Aviation safety investigations & reports

Engine failure involving Fokker 100, VH-FWI, 41 km south-east of Geraldton Airport, Western Australia on 9 July 2019

Investigation number:
AO-2019-033
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final report

Download final report
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What happened

On 9 July 2019, a Fokker F100 aircraft, registered VH-FWI, was being operated by Virgin Australia Regional Airlines (VARA) as regular public transport flight VA1788 from Geraldton to Perth, Western Australia.

During climb at about 13,000 ft, the left engine flamed out. Due to a pre-existing fault with the autothrottle system the pilot was required to manually select climb thrust on the remaining (right) engine. The crew elected to maintain the incidental speed (250 knots). Due to a desire not to ‘strain’ the right engine the pilot flying also elected not to increase thrust from climb to maximum continuous, and/or reduce the aircraft’s speed towards the recommended single engine climb speed (155–170 knots). Consequently, the crew adopted a cruise level about 6,500 ft below the maximum engine out altitude.

The crew maintained their cleared track to Perth and conducted an approach and landing via the runway 21 instrument landing system, using single engine procedures. The aircraft was accompanied from the touchdown point to the domestic terminal by airport emergency vehicles.

What the ATSB found

The ATSB found that at about 11,500 ft during initial climb the left engine fuel flow regulator (FFR) malfunctioned, resulting in over-regulation of fuel. The left engine autothrottle system attempted to reduce the thrust. Due to a pre-existing and admissible fault within the right engine autothrottle system and the action of an associated ‘clutch-tie’ mechanism, the right engine thrust lever retarded progressively reducing fuel flow demand to the right engine. At about 13,000 ft, as the right engine thrust approached flight idle, the left engine FFR ceased regulating fuel, which caused the immediate flameout of the left engine. Failure of the FFR was found to have resulted from wear related to the component’s service life.

The ATSB also identified that the failure of the FFR resulted in engine 1 thrust variation for about 45 seconds prior to the engine flame out. That went undetected by the crew due to the effects of automation, focused attention on other cockpit tasks and the absence of any alert prior to the engine failure.

The decision to continue to Perth following the engine failure resulted in a longer exposure to one engine inoperative flight risks, compared to a return to the nearest suitable airport (Geraldton).

Finally, by electing not to increase thrust on the right engine or adopt the aircraft’s recommended single engine climb speed, the pilot flying reduced the available climb performance of the aircraft, resulting in a lower cruise altitude than the maximum available. This, coupled with the decision to continue to Perth on the original indirect track, increased the duration of flight and the time that the aircraft was outside the glide range of emergency airports and controlled airspace, in the unlikely event that the situation degraded further.

What has been done as a result

Following this incident and a review of the global failure rate specific to the FFR unit utilised by the VARA F100 fleet, the engine manufacturer, Rolls-Royce, amended the applicable component management plan to revise the recommended FFR maximum overhaul interval (full-life) down from 16,000 to 10,000 hours.

Additionally, the operator provided several internal safety communiqués to all flight crew reiterating the importance of effective failure management and inflight decision making.

Safety message

This incident highlights that the initial indications of component failure/malfunction may be subtle. Automation can obscure significant changes in aircraft system status, including engine health.

The occurrence also illustrates the numerous factors to be considered when managing the initial and subsequent aspects of power loss in a complex aircraft.

Download final report
[Download  PDF: 2.13MB]
 
 
 

The occurrence

Context

Safety analysis

Findings

Sources and submissions

Appendix A

Appendix B

Appendix C

Appendix D

Appendix E

Appendix F

General details
Date: 09 July 2019   Investigation status: Completed  
Time: 1258 WST   Investigation level: Defined - click for an explanation of investigation levels  
Location   (show map): near Geraldton Airport   Investigation phase: Final report: Dissemination  
State: Western Australia   Occurrence type: Engine failure or malfunction  
Release date: 04 February 2021   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer Fokker B.V.  
Aircraft model F28 MK 0100  
Aircraft registration VH-FWI  
Serial number 11318  
Operator Virgin Australia Regional Airlines  
Type of operation Air Transport High Capacity  
Sector Jet  
Damage to aircraft Nil  
Departure point Geraldton, Western Australia  
Destination Perth, Western Australia  
Last update 09 February 2021