On January 5, 2024, about 1713 Pacific standard time, Alaska Airlines flight 1282, a Boeing 737-9 airplane, N704AL, experienced an in-flight separation of the left mid exit door plug and rapid depressurization during climb after takeoff from Portland International Airport, Portland, Oregon. One flight attendant and 7 passengers received minor injuries; the captain, the first officer, 3 flight attendants, and 164 passengers were uninjured; and the airplane sustained substantial damage. The scheduled domestic passenger flight was operated under Title 14 Code of Federal Regulations Part 121 and departed PDX about 1707 with a planned destination of Ontario International Airport, Ontario, California.
the in-flight separation of the left mid exit door (MED) plug due to Boeing Commercial Airplanes’ failure to provide adequate training, guidance, and oversight necessary to ensure that manufacturing personnel could consistently and correctly comply with its parts removal process, which was intended to document and ensure that the securing bolts and hardware that were removed from the left MED plug to facilitate rework during the manufacturing process were reinstalled. Contributing to the accident was the Federal Aviation Administration’s ineffective compliance enforcement surveillance and audit planning activities, which failed to adequately identify and ensure that Boeing addressed the repetitive and systemic nonconformance issues associated with its parts removal process.
FA2100 FDR · N704AL — 1,866,750 samples, 30 parameters, 08:20:00.0 to 13:47:30.0.
| Parameter | Max | at | Min | at | Final | at |
|---|---|---|---|---|---|---|
| Computed airspeed kts | 294.0 | 08:48:19.1 | 45.0 | 08:20:00.1 | 45.0 | 13:47:29.8 |
| Ground speed kts | 516.0 | 12:23:06.8 | 0.0 | 08:24:15.1 | 2.0 | 13:47:29.8 |
| Pitch attitude deg | 14.4 | 08:26:36.1 | -2.5 | 13:40:54.4 | 0.5 | 13:47:29.9 |
| Roll attitude deg | 29.5 | 13:37:35.9 | -12.5 | 13:33:57.9 | 0.0 | 13:47:29.9 |
| Vertical acceleration g | 1.5 | 13:41:32.6 | 0.7 | 13:41:32.9 | 1.0 | 13:47:29.9 |
| Time | Event | Page |
|---|---|---|
| 17:06:47 PST | The aircraft departed runway 28L at Portland International Airport (PDX). | 7 |
| 17:12:33 PST | The recorded cabin pressure dropped from 14.09 to 11.64 psi when the aircraft was at 14,830 ft and 271 kts. The "Cabin Altitude Greater than (>) 10k ft Warning" activated. | 7 |
| 17:12:34 PST | The master caution activated. The cabin pressure continued decreasing and was 9.08 psi at 14,850 ft and 271 kts. The aircraft magnetic heading was 123 deg. | 7 |
| 17:12:52 PST | The master caution deactivated. | 7 |
| 17:13:36 PST | The cabin pressure was 7.89 psi and was at the lowest value recorded. The aircraft was at 16,293 ft and 278 kts. | 7 |
| 17:13:41 PST | The aircraft continued to climb and reached a maximum altitude of 16,320 ft and began to descend. The airspeed was 276 kts on a magnetic heading of 120 deg. | 7 |
| 17:13:48 PST | The cabin pressure began to increase from 7.89 psi to 7.91 psi. The aircraft was at 16,266 ft and was descending. | 7 |
| 17:13:56 PST | The selected altitude changed from 23,000 ft to 10,000 ft. The cabin pressure was 7.95 psi and continued to increase for the remainder of the flight. | 8 |
| 17:14:35 PST | The master caution activated for 3 seconds. | 9 |
| 17:16:56 PST | The aircraft began a left turn from 121 deg. The altitude was approximately 10,120 ft. | 9 |
| 17:17:00 PST | The aircraft descended below 10,000 ft. | 9 |
| 17:18:05 PST | The aircraft altitude was approximately 9,050 ft and the airspeed was 271 kts. The "Cabin Altitude Greater than (>) 10k ft Warning" deactivated. The cabin pressure was 10.48 psi. | 9 |
| 17:26:46 PST | The aircraft landed on runway 28L at PDX. | 9 |
| 17:06:48 QAR PST | The aircraft departed runway 28L at PDX. Cabin pressure controller (CPC) 1 was in automatic control. | 9 |
| 17:12:33 QAR PST | The cabin differential pressure dropped from 5.72 psi to 3.28 psi and 2.48 psi for CPC1 and CPC2, respectively. | 9 |
| 17:12:34 QAR PST | The recorded cabin pressure dropped from 14.09 to 10.67 psi for CPC1 when the aircraft was at 14,859 ft and 271 kts. CPC2 did not record a change in pressure. | 9 |
| 17:12:35 QAR PST | The "Cabin Altitude Greater than (>) 10k ft Warning" activated. The cabin pressure dropped to 9.43 psi and 10.67 psi for CPC1 and CPC2, respectively, at 14,883 ft and 271 kts. The aircraft magnetic heading was 122 deg. The differential pressure was 0.22 psi and 0.17 psi for CPC1 and CPC2, respectively. | 9 |
| 17:12:40 QAR PST | The outflow valve (OFV) switch was activated. | 9 |
| 17:14:28 QAR PST | The OFV switch was deactivated. The OFV position began to increase from 1.06 deg and -0.63 deg to 8.19 deg and 1.69 deg for CPC1 and CPC2, respectively. | 9 |
| 17:14:37 QAR PST | The OFV position reached a maximum 109.50 deg and 108.69 deg for CPC1 and CPC2, respectively. | 9 |
| 17:15:05 QAR PST | The OPMODE for CPC1 changed from auto to manual. | 9 |
| 17:15:06 QAR PST | The automatic CPC1 in control changed from operational to standby. The OPMODE for CPC2 changed from auto to manual. | 9 |
| 17:17:00 QAR PST | The aircraft descended below 10,000 ft. The "Cabin Altitude Greater than (>) 10k ft Warning" deactivated. | 9 |
| 17:26:47 QAR PST | The aircraft landed on runway 28L at PDX. | 9 |
Docket: data.ntsb.gov/Docket/?NTSBNumber=DCA24MA063. This brief is an analytical aid assembled from public records; it is not an investigative finding.