A Southwest Airlines Co. passenger flight in April came within 400 feet of slamming into the ocean off the coast of Hawaii after weather conditions forced pilots to bypass a landing attempt.

The Boeing Co. 737 Max 8 jet briefly dropped at an abnormally high rate of more than 4,000 feet per minute before the flight crew pulled up to avoid disaster, according to a memo that Southwest distributed to pilots last week, which was seen by Bloomberg News. No one was injured on the flight, which safely returned to its departure airport in Honolulu.