A320
Flight Crew Air Transport Pilot (ATP)
Confusion; Human-Machine Interface; Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Other / Unknown
General None Reported / Taken
Procedure; Human Factors
We were dispatched with the APU generator inoperative. Shortly after a normal takeoff; my First Officer called my attention to an ECAM message showing RAT OUT. No chime had been heard associated with this message. There was no apparent reason why this message had appeared as all systems were normal and we had not manually activated the RAT. I assigned pilot flying [duties] to the First Officer; who was already pilot flying; while I investigated the message. I checked the electrical and hydraulics systems ECAM pages and both showed normal. The hydraulic; electrical and emergency electrical panels on the overhead panel all showed normal. At the time; we heard no unusual sounds to indicate that the RAT had actually deployed. We could find no guidance in the QRH and only a few pertinent bits and pieces in the ECAM Non-Normal Supplemental book. Our thinking at this point was that the RAT probably was not out; but what if it was? I called Line Maintenance who could not offer much help and suggested I contact Maintenance Control. I sent a message to Maintenance Control via ACARS and they responded with a WILL MEET AIRCRAFT AT GATE; message. I also sent a message to Dispatch asking for a calculation of the additional fuel burn just in case the RAT was actually deployed. Our Dispatcher; saw our messages and apparently discussed the matter with Maintenance Control. He wrote back several messages to us. First; he acknowledged our messages to him and Maintenance Control. He also said that they don't have a RAT deployment burn and would contact Maintenance and our trainers to help him on this. He then said that after discussing this with Maintenance Control; that they said; we would definitely know if the RAT was actually down. He asked if we suspected or actually knew that the RAT was down and if so; we would need to land at the nearest suitable airport. At that point; we did not know or suspect that the RAT was actually deployed. The First Officer and I agreed that it would be safe to continue on to destination. I asked our Number 1 Flight Attendant if she could hear any unusual sounds back behind First Class or mid-cabin; particularly on the left side of the aircraft and she reported back something to the effect that they could not really hear anything; but maybe a slightly different sound of some sort. No passengers had said anything about unusual noises. So I assumed at that point that the slightly different sound the Flight Attendant may have heard was probably due to the power of suggestion. We were also flying in one of our oldest A320's; which I thought may inherently have a bit more noise or vibration than most of the fleet. We received another message from our Dispatcher saying that Maintenance Control said they didn't see any messages from our aircraft that indicated that the RAT had deployed. He also said that Maintenance did have the RAT down last night for inspection. He further stated that he was able to find a fuel burn penalty of between 3 and 10 percent. He then reiterated that we would know if the RAT was out as there would be a lot of noise in the mid-cabin area and the aircraft would be vibrating. I checked our FOB and EFOB and they were both sufficient to get us to destination with the possible additional fuel burn of 10%. We continued toward destination figuring out what the potential effects might be if the RAT was actually deployed and began to plan accordingly. Our Number 1 Flight Attendant called us to say that a deadheading pilot sitting overwing had said that he thought he could feel a vibration or hear a grinding sound. This raised our level of concern a little bit and helped confirm that the best course of action to take from this point on was to assume the RAT was deployed even though Maintenance Control did not believe that the RAT was actually out. Assuming for safety's sake that the RAT was actually deployed and that we had an aircraft with the old electrical standard; considerations for the approachand landing included: 1. Would the flight controls go into Direct Law when the landing gear was extended? 2. Would we lose electrical power when the landing gear was extended or we slowed below 50 KTS? 3. Would we lose Blue hydraulic power when we went below 100 KTS? Because both the electrical and hydraulic systems were indicating normal; we did not know the answers to the above questions but wanted to be prepared. We briefed each other on what we might expect in each case. And as a precaution; we chose to have the fire trucks standing by just in case. I briefed Number 1 Flight Attendant of what the problem was; that we would be making a precautionary landing; that we expected a normal landing and that they may see the fire trucks standing by in case we needed assistance. One of the more difficult decisions I had to make was how to brief the passengers as to what the problem was and what we might expect. I decided that explaining that the RAT may have dropped; what its purpose was and the possible ramifications was too complex to deal with at that time. I wanted very much to be truthful; but didn't want to cause undue alarm. So I said that we had an indication of a possible electrical problem; expected a normal landing but; as a precaution; would have the fire trucks standing by. As I think about my announcement now without the stress and time constraint; I would have done it a little differently. But I did the best I could under the circumstances. While I was dealing with the communications; First Officer did a great job flying the arrival. He flew a nice approach and made a beautiful normal landing. We had no problems as a result of the RAT OUT message; everything was normal all the way in; with the exception of the RAT OUT message. As we exited the runway; the Fire Crew asked if we needed any assistance. We told them no and thanked them for their help and taxied to the gate. After we parked and shut down the aircraft; First Officer went down to the ramp to see if the RAT was actually deployed. He came back up and reported that it WAS out! When all was said and done; I believe that we made the correct decisions along the way based on the information we had. I inadvertently left out item #4 above: Since the RAT deployment was uncommanded; would its logic perform as it would have if it were a commanded deployment?  Maintenance may not have properly re-stowed the RAT after inspecting it; causing an uncommanded deployment sometime after takeoff. These are suggestions to help those pilots and technicians in dealing with this issue in the future. Issue a pilot read file stating that if the RAT is OUT; the sound and/or vibrations from it may be very subtle or unnoticeable; particularly from the flight deck and that there may be no indications in the flight deck other than the RAT OUT ECAM message if the deployment was uncommanded. Provide guidance on what to do if this should happen again. As for Maintenance Control; provide a correction to their manual that states that the RAT may be deployed uncommanded without any indications in the flight deck other than the RAT OUT ECAM message and that in this situation the aircraft may not send any messages to Maintenance that the RAT is OUT.
A320 Captain experiences an ECAM message showing RAT out shortly after takeoff. It cannot be determined if the RAT is actually out and the flight continues to destination. Discussions with Maintenance Control are not helpful. Post flight reveals the RAT had actually deployed; possibly due to a Maintenance error.