NTSB · Safety Recommendation
Safety Recommendation A-20-006
Recommendation
TO THE CIVIL AVIATION AGENCY OF BRAZIL: In coordination with the Federal Aviation Administration, Embraer, and US operators, determine if changes to the Embraer EMB-170/175/190/195/Lineage 1000 series airplane Pitch Trim Runaway checklists are required to adequately address all potential trim system failures, and make such changes as necessary.
Safety Issue and Context
On November 6, 2019, the flight crew of Republic Airways flight 4439, an Embraer EMB-175, declared an emergency shortly after takeoff from ATL with six passengers on board, reporting a pitch trim-related flight control issue and difficulty controlling the airplane. The captain (who was in the left seat and the pilot flying) later reported recognizing the flight control issue after a failed attempt to engage the autopilot about 2,200 ft mean sea level.
The captain stated that he conducted the single memory item on Republic’s Pitch Trim Runaway checklist to push and hold the autopilot/trim disconnect button on his side (figure 1 shows Republic’s quick reference handbook [QRH] checklist for a pitch trim runaway).1 The captain then asked the first officer to push and hold the right-side autopilot/trim disconnect button. The flight crewmembers reported that they did not notice any change in the pitch condition and continued to have difficulty holding the nose down.
The captain and first officer later reported that they both needed to use both hands to counter the airplane’s nose-up pitch motion and that doing so involved such effort that neither felt that they could reach for the QRH to troubleshoot the problem. Ultimately, the flight crew was able to trim the airplane with the first officer’s trim switch, return to ATL, and land the airplane safely about 15 minutes after declaring the emergency.
Review of data from the incident flight revealed that the airplane was in a mistrim condition for a portion of the flight. While this incident is still under investigation, three areas of concern have been identified: wire chafing, application of Embraer service bulletins (SB) related to the pitch trim switch, and potential limitations in checklist memory item(s) to help Embraer pilots address unintended operation of the pitch trim system.
Response History
February 5, 2024 · NTSB Correspondence · Foreign, Brazil, Departamento de Aviacao Civil
We note that Embraer consulted with Brazilian and US operators of affected aircraft to develop an operational bulletin. We also note that, after collaborating with the ANAC, Embraer modified the PTR Quick Reference Handbook (QRH) Checklist to better describe the characteristics of any PTR condition, and that the Flight Standardization Board evaluated and approved the modifications.
We believe your work with the FAA, Embraer, and operators to review PTR checklists, identify necessary improvements, and ensure that those improvements are incorporated into PTR QRH checklists satisfies the intent of this recommendation. Consequently, Safety Recommendation A-20-6 is classified CLOSED-- ACCEPTABLE ACTION.
July 4, 2023 · Recipient Response · Foreign, Brazil, Departamento de Aviacao Civil
-From Major General Marcelo Moreno, Chief of the Aeronautical Accident Investigation and Prevention Center (CENIPA), Ministry of Defense, Command of Aeronautics: As requested by ANAC, Embraer has evaluated the EMB-170/175/190/195/Lineage 1000 series airplane Pitch Trim Runaway checklists. Improved procedures were discussed and communicated to operators through the Operational Bulletin OB170- 003-20 and implemented in the QRH and AOM publications.
September 2, 2020 · NTSB Correspondence · Foreign, Brazil, Departamento de Aviacao Civil
We note that, in coordination with the FAA, Embraer, and other entities, you are evaluating the existing original equipment manufacturer’s pitch trim runaway checklist to determine whether individual operators’ checklists and memory items adequately address all potential trim system failures. Pending our review of your findings and completion of the recommended actions, Safety Recommendation A-20-6 is classified OPEN--ACCEPTABLE RESPONSE.