National Transportation Safety Board
Aviation Incident Final Report

 

 

Location:

Baton Rouge, LA

Incident Number:

CEN11IA615

Date & Time:

09/01/2011, 1725 CDT

Registration:

N875AS

Aircraft:

BOMBARDIER INC CL-600-2B19

Aircraft Damage:

Minor

Defining Event:

Landing gear not configured

Injuries:

53 None

Flight Conducted Under:

Part 121: Air Carrier - Scheduled

Analysis

While configuring the airplane for landing, the flight crew observed a landing gear disagree message and an indication that the left main landing gear was not down and locked. The flight crewmembers followed procedures to address the landing gear disagree message; however, they were unable to get the left landing gear to extend. The captain declared an emergency and chose to land the airplane with only the right main landing gear and nose landing gear extended. The airplane came to rest in an upright, left-wing-low position. Postincident examination of the left main landing gear system revealed that the upper attachment bolt for the left main landing gear uplock assembly, which is designed to be attached to both the uplock mechanism and the structure, was attached only to the airplane structure. The left main landing gear uplock assembly had been removed and reinstalled the day before the incident flight. The mechanic who performed the maintenance did not have training on nor prior experience performing the installation of the uplock assembly, and the maintenance inspector who inspected its installation did not have training on inspecting the uplock assembly. Neither the mechanic nor the maintenance inspector observed any problems during the postinstallation inspection. Thus, it is likely that the uplock assembly was installed incorrectly due to the lack of training in both the installation by the mechanic and the inspection by the inspector.

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this incident to be:
The improperly installed upper attachment bolt in the left main landing gear uplock assembly, which led to the failure of the left main landing gear to extend before landing. Contributing to the accident was maintenance personnel's lack of training on the installation and inspection of the uplock assembly.

Findings

Personnel issues

Installation - Maintenance personnel (Cause)

Total experience w/ equipment - Maintenance personnel (Factor)

Post maintenance inspection - Maintenance personnel (Factor)

Factual Information

On September 1, 2011, about 1725 central daylight time, a Bombardier CL-600-2B19 airplane, N875AS, operated as Delta Connection flight 5058, landed at the Baton Rouge Metropolitan Airport (BTR), Baton Rouge, Louisiana, with the left main landing gear in the retracted position. The airline transport pilot captain, first officer, flight attendant, and 50 passengers were not injured. The airplane received minor damage. Visual meteorological conditions prevailed for the landing and an instrument flight rules flight plan was filed for the 14 Code of Federal Regulations Part 121 flight. The flight originated from the Hartsfield Jackson Atlanta International Airport (ATL), Atlanta, Georgia, at 1409.

 

While configuring the airplane for landing, the flight crew observed a landing gear disagree message, and the left main gear indicated that it was not down and locked. The Quick Reference Handbook (QRH) procedures were accomplished, which included cycling the landing gear handle and the use of the alternate gear extension (manual release) system; however, the crew was unable to get the left landing gear to extend. The captain declared an emergency and elected to land the airplane with the right main landing gear and nose gear extended. The airplane came to rest in an upright and left wing low position. The captain commanded an evacuation, and all passengers departed the airplane using the left forward door.

 

Post-incident inspection of the airplane revealed minor damage to the left wing. There was no other damage to the airplane as a result of the left main landing gear being retracted at the time of landing. Examination of the left main landing gear assembly revealed that the upper attachment bolt for the left main landing gear uplock assembly, which is designed to be attached to both the uplock mechanism and the structure, was attached to the airplane structure only.

 

Maintenance had been performed on both the left and right main landing gear systems prior to the incident flight. The mechanic who performed the maintenance did not have prior experience performing the installation of the uplock assembly. Following the incident, Atlantic Southeast Airlines changed their maintenance requirements and procedures to prevent future accidents. In addition, Bombardier issued Service Letter ATA:3230 to address this maintenance discrepancy and prevent future accidents.

