Piper PA-44-180 N790GK

Summary

On 19 December 2011 at about 16:00 local time, a Piper PA-44-180 registered N790GK, operated by Airline Transport Professionals Corp of USA, was involved in an accident near Lawrenceville, Georgia, United States. 2 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

19 December 2011 at 16:00

Classification

Accident

Location

Lawrenceville, Georgia, United States

Nearest airport

Gwinnett County Airport (LZU)

Coordinates

33.9781, -83.9622

Aircraft

Piper PA-44-180

Registration

N790GK

Category

Airplane

Engines

2

Operator

Airline Transport Professionals Corp of USA

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Atlanta → Lawrenceville

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA12LA117

Nobody was injured.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

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.

Quoted verbatim from the NTSB record.