Airbus A320 N409UA

According to flight data recorder (FDR) data, the Avionics Smoke warning was active at the time the recording began. Since the caution was inactive at power up, it was most likely caused from contaminants detected before the airplane was powered up. Based on this, when the crew arrived at the airplane, they should have had three primary cues alerting them of an Avionics Smoke event, including: a master caution light illuminated amber; an amber AVIONICS SMOKE warning on the upper Electronic Centralized Aircraft Monitor (ECAM); and Blower and Extract fault lights and Gen 1 Line smoke light illuminated amber on the overhead panel. In addition, when they viewed the status page of the ECAM (as required per the captain's Cockpit Preparation checklist), VENT BLOWER and VENT EXTRACT would have been listed under inoperative systems. It is unlikely that airline personnel would have cleared or canceled this warning without communicating this information with the crew, and the crew stated that they did not cancel the warning. Had the warning been inadvertently cleared or cancelled, the overhead panel lights would have remained illuminated and vent blower and vent extract would have remained inoperative systems. Because the cockpit voice recorder (CVR) did not contain any discussion related to any Avionics Smoke event while on the ground, or after takeoff prior to about 1500 feet (during which time both crewmembers responded with surprise), it is unlikely that the crew had previously seen the warning but purposefully ignored the available cues. It is also possible that the crew did not see the cockpit indications since the captain did not complete at least one step of his cockpit preparation checklist–pushing the recorder ground control switch. Because of this, the CVR and FDR did not begin until the time that the APU started, when it should have started much sooner in the sequence of preflight events. So, the investigation was not able to determine whether the crew completed other checklist items that should have alerted them to the Avionics Smoke warning. Finally, investigators were unable to find any condition in which the caution could be recorded on the FDR but not displayed to the crew. Therefore, although the incident flight crew was not aware of the Avionics Smoke event prior to takeoff, investigators could not determine the reason for this. At 7:10:08.7, the captain began the after takeoff checklist. Item 3 of that checklist is "ECAM memo…checked." When completing this step, the captain detected the Avionics Smoke event on the upper ECAM. Primary cues available were the Avionics Smoke procedure and an amber LAND ASAP message. Although the crew were surprised when they noticed the alert message, there was no corresponding master caution aural warning during this time, which confirms that the Avionics Smoke alert had been active prior to takeoff. The captain then delegated crew duties, assigning the first officer as the pilot flying and indicated that he would complete the ECAM. At 07:10:30.8, the captain began the Avionics Smoke ECAM procedure and stated, "perceptible smoke", referring to the first conditional statement of the procedure "if perceptible smoke". Airbus stated that completion of the Avionics Smoke procedure is dependent on "direct detection by the crew [and] secondary detection by a detector which is considered as a help." Detection by crew can be by sight or smell. According to the procedure, "If perceptible smoke" is a conditional statement and if the crew did not detect smoke, they were not to continue the procedure. After the incident the first officer stated that if Avionics Smoke was detected by the sensor, then there was Avionics Smoke and he was not going to question that. About 38 seconds after the flight crew became aware of the Avionics Smoke warning, the captain stated, "hey you lost your autopilot too." The FDR indicated that the crew received an autothrust message. CVR data suggests that the captain became very apprehensive about the situation. The flight crew concluded that the failure of the autopilot meant that their situation was deteriorating and they needed to land the airplane promptly. Likely adding to the captain's apprehension was the LAND ASAP [i.e. as soon as possible] message displayed on the ECAM. Although an amber LAND ASAP message was presented, discussions with UAL instructors and pilots indicated that, to a pilot, land ASAP means land ASAP, regardless of color. After the incident, the captain stated that during his last proficiency training session, in-flight fires were emphasized. Specifically, pilots were told that delaying landing by a few minutes could be the difference between a successful landing and loss of an aircraft, such as Swissair [flight 111, that occurred September 2, 1998] and Valujet [flight 592, that occurred May 11, 1996]. The captain said, "he did not want this to be the next Valujet." The captain continued with the Avionics Smoke procedure but did not do so with the necessary thoughtfulness and made several missed steps. For example, the procedure states action item "EMER ELEC PWR…MAN ON" followed by the conditional statement "WHEN EMER GEN AVAIL:" and action item "GEN 2…OFF". In this instance, the captain should have turned on the emergency electrical power (i.e., deployed the RAT13), and then when emergency generator power was available turned off generator 2. Data show that the captain did not manually deploy the RAT prior to turning off generator 2. As a result, when generator 2 was turned off prematurely, there was a brief disruption in the power supply and the airplane entered the emergency electrical configuration. The EMER ELEC procedure and a red LAND ASAP message appeared on the ECAM. This configuration caused the RAT to automatically deploy which restored electrical power to the airplane after about 6 seconds. The airplane remained in the emergency electrical configuration. Therefore, the captain became apprehensive about the Avionics Smoke event and hastily performed the ECAM procedure resulting in the airplane entering the emergency electrical configuration. At 7:12:51.5, the first officer alerted the captain that he had no instruments. Two seconds later the captain took control of the airplane and told the first officer to call the flight attendants. The flight crew did not adequately transfer control of the airplane – the first officer did not brief the captain on the status of the airplane and the captain did not brief the status of the emergency procedures. Over the next two and a half minutes the crew focused primarily on contacting the flight attendants and did not discuss completing the EMER ELEC procedure. About 30 seconds later, the flight crew lowered the landing gear without restoring power to the airplane, per the EMER ELEC procedure, and the airplane began operating on battery power. As a result, the CVR recording ended and no further communications in the cockpit were available with the exception of ATC communications. Completion of the EMER ELEC procedure would have restored power to generators 1 and 2 prior to landing gear extension and maintained electrical power to the airplane. After the incident, the captain said when they lowered the landing gear, operating on battery power was not on his mind. After touchdown, reverser 2 did not deploy, and the airplane veered to the left and exited the runway. The flight crew was not aware that reverser 2 was an inoperative system based on the electrical configuration of the airplane. Had the first officer checked the ECAM status per the Approach Descent Checklist, the inoperative system would have been identified. However, this was not completed likely due to the time constraints. After landing, engine status cues would have alerted the first officer that reverser 2 did not deploy and he should have informed the captain. While it is unknown if the first officer monitored engine status and made the required reverser call out after landing, staff believes it is unlikely because the captain stated in a post incident interview that the airplane departed the runway because of a crosswind. Therefore, the flight crew became distracted by the emergency and focused on landing the airplane without completing necessary checklist items, resulting in the airplane operating on battery power and partial loss of reverse thrust on landing. It is the captain's responsibility as a leader to set the tone in the cockpit for the entire flight, and this is even more critical when a crew is faced with an abnormal situation. CVR data suggests the tone in the cockpit was very casual. For example, prior to performing the before takeoff checklist, the first officer asks the captain "ready to read em and weep?" And just before takeoff, the first officer stated, "let's get…outta here man." The captain then stated "Brakes released. You got it man. Throttles yours. Whatever you want to do." The casual tone in the cockpit during preflight activities and the taxi did not support the creation of a functional team environment conducive to the crew's subsequent attempts to resolve the abnormal situation. This was manifested in the crew's undisciplined management of the situation in that they failed to adequately assess and understand the situation they were presented with. For example, as the captain completed the after takeoff checklist, he noticed the Avionics Smoke warning on the ECAM; however he failed to announce what the warning was. Instead, he delegated the first officer to fly the airplane and stated he would complete the ECAM. There was no discussion between crewmembers about the situation they were faced with. It is not clear if the first officer was aware of what the warning on the ECAM was. Once the airplane entered the emergency electrical configuration, the captain stopped managing the emergency and the crew's coordination deteriorated further. After the captain stated they were in emergency electrical configuration, the first officer stated "yup confirm. Let's go back." Had the captain been properly managing the abnormal, and now emergency, situation, he should have made the decision to return to the airport rather than the first officer making that decision. In addition, the captain abandoned the EMER ELEC procedure and his pilot monitoring duties. He made radio calls to ATC requesting vectors back to the airport and declaring an emergency. Upon recognizing that the first officer did not have any instruments, the captain assumed control of the airplane. At no point did he delegate the first officer to complete the EMER ELEC procedure but only to inform the flight attendants of the emergency. Completing the EMER ELEC procedure would have resulted in power restoration prior to lowering the landing gear and maintained full use of reverse thrust on landing. After the incident, the first officer stated he did not feel that he had time to be aware of the captain's actions when acting as the pilot flying and said he "took for granted" that the captain completed the ECAM procedure. Finally, during the transfer of flight duties from the first officer to the captain, the first officer stated, "I got the radios", however, subsequent radio communications were made by both crewmembers. Therefore, the captain's failure to set the tone in the cockpit and ineffective management of the emergency resulted in neither crewmember fully understanding the situation they were faced with and subsequent escalation of an abnormal situation to an emergency. The investigation evaluated a number of criteria to determine the extent to which fatigue impacted the flight crew's performance during the incident flight including circadian factors, sleep length, acute or chronic sleep loss, and time since awakening. Based on the pilots' schedules and normal sleeping habits the incident occurred at a time when melatonin is low and body temperature is rising. Therefore, the investigation did not identify any risk of circadian factors in the incident. Investigators also evaluated the flight crew's sleep in the few nights prior to the incident. The captain and the first officer received more than the minimum required rest periods during their trip pairing in the days before the incident, and their flight and duty times in the week and month before the incident would not have precluded them from obtaining adequate sleep. However, both crew members complained of smog, heat and smell during their 29-hour layover in Mexico City on April 2, 2011, which gave them headaches and required use of over the counter pain relief medication. They did not report any difficulties sleeping in Mexico City. The night prior to the incident, the captain obtained about 7.5 hours of sleep, although he said he normally slept about 5 hours per night. This could suggest that he had a sleep debt from previous night's rest that he was trying to overcome, however, staff has no additional information to support that the captain was experiencing a sleep debt. The first officer obtained about 5.5 hours the night before the incident. Although the first officer said he felt rested on the morning of the flight, he received about 1.5 hours less sleep than he normally obtained. Although it is possible that the first officer was experiencing a small acute sleep debt on the morning of the incident, there is no evidence to suggest that this affected his performance during the flight. CVR data indicates he was alert and performed his duties per the captain's delegation and even took an assertive role in deciding to return the flight to the airport. Furthermore, there was no discussion about being tired or yawning heard on the CVR. Neither pilot ate breakfast, but both drank coffee prior to the incident flight. At the time of the incident, the captain had been awake about 2.5 hours and the first officer had been awake about 1.5 hours at the time the Avionics Smoke event was recognized. This was ample time for the body to adjust to being awake and for the crew to maintain alertness and does not believe time since awakening was a factor. Therefore, although it is possible that the first officer was experiencing an acute sleep debt, there is no evidence to suggest that this affected his performance during the flight. His performance was more consistent with poor leadership from the captain and the establishment of a casual tone in the cockpit.

Quoted verbatim from the NTSB record.