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An Emirates airline flight came within 175 feet of impacting the ground in a neighborhood near Dubai International Airport after the Boeing 777-300ER took off bound for the United States on December 20.
Little is officially known about the incident, which the airline confirms is under investigation, but data from Flightradar24 along with a subsequent notice to Emirates pilots in the days that followed point to an incorrect setting in the 777’s autopilot during the jet’s pre-flight setup that established a flight path to the ground.
The incident again puts a spotlight on pilot reliance on automated systems and how they are used during both automatic and hand flying – a foundational question that has dogged aviation safety across fatal accidents on all types of aircraft.
Subscribe to TACThe close call aboard Emirates 231 came to light in recent days, circulating in WhatsApp groups among pilots with various conclusions about what occurred and why, including a suggestion that the pilot flying the aircraft by hand was slavishly following the cues of the flight director toward a crash.
The flight director is a pair of magenta crossbars overlaid on top of the attitude indicator that provides pitch and roll guidance cues to the pilot when hand-flying the aircraft.
Yet, the incident appears far less straightforward than a dangerous, potentially fatal focus on automated systems during the critical take-off phase, but rather the result of an apparent combination of factors — including a known “quirk” in the Boeing autopilot and flight director that, 777 pilots note, is part of Boeing’s training documentation and should have been caught by the crew before takeoff.
There are a series of accompanying unconfirmed claims circulating about the incident in various private channels, but The Air Current has taken the editorial decision to only report demonstrable facts or those claims that can be explicitly disproven or verified.
The GCAA, the UAE’s aviation regulator, has not responded to a request for comment and it’s not known if the regulator has launched its own investigation of the incident. Without an official investigation, it’s unlikely many details of the incident will be known outside the airline.
According to Flightradar24 data, Emirates 231 to Washington’s Dulles International Airport did not climb after it took off from runway 30R a few minutes after 3 am, instead accelerating to a speed of more than 260 knots less than 200 feet off the ground. One datapoint taken from the tracking data at 1.7 nautical miles from the end of the runway showed the aircraft at 175 feet and 262 knots over the neighborhood of Deira.
For comparison, a similar departure to Washington Dulles two days later was tracked at an altitude of 1,550 feet over the same point. The wingspan of the 777-300ER is 213 feet.
An Emirates spokesperson in a statement to The Air Current said the airline “can confirm that a technical incident occurred on the departure of EK231 on 20 December 2021.
“The flight continued safely to its destination, and after technical clearances the aircraft operated the return flight to Dubai. The incident is under investigation and we are unable to provide further comment at this time. Safety is at the heart of everything we do and would never be compromised.”
If that Flightradar24 data is accurate, the crew significantly exceeded the speed restriction for the standard takeoff flaps setting. Excessive aerodynamic forces on the flaps can cause structural damage and typically necessitates a quick return to the airport for inspection. Instead, Emirates 231 continued the 14-hour and 31-minute journey to the Washington, D.C.-area airport.
Spokespersons for both the Federal Aviation Administration and the Washington Metropolitan Airports Authority said they were not aware of any incident with EK231, which landed uneventfully in the United States at 8:31 am on December 20. The FAA spokesman noted that any incident outside of U.S. airspace on a non-U.S. carrier is outside of its purview. Boeing deferred comment to Emirates.
Upon its return to Dubai on December 21, the 777 did not fly for three days before returning to service on December 24 for a flight to Brussels.
An Emirates notice about setting the autopilot
Among the rumors circulating in social media about the incident is the suggestion that the autopilot altitude selection was left dialed in at 0000, or zero feet at takeoff, a glaring error that should have been caught by the crew during standard pre-departure checks.
In layman’s terms, several Boeing rated pilots tell TAC that leaving the window at an altitude of zero feet would cause the flight director guidance to cue to the pilot to fly the aircraft back to the “captured” altitude, in this case, zero feet while locked in a mode that creates a path to the set altitude. The autopilot on the 777 cannot be activated below 200 feet.
A granular review of data streaming off of Emirates 231’s flight track provided to TAC by Flightradar24, shows that the altitude window on the autopilot was set to 4,000 feet at the time of the aircraft’s takeoff roll. It is not clear from the data stream when the setting was programmed to 4,000 feet. ADS-B telemetry on modern aircraft collected by tracking services like Flightradar24 includes autopilot settings.
However, two Boeing pilots deeply familiar with the 777’s navigation systems say that even if the altitude window was properly set for takeoff, the system if previously set to 0000 (zero feet) will remain locked there unless the flight director is reset or a different mode of the autopilot is selected. Another Emirates pilot called it a “quirk in the system,” and quickly noted that the documented subtlety in the automation “should’ve been caught.”
Both Boeing and Airbus cockpits display or “annunciate” the changing automation modes directly above the attitude indicator in front of both flight crew and many airline procedures include calling out any changes in those modes during all phases of flight, as well.
On December 27, a week after the Dubai incident, Emirates Flight Operations sent a company notice to airmen, reminding 777 crews about post-arrival changes made to the mode control panel (MCP) that is home to the jet’s autopilot — including its speed, altitude, vertical speed and heading. Four small digital “windows” on the panel’s glareshield indicate the commanded settings.
According to the alert reviewed by The Air Current, Emirates wrote that “crews are reminded that there are no…normal procedure requirements to change [settings on] the MCP after landing or shutdown.” Noting, “there have been times when the MCP ‘altitude window’ has been set to the airport elevation which may cause issues on the subsequent departure.”
On descent, the altitude setting in the autopilot is typically dialed to the published altitude for the missed approach procedure in the event of an aborted landing. After parking at the gate, one former veteran Emirates 777 pilot said crews on preceding flights have been known to occasionally reset the altitude window to 0000 or zero feet and speed to 100 (the lowest value) before leaving the aircraft.
Emirates’ notice to the crew states that the automatic flight director system “will engage in “ALT” when the first flight director switch is turned on, if the MCP selected altitude is within 20 feet of the displayed baro[metric] altitude.” In short, the flight director will be locked to the 0000 and the cues provided would guide a pilot back to the ground.
Another veteran Emirates pilot said dialing in those minimum values for speed and altitude was a “bad habit” some crews have so that the speed and departure altitudes are not incorrectly set on the next flight by the incoming crew.
Write to Jon Ostrower at jon@theaircurrent.com
