11-04-2017, 10:29 AM
(This post was last modified: 11-04-2017, 01:24 PM by thorn bird.)
I was trawling through some of the submissions to the Senate Enquiry regarding the Pelair incident. One that stood out in my mind was a submission by Richard Davies. He completed an in depth analysis of the event including fuel plans as well as an examination of Pelairs planning policies and SOP's.
His submission is incredibly detailed and is somewhat large to post here so I have taken the liberty to highlight some of his conclusions, which support the prognosis that by the time the commander of the flight became aware that Met. conditions at Norfolk Island were below an acceptable level, a diversion to Noumea was very problematic and in all likelihood the flight would have ended up ditching in open water before reaching that safe haven. For those interested studying the entire submission a link to the Senate submissions;
https://www.aph.gov.au/Parliamentary_Bus...2012/index
Opening gambit:
2. I make this submission as an individual who is concerned regarding the standards and practices of the Australian Transport Safety Bureau (ATSB) and the Civil Aviation Safety Authority (CASA), as exhibited in the matters relating to the accident on 18 November 2009 involving the Westwind II aircraft, registered VH-NGA, operated by Pel-Air Pty Ltd.
3. I became involved in this matter at the request of parties involved or associated with the accident. My subsequent enquiries and analysis indicated deficiencies by both the ATSB and CASA in aspects that I have reviewed.
I think he smelt a rat.
Fuel System and Fuel on Board
8. The ATSB report (page 15), in its section on ‘Fuel System’, discusses the capacity of the aircrafts fuel system. However, it refers to the capacity in units of pounds (lbs) or kilograms (kg). These figures are incorrect in that they represent a weight (of fuel) and not a volumetric capacity of the tanks.
10. The ATSB report frequently refers to a fuel load of 7330 lbs as being the main fuel tanks containing full fuel (pages 3, 16 and 32).
The statement is incorrect for the reasons specified below. I am not aware where the ATSB obtained this figure from, however it is referred to in Pel-Air documentation as being the standard figure for full main tanks.
Already inconsistencies from the ATSB.
15. The aircraft had fuel tank capacities of 1100 USG for the main tanks, and an additional 230 USG for the wingtip tanks. Therefore, if the aircraft was fuelled to the main tanks being full, and an SG of 0.78 applied (as specified by Pel-Air), the aircraft had 7160 lbs of fuel on board preflight, not the reported 7330 lbs.
16. The ATSB Report had a paucity of information regarding their methods of fuel and flight planning calculations.
Scant details included:
“The investigation used a BoM wind/temperature chart to derive the temperature at the cruising altitude as approximating ISA + 10oC.”
and that the calculation included:
“The application of that temperature to the available aircraft performance figures and the PIC-anticipated 50 kts headwind to the relevant cruise speed from the AFM to the distance from Apia to Norfolk Island of 1,450 NM (2,688 km)”
thus deriving:
“resulted in an estimated planned fuel consumption of 5,550 lb (2,517 kg).”
17. The report does not specify the ATSB’s methodology for calculations. I did obtain a copy of a “Jeppesen FliteMap” calculation, purportedly completed or commissioned by the ATSB for use in the investigation. No weight details are included in the document (eg Takeoff weight). However, for the correlating distance (1449 nm), altitude (FL390) and a 70 knot headwind the calculated fuel used was 5150 lbs.
This is a difference of 400 lbs less despite an extra 20 kts of headwind. The reason for this anomaly could not be identified.
18. The report does not contain details of the calculated fuel remaining at any point enroute. Thus the basis for calculating the viability of diversions whilst enroute cannot be justified.
Some inconsistencies from Pelair;
19. The ‘Pel-Air Operations Manual Part B’ specifies
“16.5.1.1 The following planning data shall be used for Company Westwind operations.”
(my emphasis)
However, in the very next paragraph states:
“16.5.2 Fuel Consumption and Block Speeds
16.5.2.1 The following table is a guide only to planning. Refer to A/C OPS
Planning Manual for precise information.” (my emphasis)
The document then continues with planning information with fuel usage based on hourly time frames, irrespective of the weight of the aircraft. Similarly, a standard figure is used for True Air Speed (TAS), despite this also varying with weight and altitude.
