Narrative:

During cruise; ECAM alerted indicating auto fuel feed fault. First officer followed ECAM steps. I can not remember exactly what the ECAM steps were; but the resulting configuration indicated on the ECAM screens was confusing and did not make sense at the time. Considering a mis-step we reconfigured the fuel panel back to normal. Alert repeated and again we followed ECAM steps; which again resulted in a configuration that did not seem to make sense; plus the ECAM did not have any further steps or procedural prompt to follow. First reading as follows: lo 7.4 ro 6.73 li 0.0 center 6.67 ri 4.3 trm 4.47 this was quite alarming since it indicated serious fuel imbalance; and possible fuel leak and also since following ECAM had not provided procedural path and configuration that was making sense. My exact recall of all this may have been lost in the 'heat of battle' and my confusion as to exactly what was going on. I was concerned about big difference between left and right inner tank indications; and wondered where the fuel from the left inner tank had gone. First officer said that he had checked the fuel only a few minutes earlier and he was sure that there had been no imbalance then and it did not seem likely that imbalance should occur so quickly. I noted flight control displacement quite normal and autopilot did not seem to be compensating for imbalance. I compared fuel burn with calculated fuel burn from the flight plan and found indicated fuel was approx 5000 lbs more than calc/flight plan predicted. Suspect that the right inner tank indication in error with likely zero fuel in that tank. Reconfigured the fuel panel back to normal (auto.... All pumps on) with a view to setting manual fuel feed from the center tank. However; auto fuel feed did not fault this time. Relieved to see it reconfigured to isolate the right inner; and feed both engines from the center; and that the trim tank started to transfer forward into the center tank. I elected to keep the fuel panel in auto mode and briefed that we would continue to monitor and immediately revert to manual should it fault again; and assume the right inner zero. At this point; right inner showed 4.7 but over a period of 10 minutes it increased to show 5.71 further suggesting erroneous indications. During descent; we noted that the right inner indication started to roll back steadily. After 5 minutes it had rolled back to approx 0.6 where it remained until shutdown. I disconnected the auto pilot for short time to check aircraft trim and balance normal. Landed with no further problems. I am troubled by several things. I have difficulty in recalling exactly what the initial steps were that the ECAM had us perform; and exactly why it resulted in so much confusion for us; but I do know that I was distracted by my initial reaction of great concern over the apparent fuel imbalance; a possible severe fuel leak; potential fuel starvation of the left engine; and the consideration of a possible need for an immediate emergency diversion. As I review my flight manual this morning; I note that the ECAM display should provide one or both of two 'if' statements........... 'If both left and right center tnk pumps fault (or one etc...' and 'if all four inr tk pumps fault or off lights illuminated...'. I don't know if both 'if' statements are supposed to display at the same time; but I don't recall having a choice of these two possibilities; though I have conferred with my first officer about this; and we both remain confused as to what exactly we were presented with. I remain convinced that following the ECAM steps had us turning off pumps; which the ECAM then confirmed; but that the ECAM had no further steps to follow; nor any blue procedure prompt; which is why I felt so stumped by this apparent procedural dead-end. Is it possible that fuel system logic mis-interprets a positive fuel reading in an actually empty tank? I am also concerned that if we had quicklybitten off on assuming the auto fuel feed had created a large fuel imbalance; and then attempted to transfer fuel to correct a fuel imbalance; we could have quickly created a real imbalance when none had actually existed in the first place. There might have been much greater danger of this scenario developing had we actually noticed an indicated imbalance before we had an auto fuel feed fault alert. I know that my train of thought was especially vulnerable to the following... 1. Expectation bias that the auto fuel feed fault was going to be an erroneous alert that self-cancels and is so often seen on the line. 2. Expectation bias that an empty tank would be the source of the problem; and not the tank with significant quantity apparently still remaining. In my report I have suggested that someone check on the eventual diagnosis of whatever fault we had; analyze what it is in this set of circumstances that triggers the auto fuel feed alert; and check if this can cause fuel system logic or ECAM system logic to create an incorrect response from the ECAM. However; if this is not the case then the only other explanation is that we were confused by the tank indication error and incorrectly followed the ECAM procedures.

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Original NASA ASRS Text

Title: A300 Captain experiences an ECAM warning for a Auto Fuel Feed Fault at FL370; apparently caused by a false indication of fuel in the Right Inner fuel tank. After twice complying with the ECAM actions and being completely confused by the resultant configuration; the fuel system is returned to normal (Auto) and the ECAM does not reappear.

