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Last updated: 27 November 2021
Statuts:Enquête Officielle
Date:mardi 8 septembre 1970
Type/Sous-type:Silhouette image of generic DC93 model; specific model in this crash may look slightly different
McDonnell Douglas DC-9-32
Compagnie:Delta Air Lines
Immatriculation: N3329L
Numéro de série: 47108/251
Année de Fabrication: 1968
Heures de vol:7601
Moteurs: 2 Pratt & Whitney JT8D-7
Equipage:victimes: 0 / à bord: 5
Passagers:victimes: 0 / à bord: 89
Total:victimes: 0 / à bord: 94
Dégats de l'appareil: Substantiels
Conséquences: Repaired
Lieu de l'accident:Louisville-Standiford Field, KY (SDF) (   Etats-Unis d'Amérique)
Phase de vol: A l'atterrissage (LDG)
Nature:Transport de Passagers Nat.
Aéroport de départ:Chicago-O'Hare International Airport, IL (ORD/KORD), Etats-Unis d'Amérique
Aéroport de destination:Louisville-Standiford Field, KY (SDF/KSDF), Etats-Unis d'Amérique
Numéro de vol:DL439
Delta Air Lines Flight 439 was a scheduled flight from Chicago to Atlanta with intermediate stops at Louisville and Lexington. The DC-9 departed Chicago at 20:13 on an Instrument Flight Rules (IFR) flight plan. At 21:01, Louisville Approach Control established radar contact with Flight 439. Vectors and altitude information were given the crew until the flight was turned to a heading that would intercept the inbound ILS localizer course to runway 29. The flight was subsequently cleared for an ILS approach. Landing weight had been computed to be 92,000 pounds, which established an approach reference airspeed of 123 knots. Flaps had been extended to 50 degrees. When Flight 439 made the approach which terminated in the accident, the high intensity runway lights were set at step 3, medium bright, and the reported flight visibility was 7 miles. Runway 29 did not have a prepared underrun/overrun area. The ground leading to the threshold slopes upward 2deg 44’, a gradient of approximately 5 percent. Flight 439 made initial ground contact on this incline 156 feet short of the threshold of the runway, rolled forward 73 feet, and became airborne. The aircraft then contacted the runway 262 feet beyond the threshold and continued to roll/skid on the runway before it came to rest 4,457 feet beyond the threshold. Wreckage examination showed that the fuselage had fractured and buckled in the area between fuselage stations 737 and 794. The tail cone rested on the runway.

Probable Cause:

PROBABLE CAUSE: "The National Transportation Safety Board determines that the probable cause of this accident was the pilot’s misjudgment of altitude due to the absence of sufficient lights in the approach area, misleading information produced by deceptive sloping terrain, and that the pilot did not position the aircraft on the ILS glide slope while he was establishing the final approach profile."

Accident investigation:
Investigating agency: NTSB
Status: Investigation completed
Duration: 1 year and 2 months
Accident number: NTSB/AAR-71-15
Download report: Final report

» NTSB-AAR-71-15


photo of DC-9-32-N3329L
accident date: 08-09-1970
type: McDonnell Douglas DC-9-32
registration: N3329L
photo of DC-9-32-N3329L
accident date: 08-09-1970
type: McDonnell Douglas DC-9-32
registration: N3329L

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 Chicago-O'Hare International Airport, IL et Louisville-Standiford Field, KY est de 458 km (286 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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