Individually Owned: 150,657
Corporate Owned: 137,281
Detroit Metro Airport
Aircraft Accident/Incident Report
Detroit, Michigan 48242
Wednesday, January 9, 2008 7:49 EST
NTSB Narrative Summary Released at Completion of Accident
The accident flight was the first one for the airplane after having maintenance performed on the number two (right) engine during the previous evening. The first officer reported the engine cowls were flush and he did not see any "hanging" cowl latches when he looked underneath the engine cowls during the preflight. The captain reported the preflight, taxi, and takeoff were normal. During climb out the lead flight attendant informed the pilots that a passenger reported that the number two engine cowling was flapping after takeoff. The captain then began to monitor the N1 vibration indications on the number two engine. He reported that the vibration was approximately double the indication from the number one engine, but the indicator was not flashing, nor had it turned amber. The captain reported that during cruise flight the number two engine vibration decreased and about 20 minutes after they leveled off, the airplane shuddered. He reported the remainder of the flight was normal until they were taxiing after landing and the lead flight attendant called the cockpit stating that "part of the right engine had come off." Half of the engine cowl departed the airplane when it was on a one mile final. The other half departed the airplane as it touched down. Another airplane subsequently contacted this part of the cowling when it landed after the accident airplane. Contract maintenance personnel reported they changed the N1 sensor on the number two engine. They reported they shut the fan cowling, but did not latch it as they still needed to perform an engine run and check for leaks. They performed the engine run and were in the cockpit when another mechanic asked for help on another airplane. The mechanics left the accident airplane to assist the other mechanic. Neither mechanic returned to the accident airplane to either latch or verify that the fan cowling had been latched. The aircraft maintenance manual (AMM) instructions for replacing the N1 sensor states, "Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-040)." This task was not completed prior to the airplane being returned to service. The separated cowling contacted the right side of the horizontal stabilizer which resulted in substantial damage to the stabilizer. In addition, the fan cowl doors, number two engine pylon, the number two engine reverser, and the right wing number one slat were damaged.
NTSB Probable Cause Narrative
The separation of the engine cowling which resulted from maintenance personnel failing to follow maintenance procedures in that they did not latch the engine cowling following the maintenance inspection. A factor associated with the accident was their attention was divereted from the task when another mechanic asked for assistance.
Event Information
| Type of Event | Accident |
| Event Date | 1/9/2008 |
| Event Day of the Week | Wednesday |
| Time of Event | 749 |
| Event Time Zone | Eastern Standard Time |
| Event City | Detroit |
| Event State | MICHIGAN |
| Event Country | -- |
| Zipcode of the event site | 48242 |
| Event Date Year | 2008 |
| Event Date Month | 1 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 421245N |
| Event Location Longitude | 0832112W |
| Event Location Airport | Detroit Metro |
| Event Location Nearest Airport ID | DTW |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | 1 |
| Degrees magnetic from airport | -- |
| Airport Elevation | 645 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 753 Eastern Standard Time |
| Direction of event from weather observation facility (degrees) | 270 |
| Weather Observation Facility ID | DTW |
| Elevation of weather observation facility | 645 |
| Distance of event from weather observation facility (units?) | 1 |
| Time Zone of the weather observation | EST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 3800 |
| 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) | 4 |
| Dew Point at event time (in degress fahrenheit) | -1 |
| Wind Direction (degrees magnetic) | 280 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 15 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.9 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 73 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 23629 |
| NTSB Notification Source | FAA |
| NTSB Notification Date | Jan 23 2008 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | May 28 2008 12:03PM |
| User who most recently changed record | NTSB\johb |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Detroit, MI FSDO |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N349NB |
| NTSB Number | CHI08LA071 |
| 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 | Airbus Industrie |
| Aircraft Model | A319-114 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 1815 |
| Certified Max Gross Weight | 155200 |
| 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 | 132 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | Jul 1 2007 12:00AM |
| Airframe hours since last inspection | 317 |
| Airframe Hours | 15029 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | NORTHWEST AIRLINES INC |
| Aircraft Owner Street Address | 7500 Airline Drive |
| Aircraft Owner City | Minneapolis |
| Aircraft Owner State | MN |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 55450 |
| Operator is an individual? | No |
| Operator Name | -- |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | -- |
| Operator State | -- |
| Operator Country | -- |
| Operator Zip code | -- |
| Operator Code | NWAA |
| Owner has at least one certificate | -- |
| Other Operator of large aircraft? | -- |
| 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 | Domestic |
| 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 | LGA |
| Departure City | NEW YORK |
| Departure State | NY |
| Departure Country | USA |
| Departure Time | 618 |
| Departure Time Zone | EST |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | DTW |
| Destination City | DETROIT |
| Destination State | MI |
| Destination Country | USA |
| Specific Phase of Flight | Approach |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | May 12 2008 10:14AM |
| User who most recently changed record | BOWL |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | 27R |
| Runway Length | 8700 |
| Runway Width | 200 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |