Piper PA-44-180 accident near Lawrenceville, Georgia, December 19, 2011
On December 19, 2011 at about 4:00 pm local time, a Piper PA-44-180, registered N790GK, was substantially damaged in an accident during landing (landing roll) near Lawrenceville, Georgia (Gwinnett County Airport). It was an instructional flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
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.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 19, 2011 · about 4:00 pm local time
- Place
- Lawrenceville, Georgia · Gwinnett County Airport · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-44-180 · all PA-44-180s on the register
- Registration
- N790GK · registry record · serial 44-7995316
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Aircraft maintenance event during prior to flight
- Landing gear collapse during landing (landing roll) defining event
The NTSB's findings
- cause Personnel issues › Task performance › Maintenance › (general) › Maintenance personnel
- cause Personnel issues › Task performance › Maintenance › Installation › Maintenance personnel
- cause Aircraft › Aircraft systems › Landing gear system › Main landing gear › Malfunction
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 1,212 hours in all; 312 in this make and model; 123 in the last 90 days; 64 in the last 30 days
- Last flight review: June 29, 2010
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: rgt
- Injury: no injuries
Dual student
- Certificate: private
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 360 hours in all; 5 in this make and model; 5 in the last 90 days; 5 in the last 30 days; 260 as pilot in command
- Last flight review: December 20, 2011
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 9,819 hours
- Last inspection: 100-hour inspection, November 16, 2011; 38 hours since
- Maximum gross weight: 3,800 lb
- Seats: 4
- Landing gear: retractable
- Engine 1: Lycoming O&VO-360 SER (piston); 0 hours total
- Engine 2: Lycoming O&VO-360 SER (piston); 0 hours total
- Operator: Airline Transport Professionals CORP Of USA
The flight
- Departed from: PDK Atlanta GA at 3:00 pm
- Destination: LZU Lawrenceville GA
- Flight plan: none
- Runway 07, 6,000 ft by 1,000 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 52°F (11°C), dew point -8°F (-22°C)
- Altimeter: 30.35 inHg
- Observation at 3:50 pm from LZU
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.