Incident Overview

Description
Northwest Flight 74 was a scheduled flight from Tokyo-Narita Airport (NRT) to Guam (GUM). The flight up to the approach to Guam was uneventful. About 14::03:28, the local controller at Guam cleared flight 74 for the visual approach to runway 6L and subsequently cleared the flight to land. About 14:05:56, the captain called for “gear down, flaps 20” and the first officer immediately responded “gear down.” About 14:06:36, the captain requested, “flaps 25, the landing check.” The landing gear warning horn then started. The first officer stated, “oh sorry,” a crewmember stated, “we didnt get a gear,” and then the captain requested, “put it back to 20.” About 14:06:47, the second officer stated “red gear light,” and the landing gear warning horn sound stopped. About 14:06:54, the captain stated, “uh, tell ’em were gonna have to go around. Hold out to the left here. Flaps ten.” About 14:07:02, the first officer called the local controller and advised, “tower, Northwest 74, were gonna uh, do a go-around. Wed like to hold out to the west while we work on a problem.” The local controller then cleared the flight to fly the runway heading and climb and maintain 2,600 feet. During the go-around, the captain asked the second officer, “what do you have for the gear lights?” The second officer responded, “four here.” When all gear are down and locked on the Boeing 747-200, the landing gear indication module located on the SOs instrument panel has five green lights: one nose gear light above four main landing gear lights. The crew then read through the “Red Gear Light Remains On (After Gear Extension)” emergency/abnormal procedure from the cockpit operations manual to troubleshoot the problem. Although the checklist twice presented in boldface type that five lights must be present for the gear to be considered down and locked, the crew did not verbalize the phrase either time. The captain did not directly request a count, and the second officer did not verbally confirm, the number of gear down annunciator lights that were illuminated; instead, the flight crew made only general comments regarding the gear, such as “all gear,” “all green,” or “got ’em all.” Because the crew believed that all of the gear annunciator lights were illuminated, they considered all gear down and locked and decided not to recycle the landing gear or attempt to extend any of the gear via the alternate systems before attempting a second approach. During all communications with air traffic control, the flight crew did not specify the nature of the problem that they were troubleshooting. The flight then positioned for another approach. About 14:15:27, the first officer radioed the controller, and the flight was subsequently cleared to land on runway 6L. About 14:18:17, the airplane touched down, and, about 14:18:22, the second officer stated, “reversers normal.” Three seconds later, the local controller radioed “Northwest 74, go around. Uh, negative, uh, nosewheel.” Engine rpm increased and the second officer stated, “seventy percent,” and then the first officer and second officer both stated “go around” multiple times. About 14:18:37 the local controller queried “Northwest 74, tower,” but the first officer radioed “were unable.” About 14:18:51, the nose contacted the runway surface, and then the captain stated “standby with the evacuation checklist.” The first officer then radioed the LC, asking if he could see any fire, and the local controller responded, “negative.” About 14:19:56, the captain informed the passengers via the public address system that the nose gear had collapsed and that they were to remain seated. The captain then “saw smoke coming from an access hatch and told the flight attendants to evacuate. PROBABLE CAUSE: “The flight crews’ failure to verify that the number of landing gear annunciations on the second officers panel was consistent with the number specified in the abnormal/emergency procedures checklist, which led to a landing with the nose gear retracted.”
Primary Cause
Failure to verify landing gear light count in the second officer’s panel against the emergency procedures checklist, leading to a retraction of the landing gear.Failure to verify landing gear light count in the second officer’s panel against the emergency procedures checklist, leading to a retraction of the landing gear.Share on: