Back to home pageZQ-ZQG Stab Trim Incident

Home > Accident Reports

Contents

Illustrated technical information covering Vol 2 Over 800 multi-choice systems questions Study notes and technical information Close up photos of internal and external components A compilation of links to major 737 news stories with a downloadable archive Illustrated history and description of all variants of 737 Detailed tech specs of every series of 737 Databases and reports of all the major 737 accidents & incidents General flightdeck views of each generation of 737's Description & news reports of Advanced Blended Winglets Press reports of orders and deliveries A collection of my favourite photographs that I have taken of or from the 737 Details about 737 production methods A compilation of links to other sites with useful 737 content History and Development of the Boeing 737 - MAX A quick concise overview of the pages on this site

spacer

28 Mar 2015 - Final report published by NZ TAIC into 737-800 ZK-ZQG, stabiliser trim mechanism damage, 7 June 2013

 

Executive summary

On 7 June 2013 a Boeing 737-838 operated by Jetconnect Limited was undergoing scheduled maintenance at Auckland International Airport. During an inspection of the forward electronics and equipment compartment area under the flight deck, metal filings were found next to the stabiliser trim cable drum. On closer inspection a rag was found trapped under the stabiliser trim cable windings on the forward cable drum.

The rag had made the cable windings bulge outwards, which caused the cables to contact the cable guides, creating the metal filings and damaging the guides. The rag had increased the cable tension of the stabiliser trim system, which resulted in damage to a number of cable pulleys through which it was rigged. The control cables had also started to wear through contact with the steel bolts that held the cable guide spacers in place.

The Transport Accident Investigation Commission (Commission) found that it was highly likely the rag originated from the Qantas Sydney maintenance hangar, and that the presence of the rag trapped in the cable drum windings compromised the integrity of the aeroplane's stabiliser trim system manual control.

This report also comments on a maintenance-related incident involving a Jetconnect aircraft that had undergone maintenance at the Qantas Melbourne maintenance hangar in September 2013. The Commission did not investigate that incident, but notes that, as with this incident, compliance with procedures during maintenance operations is important for aviation safety.

The key lesson learnt from the inquiry into this occurrence was that all personnel must take care not to leave anything behind inside an aircraft after completing maintenance or cleaning tasks, especially in areas or near systems critical to flight safety.

Link to full report

See more details about the book

All of the information, photographs & schematics from this website and much more is now available in a 374 page printed book or in electronic format.

*** Updated 17 Jan 2017 ***

The 737 Tech Site on Facebook The 737 Tech Site on Twitter

Photographs from the final report showing the forward cable drum and the bulge caused by the rag on the drum under the cables and the subsequent damage to the cable guide.

Footer block

This site has had visitors to date.