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A346, en-route, Amsterdam Netherlands, 2005

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Summary
On 8 February 2005, a Virgin Atlantic Airways A340-600 experienced in-flight fuel management problem which led to loss of power of No 1 engine and temporary power loss of No 4. The captain decided to divert to Amsterdam where the aircraft landed safely on three engines.
Event Details
When February 2005
Actual or Potential
Event Type
AW, LOC
Day/Night Night
Flight Conditions IMC
Flight Details
Aircraft AIRBUS A-340-600
Operator Virgin Atlantic
Domicile United Kingdom
Type of Flight Public Transport (Passenger)
Origin Hong Kong International Airport
Intended Destination London Heathrow Airport
Actual Destination Amsterdam Airport Schiphol
Flight Phase Cruise
ENR
Location
Approx. near Amsterdam, Netherlands
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LOC
Tag(s) Significant Systems or Systems Control Failure
Loss of Engine Power
EPR
Tag(s) MAYDAY declaration


Outcome
Damage or injury No
Causal Factor Group(s)
Group(s) Aircraft Technical
Safety Recommendation(s)
Group(s) Aircraft Airworthiness
Investigation Type
Type Independent

Description

On 8 February 2005, a Virgin Atlantic Airways A340-600 was nearing the end of an overnight flight from Hong Kong to London Heathrow when “some 11 hours after takeoff, at about 0330 hrs with the aircraft in Dutch airspace and at Flight Level 380, the No 1 (number one) engine lost power and ran down. Initially the pilots suspected a leak had emptied the contents of the fuel tank feeding No 1 engine but a few minutes later, the No 4 engine started to lose power. At that point all the fuel crossfeed valves were manually opened and No 4 engine recovered to normal operation. The pilots then observed that the fuel tank feeding No 4 engine was also indicating empty and they realised that they had a fuel management problem. Fuel had not been transferring from the centre, trim and outer wing tanks to the inner wing tanks so the pilots attempted to transfer fuel manually. Although transfer was partially achieved, the expected indications of fuel transfer in progress were not displayed so the commander decided to divert to Amsterdam (Schiphol) Airport where the aircraft landed safely on three engines.” [extract from the Synopsis of the Annex 13 Report published in July 2007]

Causal Factors

The investigation was delegated by the Dutch TSB to the UK AAIB who determined in the Final Report “that the following causal factors led to the starvation of Inner fuel tanks 1 and 4 and the subsequent rundown of engine numbers 1 and 4:

  1. Automatic transfer of fuel within the aircraft stopped functioning due to a failure of the discrete outputs of the master Fuel Control and Monitoring Computer (FCMC).
  2. Due to FCMC ARINC data bus failures, the flight warning system did not provide the flight crew with any timely warnings associated with the automated fuel control system malfunctions.
  3. The alternate low fuel level warning was not presented to the flight crew because the Flight Warning Computer (FWC) disregarded the Fuel Data Concentrator (FDC) data because its logic determined that at least one FCMC was still functioning.
  4. The health status of the slave FCMC may have been at a lower level than that of the master FCMC, thus preventing the master FCMC from relinquishing control of the fuel system to the slave FCMC when its own discrete and ARINC outputs failed.”

[extract from the Annex 13 Final Report published in July 2007]

Safety Recommendations

During the course of the investigation the UK AAIB issued six Safety Recommendations, two published in Special Bulletin S1/2005 in March 2005 and four more in an Interim Report published in February 2006. Two were specific about the design of the A340 Fuel System and the other four were to EASA and FAA recommending that aircraft certification requirements under CS-25 and FAR-25 respectively be enhanced to require that:

  • New aircraft should be required to have a low fuel warning system for each engine feed fuel tank which should be independent of the fuel control and quantity indication system(s).
  • Existing aircraft which have an engine fuel feed low fuel warning system installed, should be required to have such a system function independently of the fuel control and quantity indication system(s).

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