Gear-up landing Accident Swearingen SA227-AT Merlin IVC VH-UZA,
ASN logo
 
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information. If you feel this information is incomplete or incorrect, you can submit corrected information.

Date:Wednesday 15 February 2012
Time:02:32
Type:Silhouette image of generic SW4 model; specific model in this crash may look slightly different    
Swearingen SA227-AT Merlin IVC
Owner/operator:Toll Aviation
Registration: VH-UZA
MSN: AT-502
Fatalities:Fatalities: 0 / Occupants: 2
Aircraft damage: Substantial
Category:Accident
Location:Brisbane International Airport, QLD (BNE/YBBN) -   Australia
Phase: Approach
Nature:Test
Departure airport:Brisbane International Airport, QLD (BNE/YBBN)
Destination airport:Brisbane International Airport, QLD (BNE/YBBN)
Investigating agency: ATSB
Confidence Rating: Information verified through data from accident investigation authorities
Narrative:
At 01:27 local time, an SA227-AT Merlin IVC aircraft, registered VH-UZA, departed from Brisbane Airport for a test flight following maintenance. There were two pilots and no passengers on board.

While returning to the airport, the crew advised air traffic control that they had a landing gear problem. The crew conducted two fly-overs of the airport to allow maintenance engineers to observe the aircraft, and the engineers confirmed that the landing gear was still retracted. The crew decided to land the aircraft with the landing gear retracted, and a full emergency was declared. The aircraft belly landed at 02:32. Both pilots escaped unhurt.

The ATSB found that an electrical wire to the landing gear selector valve had separated at a connector adjacent to its terminal preventing normal operation of the landing gear to the down position. The investigation also identified an out of rig condition in the landing gear emergency extension system, which prevented correct operation of that system. Factors including the maintenance practices by a number of personnel and inconsistent maintenance documentation contributed to the existence of the defects.

Contributing factors
• The proximity of the landing gear selector valve electrical wiring loom to the external hydraulic power connectors within the left engine nacelle on Fairchild SA227-AT Metro aircraft resulted in the ‘down selection’ wire being damaged during routine maintenance activities [Safety issue].
• The separation of the ‘down selection’ wire interrupted the supply of electrical power to the down solenoid, preventing extension of the landing gear in the normal operating mode.
• The maintenance practices by a number of personnel prior to the occurrence resulted in missed opportunities to identify an out of rig cable within the landing gear emergency extension system.
• The landing gear did not extend in the emergency extension mode in-flight due to the out of rig cable preventing correct actuation of the by-pass and shut-off valves.
• The flight crew were unable to extend the landing gear using the normal and emergency extension procedures, resulting in the need for a gear-up landing.
Other factors that increased risk
• The manufacturer’s operational and maintenance documentation suite contained inconsistencies in some procedures.
Other findings
• The crew conducted the emergency procedures to extend the landing gear in a manner that should have allowed the landing gear to extend.
• The low-level fly-past provided for independent confirmation that the landing gear was fully retracted and the gear doors closed.

Accident investigation:
cover
  
Investigating agency: ATSB
Report number: AO-2012-024
Status: Investigation completed
Duration:
Download report: Final report

Sources:

http://www.atsb.gov.au/publications/investigation_reports/2012/aair/ao-2012-024.aspx
http://www.heraldsun.com.au/travel/news/light-plane-belly-flops-at-brisbane-airport-closing-main-runway-expect-delays/story-fn32891l-1226271375138

Images:


Photo: ATSB

Revision history:

Date/timeContributorUpdates
15-Feb-2012 03:36 harro Added
15-Feb-2012 03:40 harro Updated [Narrative]
15-Feb-2012 04:01 RobertMB Updated [Aircraft type, Narrative]
16-Feb-2012 09:49 harro Updated [Aircraft type, Narrative]
31-Aug-2014 19:50 Aerossurance Updated [Narrative]
29-Sep-2014 17:52 Aerossurance Updated [Narrative]

Corrections or additions? ... Edit this accident description

The Aviation Safety Network is an exclusive service provided by:
Quick Links:

CONNECT WITH US: FSF on social media FSF Facebook FSF Twitter FSF Youtube FSF LinkedIn FSF Instagram

©2024 Flight Safety Foundation

1920 Ballenger Av, 4th Fl.
Alexandria, Virginia 22314
www.FlightSafety.org