What happened
On December 4, 1982, at 8:33 PM, a Boeing 707, registration N 8434, operated by Global International Airways, was preparing for a cargo and passenger flight from Brasília, Brazil, to Atlanta, USA. During the takeoff roll on runway 10, the aircraft failed to rotate before the end of the runway. The aircraft utilized the downward slope at the end of the runway, gaining speed and beginning a climb that resulted in a collision with the ILS (Instrument Landing System) platform located 300 meters from the runway threshold. The impact caused the loss of the left landing gear and damaged the right gear. The crew performed an emergency landing on runway 28 after jettisoning fuel. There were no fatalities among the passengers or crew.
The investigation
CENIPA's investigation focused on the discrepancy between the planned takeoff weight and the actual weight of the aircraft. The investigation established that the flight planning was flawed, with the planned takeoff weight exceeding the maximum allowable weight for Brasília's runway conditions. Furthermore, the investigation found that the actual weight of the aircraft, measured at 313,771 lbs, significantly exceeded the maximum performance limit of 287,720 lbs. The investigation also noted that the crew had not verified the weight of the cargo before loading, relying instead on information provided by the client. Additionally, the investigation examined the proficiency of the crew in using aircraft performance charts and the accuracy of the flight planning software used.
Findings
- Excessive takeoff weight: The aircraft was operating at a weight approximately 26,051 lbs above the maximum allowable limit for the runway length and conditions.
- Inaccurate flight planning: The computerized flight plan contained errors regarding both the maximum takeoff weight and the actual cargo weight being transported.
- Lack of cargo verification: The crew did not perform a physical weighing of the cargo prior to embarkation.
- Improper use of performance charts: The co-pilot demonstrated a lack of proficiency in utilizing aircraft performance graphs, and the crew failed to correctly consult takeoff performance charts for the specific airfield.
- Inaccurate weight distribution knowledge: The crew was unaware of the exact distribution of the load within the aircraft.
- Infrastructure impact: The rigidity of the ILS tower structure contributed to the severity of the damage during the collision.