Pilot Debrief

Raytheon HAWKER near Fort Myers, FL — 2019-10-08

Final reportERA20LA008
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Date
2019-10-08
Location
Fort Myers, FL, USA
Airport
RSW
Aircraft
Raytheon HAWKER
Registration
N86MN
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Initial climb

Probable cause

Maintenance personnel's improper installation of the nose landing gear assembly, which resulted in separation of the actuator arm and the failure of a nose landing gear to lock in place.

NTSB narrative

During the initial climb, the flight crew attempted to retract the landing gear; the main landing gear retracted normally but the nose landing gear failed to retract. Several attempts to retract and extend the nose landing gear to a locked position were unsuccessful and the flight crew completed an emergency landing, during which the airplane skidded to a stop on its nose and fuselage. The fuselage sustained substantial damage. Examination of the nose landing gear actuator drag stay found that it was missing its nut, washer, and split pin, and deformation was observed in the attachment area. The nose landing gear leg was removed, overhauled, and re-installed by a contract maintenance facility as part of a broader routine maintenance inspection about 9 months before the accident. The airplane had flown 124 cycles since the removal and re-installation. The maintenance task reportedly followed in the maintenance manual required that the nut, washer, and split pin be installed during the installation, and records indicated that the installation task was performed by a mechanic and verified by a separate quality assurance inspector mechanic at the contract maintenance facility. There were no other inspections performed on the nose landing gear since the overhaul. Thus, it is likely that the split pin was not installed during installation of the nose landing gear following the overhaul, and over the course of the 124 cycles after installation, the nut and washer backed out, which allowed for the actuator arm to disconnect from its attach point. As a result, the actuator arm was free to move during the retraction and extension cycles, which damaged its attachment area and ultimately led to its complete separation. This is consistent with the pilot’s report of hearing a thud and feeling vibration emanating from the nose landing gear area during the retraction cycle.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Properly securing the NLG actuator drag stay during maintenance could have prevented failure.

NTSB coding

Evidence available

  • Photos
  • 6 docket documents
View NTSB final reportView NTSB docket

Docket documents6

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