This one was AF...
Airbus A340: July 2004
Location: Paris, France
History of the flight:
On 14 July 2004, an Airbus A340-300 aircraft, registered F-GLZR, was being prepared for a passenger service, departing from Charles de Gaulle Airport, France. In preparation for the flight, the crew received an expected TOW of 268,600 kg, which was close to the aircraft’s maximum take-off weight (MTOW) of 271,000 kg. The TOW, rounded up to 270,000 kg, was used to submit a take-off data calculation request via the ACARS. The resultant take-off performance parameters were verified by the crew.
Shortly after, the crew were advised that the TOW was 5,200 kg less than that previously provided, resulting in a TOW of 264,800 kg. As the change in weight was greater than 5,000 kg, the crew were required to submit a new ACARS request. When entering the revised TOW into the ACARS via the FMGS interface, a weight of 165,000 kg was inadvertently entered. This weight was close to the ZFW of 164,480 kg. The resultant V speeds and FLEX temperature were then entered into the FMGS. The captain confirmed the parameters; however, he did not detect the error as he read the MTOW from the ACARS printout instead of the TOW.
During the takeoff, the pilot flying reported the aircraft feeling heavy and noticed that the V2 speed was slower than the VLS speed (the lowest selectable speed, which provides an appropriate margin above the stall speed); take-off/go-around thrust was not applied. The aircraft sustained a tailstrike, with the fuselage remaining in contact with the runway for a distance of about 100 metres.
Contributing factors:
The following factors were identified throughout the subsequent investigation:
• A weight similar to the ZFW was inadvertently entered into the ACARS instead of the actual TOW, resulting in low V speeds.
Take-off performance data:
Data Required Used
TOW 265,000 kg 165,000 kg
V1 143 kts 129 kts
VR 153 kts 131 kts
V2 161 kts 137 kts
• The FMGS would accept unrealistic low V speeds without challenge.
• The FMGS did not compare the V2 and VLS speeds, despite the fact that both values were known before takeoff.
The following information is based on a translation of the Bureau d’Enquétes et d’Analyses pour la sécurité de l’aviation civile’s (BEA) investigation report. Some information may have been omitted or incorrectly interpreted through the translation process.
•The presentation of the parameter values on the ACARS printout may have led to some confusion in reading between the TOW and ZFW.
•The take-off briefing procedures did not require a comparison between the TOW and speed characteristics.
Last edited by JammedStab; 21st Jun 2015 at 16:56.