Estado: | Accident investigation report completed and information captured |
Fecha: | martes 31 julio 1973 |
Hora: | 11:08 |
Tipo: | McDonnell Douglas DC-9-31 |
Operador: | Delta Air Lines |
Registración: | N975NE |
Numéro de série: | 47075/166 |
Año de Construcción: | 1967 |
Horas Totales de la Célula: | 14639 |
Motores: | 2 Pratt & Whitney JT8D-7 |
Tripulación: | Fatalidades: 6 / Ocupantes: 6 |
Pasajeros: | Fatalidades: 82 / Ocupantes: 83 |
Total: | Fatalidades: 88 / Ocupantes: 89 |
Daños en la Aeronave: | Destruido |
Consecuencias: | Written off (damaged beyond repair) |
Ubicación: | Boston-Logan International Airport, MA (BOS) ( Estados Unidos de América)
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Elevación del lugar del accidente: | 6 m (20 feet) amsl |
Fase: | Aproximación (APR) |
Naturaleza: | Vuelo Doméstico Programado |
Aeropuerto de Salida: | Manchester Municipal Airport, NH (MHT/KMHT), Estados Unidos de América |
Aeropuerto de Llegada: | Boston-Logan International Airport, MA (BOS/KBOS), Estados Unidos de América |
Número de Vuelo: | DL723 |
Descripción:As Delta Flight 723 was descending, the approach clearance was given by the controller after a delay, because the controller was preoccupied with a potential conflict between two other aircraft. This caused the flight to be poorly positioned for approach. The aircraft passed the Outer Marker at a speed of 385 km/h (80 km/h too fast) and was 60 m above the glide slope.
The flight director was inadvertently used in the 'go-around-mode', which led to abnormal instrument indications. This caused some confusion. The first officer, who was flying the approach became preoccupied with the problem. The DC-9 continued to descend and struck a seawall 3000 feet short of and 150 feet to the right of runway 04R, crashed and caught fire. RVR at the time was 500 m with 60 m overcast.
All occupants, except one passenger, were killed in the crash. The lone survivor, who had been injured critically, died on December 11, 1973.
Probable Cause:
PROBABLE CAUSE: "The failure of the flight crew to monitor altitude and to recognize passage of the aircraft through the approach decision height during an unstabilized precision approach conducted in rapidly changing meteorological conditions. The unstabilized nature of the approach was due initially to the aircraft's passing the outer marker above the glide slope at an excessive airspeed and thereafter compounded by the flight crew's preoccupation with the questionable information presented by the flight director system. The poor positioning of the flight for the approach was in part the result of nonstandard air traffic control services."
Accident investigation:
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Investigating agency: | NTSB |
Status: | Investigation completed |
Duration: | 219 days (7 months) | Accident number: | NTSB/AAR-74-03 | Download report: | Final report
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Fuentes:
» Air Disasters / D.Gero (118-120)
» ICAO Circular 132-AN/93 (79-90)
» NSTB-AAR-74-3
Subsiguiente / acciones de seguridad
NTSB issued 8 Safety Recommendations
Issued: 16-AUG-1973 | To: | A-73-62 |
INVESTIGATE THE ADEQUACY OF THE MODIFICATION PROGRAM, ITS IMPLEMENTATION, AND THE QUALITY CONTROL ASPECTS MONITORED BY THE APPROPRIATE FAA OFFICE. (Closed - Acceptable Action) |
Issued: 16-AUG-1973 | To: | A-73-63 |
REVIEW THE ADEQUACY OF THE DELTA AIR LINES\' QUALITY CONTROL PROCEDURES IN DETECTING AND CORRECTING THE REPORTED DISCREPANCIES. (Closed - Acceptable Action) |
Issued: 16-AUG-1973 | To: | A-73-64 |
CONSIDER THE NECESSITY OF IMPOSING APPROPRIATE OPERATIONAL RESTRICTIONS ON THE MODIFIED DC-9 AIRCRAFT UNTIL THE UNDERLYING REASONS FOR THE AVIONICS DISCREPANCIES HAVE BEEN IDENTIFIED AND CORRECTED. (Closed - Acceptable Action) |
Issued: 25-JAN-1974 | To: | A-74-1 |
REQUIRE THAT THE SPERRY FLIGHT DIRECTOR MODE SELECTION SWITCH BE MODIFIED TO PREVENT INADVERTENT SELECTION OF THE G/A MODE. (Closed - Unacceptable Action) |
Issued: 25-JAN-1974 | To: | A-74-2 |
REQUIRE AN ANNUNCIATOR PANEL WHENEVER ANY FLIGHT DIRECTOR SYSTEM IS INSTALLED. THE PANEL WOULD INDICATE ELECTRONICALLY THE MODE IN WHICH THE FLIGHT DIRECTOR IS OPERATING, REGARDLESS OF THE POSITION OF THE MODE SELECTOR SWITCH. (Closed - Unacceptable Action) |
Issued: 25-JAN-1974 | To: | A-74-3 |
REQUIRE THAT CONTROLLERS RECEIVE FORMAL TRAINING IN PROCEDURES FOR USING THE APPROACH LIGHT SYSTEM MONITOR PANEL. (Closed - Acceptable Action) |
Issued: 25-JAN-1974 | To: | A-74-4 |
REVISE AIR TRAFFIC CONTROL OPERATIONAL PROCEDURES TO ASSURE THAT THE GROUND CONTROLLER IS PROVIDED, CONCURRENTLY, WITH THE SAME ARRIVAL SEQUENCE INFORMATION THAT IS PROVIDED THE ASSOCIATED LOCAL CONTROLLER. (Closed - Acceptable Action) |
Issued: 14-MAR-1974 | To: | A-74-19 |
ISSUE AN ADVISORY CIRCULAR WHICH DESCRIBES THE RVR EQUIPMENT AND EMPHASIZES THAT THE RVR VALVE IS A SAMPLING OF A SMALL SEGMENT OF THE ATMOSPHERE, USUALLY NEAR THE TOUCHDOWN POINT. IT SHOULD ALSO BE EMPASIZED THAT RVR VALUE DOES NOT NECESSARILY REPRESENT ACTUAL RUNWAY VISIBILITY CONDITIONS NEAR THE TOUCHDOWN POINT AND INCLUDES A SIGNIFICANT TIME DELAY BEFORE REACHING THE CREW. THIS INFORMATION SHOULD ALSO BE PLACED IN THE AIRMAN\'S INFORMATION MANUAL. (Closed - Acceptable Action) |
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Fotos
accident date:
31-07-1973type: McDonnell Douglas DC-9-31
registration: N975NE
Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does
not display the exact flight path.
Distance from Manchester Municipal Airport, NH to Boston-Logan International Airport, MA as the crow flies is 72 km (45 miles).
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.