Accident
Last updated: 19 June 2013
Status:Schlussbericht
Datum:10 SEP 1976
Zeit:10:14
Flugzeugtyp:Hawker Siddeley HS-121 Trident 3B
Fluggesellschaft:British Airways
Kennzeichen: G-AWZT
Werknummer: 2320
Baujahr: 1972
Betriebsstunden:8627
Anzahl Zyklen der Zelle:6952
Triebwerk: 3 Rolls Royce 512-5W Spey
Besatzung:Todesopfer: 9 / Insassen: 9
Fluggäste:Todesopfer: 54 / Insassen: 54
Gesamt:Todesopfer: 63 / Insassen: 63
Opfer des Zusammenstoßes:Todesopfer: 113
Sachschaden: Zerstört
Konsequenzen: Written off (damaged beyond repair)
Unfallort:nahe Vrbovec (Kroatien) show on map
Flugphase: Während des Fluges (ENR)
Betriebsart:Internationaler Linienflug
Flug von:London-Heathrow Airport (LHR/EGLL), Großbritannien
Flug nach:Istanbul-Yesilköy Airport (IST/LTBA), Türkei
Flugnummer: 475
Unfallbericht:
Flight BA475 (a HS-121 Trident) took from London-Heathrow at 08:32 GMT for a flight to Istanbul. About 1½ hours later, the aircraft approached the ZAG VOR beacon on airway UB5 at FL330 (10000m), heading 116° (speed 905km/h).
At the same time the Inex Adria DC-9-31 also approached the ZAG VOR, but flew airway UB9, climbing from FL260 to FL350. The DC-9 had taken off from Split at 09:48 GMT for a flight to Köln.
At 10:14:14 the DC-9 captain radioed that they were climbing through FL325. According to ATC data the Flight BA475 was approaching ZAG VOR at FL335 (FL330 actually). Zagreb ATC asked (in Serbo-Croatian) the Inex flight to maintain their present altitude. At 10:14:38 the crew of flight JP550 replied (also in Serbo-Croatian) that they where maintaining FL330.
Three seconds afterwards the outer five meters of the DC-9's left wing cut through the Trident's cockpit.
Due to the sudden decompression, the forward part of the Trident's fuselage disintegrated. The remaining part of the fuselage struck the ground tail-first and slid some 4-5m. to the left.
With it's left wing torn off, the DC-9 tumbled down and hit the ground right-wing first.
CAUSES OF THE ACCIDENT: "1) Direct cause of the accident was the struck of the DC-9 wing into the middle side of the TRIDENT THREE fuselage which occurred at the height of 33.000 feet above Zagreb VOR so that both aircraft became uncontrollable and fell on the ground.; 2) Improper ATC operation; 3) Non-compliance with regulations on continuous listening to the appropriate radio frequency of ATC and non-performance of look-out duty from the cockpits of either aircraft."


Informationsquelle:
» Air Disasters
» Aviation Week & Space Technology
» Collision course / by Tony Brkic

Official accident investigation report
investigating agency: Air Accidents Investigation Branch (AAIB) - U.K.
report status: Final
report number: AAIB AAR 5/1977
download report: Report on the collision to British Airways Trident, G-AWZT and Inex Adria DC9, YU-AJR, in the Zagreb area, Yugoslavia, 10 September 1976 (AAIB AAR 5/1977)

investigating agency: Air Accidents Investigation Branch (AAIB) - U.K.
report status: Final
report number: AAIB AAR 9/1982
download report: Report on the accident to British Airways Trident, G-AWZT and Inex Adria DC9 YU-AJR, Zagreb Yugoslavia, 10 September 1976 (AAIB AAR 9/1982)
cover
Sample newspaper article from Newspaperarchive.com

Fotos
photo of
photo of Hawker Siddeley HS-121 Trident 3B G-AWZT
 

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 London-Heathrow Airport to Istanbul-Yesilköy Airport as the crow flies is 2495 km (1560 miles).

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HS-121 Trident

  • 11th loss
  • 117 built
  • 2nd worst accident (Zu diesem Zeitpunkt)
  • 3rd worst accident (Momentan)
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 Kroatien
  • 2nd worst accident (Zu diesem Zeitpunkt)
  • 3rd worst accident (Momentan)
»safety profile