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Last updated: 1 December 2021
Date:lundi 20 février 1956
Type/Sous-type:Silhouette image of generic VISC model; specific model in this crash may look slightly different
Vickers 744 Viscount
Compagnie:Capital Airlines
Immatriculation: N7404
Numéro de série: 90
Année de Fabrication: 1955
Equipage:victimes: 0 / à bord: 5
Passagers:victimes: 0 / à bord: 37
Total:victimes: 0 / à bord: 42
Dégats de l'appareil: Perte Totale
Conséquences: Written off (damaged beyond repair)
Lieu de l'accident:Chicago-Midway Airport, IL (MDW) (   Etats-Unis d'Amérique)
Phase de vol: A l'atterrissage (LDG)
Nature:Transport de Passagers Nat.
Aéroport de départ:Detroit-Willow Run Airport, MI (YIP/KYIP), Etats-Unis d'Amérique
Aéroport de destination:Chicago-Midway Airport, IL (MDW/KMDW), Etats-Unis d'Amérique
The Capital Airlines Viscount took off from Detroit-Willow Run Airport at 07:00 CST for a flight to Chicago-Midway. The flight had been uneventful when the aircraft approached Chicago, making a right hand turn to finals for a landing on runway 31R. When over the boundary of the airport the captain reduced power and called for 47deg flaps. As the first officer moved the flap control to 47deg, he felt the aircraft decelerate and settle. Glancing at the instrument panel, he noticed 3 of the 4 17-degree pitch lights were illuminated. These lights illuminate when the propeller blades are at a 17deg pitch or below; 21 degrees is normally the minimum in-flight blade angle. Knowing this was an abnormal situation he chose to apply power. Advancing power caused the propellers to immediately seek the lowest possible angle. When the throttles were 3/4 fully forward the aircraft sank quickly, touching down on the east taxiway, 414 feet short of the runway threshold. The aircraft skidded onto the runway on its belly coming to rest 1626 feet past the point of first touchdown.
It appeared that at least two microswitches had failed, permitting the energizing of the 21-degree pitch lock solenoid. This made it possible for the stops to be withdrawn during the approach. As the crew didn't see the 21-degree pitch lock solenoid warning light, the emergency switch preventing the propellers from going into ground fine pitch range while in flight, was not actuated.
The hull was used to build Vickers 757 Viscount c/n 301 which entered service with Trans Canada Air Lines May 1957.

Probable Cause:

PROBABLE CAUSE: "A malfunctioning of the propeller control switches which culminated in an abrupt loss of lift."

» ICAO Accident Digest No.8, Circular 54-AN/49 (51-55)


photo of Vickers-744-Viscount-N7404
accident date: 20-02-1956
type: Vickers 744 Viscount
registration: N7404

Ce plan montre l'aéroport de départ ainsi que la supposée destination du vol. La ligne fixe reliant les deux aéroports n'est pas le plan de vol exact.
La distance entre Detroit-Willow Run Airport, MI et Chicago-Midway Airport, IL est de 350 km (219 miles).

Les informations ci-dessus ne représentent pas l'opinion de la 'Flight Safety Foundation' ou de 'Aviation Safety Network' sur les causes de l'accident. Ces informations prélimimaires sont basées sur les faits tel qu'ils sont connus à ce jour.
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