[Peetwo]

The latest ATSB REX final report -  


Via Oz Aviation.. :

ATSB releases Rex engine failure report
September 18, 2017 by australianaviation.com.au 2 Comments

A file image of VH-RXS (Andrew McLaughlin)

The Australian Transport Safety Bureau (ATSB) says a lack of lubrication was the most likely cause of an engine failure involving a Regional Express (Rex) Saab 340B on March 23 this year.

The incident occurred shortly after the turboprop VH-RXS took off from Dubbo bound for Sydney carrying 26 passengers and three crew.

When the aircraft was climbing through 4,300ft, the flightcrew “heard several bangs from the right engine accompanied by jolts through the aircraft”, the ATSB final report published on Monday said.

This was accompanied by a burning smell in the flightdeck alongside cockpit master warnings.

The pilots conducted a shutdown of the right hand engine, declared a PAN to air traffic control and requested emergency services at Dubbo Airport.

They then completed standard failure management procedures before the captain conducted a visual approach back to Dubbo Airport, landing on Runway 05.

There were no injuries, while the aircraft suffered minor damage.

The ATSB report said an initial engineering examination found the number four bearing on the right hand engine failed.

“The bearing failure allowed the high pressure compressor to move off-centreline within the engine. This caused further damage and led to complete failure of the engine,” the ATSB said.

“The damage to the failed bearing was consistent with overheating due to a lack of lubrication. At the time of the release of this report, the reason for the lack of lubrication to the number four bearing had not been determined.”

The ATSB said the engine manufacturer’s engineering examination of the failed engine was not completed at the time its final report into the incident was released.

The Saab 340B is powered by two General Electric CT7-9B turboprop engines.

Meanwhile, the report said comments from the captain indicated emergency procedures and simulator training prepared the flightcrew well for the incident and allowed it to effectively manage the engine failure.

“Faced with an abnormal situation, the training provided to the flightcrew ensured they were able to effectively implement the standard failure procedures, secure the failed engine and return for a safe landing,” the ATSB report said.

“During an emergency, flight crew prioritise the management of the emergency to ensure that the safety of the flight is not compromised. Completing the emergency procedures, along with the coordination of emergency services and communications with supporting agencies may absorb a significant amount of time before the flightcrew are able to provide an update to passengers.”

The two comments are IMO also worth regurgitating:

Comments

1. AlanH says
   
   September 18, 2017 at 8:47 pm
   
   This, along with the loss of a propeller above Camden. The Saab 340Bs are a terrific aircraft that have served Rex exceptionally well and certainly are a good “fit for purpose” for Rex operations, but they are getting long in the tooth. Perhaps Rex needs to look at updating its fleet sooner rather than later before a catastrophe occurs. ATR 42 perhaps?
   
   
2. Adrian P says
   
   September 19, 2017 at 10:20 am
   
   Not sure how it is possible to have a final report when the engine manufacturer’s engineering examination of the failed engine is not completed. If the primary issue is a lubrication failure, need to know why, before another lubrication failure occurs.
   
   

Adrian makes an excellent point and I would add that it is normally accepted that a 'serious incident' investigation will inevitably take at least a year to complete and therefore given this incident occurred on 23 March 2017 I have to ask - what the hell is the rush??

For those interested here is the link for the final report: https://www.atsb.gov.au/publications/inv...-2017-034/

P2 comment - This bit under the 'WTD happened' kind of bemused me...

Figure 1: Regional Express SAAB 340B, registered VH-RXS

Source: VJ Bhana

After completing the memory items, the flight crew commenced the standard failure management procedures. The flight crew secured the right engine and established that the aircraft was performing satisfactorily. The flight crew declared a PAN[2] to air traffic control and requested emergency services. The flight crew then descended the aircraft to 4,000 ft and identified an area to the south-east of Dubbo which was clear of cloud and other traffic. The first officer manoeuvred the aircraft to this area in order to reduce workload while the flight crew continued the standard failure procedures. The captain identified Dubbo as the most suitable airport for landing. The flight crew reviewed the weather conditions for Dubbo and elected to conduct a visual approach and landing. The flight crew then briefed the cabin crew member on the situation, advised that they were returning to Dubbo and to expect a normal disembarkation.

Maybe it is the disjointed way it is written but the above text gets even more confused when you consider the Captain's comments:

Captain comments

The captain of the flight provided the following comments:

• The first officer remained as the pilot flying until they were prepared to make the approach, as this allowed the captain to focus on the engine failure checklist.
  
• Emergency procedures and simulator training undertaken by the flight crew was effective. The training prepared the flight crew well for the incident and along with the procedures in place, allowed the flight crew to effectively manage the engine failure.
  
• During emergencies, it is important to follow procedures and not rush. This ensures all necessary actions are completed correctly. At each step, take a moment to review the overall situation and aircraft performance to ensure that it is safe to continue.
  
• The engine failure checklist instructs the flight crew to consider a restart of the failed engine. At the time of the failure the right engine low oil pressure, over-temperature and chip detector[3] warnings all illuminated. As the warnings indicated that the engine was damaged and not recoverable, the captain elected not to attempt to restart it.
  
• There was cloud in the area of the runway 05 area navigation (RNAV)[4] approach, the captain elected to remain clear of cloud and conduct a visual approach. As the runway 05 RNAV approach had quite a high minimum descent altitude, entering cloud may have resulted in a single engine missed approach.
  
• After the flight, the captain received reports that passengers were concerned at the length of time taken after the engine failure for the flight crew to update them on the situation.
  

Maybe it is lost in translation in the butchered ATSB desk top report but the Captain's comments would seem to be attempting to justify why it was that the flight crew elected to conduct a single-engine cloud break procedure in lieu of a much safer runway 05 IAP...


MTF...P2