Near miss sparks docs' safety plea
Additionally, a normal profile for an RFDS pc12 is a 2 to 1 (although 3 degree approaches are not uncommon), which actually increases the number of question marks about why the pc12 was down there so far out
morno
As other posters have pointed out, there will always be faulty, inaccurate or completely unserviceable transponders; especially the ones fitted to aircraft that don’t go near C very often.
So, given that fact, what rules should sensibly be put into place to deal with the risk that aircraft outside C (or beyond the range of a friendly controller who’s willing to confirm a cockpit reading or chase apparently anomalous returns) may have a faulty, inaccurate or completely unserviceable transponder?
I’m thinking there should be rules about:
(1) minimum distances from cloud for VFR aircraft, with the distances determined by reference to altitude and height, and
(2) eyes out of the cockpit for everyone in VMC, especially when near the ground or aerodromes,
when OCTA (or whatever the correct term is, this year).
What other rules could sensibly be put in place to deal with the fact that no technology is perfect?
So, given that fact, what rules should sensibly be put into place to deal with the risk that aircraft outside C (or beyond the range of a friendly controller who’s willing to confirm a cockpit reading or chase apparently anomalous returns) may have a faulty, inaccurate or completely unserviceable transponder?
I’m thinking there should be rules about:
(1) minimum distances from cloud for VFR aircraft, with the distances determined by reference to altitude and height, and
(2) eyes out of the cockpit for everyone in VMC, especially when near the ground or aerodromes,
when OCTA (or whatever the correct term is, this year).
What other rules could sensibly be put in place to deal with the fact that no technology is perfect?
Slippery_Pete, any pilot worth his salt would know that the 270 below 10 would refer to IAS. Naughty, naughty. Over to you......
The original post was talking about head-on closing speeds for a collision - ie the speed of the PC12 compared to the other aircraft.
Closing speeds of two aircraft are a TAS consideration, not IAS.
I made my comment to you because an aircraft can quite easily TAS 270 below 10,000 without breaking the max 250 indicated rule.
If you need more explanation than this, try enrolling in aerodynamics 101.
Anyway, after all that, it was just a number that someone guessed at when considering the collision speed. And I think with the PC12 Vne info and the fact it occurred at 2500, it was most probably a lot less than 270.
...Give me a break. Whilst all the "see and avoid" lecturers are right in a general sense, in this instance it is not relevent.
As I understand it, the RFDS aircraft emerged from solid cloud, and within no more than a few seconds the other aircraft had flashed by...
As I understand it, the RFDS aircraft emerged from solid cloud, and within no more than a few seconds the other aircraft had flashed by...
Via the thread starter post...
"...the pilot of the small plane said he did not have a full appreciation of the proximity of his planned outbound track with the Adelaide-Mt Gambier inbound track.
His plane was not fitted with a transponder and he was flying directly into the sun..."
Late afternoon sun ?
.
Morno,
I'm sure you wouldn't make a statement like that unless you had some knowledge of the operation, but I can tell you central ops fly the two to one as default unless it's a day visual approach and either the terrain is forgiving or there are other options that warrant giving away the ability to glide to the destination if need be. It also keeps one out of the thermal turbulence for a bit longer in summer.
I would, however, unless shown otherwise, certainly give this pilot the benefit of the doubt that he was that low on profile for one justified reason or another. As stated earlier, both aircraft had every right to be in that location just below the cloud base. A working radio would have helped, as would have a transponder. Vanishingly small, eh.
Your stated Vne was also incorrect, not that it's relevant.
I'm sure you wouldn't make a statement like that unless you had some knowledge of the operation, but I can tell you central ops fly the two to one as default unless it's a day visual approach and either the terrain is forgiving or there are other options that warrant giving away the ability to glide to the destination if need be. It also keeps one out of the thermal turbulence for a bit longer in summer.
I would, however, unless shown otherwise, certainly give this pilot the benefit of the doubt that he was that low on profile for one justified reason or another. As stated earlier, both aircraft had every right to be in that location just below the cloud base. A working radio would have helped, as would have a transponder. Vanishingly small, eh.
Your stated Vne was also incorrect, not that it's relevant.
via ATSB... Time: 1429 CST
Investigation: AO-2010-048 - Aircraft proximity event - Pilatus aircraft PC-12, VH-FDK, 50 km NW of Mount Gambier aerodrome, SA, 1 July 2010
Hmmm... what angle is the sun around Mount Gambier at 1429 Central Standard Time ?
.
Investigation: AO-2010-048 - Aircraft proximity event - Pilatus aircraft PC-12, VH-FDK, 50 km NW of Mount Gambier aerodrome, SA, 1 July 2010
Hmmm... what angle is the sun around Mount Gambier at 1429 Central Standard Time ?
.
Last edited by Flying Binghi; 6th Jun 2011 at 12:23. Reason: try angle
S'pose that's what happens when you haven't flown the thing for a while now. 236kts Vne (or Vmo if you want to get technical).
morno
morno
All good. The new shiny ones do 240, but that's only because the computers make ias=cas, and they ping you at 241 so we tend to not go as hard on descent anyway. That's enough thread drift for now though.
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The crew of ELI reported that while visibility was greater than 10 km, their outbound track of 334 degrees was directly into the sun. While this affected their visual scan for traffic and consequently, their ability to sight FDK, the crew believed that this was not a factor in the occurrence.
Naturally you would expect me to side with the DOC's on this one. Transponders
.
