[Peetwo]

Three years for this? - Part III 

Risk mitigation in the real World
  
Meanwhile in Dunce-under land the ATSB is putting out crap like this:

AO-2013-100 - Landing below minima due to fog involving Boeing 737s, VH-YIR and VH-VYK Mildura Airport, Victoria on 18 June 2013.

[b]Nothing to see here.
[/b]

Quote: This occurrence has highlighted the effect of various factors coming together to create and influence a rare event.

The VA 737 landed with less than 15 mins of fuel and essentially no one stuffed up (not BOM, not ATC, not Crew, not Ops Control/Dispatch). - and if it wasn't for the QF skipper taking extra fuel they would have been in the same boat...

What is wrong with the ATSB?!!



[b]When will we be like the rest of real world and carry technical alternates.[/b]

ATSB Safety Issue No: AO-2013-100-SI-01
 
ATSB Safety Issue No: AO-2013-100-SI-02

ATSB Recommendation No: AO-2013-100-SR-057 

Recommendation

Action organisation:Airservices Australia
Action number: AO-2013-100-SR-057
Date: 31 May 2016
Action status: Released

The ATSB recommends that Airservices Australia as the safety issue owner works in collaboration with the Bureau of Meteorology to instigate a system change to reinstate the alerting function of SPECI reports currently not available through an automatic broadcast service

 
No further comment, just disgusted

At the risk of flogging a dead horse, in regard to ATSB O&O'd & PC'd investigations and final reports, I came across yet another disturbing historical revelation in regards to alternate fuel requirements and related min/exhausted fuel occurrences. This despicable revelation has yet another connection to the PelAir Norfolk Island ditching of VH-NGA and lends more weight to there being nefarious reasons that the 'powers to be' wanted to slate all blame to the pilot Dominic James.

Fortunately the thread on the UP (quoted from above) has continued and there is still some excellent discussion on the subject of the ATSB Mildura fog duck-up final report. One of the contributor's (Buzzbox) further posts included a link to an old (2006) ATSB research paper:

BB - It could also be argued that the INTER/TEMPO holding fuel requirements are only intended to cater for inaccuracies in the weather forecast. They provide some protection in case the weather is worse than forecast and ends up below landing minima, preventing the aircraft from landing. In that light, the enroute holding has no bearing on the destination holding requirement. The INTER/TEMPO holding fuel should therefore be available until the aircraft is close to the destination and likely to land within the 30/60 minute period.


Some interesting reading:
https://www.atsb.gov.au/media/32921/b20040246.pdf

 
 To which 'CurtainTwitcher' later responded and reposted:

Buzzbox, thank you for the link, I am making my way through it, and this section caught my eye:

The use of en-route weather reports for updating operational decisions as a potential risk mitigant was examined to assess their capacity to provide a timely en-route warning that the destination weather would prevent a safe landing from being assured, thereby enabling an early diversion to an alternate airport.

The comparisons in this study suggests that the use of Australian rule sets alone to assess the risk of deteriorated weather at a destination airport by themselves does not ensure a level of safety as described in the International Civil Aviation Organization Continuing Airworthiness Manual. The fact that there have been very few serious incidents or accidents associated with landing at a destination with unforecast deteriorated weather, suggests that one or more other factors are also reducing risk. From this it may be suggested that although other risk mitigants appear to be effective, they may not be known or consistently managed.

ATSB document: Destination Weather Assurance, Risk associated with the Australian Operational Rules for Weather Alternate Minima, page VIII

The assumption that "timely en-route warnings" will be passed on to crew(s) as a mitigator goes to the heart of this incident, I also note this document was published in 2006.

So yes, a decade ago this excellent paper was produced??  

From the executive summary:

...A comparison for these results was achieved from a survey of the Australian Transport Safety Bureau occurrence database, which found 62 occurrences in the nine years leading up to the end of 2004 where unforecast destination weather degradation had been a contributing factor to the occurrence. The occurrences were sorted by reference to defences that were appropriate to the occurrence.
 
The comparisons in this study suggests that the use of Australian rule sets alone to assess the risk of deteriorated weather at a destination airport by themselves does not ensure a level of safety as described in the International Civil Aviation Organization Continuing Airworthiness Manual. The fact that there have been very few serious incidents or accidents associated with landing at a destination with unforecast deteriorated weather, suggests that one or more other factors are also reducing risk. From this it may be suggested that although other risk mitigants appear to be effective, they may not be known or consistently managed.

200404385 Boeing 747-438

The aircraft landed with insufficient fuel due to unforecast fog at the destination. Prior to departure, weather forecasts had indicated that the carriage of extra fuel was not required.