Then CAsA enters the mix;
21. These various statements would appear confusing and contradictory, yet are contained in a manual accepted by CASA that is the primary reference source for the crew.
Dom James was pilloried for not diverting to Noumea when he became aware the Norfolk weather was below minimums, in fact part of Rodger Chambers embuggerance requirements is a check flight in a westward or similar to judge mr James decision making processes and calculation of an inflight diversion. No doubt if he had decided to divert and finished up ditching in open waters short of Noumea, he'd be faced with an inquisition as to why he diverted with insufficient fuel. DAMNED IF HE DID, and DAMNED IF HE DIDNT.
here's the rub from Mr Davies;
Fuel Calculations for Diversion
31. Based on these calculations, the fuel remaining on board at position DOLSI (at time 0839 UTC) was 2282 lbs (assuming the 10 percent Variable Fuel Reserve had been used to this point)
32. The ATSB report identified the “Approximate Last point of safe diversion to Noumea” as being between time 0902 UTC and 0928 UTC
33. At time 0904 UTC the crew received advice of a weather observation (SPECI) issued at 0902 UTC. As identified in the ATSB report, this was the first time the crew assimilated information about the deteriorating weather at YSNF.
34. Time 0904 UTC was 25 minutes after DOLSI, at an average Ground Speed of 352 kts and Fuel Flow of 1326 lb/hr. Therefore, the distance past DOLSI was 146 nm and fuel remaining was 1677 lb (assuming the 10 percent Variable Fuel Reserve had been used to this point)
From a position on track 146 nm past DOLSI to NWWW was 436 nm
Based on a diversion direct to NWWW at that time, at FL390 with a 20 kt headwind component throughout, having used 1409 lbs for the subsequent cruise and descent for the segment (assuming the 10 percent Variable Fuel Reserve has been used), the aircraft would arrive overhead to commence its approach and landing with 269 lbs total at time 1014 UTC
Calculations for this are attached as Annex E.
35. Time 0928 UTC was 49 minutes after DOLSI. Based on the previous figures, the distance past DOLSI was 287 nm and fuel remaining was 1093 lb (assuming the 10 percent Variable Fuel Reserve has been used to this point)
From a position on track 287 nm past DOLSI to NWWW was 410 nm
Based on a diversion direct to NWWW at that time, at FL390 with no wind component throughout, having used 1214 lbs for the subsequent cruise and descent for the segment (assuming the 10 percent Variable Fuel Reserve has been used), the aircraft would not complete its diversion as it would run out of fuel, having a shortfall of 122 lbs
36. By comparison, if the aircraft continued to YSNF (as planned) it would arrive with 709 lbs (Annex D)
37. Based on these calculations, the information contained in the ATSB report is incorrect.
The fateful timeline;
50. The first time the crew became cognizant of a need to consider the option of an alternate aerodrome due to deteriorating weather at YSNF was 0904 UTC; by which time they had passed LPSD for NFFN (time 0845 UTC) (see para 54 and Annex G), and (based on the calculations above) the airport that would result in the greatest amount of fuel being available on arrival was YSNF. (See paras 35 and 36).
269 lb remaining at NWWW (less than FFR), 709 lb remaining at YSNF
The point?
53. At 0904 UTC the latest TAF for YSNF was for conditions below alternate minima, but above landing minima. The latest observation (SPECI 0902 UTC) also identified weather conditions below alternate minima, but above landing minima. As such the crew could have a reasonable expectation of becoming ‘visual’ prior to the completion of an instrument approach and landed.
54. Given that the aircraft was past its ‘last possible diversion’ to arrive with FFR remaining, and at YSNF there were two separate runways, and the expected weather conditions were above landing minima, the crew complied with the Pel-Air procedure (as accepted by CASA).
55. By the time the crew obtained the 0930 SPECI at time 0932 their options were:
Proceed to YSNF to attempt a landing, irrespective of the conditions, or Ditch in open water enroute to NWWW.
Conclusions;
ATSB:
79. As is apparent from the analysis above, the ATSB report contains insufficient factual material to support its analysis and findings. Therefore, the veracity of the ATSB report is questionable.
and CAsA:
83. In the events and conditions associated with this accident it is apparent the risk controls were inadequate and unreliable. This in turn identifies a lack of effective regulatory oversight of the operator by CASA.
