Boeing 767-375BCF accident at Trinity Bay, Texas, 23 Feb 2019

Accident narrative

On February 23, 2019, at 1239 central standard time, Atlas Air Inc. flight 3591, a Boeing 767-375BCF, was destroyed after it rapidly descended from an altitude of about 6,000 feet mean sea level and crashed into a shallow, muddy marsh in Trinity Bay, Texas. The captain, first officer, and a nonrevenue pilot riding in the jumpseat died. Atlas operated the airplane as a Title 14 Code of Federal Regulations Part 121 domestic cargo flight for Amazon.com Services LLC. The flight departed from Miami International Airport at 1033 and was destined for George Bush Intercontinental/Houston Airport.

**The flight**

The captain, 60, had accumulated about 11,172 hours of total flying time, including 1,252 hours in Boeing 767-series airplanes. He was hired by Atlas in 2015 and upgraded to captain in August 2018.

The first officer (FO), 44, had accumulated about 5,073 hours of total flying time, with 520 hours in Boeing 767-series airplanes. He was hired by Atlas in 2017. The investigation noted that the FO had a history of training performance difficulties at multiple previous employers, including failures to complete initial training and an unsuccessful attempt to upgrade to captain.

**Sequence of events**

The departure from Miami, en route cruise, and initial descent toward Houston were uneventful. The FO was the pilot flying, the captain was the pilot monitoring, and the autopilot and autothrottle were engaged. At 1230:37, the captain checked in with the approach controller, reporting that the flight was descending through about 17,800 feet. At 1234:09, the controller advised the crew of precipitation ahead and that they could expect vectors to navigate around it.

At 1236:07, the FO said, "okay – I just had a..." and initiated a positive transfer of airplane control to the captain, stating, "your controls." One minute later, the FO made a comment about the electronic flight instrument (EFI) switch. Two seconds later, the FO said, "okay, I got it back," and the captain acknowledged. The FO then said, "I press the EFI button, it fixes everything."

The FO requested a vector west of the weather. The controller instructed the flight to "hustle all the way down" to 3,000 feet, and the speedbrakes were extended. At 1237:24, the captain transferred pilot flying duties back to the FO. The crew lowered the slats and began setting up the flight management computer for the approach.

At 1238:25, flight data recorder (FDR) data showed vertical load factor variations consistent with light turbulence as the airplane began to penetrate the leading edge of a cold front. At 1238:31, the airplane’s go-around mode was activated. The flight was about 40 miles from the airport, descending through 6,300 feet toward the target altitude of 3,000 feet. Neither pilot made a go-around callout to indicate intentional activation.

During the next six seconds, the automated flight functions commanded nose-up pitch and an increase in engine thrust. At 1238:36, the speedbrakes were retracted, and the airplane's elevators moved in response to manual control inputs to command nose-down pitch. The airplane entered a steep descent.

Beginning at 1238:44, the FO said, "oh," then said in an elevated voice "whoa... (where's) my speed, my speed...we're stalling." He exclaimed "stall" at 1238:51. FDR data indicated that the airplane's airspeed and pitch were not consistent with a stalled condition, and none of the stall warning system indications activated.

At 1238:56, the captain asked, "what's goin' on?" Three seconds later, the jumpseat pilot shouted, "pull up." The elevators moved consistent with manual control inputs to command nose-up pitch, which were held for the remaining seven seconds of the flight but were unsuccessful in arresting the descent.

**What the investigation found**

The wreckage was highly fragmented and dispersed over a 12.3-acre debris field in water and soft mud. Examinations of the structures, engines, and systems revealed no evidence of fire, preexisting cracking, or preimpact failures. The engines responded appropriately to changes in thrust lever position. The Board concluded that the condition and maintenance of the airplane were not factors in the accident. The Board also concluded that whatever EFI display anomaly the FO experienced was resolved to both crewmembers' satisfaction by his cycling of the switch before the accident sequence occurred.

The Board found that the activation of the go-around mode was unintended and unexpected. Atlas procedures stated that the pilot flying should keep a hand on the speedbrake lever when it is extended. Simulator observations showed that a pilot holding the speedbrake lever could have their left wrist or watch close to the left go-around switch on the thrust lever. The Board concluded that the inadvertent activation likely resulted from unintended contact between the FO's left wrist or watch and the switch due to turbulence-induced loads that moved his arm.

Despite go-around mode indications on the flight mode annunciator, neither pilot recognized that the automated flight mode had changed. The Board concluded that the manual forward elevator control inputs applied seconds after the mode change were likely made by the FO. The FO likely experienced a pitch-up somatogravic illusion as the airplane accelerated due to the go-around mode, which prompted him to push forward on the control column. The Board found that the FO had fundamental weaknesses in his flying aptitude and stress response that further degraded his ability to accurately assess the airplane's state and respond with appropriate procedures.

While the captain was setting up the approach and communicating with air traffic control, his attention was diverted from monitoring the airplane's state. This delayed his recognition of the FO's unexpected actions. When the captain intervened on the controls, he pulled back on the left control column but failed to command a positive transfer of control. FDR data showed the right elevator in a more nose-down position than the left, consistent with the captain and the FO applying differing manual inputs on their respective columns. The Board concluded that the captain's failure to assume positive control enabled the FO to continue to force the airplane into a steepening dive, and that the captain's degraded performance resulted from the ambiguity, high stress, and short timeframe of the situation.

The investigation also examined the FO's hiring background. The Board found that the FO's repeated uses of incomplete and inaccurate information about his employment history on resumes and applications were deliberate attempts to conceal his history of performance deficiencies. Atlas's human resources personnel and designated agent failed to evaluate the FO's unsuccessful attempt to upgrade to captain at a previous employer. The Board noted that the manual process by which Pilot Records Improvement Act records are obtained could preclude a hiring operator from obtaining all background records if an applicant fails to disclose a previous employer. The Board concluded that had the Federal Aviation Administration met the deadline and complied with the requirements for implementing the pilot records database (PRD) as stated in the Airline Safety and Federal Aviation Administration Extension Act of 2010, the PRD would have provided hiring employers relevant information about the FO's employment history and training performance deficiencies.

**Probable cause**

The NTSB determines that the probable cause of this accident was the inappropriate response by the first officer as the pilot flying to an inadvertent activation of the go-around mode, which led to his spatial disorientation and nose-down control inputs that placed the airplane in a steep descent from which the crew did not recover. Contributing to the accident was the captain’s failure to adequately monitor the airplane’s flightpath and assume positive control of the airplane to effectively intervene. Also contributing were systemic deficiencies in the aviation industry’s selection and performance measurement practices, which failed to address the first officer’s aptitude-related deficiencies and maladaptive stress response. Also contributing to the accident was the Federal Aviation Administration’s failure to implement the pilot records database in a sufficiently robust and timely manner.