ATSB Summary

Following an unforecast weather deterioration at the destination, the aircraft diverted to an alternate destination and landed in weather above the landing minima, but below the minimum fuel requirement.

And the conclusion:

...Aircraft accidents associated with IFR flight into unforecast deteriorated weather at the destination are very rare. The effectiveness of the procedures that exist to ensure that a pilot does not encounter unforecast deteriorated weather at the destination does not explain the associated lack of accidents, but other risk mitigators are probably proving effective. It is possible that conservative decision making by flight crews, consuming fuel reserves to reach an alternate and conducting successful instrument approaches in weather conditions that are below landing minima are some of the mitigators that have been effective. However, these mitigators have not been assessed in this study.
   

199906031 Boeing 737- 376

On the basis of the weather forecast that was available prior to departure from Perth, the crew of B737, VH-TAW had planned to arrive at Melbourne without extra fuel. The crew received weather reports during the flight indicating that the weather at the destination was worse than forecast. On arrival at Melbourne, the weather was found to be such that there was a requirement for the aircraft to be carrying extra fuel. The aircraft landed without incident at 11:34 eastern summer time.

The Bureau of Meteorology reported that at the time of the occurrence a high pressure system was located in the Great Australian Bight. This resulted in a moist southerly airstream being directed over Victoria. However the low cloud, showers and drizzle associated with the moist airstream were expected to clear by mid to late morning because of drier air moving into the area from the south. The arrival of the drier air was later than anticipated, and reduced visibility in drizzle fluctuated around the alternate minima until 13:00 hours. The forecaster, being aware of the operational impact of his decisions, considered that a trend of INTER was sufficient to cover these fluctuating conditions. However, between 11:00 and 13:00 conditions were below the special alternate minima. The timing of the arrival of the drier air was critical in the situation. Unfortunately, neither the data network nor the forecasting skills were adequate to facilitate forecasting of a cloud base to within a couple of hundred feet when the cloud base was fluctuating around the alternate minima. The Bureau of Meteorology advised that it would have been more prudent to trend alternate conditions until there was clear evidence that the drier air had reached the airport. Following the occurrence, the Bureau of Meteorology issued a recommended preventative action to prevent further recurrence

ATSB Summary

Following an unforecast weather deterioration at the destination, the aircraft landed in weather above the destination landing minima.

Since reading that report I have gone over my records and the Senate Pel-Air publicly available documents tabled/submissions webpage. There is no mention or copy of the ATSB 2006 that I can find; nor could I remember any Hansard mention made or reference since despite repeated historical reference to other related matters. Like for example the O&O'd 2000 ATSB safety recommendation to the BOM on the reliability of forecasts at Norfolk Island -  R20000040.

These ATSB research reports are painstakingly compiled in order to maximise the potential safety risk mitigation. From introduction of B2004/0246:

The aim of the Australian Transport Safety Bureau (ATSB) is to help maintain and improve transport safety. The ATSB investigates aircraft occurrences (accidents and incidents) in order to identify the factors that contributed to an occurrence and to seek to prevent a recurrence. The ATSB also conducts research into matters that affect or may affect safety.

Aviation safety can be enhanced by aiming to seek for a known and provable zero frequency of all factors of a flight that may compromise its safety. Such safety-critical aspects are sometimes independent (such as the reliability of power sources, wing structural integrity and navigational fidelity), and therefore the level of safety of the whole flight may be no more reliable than the least reliable safety-critical aspect of the flight. The safety of a flight may be only as strong as its weakest link.

Historically, transport aircraft operations have been demonstrably successful in identifying and controlling safety-critical risks. However, effective analysis can often be difficult because analysis of the probability of a specific risk is very low, therefore secondary indicators, such as the use of processes for protecting against risk, may be used to imply a relationship with risk.
 

A worthy objective and very much in line with the principles as outlined in ICAO Annex 13 (& now Annex 19). However six years later we get the PelAir report aberration and a decade later we now get the - total bollocks - Mildura duck-up report, neither report even references the 2006 research paper (although the Mildura FR did mention under tests & research some of the historical occurrences also covered by B2004/0246). And in light of those two examples (PelAir, Mildura), I would strenuously argue that we have not progressed in anyway in mitigating the related safety issues and if anything we have actually gone backwards.

One final coincidence/irony of the 2006 report, is that one of the co-authors is a M Watson, the IIC for VH-NGA was a Mike Watson - what are the chances that the ATSB had two TSIs that were called M Watson??

MTF...P2