How A United Airlines Boeing 777 Almost Crashed Into The Pacific

In December 2022, a United Airlines Boeing 777 had a terrifying takeoff while departing Hawaii. The National Transportation Safety Board (NTSB) has now released its final report on the incident, and it’s quite something…

A United 777’s terrifying takeoff from Maui

First let’s go over the background of the incident. On December 18, 2022, United Airlines flight UA1722 was scheduled to operate from Maui (OGG) to San Francisco (SFO) with a 22-year-old Boeing 777-200 that had the registration code N212UA.

The plane took off at 2:49PM and climbed to 2,100 feet. At that point the plane began a steep dive, descending at nearly 8,600 feet per minute, which would have produced forces of nearly 2.7x the force of gravity. The plane descended down to 748 feet above sea level.

Fortunately at that point the pilots recovered the aircraft, and the flight continued to San Francisco without further issues. There were no injuries, and no damage to the aircraft. It can’t be overstated just how close of a call this was. At a descent rate of 8,600 feet per minute and an altitude of 775 feet, the plane was seconds from catastrophe.

What caused this United 777 incident?

How could two pilots nearly crash a 777 into the ocean when visibility was good? The NTSB has just released its final report about this incident, so now we know what caused this incident.

The first thing to note is that the pilots were pretty experienced, with the captain being a lot more experienced than the first officer on this aircraft. The captain had a total of 19,600 flight hours (including 5,000 hours on the 777), while the first officer had 5,300 flight hours (including 120 hours on the 777). So around 25,000 hours of experience in the cockpit is quite a bit, though the first officer was basically brand new on the 777.

What’s the cause of this incident? Well, it boils down to a miscommunication between the captain and first officer, and a failure to recover quickly from that miscommunication. Here’s what the NTSB’s investigation revealed:

  • The captain and first officer had agreed to take off with flaps set at 20 degrees, based on performance calculations
  • The captain was the one flying this segment, and while the initial climb out was normal, the flight crew noticed airspeed fluctuations due to wind shear, so the captain called for the flaps to be reduced to five degrees
  • The first officer thought he heard the captain say 15 degrees, rather than five degrees, so that’s what the first officer set the flaps to (the pilot not flying is the one who sets flaps)
  • The captain noticed the plane wasn’t responding the way he expected, and that the airspeed was accelerating rapidly
  • Therefore the captain reduced the engine thrust manually, to avoid flying too fast with flaps
  • He again called for the flaps to be moved to five degrees, and at this point the first officer moved the flaps to five degrees
  • The first officer “knew the captain was having difficulty with airspeed control,” and asked the captain if maybe his instruments were wrong, but he didn’t receive an immediate response
  • Both pilots remembered feeling the airplane’s pitch decreasing, and the airspeed increasing
  • The captain then called for flaps to be set to one degree
  • Alarms were going off in the cockpit, including the ground proximity warning system going off
  • The captain pulled up on the control column, which is the point at which the plane was at 748 feet, and began its recovery

Below is a map showing the aircraft’s path as it took off.

The United 777’s path on takeoff

Here’s how the NTSB describes the probable cause of the incident:

“The flight crew’s failure to manage the airplane’s vertical flightpath, airspeed, and pitch attitude following a miscommunication about the captain’s desired flap setting during the initial climb.”

My take on this United 777 incident

Aviation is incredibly safe, despite how much goes into it, and how many human factors there are. Along those lines, it’s wild how a simple miscommunication of a single number nearly caused a catastrophic incident. With that in mind, a few thoughts:

  • It’s hard to put the blame on one specific pilot here; the first officer misunderstood the captain, and the captain was the one flying the plane
  • Typically if there’s a small miscommunication, there’s plenty of time to recover, though takeoff is such a critical phase of flight, so a small error can have big implications
  • I think what’s perhaps most alarming here is how this incident was never reported to the NTSB voluntarily by United, but rather it wasn’t until this got media coverage a couple of months later that United finally opened an investigation
  • Honestly, this flight was within seconds of having a very different ending, so thank goodness the pilots at least recovered the way they did

Bottom line

The NTSB has released its final report about a scary incident that happened in late 2022, when a United Airlines Boeing 777 was departing Maui. During the climb out, the aircraft accidentally descended all the way to 748 feet.

The cause of the incident was determined to be a miscommunication between the two pilots over the flap settings. The captain asked for flaps to be set to five degrees, though the first officer thought he said 15 degrees. On top of that, the NTSB blames the pilots’ failure to manage the aircraft following a miscommunication.

What do you make of this United 777 incident?

Conversations (33)
The comments on this page have not been provided, reviewed, approved or otherwise endorsed by any advertiser, and it is not an advertiser's responsibility to ensure posts and/or questions are answered.
Comment as a member

Membership is free and takes no more information than commenting as a guest. Earn status points for good contributions, and see fewer ads as your status grows.

Type your response here.

If you'd like to participate in the discussion, please adhere to our commenting guidelines. Anyone can comment, and your email address will not be published. Register to save your unique username and earn special OMAAT reputation perks!

  1. Loading comments…
Recent Comments
The latest from the OMAAT community.

The comments on this page have not been provided, reviewed, approved or otherwise endorsed by any advertiser, and it is not an advertiser's responsibility to ensure posts and/or questions are answered.

Stephen Daniels Guest

Two questions arise in my amateur mind: 1. Should the flap setting not have been read back to the Captain by the co-pilot just as it done over the radio with ATC regarding altitude etc. to ensure everyone is on the same page? 2. Are there consequences for United for not reporting this immediately?

0
‼ 0
Ray C Guest

Miscommunication was not the cause of this - it was only a minor contributor. The captain's choice to hand fly the departure followed by his getting distracted from flying the airplane (the flying pilot's first responsibility). The triple autopilot system on this aircraft is very capable of handling the aircraft in conditions such as this and would have been the better choice to begin with. Had the autopilot been engaged early after liftoff the captain would have been in a better position to monitor the flight and the departure would likely have been completely uneventful.

0
‼ 0
Mike Guest

Looks to me like the pilots, while messing with the flaps, got disoriented, distracted and quit “flying” the plane. As a result, found themselves in a dive very close to the water. The GPWS system alert AND pilot compliance saved the day. There are other procedural oddities here but they are too obtuse for this venue.

1
‼ 0
John Heard Guest

I’m somewhat surprised & confused as to the NTSB’s investigative conclusion regarding UAL 1722 - PHOG departure on 12/18/22.   Certainly the communication CRM aspect contributed, seems like the Captain was very much tasked loaded with flying the aircraft.   The Captain’s airmanship was the main component. A flaps 20 t/o at MAX thrust will result in a time compressed transition to a normal climb profile if you’re not ready for such.  Sounds like the Captain failed to appropriately brief the departure to include the non-standard profile. I believe the NTSB failed miserably regarding this investigation.  Would be interesting to know Boeing’s involvement in the investigation.

0
‼ 0
Ric Guest

Ground proximity warning system have prevented a lot of accidents. Controlled descent into terrain used to be the primary cause of commercial airline hull losses.

0
‼ 0

Save posts to read later

Saving posts is a member feature. Become an OMAAT member to build a reading list you can come back to from any device.

Become a member
Meet Ben Schlappig, OMAAT Founder
5,883,136 Miles Traveled

43,914,800 Words Written

47,187 Posts Published