 

History of Flight

Landing

Landing gear not configured (Defining event)

 

 

Pilot Information

Certificate:

Airline Transport; Commercial

Age:

31

Airplane Rating(s):

Multi-engine Land; Single-engine Land

Seat Occupied:

Left

Other Aircraft Rating(s):

None

Restraint Used:

Seatbelt, Shoulder harness

Instrument Rating(s):

Airplane

Second Pilot Present:

Yes

Instructor Rating(s):

None

Toxicology Performed:

Yes

Medical Certification:

Class 1 Unknown

Last FAA Medical Exam:

02/23/2011

Occupational Pilot:

Yes

Last Flight Review or Equivalent:

03/18/2011

Flight Time:

5305 hours (Total, all aircraft), 4312 hours (Total, this make and model), 198 hours (Last 90 days, all aircraft)

 

 

Co-Pilot Information

Certificate:

Commercial

Age:

27

Airplane Rating(s):

Multi-engine Land; Single-engine Land

Seat Occupied:

Right

Other Aircraft Rating(s):

None

Restraint Used:

 

Instrument Rating(s):

Airplane

Second Pilot Present:

Yes

Instructor Rating(s):

None

Toxicology Performed:

No

Medical Certification:

Class 1 Without Waivers/Limitations

Last FAA Medical Exam:

07/21/2011

Occupational Pilot:

Yes

Last Flight Review or Equivalent:

 

Flight Time:

998 hours (Total, all aircraft), 715 hours (Total, this make and model), 175 hours (Last 90 days, all aircraft)

 

 

Aircraft and Owner/Operator Information

Aircraft Make:

BOMBARDIER INC

Registration:

N875AS

Model/Series:

CL-600-2B19

Aircraft Category:

Airplane

Year of Manufacture:

 

Amateur Built:

No

Airworthiness Certificate:

Transport

Serial Number:

7559

Landing Gear Type:

Retractable - Tricycle

Seats:

54

Date/Type of Last Inspection:

08/31/2011, AAIP

Certified Max Gross Wt.:

53000 lbs

Time Since Last Inspection:

 

Engines:

2 Turbo Fan

Airframe Total Time:

30563 Hours at time of accident

Engine Manufacturer:

General Electric

ELT:

Installed, not activated

Engine Model/Series:

CF34-3B1

Registered Owner:

ATLANTIC SOUTHEAST AIRLINES INC

Rated Power:

9140 lbs

Operator:

ATLANTIC SOUTHEAST AIRLINES INC

Operating Certificate(s) Held:

Commuter Air Carrier (135)

Operator Does Business As:

 

Operator Designator Code:

ASOA

 

Meteorological Information and Flight Plan

Conditions at Accident Site:

Visual Conditions

Condition of Light:

Day

Observation Facility, Elevation:

BTR, 70 ft msl

Distance from Accident Site:

 

Observation Time:

1643 CDT

Direction from Accident Site:

 

Lowest Cloud Condition:

Few / 8000 ft agl

Visibility

10 Miles

Lowest Ceiling:

None

Visibility (RVR):

 

Wind Speed/Gusts:

11 knots /

Turbulence Type Forecast/Actual:

/

Wind Direction:

100°

Turbulence Severity Forecast/Actual:

/

Altimeter Setting:

29.94 inches Hg

Temperature/Dew Point:

29°C / 24°C

Precipitation and Obscuration:

No Obscuration; No Precipitation

Departure Point:

Atlanta, GA (ATL)

Type of Flight Plan Filed:

IFR

Destination:

Baton Rouge, LA (BTR)

Type of Clearance:

IFR

Departure Time:

1409 CDT

Type of Airspace:

 

 

Airport Information

Airport:

Baton Rouge Metropolitan (BTR)

Runway Surface Type:

Asphalt

Airport Elevation:

70 ft

Runway Surface Condition:

Dry

Runway Used:

13

IFR Approach:

None

Runway Length/Width:

6407 ft / 150 ft

VFR Approach/Landing:

None

 

Wreckage and Impact Information

Crew Injuries:

3 None

Aircraft Damage:

Minor

Passenger Injuries:

50 None

Aircraft Fire:

None

Ground Injuries:

N/A

Aircraft Explosion:

None

Total Injuries:

53 None

Latitude, Longitude:

30.532778, -91.149722 (est)

 


 


Administrative Information

Investigator In Charge (IIC):

Timothy LeBaron

Report Date:

01/30/2014

Additional Participating Persons:

T.R. Proven; Federal Aviation Administration; Washington, DC

Brad Sheehan; Atlantic Southeast Airlines; Atlanta, GA

Publish Date:

01/30/2014

Investigation Docket:

http://dms.ntsb.gov/pubdms/search/dockList.cfm?mKey=81683