Unfallbericht: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 385km/h (80km/h too fast) and was 60m above the glide slope.
|Datum:||Dienstag 31 Juli 1973|
|Flugzeugtyp:||McDonnell Douglas DC-9-31|
|Fluggesellschaft:||Delta Air Lines|
|Triebwerk:|| 2 Pratt & Whitney JT8D-7|
|Besatzung:||Todesopfer: 6 / Insassen: 6|
|Fluggäste:||Todesopfer: 82 / Insassen: 83|
|Gesamt:||Todesopfer: 88 / Insassen: 89 |
|Konsequenzen:|| Written off (damaged beyond repair)|
|Unfallort:||Boston-Logan International Airport, MA (BOS) (USA)
|Flugphase:|| Annäherung (APR)|
|Betriebsart:||Inländischer planmäßiger Passagierflug|
|Flug von:||Manchester Municipal Airport, NH (MHT/KMHT), USA|
|Flug nach:||Boston-Logan International Airport, MA (BOS/KBOS), USA|
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 500m with 60m 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: "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."
» Air Disasters / D.Gero (118-120)
» ICAO Circular 132-AN/93 (79-90)
Official accident investigation report
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).