Accident description
Last updated: 31 October 2014
Status:Final
Date:Sunday 5 September 1954
Time:02:39
Type:Silhouette image of generic CONI model; specific model in this crash may look slightly different
Lockheed L-1049C-55-81 Super Constellation
Operator:KLM Royal Dutch Airlines
Registration: PH-LKY
C/n / msn: 4509
First flight: 1953
Total airframe hrs:2498
Engines: 4 Wright R-3350 (972TC18DA1)
Crew:Fatalities: 3 / Occupants: 10
Passengers:Fatalities: 25 / Occupants: 46
Total:Fatalities: 28 / Occupants: 56
Airplane damage: Damaged beyond repair
Location:2,5 km (1.6 mls) SE off Shannon Airport (SNN) (   Ireland) show on map
Phase: Initial climb (ICL)
Nature:International Scheduled Passenger
Departure airport:Shannon Airport (SNN/EINN), Ireland
Destination airport:New York-Idlewild International Airport, NY (IDL/KIDL), United States of America
Flightnumber: 633
Narrative:
The KLM Super Constellation, named "Triton", operated on the Amsterdam-New York route. A scheduled refueling stop was made at Shannon. The flight left Shannon Terminal Building at 02:30 hours at night and taxied to runway 14 (5643 feet long). The before take-off run-up was completed in take-off position.
Take-off was made at 02:38. V1 speed was reached at 3500 feet and lift-off at 125 knots was made just over the V2 speed at approximately 4000 feet from threshold. The flight then passed over the remaining 1600 feet of runway in a shallow climb, retracting its landing gear. The Constellation entered a shallow descent over the River Shannon. The duration of the flight was about 31 seconds from the time it passed over the end of the runway until the aircraft first contacted the water in a tail-down slightly right-wing low attitude. It came to rest on the Middle Ground, a shallow mudbank 8170 feet from the end of the runway, after losing engines nr. 3 and 4.


PROBABLE CAUSE: "1) Failure of the captain to correlate and interpret his instrument indications properly during flap retraction, resulting in necessary action not being taken in sufficient time. This failure was partially accounted for by the effect on instrument indications of inadvertent and unexpected gear re-extension. 2) Loss of aircraft performance due to inadvertent landing gear re-extension. 3) The captain failed to maintain sufficient climb to give him an opportunity of meeting unexpected occurrences."

Classification:
Ditching

Sources:
» ICAO Accident Digest Circular 50-AN/45 (20-33)
» Nederlandse Constallations / H.Dekker


Photos

photo of Lockheed L-1049C-55-81 Super Constellation PH-LKY
photo of
Flight path of KLM Flt 633 after takeoff from Shannon - 5 SEP 1954
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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 Shannon Airport to New York-Idlewild International Airport, NY as the crow flies is 4910 km (3069 miles).

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Lockheed L-1049

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