“We’re in a stalling situation” said the pilot
American Eagle (Operated by Republic) flight 4439 took off from Atlanta Hartsfield International Airport on November 6th with a crew of four and six passengers onboard. They were headed to New York’s LaGuardia Airport on a regularly scheduled flight. Passing through 14,000 feet, the Embraer 175 experienced a suspected runaway trim event.
The audio from the event is pretty sobering. You can listen the ATC tapes in the YouTube video below. The pilot initially requested to stop the climb at 14,000, then asked for a return to Atlanta airport. Over the course of the next few minutes the situation sounded increasingly dire as one of the pilots reported, “We’re in a stalling situation.” adding that they couldn’t pitch the aircraft down.
Based on the ground track, it appears that the pilots then banked the jet in a left turn in an attempt to reduce the climb rate in accordance with the ‘runaway trim’ checklist suggestion. While such a maneuver sounds aggressive, it is actually a technique to avoid a stall when pitch authority is compromised. At this point, the crew sounds like they executed the entire “Pitch Trim Runaway” checklist. The crew reported soon afterwards that the jet appeared to be under control. The crew landed the Embraer under ‘direct law’ without further incident back at Atlanta’s airport. It is important to also call out the controllers for presumably working so well behind the scenes to clear all possible conflicting traffic in very busy airspace. You can see the full flight path here in detail from FlightAware with both the initial turn to the left and subsequent turns presumably to lose altitude before landing.
The preliminary report has not been released yet. It will be interesting to read when they first noticed the runaway trim. With such a light jet (only 6 passengers) and a cool fall evening, it is possible to have initially interpreted a higher climb rate due to a light aircraft when it actually might have been the initial stages of a runaway trim condition. It will also be interesting to learn whether this was only a runaway trim situation or a more complex emergency that involved the malfunction of multiple flight control systems.
Crew Coordination and Systems Knowledge Saves Lives
While it is too early to speculate on the cause or the actions of the pilots on American Eagle (callsign Brickyard) 4439, it is apparent from the ATC audio that they faced a very serious mechanical malfunction. Along with engine failures at critical times of flight, scenarios like runaway pitch trim are some of the most challenging mechanical emergencies to deal with while flying crew aircraft. In such moments, it is vital that crews successfully execute memory items (called boldface in military aircraft). These initial memorized checklist steps are intended to address the most critical actions necessary to keep the aircraft flying.
The memory items for the E175 in such an incident are designed to disconnect the autopilot and cut off both trim systems. After the initial items are completed, the theory is that there is now time to identify the malfunctioning system, diagnose the problem and safely continue the flight or land when able.
While all we have to go on right now is the audio from Brickyard flight 4439, it sounds like overall they made the right decisions in an extraordinarily difficult situation and safely landed the jet. Working together as a crew is critical to safely resolving emergencies, especially control malfunctions. In such a situation, it is important to first fly the airplane, execute the checklist (including the memory items/boldface immediately), communicate your intentions with the crew, then ATC, plan for the next steps, and then safely land the jet.