Narrative: During cruise; ECAM alerted indicating Auto Fuel Feed Fault. First Officer followed ECAM steps. I can not remember exactly what the ECAM steps were; but the resulting configuration indicated on the ECAM screens was confusing and did not make sense at the time. Considering a mis-step we reconfigured the fuel panel back to normal. Alert repeated and again we followed ECAM steps; which again resulted in a configuration that did not seem to make sense; plus the ECAM did not have any further steps or Procedural Prompt to follow. First reading as follows: LO 7.4 RO 6.73 LI 0.0 CTR 6.67 RI 4.3 TRM 4.47 This was quite alarming since it indicated serious fuel imbalance; and possible fuel leak and also since following ECAM had not provided procedural path and configuration that was making sense. My exact recall of all this may have been lost in the 'heat of battle' and my confusion as to exactly what was going on. I was concerned about big difference between Left and Right Inner Tank indications; and wondered where the fuel from the Left Inner Tank had gone. First Officer said that he had checked the fuel only a few minutes earlier and he was sure that there had been no imbalance then and it did not seem likely that imbalance should occur so quickly. I noted flight control displacement quite normal and autopilot did not seem to be compensating for imbalance. I compared fuel burn with calculated fuel burn from the flight plan and found indicated fuel was approx 5000 lbs more than calc/flight plan predicted. Suspect that the Right Inner Tank indication in error with likely zero fuel in that tank. Reconfigured the fuel panel back to normal (Auto.... all pumps on) with a view to setting manual fuel feed from the Center Tank. However; Auto Fuel Feed did NOT fault this time. Relieved to see it reconfigured to isolate the Right Inner; and feed both engines from the Center; and that the Trim Tank started to transfer forward into the Center Tank. I elected to keep the fuel panel in Auto mode and briefed that we would continue to monitor and immediately revert to manual should it fault again; and assume the Right Inner zero. At this point; Right Inner showed 4.7 but over a period of 10 minutes it increased to show 5.71 further suggesting erroneous indications. During descent; we noted that the Right Inner indication started to roll back steadily. After 5 minutes it had rolled back to approx 0.6 where it remained until shutdown. I disconnected the auto pilot for short time to check aircraft trim and balance normal. Landed with no further problems. I am troubled by several things. I have difficulty in recalling exactly what the initial steps were that the ECAM had us perform; and exactly why it resulted in so much confusion for us; but I do know that I was distracted by my initial reaction of great concern over the apparent fuel imbalance; a possible severe fuel leak; potential fuel starvation of the left engine; and the consideration of a possible need for an immediate emergency diversion. As I review my Flight Manual this morning; I note that the ECAM display should provide one or both of two 'If' statements........... 'If both L and R CTR TNK Pumps Fault (or one etc...' and 'If all four INR TK Pumps Fault or OFF lights illuminated...'. I don't know if both 'If' statements are supposed to display at the same time; but I don't recall having a choice of these two possibilities; though I have conferred with my First Officer about this; and we both remain confused as to what exactly we were presented with. I remain convinced that following the ECAM steps had us turning off pumps; which the ECAM then confirmed; but that the ECAM had no further steps to follow; nor any blue Procedure Prompt; which is why I felt so stumped by this apparent procedural dead-end. Is it possible that Fuel System logic mis-interprets a positive fuel reading in an actually empty tank? I am also concerned that if we had quicklybitten off on assuming the Auto Fuel Feed had created a large fuel imbalance; and then attempted to transfer fuel to correct a fuel imbalance; we could have quickly created a real imbalance when none had actually existed in the first place. There might have been much greater danger of this scenario developing had we actually noticed an indicated imbalance before we had an Auto Fuel Feed Fault alert. I know that my train of thought was especially vulnerable to the following... 1. Expectation bias that the Auto Fuel Feed Fault was going to be an erroneous alert that self-cancels and is so often seen on the line. 2. Expectation bias that an empty tank would be the source of the problem; and not the tank with significant quantity apparently still remaining. In my Report I have suggested that someone check on the eventual diagnosis of whatever fault we had; analyze what it is in this set of circumstances that triggers the Auto Fuel Feed alert; and check if this can cause Fuel System logic or ECAM system logic to create an incorrect response from the ECAM. However; if this is not the case then the only other explanation is that we were confused by the tank indication error and incorrectly followed the ECAM procedures.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.