The device may often be referred to as a "black box", an outdated name which has become a misnomer—they are now required to be painted bright orange, to aid in their recovery after accidents. There are two types of flight recording devices: the flight data recorder (FDR) preserves the recent history of the flight through the recording of dozens of parameters collected several times per second; the cockpit voice recorder (CVR) preserves the recent history of the sounds in the cockpit, including the conversation of the pilots. The two devices may be combined into a single unit. Together, the FDR and CVR objectively document the aircraft's flight history, which may assist in any later investigation. The two flight recorders are required by international regulation, overseen by the International Civil Aviation Organiza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Runway Visual Range
In aviation, the runway visual range (RVR) is the distance over which a pilot of an aircraft on the centreline of the runway can see the runway surface markings delineating the runway or identifying its centre line. RVR is normally expressed in meters or feet. RVR is used to determine the landing and takeoff conditions for aircraft pilots, as well as the type of operational visual aids used at the airport. Measurement Originally RVR was measured by a person, either by viewing the runway lights from the top of a vehicle parked on the runway threshold, or by viewing special angled runway lights from a tower at one side of the runway. The number of lights visible could then be converted to a distance to give the RVR. This is known as the ''human observer method'' and can still be used as a fall-back. Today most airports use instrumented runway visual range (IRVR), which is measured by devices called scatterometers which provide simplified installation as they are integrated units ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceiling (cloud)
In aviation, ceiling is a measurement of the height of the base of the lowest clouds (not to be confused with cloud base which has a specific definition) that cover more than half of the sky (more than 4 oktas) relative to the ground. Ceiling is not specifically reported as part of the METAR (METeorological Aviation Report) used for flight planning by pilots worldwide, but can be deduced from the lowest height with broken (BKN) or overcast (OVC) reported. A ceiling listed as "unlimited" means either that the sky is mostly free of cloud cover, or that the cloud is high enough not to impede Visual Flight Rules ( VFR) operation. Definitions ; ICAO : The height above the ground or water of the base of the lowest layer of cloud below 6000 meters (20,000 feet) covering more than half the sky. ; United Kingdom : The vertical distance from the elevation of an aerodrome to the lowest part of any cloud visible from the aerodrome which is sufficient to obscure more than half of the sky. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Displaced Threshold
A displaced threshold or DTHR is a runway threshold located at a point other than the physical beginning or end of the runway. The portion of the runway behind a displaced threshold may be used for takeoff in either direction and landings from the opposite direction. After landing at the other end, the landing aircraft may use the area behind the displaced threshold for roll out.Aircraft Information Manual 2013, Chapter 2-3-3 h (2) Section 3. Airport Marking Aids and Signs /ref> Most often, the offset threshold is in place to give arriving aircraft clearance over an obstruction, while still allo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seawall
A seawall (or sea wall) is a form of coastal defense constructed where the sea, and associated coastal processes, impact directly upon the landforms of the coast. The purpose of a seawall is to protect areas of human habitation, conservation and leisure activities from the action of tides, waves, or tsunamis. As seawall is a static feature it will conflict with the dynamic nature of the coast and impede the exchange of sediment between land and sea. Seawall designs factor in local climate, coastal position, wave regime (determined by wave characteristics and effectors), and value (morphological characteristics) of landform. Seawalls are hard engineering shore-based structures which protect the coast from erosion. Various environmental issues may arise from the construction of a seawall, including the disruption of sediment movement and transport patterns. Combined with a high construction cost, this has led to an increasing use of other soft engineering coastal management op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airspeed
In aviation, airspeed is the speed of an aircraft relative to the air. Among the common conventions for qualifying airspeed are: * Indicated airspeed ("IAS"), what is read on an airspeed gauge connected to a Pitot-static system; * Calibrated airspeed ("CAS"), indicated airspeed adjusted for pitot system position and installation error; * Equivalent airspeed ("EAS"), calibrated airspeed adjusted for compressibility effects; * True airspeed ("TAS"), equivalent airspeed adjusted for air density, and is also the speed of the aircraft through the air in which it is flying. Calibrated airspeed is typically within a few knots of indicated airspeed, while equivalent airspeed decreases slightly from CAS as aircraft altitude increases or at high speeds. With EAS constant, true airspeed increases as aircraft altitude increases. This is because air density decreases with higher altitude. The measurement and indication of airspeed is ordinarily accomplished on board an aircraft by an ai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Final Approach (aviation)
In aeronautics, the final approach (also called the final leg and final approach leg) is the last leg in an aircraft's approach to landing, when the aircraft is lined up with the runway and descending for landing.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 213 and 241. Aviation Supplies & Academics, 1997. In aviation radio terminology, it is often shortened to "final". In a standard airport landing pattern, which is usually used under visual meteorological conditions (VMC), aircraft turn from base leg to final within one-half to two miles of the airport. For instrument approaches, as well as approaches into a controlled airfield under visual flight rules (VFR), often a "straight-in" final approach is used, where all the other legs are dispensed with. Straight-in approaches are discouraged at non-towered airports in the United States. Approach slope An approach slope is the path that an airplane follows on its final approach to land on a runwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terminal Control Center
Air traffic control (ATC) is a service provided by ground-based air traffic controllers who direct aircraft on the ground and through a given section of controlled airspace, and can provide advisory services to aircraft in non-controlled airspace. The primary purpose of ATC worldwide is to prevent collisions, organize and expedite the flow of air traffic, and provide information and other support for pilots. Air traffic controllers monitor the location of aircraft in their assigned airspace by radar and communicate with the pilots by radio. To prevent collisions, ATC enforces traffic separation rules, which ensure each aircraft maintains a minimum amount of empty space around it at all times. In many countries, ATC provides services to all private, military, and commercial aircraft operating within its airspace. Depending on the type of flight and the class of airspace, ATC may issue ''instructions'' that pilots are required to obey, or ''advisories'' (known as ''flight infor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft Vectoring
Aircraft vectoring is a navigation service provided to aircraft by air traffic control. The controller decides on a particular airfield traffic pattern for the aircraft to fly, composed of specific legs or vectors. The aircraft then follows this pattern when the controller instructs the pilot to fly specific headings at appropriate times. Vectoring is used to separate aircraft by a specified distance, to aid the navigation of flights, and to guide arriving aircraft to a position from which they can continue their final approach to land under the guidance of an approach procedure published by the FAA.FAA Order JO 7110.65Z - Air Traffic Controlchapter 5, "Radar", section 6 "Vectoring" Effective: December 2, 2021. FAA National Headquarters (FOB−10B) Publications & Administration (AJV-P12), Department of Transportation, Federal Aviation Administration. Retrieved March 24, 2022. Vectoring is the provision of navigational guidance to aircraft in the form of specific headings, based o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glideslope
Instrument landing system glide path, commonly referred to as a glide path (G/P) or glide slope (G/S), is "a system of vertical guidance embodied in the instrument landing system which indicates the vertical deviation of the aircraft from its optimum path of descent", according to ''Article 1.106'' of the ITU Radio Regulations (ITU RR).ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.106, definition: ''instrument landing system (ILS)'' Principle of operation A glide slope station uses an antenna array sited to one side of the runway touchdown zone. The GS signal is transmitted on a carrier signal using a technique similar to that for the localizer. The centre of the glide slope signal is arranged to define a glide path of approximately 3° above horizontal (ground level). The beam is 1.4° deep (0.7° below the glide-path centre and 0.7° above). The pilot (or the autopilot, if using autoland) controls the aircraft so that the glide slope indicator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
