What happened
On 10 August 2004, a Boeing 737-300, registration CS-TGP, was preparing for a scheduled passenger flight from Jersey Airport to Funchal Airport. To comply with field length requirements, the commander had coordinated with the load controller to reduce the aircraft's weight, resulting in the removal of 15 bags. The flight departed with 152 passengers and 6 crew members.
While the flight crew described the departure as uneventful, ground personnel and an air traffic control assistant observed that the aircraft utilized nearly the entire length of the runway and appeared to rotate much later than expected. There were no injuries and no damage to the aircraft.
The investigation
The AAIB investigation focused on the discrepancy between the planned takeoff weight and the actual environmental conditions. The investigation found that the crew had used a performance sheet to determine a Regulated Take-Off Weight (RTOW) of 57,600 kg. This calculation was based on a 10-knot headwind and a temperature of 20°C, but it failed to account for the specific QNH at the time.
Further analysis revealed that when using the actual takeoff card data—which indicated a zero headwind component—the allowable RTOW should have been only 56,188 kg. Additionally, the crew had incorrectly referenced takeoff speeds from the Quick Reference Handbook. They applied speeds intended for a Flap 5 configuration rather than the Flap 15 setting actually in use, which meant the rotation speed was approximately 10 knots too high.
Findings
- The aircraft departed with a weight of 57,191 kg, which was 993 kg above the actual allowable RTOW.
- The crew used incorrect takeoff speeds, initiating rotation later than necessary due to using Flap 5 data for a Flap 15 configuration.
- Discrepancies existed between the crew's performance calculations and the actual atmospheric conditions at the time of departure.