A Southwest Airlines flight from Honolulu to Lihue made an “excessive descent” during a go around at Lihue, flying as low as 400 feet above the ocean. The incident was first publicly reported by Bloomberg News based on a Southwest Airlines memo.
Unfortunately, as the aircraft approached Lihue and descended below 2,350 ft AMSL reception of ADS-B signals by Flightradar24 receivers in the area was inhibited. There is an approximately 2 minute 30 second period during which no ADS-B data was received from the aircraft. It is during this period that the aircraft conducted its missed approach and experienced the “excessive descent” and Ground Proximity Warning System alerts.
Weather at Lihue at the time of the incident was poor. The flight departed Honolulu at 04:45 UTC and approached Lihue at 05:05. The pilots were aware of the weather conditions and briefed the likely need for a missed approach/go around. METAR for the period in question.
PHLI 120411Z 12012KT 2 1/2SM BR FEW009 BKN025 OVC050 23/22 A2993 RMK AO2 T02280217 $,M
PHLI 120422Z 12013KT 2 1/2SM BR SCT010 BKN042 OVC070 23/22 A2992 RMK AO2 T02280217 $,M
PHLI 120430Z 11015G24KT 3SM BR SCT010 BKN042 OVC070 23/22 A2991 RMK AO2 T02280217 $,M
PHLI 120448Z 11020G26KT 6SM BR BKN012 BKN043 OVC070 22/21 A2990 RMK AO2 PK WND 12026/0446 $,M
PHLI 120453Z 12019G26KT 6SM BR SCT010 BKN047 OVC065 23/21 A2991 RMK AO2 PK WND 12026/0446 SLP126 T02280211 $,M
PHLI 120505Z 11017G24KT 4SM BR FEW007 BKN019 OVC047 23/21 A2991 RMK AO2 T02280211 $,M
PHLI 120515Z 12017KT 2SM BR SCT007 BKN018 OVC046 23/22 A2992 RMK AO2 T02280217 $,M
PHLI 120518Z 12015G23KT 2SM BR FEW007 BKN014 OVC030 23/22 A2992 RMK AO2 T02280217 $,M
Per the Southwest Airlines memo, which can be viewed here, the “First Officer did not have the runway in sight by minimums and called, ‘Go-Around.’” During the go around the first officer “inadvertently pushed forward on the control column while following thrust lever movement commanded by the autothrottle.” This increased the aircraft’s speed and the FO responded by reducing thrust, which led to the aircraft descending. According to the memo, “the aircraft’s maximum descent rate was -4,400 feet per minute and the aircraft descended to nearly 400 feet” above the ocean surface.
The crew received Ground Proximity Warning Systems (GPWS) alerts, which they actioned by increasing thrust and ascending. Southwest reports the maximum vertical rate reached by the aircraft as +8,500 feet per minute.
As the aircraft climbed, it exceeded the missed approach altitude of 3,000 feet. Flightradar24 resumed receiving data from the aircraft at this time, with a maximum altitude of 3,625 recorded before the aircraft leveled off at 3,000 feet and entered a hold southeast of Lihue. The crew decided to return to Honolulu, landing safely at 06:08 UTC.
Aircraft information
Southwest Airlines flight WN2786 was operated by a Boeing 737-8 MAX, powered by two CFM LEAP1-B engines. The aircraft was delivered new to Southwest on 4 November 2022.
