Individually Owned: 150,657
Corporate Owned: 137,281
Gwinnett County Airport
Aircraft Accident/Incident Report
Lawrenceville, Georgia 30045
Monday, December 19, 2011 11:00 EST
NTSB Narrative Summary Released at Completion of Accident
While configuring the airplane for a power-off stall, the pilots noted that there was an unsafe gear indication after selecting the landing gear to the down position. The flight instructor made several unsuccessful attempts to extend the landing gear using the emergency gear extension procedures, but the light did not illuminate. The pilot reported the condition to the air traffic controller, and he maneuvered the airplane for a low approach, and the controller advised the pilot that the gear appeared to be down. During the landing roll all three landing gears remained extended, but as the airplane slowed, the right main landing gear collapsed, and the airplane veered off the runway colliding with a runway light. A postaccident examination of the right main landing gear revealed that the truss assembly hook assembly did not travel over the truss pin. The landing gear was tested, and the right main landing gear did not lock on any attempt. In addition, the right main landing gear truss bracket and stud had excessive friction and prevented the side brace from fully rotating, subsequently preventing the truss hook from traveling over the lock pin. The right main landing gear truss bracket pin had little or no grease present; however, the left main landing gear truss bracket pin had grease indications around the pin and zerk fitting. A review of the airframe maintenance records indicated that about a month before the accident, the airplane had completed a 100-hour inspection and a side brace mount assembly was installed in the right main landing gear. The mechanic who performed the maintenance stated that he could not find any guidance in the maintenance manual on how to remove and install the new bushing; therefore, he replaced the bushing and verified that there was movement between the two parts, and then reinstalled the side brace assembly on the airplane. The mechanic did not follow the proper procedures as described in the manufacturer maintenance manual. The accident occurred about 38 hours after the 100-hour inspection.
NTSB Probable Cause Narrative
The mechanic's improper installation and lubrication of the bushing on the right main landing gear truss assembly, which resulted in the landing gear not locking in the down position.
Event Information
| Type of Event | Accident |
| Event Date | 12/19/2011 |
| Event Day of the Week | Monday |
| Time of Event | 1100 |
| Event Time Zone | Eastern Standard Time |
| Event City | Lawrenceville |
| Event State | GEORGIA |
| Event Country | -- |
| Zipcode of the event site | 30045 |
| Event Date Year | 2011 |
| Event Date Month | 12 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 335841N |
| Event Location Longitude | 0835744W |
| Event Location Airport | Gwinnett County Airport |
| Event Location Nearest Airport ID | LZU |
| 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 | 1062 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1050 Eastern Standard Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | LZU |
| Elevation of weather observation facility | 1003 |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | EST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | Clear |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 11 |
| Dew Point at event time (in degress fahrenheit) | -22 |
| Wind Direction (degrees magnetic) | -- |
| Variable Wind Indicator | -- |
| Wind Speed (knots) | -- |
| Wind Velocity Indicator | Calm |
| Wind Gust Indicator | -- |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.35 |
| 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 | 2 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 30778 |
| NTSB Notification Source | Aircraft Operator |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Jan 25 2013 11:03AM |
| User who most recently changed record | johb |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N790GK |
| NTSB Number | ERA12LA117 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | PIPER |
| Aircraft Model | PA-44-180 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 44-7995316 |
| Certified Max Gross Weight | 3800 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | 1 |
| Cabin Crew Seats | -- |
| Passenger Seats | 3 |
| Total number of seats on the aircraft | 4 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Nov 16 2011 12:00AM |
| Airframe hours since last inspection | 38 |
| Airframe Hours | 9819 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | C91 |
| Aircraft Owner Name | AIRLINE TRANSPORT PROFESSIONALS CORP OF USA |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | WILMINGTON |
| Aircraft Owner State | DE |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 19808-1645 |
| Operator is an individual? | No |
| Operator Name | AIRLINE TRANSPORT PROFESSIONALS CORP OF USA |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | WILMINGTON |
| Operator State | DE |
| Operator Country | USA |
| Operator Zip code | 19808-1645 |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | -- |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | -- |
| Indicates Domestic or International Flight | -- |
| Operator carrying Pax/Cargo/Mail | -- |
| Type of Flying (Per_Bus / Primary) | Instructional |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | PDK |
| Departure City | Atlanta |
| Departure State | GA |
| Departure Country | USA |
| Departure Time | 1000 |
| Departure Time Zone | EST |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | LZU |
| Destination City | Lawrenceville |
| Destination State | GA |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Nov 27 2012 3:27PM |
| User who most recently changed record | kenj |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | 07 |
| Runway Length | 6000 |
| Runway Width | 1000 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |