Individually Owned: 150,657
Corporate Owned: 137,281
Guam-Antonio B. Won Pat Airport
Aircraft Accident/Incident Report
Agana, Guam
Friday, August 19, 2005 14:18
NTSB Narrative Summary Released at Completion of Accident
During the initial approach, the red GEAR annunciator light above the gear lever illuminated, and the landing gear warning horn sounded after the gear handle was selected down and the flaps were selected to 25 degrees. During the go-around, the captain asked the second officer (SO), "what do you have for the gear lights?" The SO responded, "four here." When all gear are down and locked on the Boeing 747-200, the landing gear indication module located on the SO’s 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 SO 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. Although the checklist did not authorize a low flyby, if the flight crewmembers had verbalized that they had a gear warning, the controller most likely would have been able to notify the crew of the nose gear position before the point at which a go-around was no longer safe. Multiple gear cycles were conducted after the accident, and the nose gear extended each time with all nose gear door and downlock indications correctly displayed on the landing gear indication module. Postaccident examination of the nose gear door actuator found that one of the two lock keys was installed 180 degrees backward. Although this improper configuration could prevent proper extension of the nose gear, the actuator had been installed on the accident airplane since 2001 after the actuator was overhauled by the operator. No anomalies were found with the landing gear indication module, the nose gear-operated door sequence valve, and the nose/body landing gear selector valve.
NTSB Probable Cause Narrative
the flight crews' failure to verify that the number of landing gear annunciations on the second officer’s panel was consistent with the number specified in the abnormal/emergency procedures checklist, which led to a landing with the nose gear retracted.
Event Information
| Type of Event | Accident |
| Event Date | 8/19/2005 |
| Event Day of the Week | Friday |
| Time of Event | 1418 |
| Event Time Zone | -- |
| Event City | Agana |
| Event State | GUAM |
| Event Country | -- |
| Zipcode of the event site | -- |
| Event Date Year | 2005 |
| Event Date Month | 8 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | -- |
| Event Location Longitude | -- |
| Event Location Airport | Guam-Antonio B. Won Pat |
| Event Location Nearest Airport ID | GUM |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | -- |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | -- |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 2500 |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | -- |
| Sky Condition for Lowest Ceiling | Broken |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 29 |
| Dew Point at event time (in degress fahrenheit) | 25 |
| Wind Direction (degrees magnetic) | 350 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 4 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.83 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | Minor |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | 2 |
| Injury Total None | 338 |
| Injury Total Serious | -- |
| Injury Total All | 2 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 24781 |
| NTSB Notification Source | NWA |
| NTSB Notification Date | Aug 19 2005 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Dec 17 2008 10:39AM |
| User who most recently changed record | schd |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N627US |
| NTSB Number | DCA05MA095 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | Yes |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | BOEING |
| Aircraft Model | 747-200 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 21709 |
| Certified Max Gross Weight | 816000 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | -- |
| Number of Engines | 4 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | AAIP |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | 95270 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | Unknown |
| Aircraft Owner Name | NORTHWEST AIRLINES INC |
| Aircraft Owner Street Address | 5101 Northwest Drive |
| Aircraft Owner City | St. Paul |
| Aircraft Owner State | MN |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 55111 |
| Operator is an individual? | No |
| Operator Name | -- |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | -- |
| Operator State | -- |
| Operator Country | USA |
| Operator Zip code | -- |
| Operator Code | NWAA |
| Owner has at least one certificate | Yes - certificate holder |
| Other Operator of large aircraft? | Yes |
| Certified for Part 133 or 137 Operation | -- |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | Scheduled |
| Indicates Domestic or International Flight | International |
| Operator carrying Pax/Cargo/Mail | Passenger Only |
| Type of Flying (Per_Bus / Primary) | -- |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | RJAA |
| Departure City | TOKYO |
| Departure State | -- |
| Departure Country | JA |
| Departure Time | -- |
| Departure Time Zone | -- |
| Destination Same as Local Flt | -- |
| Destination Airport Code | PGUM |
| Destination City | AGANA |
| Destination State | GU |
| Destination Country | USA |
| Specific Phase of Flight | Landing - roll |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Nov 4 2008 12:46PM |
| User who most recently changed record | sedj |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 06L |
| Runway Length | 10015 |
| Runway Width | 150 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |