Summary
- Miscommunication between pilots led to a United Airlines Boeing 777 losing altitude after departing from Maui.
- The plunged in altitude shortly after takeoff, however the crew was in a position to recuperate before any harm was done.
- The error resulted within the failure to administer the aircraft’s vertical flight path, airspeed, and pitch attitude.
The National Safety Board (NTSB) confirmed on Thursday that “miscommunication” was the explanation for what led to a United Airlines Boeing 777 losing altitude after departing from Maui. The incident happened in December with none injuries or damage to the aircraft.
Each pilots in command recalled hearing initial warnings from the plane’s warning system. Amid the error, the aircraft got here inside 1,000 feet of the ocean.
Details of the incident
On December 18, 2022, UAL1722 traveled from Kahului Airport to San Francisco International Airport. The flight was operated by N212UA, a 777-200, and departed while OGG was experiencing heavy rain conditions. In an announcement, the NTSB said the aircraft lost altitude shortly after takeoff.
“United flight 1722 lost altitude about 1 minute after departure while in instrument meteorological conditions, which included heavy rain. The airplane descended from 2,100 ft to about 748 ft above the water before the crew recovered from the descent. No injuries were reported, and the airplane was not damaged.”
Photo: Santi Rodriguez/Shutterstock
In response to the NTSB, the captain reported that it was agreed with the primary officer to plan for takeoff with flaps set to twenty degrees and reduced thrust, per performance calculations. When the plane was taxiing, ground air traffic control (ATC) informed the pilots that low-level wind shear advisories were in effect, which prompted the captain to decide on a flaps-20 departure with maximum thrust. The captain reportedly hand-flew the aircraft while the autothrottles were engaged, contributing to a traditional rotation and initial climb.
Because the widebody aircraft climbed, its airspeed fluctuated as a consequence of turbulence and wind shear. Once reaching acceleration altitude, the captain barely reduced the plane’s pitch and called for the flap setting to be decreased to 5 degrees. Nevertheless, the primary officer reportedly thought the captain announced the flaps to be set at 15 degrees and did so without contacting the departure ATC to debate the weather conditions.
Gaining speed but losing altitude
Once this happened, the captain noticed that the aircraft’s maximum operating speed indicator shifted to a lower value than expected, and the airspeed began to speed up rapidly, based on the NTSB. To avoid going overspeed, the captain manually reduced the engine thrust, which overrode the auto throttle engagement. The captain also noticed the flaps indicator showed 15 degrees and called again for the flaps to be set at five degrees – to which the primary officer then adjusted.
At the moment, the plane’s pitch attitude was decreasing, which caused its airspeed to extend. Soon after the captain called for flaps five, he then called for the flaps to be set at one degree, based on the primary officer.
“Pull up, pull up”
Each pilots told the NTSB that they heard the initial warnings from the bottom proximity warning system (GPWS), and the primary officer recalled announcing, “Pull up, pull up.” The captain then pulled back on the controls to lift the aircraft, reducing power to diminish speed. Then, the captain applied full power to initiate the CFIT (controlled flight to terrain) recovery.
The move caused the aircraft to nose-dive dramatically for around 10 seconds. In response to CNN, passengers on the flight said there have been several screams in the course of the terrifying event.
the Board explained.
Photo: NTSB
Within the NTSB’s final report, “miscommunication” was deemed a probable cause.
“The flight crew’s failure to administer the airplane’s vertical flightpath, airspeed, and pitch attitude following a miscommunication concerning the captain’s desired flap setting in the course of the initial climb.”
Addressing the incident, United has since modified considered one of its operations training modules and reportedly issued an awareness campaign at its training center regarding managing flight paths.
Because the incident didn’t reportedly meet the necessities of federal regulations, the NTSB was not immediately notified. In response to Reuters, the pilots voluntarily reported the incident two months after, which prompted the Board to open an investigation.