The US National Transportation Safety Board (NSTB) has released its report on Atlas Air flight 3591 that crashed in the US in 2019, citing human error.
The NSTB says the first officer made an inappropriate response to inadvertent activation of the airplane’s go-around mode.
That response led to spatial disorientation that caused him to place the aircraft into a steep descent from which the crew did not recover.
The accident happened 23 February 2019, when the Atlas Air B767 Converted Freighter entered a rapid descent from about 6,000 feet (1,829 metres) and impacted a marshy bay about 64 km from Houston’s George Bush Intercontinental Airport.
The captain, first officer, and a non-revenue, jumpseat pilot, died in the crash. The aircraft – which was carrying cargo from Miami to Houston for Amazon.com and the US Postal Service – was destroyed. The first officer was the pilot flying the airplane at the time of the accident.
The NTSB also determined the captain’s failure to adequately monitor the aircraft’s flight path and to assume positive control of the aircraft to effectively intervene contributed to the crash.
Also cited as a contributing factor is the aviation industry’s “selection and performance measurement practices that failed to address the first officer’s aptitude related deficiencies and maladaptive stress response”.
The NTSB concluded the first officer likely experienced a pitch-up somatogravic illusion – a specific kind of spatial disorientation in which forward acceleration is misinterpreted as the airplane pitching up – as the aircraft accelerated due to the inadvertent activation of the go-around mode, which prompted the first officer to push forward on the elevator control column.
The first officer subsequently believed the airplane was stalling and continued to push the control column forward, exacerbating the airplane’s dive. But the report, released on 14 July, says no cues consistent with an aerodynamic stall – such as stick shaker activation, stall warning annunciations, nose-high pitch indications, or low airspeed indications – were present.
Additionally, the NTSB’s aircraft performance study found “the aircraft’s airspeed and angle of attack were not consistent with having been at or near a nose-high stalled condition”. The first officer’s response was contrary to standard procedures and training for responding to a stall, the NTSB says.
Investigators also concluded the captain’s failure to command a positive transfer of control of the airplane as soon as he attempted to intervene on the controls enabled the first officer to continue to force the airplane into a steepening dive.
The report also identified that the first officer took deliberate actions to conceal his history of performance deficiencies. It added that Atlas’ reliance on designated agents to review pilot background records and to flag significant concerns was inappropriate and resulted in the company’s failure to evaluate the first officer’s unsuccessful attempt to upgrade to captain at his previous employer.
“The first officer in this accident deliberately concealed his history of performance deficiencies, which limited Atlas Air’s ability to fully evaluate his aptitude and competency as a pilot,” said NTSB chairman Robert Sumwalt. “Therefore, today we are recommending that the pilot records database include all background information necessary for a complete evaluation of a pilot’s competency and proficiency.”
As a result of its investigation, the NTSB issued six new safety recommendations to the Federal Aviation Administration and reiterated six previously issued safety recommendations to the FAA.
John Dietrich, president and CEO of Atlas Air Worldwide says the company has been working closely with the NTSB and that the agency’s report provides valuable findings “that will help our company and the aviation community as a whole as we continue to improve safety across our industry.
“Of critical importance is the need for an improved federal pilot records database to provide airlines with full visibility of pilot history in the hiring process,” he adds.
An abstract of the final report, which includes the findings, probable cause, and all safety recommendations, is available here. Links to the accident docket and other publicly released information about this investigation are available here.
The final report for the investigation of the accident is expected to be released in the next few weeks the NSTB says.