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Air Wisconsin Airlines Flight 3919

14 Dec 2008 · Philadelphia, PA, United States

Bombardier CL-600-2B19 · Incident: system/component malfunction/failure (non-power) on approach

From Norfolk International Airport (ORF) to Philadelphia International Airport (PHL)

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Event

NTSB case
DCA09IA017
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Incident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
0 · all aircraft and ground
Ground fatalities
Unknown
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
Airline
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Visual Meteorological Cond

Bombardier CL-600-2B19

Aircraft type
Bombardier CL-600
Category
Airplane
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N407AW
Onboard fatalities
Unknown
Route
From Norfolk International Airport (ORF), Norfolk, VATo Philadelphia International Airport (PHL), Philadelphia, PA
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 121: Air Carrier
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
Approach
Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
System/component malfunction/failure (non-power)
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Minor

Cause areas

  • Personnel issues › Task performance

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

The flight crew had indications of a landing gear problem during approach. After unsuccessfully attempting to lower the gear, the flight crew elected to make an emergency landing with only the nose gear and right main landing gear "down and locked". After touch down, the airplane came to rest on its right main landing gear, nose gear and the left wingtip and flaps, resulting in minor damage. Post-incident examination of the maintenance records and airplane revealed that the left and right main landing gear (MLG) uplock assemblies had been replaced prior to the incident flight. No anomalies were found with the installation of the right MLG uplock assembly; however, the upper attachment bolt in the left MLG uplock assembly was improperly installed and had not properly been inspected. As installed, the upper attachment bolt did not engage the uplock assembly, which allowed the uplock assembly to pivot inboard about the lower attachment bolt and the uplock release cable no longer allowed the lever full travel to release the uplock. The left and right uplock assemblies had been replaced by two different mechanics and neither mechanic witnessed the gear swing test, but each signed the work package off as being completed after making a verbal turnover to the day shift supervisor. This was inconsistent with company policies and procedures. The installation was inspected and there were several discrepancies noted concerning the left gear assembly installation. Although the discrepancies were corrected, they were not properly documented. Additionally, the inspector did not use a mirror to examine the components in the darkened gear well and used an abbreviated functional check procedure instead of the manual gear extend test procedure specified in the maintenance manual. The mechanic who replaced the right uplock assembly stated that he had replaced uplocks on other airplanes but not the accident type airplane. The inspector stated that he had no experience inspecting uplock assemblies, nor did he recall ever having removed or replaced a gear uplock assembly as a mechanic. Based upon findings of the investigation, the NTSB issued Safety Recommendation A-10-96 and -97, dated May 28, 2010.

Probable cause

the failure of the maintenance personnel to properly complete the installation, and the inspection personnel to conduct the proper functional test, of the left main landing gear uplock assembly.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record DCA09IA017
Event ID
20081215X93019
Case number
DCA09IA017
Dataset
full-current
Source SHA-256
5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (5)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: 7e69f4e941a02f98a96257312f98d38d98b84f209a42ca96e2472b40d4272ce6; retrieved 2026-09-15T10:36:17.616Z.
  • Corrected after a review of the NTSB narrative, which states these values explicitly: departure. Typo in city name; airport code ORF is Norfolk International Airport, Norfolk, VA.