His submission is incredibly detailed and is somewhat large to post here so I have taken the liberty to highlight some of his conclusions, which support the prognosis that by the time the commander of the flight became aware that Met. conditions at Norfolk Island were below an acceptable level, a diversion to Noumea was very problematic and in all likelihood the flight would have ended up ditching in open water before reaching that safe haven. For those interested studying the entire submission a link to the Senate submissions;
https://www.aph.gov.au/Parliamentary_Bus...2012/index
Opening gambit:
2. I make this submission as an individual who is concerned regarding the standards and practices of the Australian Transport Safety Bureau (ATSB) and the Civil Aviation Safety Authority (CASA), as exhibited in the matters relating to the accident on 18 November 2009 involving the Westwind II aircraft, registered VH-NGA, operated by Pel-Air Pty Ltd.
3. I became involved in this matter at the request of parties involved or associated with the accident. My subsequent enquiries and analysis indicated deficiencies by both the ATSB and CASA in aspects that I have reviewed.
I think he smelt a rat.
Fuel System and Fuel on Board
8. The ATSB report (page 15), in its section on ‘Fuel System’, discusses the capacity of the aircrafts fuel system. However, it refers to the capacity in units of pounds (lbs) or kilograms (kg). These figures are incorrect in that they represent a weight (of fuel) and not a volumetric capacity of the tanks.
10. The ATSB report frequently refers to a fuel load of 7330 lbs as being the main fuel tanks containing full fuel (pages 3, 16 and 32).
The statement is incorrect for the reasons specified below. I am not aware where the ATSB obtained this figure from, however it is referred to in Pel-Air documentation as being the standard figure for full main tanks.
Already inconsistencies from the ATSB.
15. The aircraft had fuel tank capacities of 1100 USG for the main tanks, and an additional 230 USG for the wingtip tanks. Therefore, if the aircraft was fuelled to the main tanks being full, and an SG of 0.78 applied (as specified by Pel-Air), the aircraft had 7160 lbs of fuel on board preflight, not the reported 7330 lbs.
16. The ATSB Report had a paucity of information regarding their methods of fuel and flight planning calculations.
Scant details included:
“The investigation used a BoM wind/temperature chart to derive the temperature at the cruising altitude as approximating ISA + 10oC.”
and that the calculation included:
“The application of that temperature to the available aircraft performance figures and the PIC-anticipated 50 kts headwind to the relevant cruise speed from the AFM to the distance from Apia to Norfolk Island of 1,450 NM (2,688 km)”
thus deriving:
“resulted in an estimated planned fuel consumption of 5,550 lb (2,517 kg).”
17. The report does not specify the ATSB’s methodology for calculations. I did obtain a copy of a “Jeppesen FliteMap” calculation, purportedly completed or commissioned by the ATSB for use in the investigation. No weight details are included in the document (eg Takeoff weight). However, for the correlating distance (1449 nm), altitude (FL390) and a 70 knot headwind the calculated fuel used was 5150 lbs.
This is a difference of 400 lbs less despite an extra 20 kts of headwind. The reason for this anomaly could not be identified.
18. The report does not contain details of the calculated fuel remaining at any point enroute. Thus the basis for calculating the viability of diversions whilst enroute cannot be justified.
Some inconsistencies from Pelair;
19. The ‘Pel-Air Operations Manual Part B’ specifies
“16.5.1.1 The following planning data shall be used for Company Westwind operations.”
(my emphasis)
However, in the very next paragraph states:
“16.5.2 Fuel Consumption and Block Speeds
16.5.2.1 The following table is a guide only to planning. Refer to A/C OPS
Planning Manual for precise information.” (my emphasis)
The document then continues with planning information with fuel usage based on hourly time frames, irrespective of the weight of the aircraft. Similarly, a standard figure is used for True Air Speed (TAS), despite this also varying with weight and altitude.
Then CAsA enters the mix;
21. These various statements would appear confusing and contradictory, yet are contained in a manual accepted by CASA that is the primary reference source for the crew.
Dom James was pilloried for not diverting to Noumea when he became aware the Norfolk weather was below minimums, in fact part of Rodger Chambers embuggerance requirements is a check flight in a westward or similar to judge mr James decision making processes and calculation of an inflight diversion. No doubt if he had decided to divert and finished up ditching in open waters short of Noumea, he'd be faced with an inquisition as to why he diverted with insufficient fuel. DAMNED IF HE DID, and DAMNED IF HE DIDNT.
here's the rub from Mr Davies;
Fuel Calculations for Diversion
31. Based on these calculations, the fuel remaining on board at position DOLSI (at time 0839 UTC) was 2282 lbs (assuming the 10 percent Variable Fuel Reserve had been used to this point)
32. The ATSB report identified the “Approximate Last point of safe diversion to Noumea” as being between time 0902 UTC and 0928 UTC
33. At time 0904 UTC the crew received advice of a weather observation (SPECI) issued at 0902 UTC. As identified in the ATSB report, this was the first time the crew assimilated information about the deteriorating weather at YSNF.
34. Time 0904 UTC was 25 minutes after DOLSI, at an average Ground Speed of 352 kts and Fuel Flow of 1326 lb/hr. Therefore, the distance past DOLSI was 146 nm and fuel remaining was 1677 lb (assuming the 10 percent Variable Fuel Reserve had been used to this point)
From a position on track 146 nm past DOLSI to NWWW was 436 nm
Based on a diversion direct to NWWW at that time, at FL390 with a 20 kt headwind component throughout, having used 1409 lbs for the subsequent cruise and descent for the segment (assuming the 10 percent Variable Fuel Reserve has been used), the aircraft would arrive overhead to commence its approach and landing with 269 lbs total at time 1014 UTC
Calculations for this are attached as Annex E.
35. Time 0928 UTC was 49 minutes after DOLSI. Based on the previous figures, the distance past DOLSI was 287 nm and fuel remaining was 1093 lb (assuming the 10 percent Variable Fuel Reserve has been used to this point)
From a position on track 287 nm past DOLSI to NWWW was 410 nm
Based on a diversion direct to NWWW at that time, at FL390 with no wind component throughout, having used 1214 lbs for the subsequent cruise and descent for the segment (assuming the 10 percent Variable Fuel Reserve has been used), the aircraft would not complete its diversion as it would run out of fuel, having a shortfall of 122 lbs
36. By comparison, if the aircraft continued to YSNF (as planned) it would arrive with 709 lbs (Annex D)
37. Based on these calculations, the information contained in the ATSB report is incorrect.
The fateful timeline;
50. The first time the crew became cognizant of a need to consider the option of an alternate aerodrome due to deteriorating weather at YSNF was 0904 UTC; by which time they had passed LPSD for NFFN (time 0845 UTC) (see para 54 and Annex G), and (based on the calculations above) the airport that would result in the greatest amount of fuel being available on arrival was YSNF. (See paras 35 and 36).
269 lb remaining at NWWW (less than FFR), 709 lb remaining at YSNF
The point?
53. At 0904 UTC the latest TAF for YSNF was for conditions below alternate minima, but above landing minima. The latest observation (SPECI 0902 UTC) also identified weather conditions below alternate minima, but above landing minima. As such the crew could have a reasonable expectation of becoming ‘visual’ prior to the completion of an instrument approach and landed.
54. Given that the aircraft was past its ‘last possible diversion’ to arrive with FFR remaining, and at YSNF there were two separate runways, and the expected weather conditions were above landing minima, the crew complied with the Pel-Air procedure (as accepted by CASA).
55. By the time the crew obtained the 0930 SPECI at time 0932 their options were:
Proceed to YSNF to attempt a landing, irrespective of the conditions, or Ditch in open water enroute to NWWW.
Conclusions;
ATSB:
79. As is apparent from the analysis above, the ATSB report contains insufficient factual material to support its analysis and findings. Therefore, the veracity of the ATSB report is questionable.
and CAsA:
83. In the events and conditions associated with this accident it is apparent the risk controls were inadequate and unreliable. This in turn identifies a lack of effective regulatory oversight of the operator by CASA.