"While the operator (Flying Doc) determined that the pilot of FDK had complied with the required procedures, they advised the ATSB that they will be conducting internal education to remind pilots that maintaining a lookout and...."
http://www.atsb.gov.au/media/2907457...03.pdf#page=15
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"While the operator (Flying Doc) determined that the pilot of FDK had complied with the required procedures, they advised the ATSB that they will be conducting internal education to remind pilots that maintaining a lookout and...."
http://www.atsb.gov.au/media/2907457...03.pdf#page=15
.
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Bring on compulsory ADS-B!
A lot of gliders use FLARM units (a form of ADS-B) costing $1000 and now fitted to all gliders participating in competitions. You can't tell me it's not possible to produce a similar unit for GA aircraft at a similar cost, especially if there is a sudden demand to fit the entire fleet. Especially when I can buy a phone with gps and wireless for $200.
Car seatbelts are compulsory and have been for a number of years. Five seatbelts cost around $600 plus fitting, I'm sure there were the same group of whingers saying there's no need, just drive at a reasonable speed and don't hit anything. But now, nobody blinks an eyelid. Every new car is fitted with a seatbelt, every second hand car you get in to is fitted with seatbelts.
See and avoid combined with radio is a useful tool, but it has it's limitations, one being the human element. I've lost count of the number of radio calls I've heard from commercial pilots claiming "5nm north of the airfield" only to find them approaching from the south. If these are guys flying in GA for living, I dread to think how the weekend warriors go. Not to mention the ghost planes who manage to fly without a single radio call (wrong frequency?) We also have to realise the limitations of the human eye - there are now plenty of Kingairs, Conquests, PC12s, TBM850s, dropping in to airfields with groundspeeds up to 300kts combine that with a tiny ultralight or 152 and the time available to "see and avoid" each other becomes minimal at best (assuming no other distractions in the cockpit).
We all talk about the swiss cheese model. This incident illustrates how important it is to add another layer of swiss cheese, especially when there is a solution readily available.
A lot of gliders use FLARM units (a form of ADS-B) costing $1000 and now fitted to all gliders participating in competitions. You can't tell me it's not possible to produce a similar unit for GA aircraft at a similar cost, especially if there is a sudden demand to fit the entire fleet. Especially when I can buy a phone with gps and wireless for $200.
Car seatbelts are compulsory and have been for a number of years. Five seatbelts cost around $600 plus fitting, I'm sure there were the same group of whingers saying there's no need, just drive at a reasonable speed and don't hit anything. But now, nobody blinks an eyelid. Every new car is fitted with a seatbelt, every second hand car you get in to is fitted with seatbelts.
See and avoid combined with radio is a useful tool, but it has it's limitations, one being the human element. I've lost count of the number of radio calls I've heard from commercial pilots claiming "5nm north of the airfield" only to find them approaching from the south. If these are guys flying in GA for living, I dread to think how the weekend warriors go. Not to mention the ghost planes who manage to fly without a single radio call (wrong frequency?) We also have to realise the limitations of the human eye - there are now plenty of Kingairs, Conquests, PC12s, TBM850s, dropping in to airfields with groundspeeds up to 300kts combine that with a tiny ultralight or 152 and the time available to "see and avoid" each other becomes minimal at best (assuming no other distractions in the cockpit).
We all talk about the swiss cheese model. This incident illustrates how important it is to add another layer of swiss cheese, especially when there is a solution readily available.
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Education of the pilots is a wonderful thing and the RFDS should be commended for doing this. As they are for excellent comms in CTAF environments, and for fitting TCAS. RFDS 
That being said the PC12 pilot was looking out, and in the flash of the near hit he did see it after all.
Interesting that two pilots in the other aircraft did not see, or do anything and when one did they did nothing as it was too late anyway.....
Of course it was the IFR Pilot of the RFDS PC12 that was not doing his job and that was the main reason for the near hit. Nothing to do with two pilots, off track, wondering about the fuel gauges, a radio that did not work etc and they did not have a transponder.
I get it now...........
That being said the PC12 pilot was looking out, and in the flash of the near hit he did see it after all.
Interesting that two pilots in the other aircraft did not see, or do anything and when one did they did nothing as it was too late anyway.....
Of course it was the IFR Pilot of the RFDS PC12 that was not doing his job and that was the main reason for the near hit. Nothing to do with two pilots, off track, wondering about the fuel gauges, a radio that did not work etc and they did not have a transponder.
I get it now...........
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It's a well documented fact that most accidents occur because "the plane disappeared from the radar screen" or "the pilot had not submitted a flight plan" or "the engine stalled".
I can't afford a $1000 mobile phone, most gliders using FLARM use the one club owned unit which is shared around, and it's not TSO'd, it's not an ADSB and even if it was its not even legal to turn it on if you intend to fly in CTR or class E airspace.
On a positive note, and because nobody bothers to read all the posts leading up to the last, may I suggest you read back a page or two and look at the link I provided for a non TSO'd unit that would probably interface quiet well with a TCAS and stop the constant harping by people that fail to adhere to the basic laws of VFR in VMC and in CTAF's where a SAAB lands once a day. It wouldn't wash with the Airservices mob though even though RA-Aus can't fly in CTR.
Has anybody the time or inclination to investigate the device and find out a projected price? I couldn't be bothered. Laziness tells me some "expert" wll tell me anyway, some day, and how bad it is compared with some other at a marginally higher price.
A bit like that $1000 phone which does the same as my $150 model when it comes to talking with someone.
FLARM units (a form of ADS-B) costing $1000
On a positive note, and because nobody bothers to read all the posts leading up to the last, may I suggest you read back a page or two and look at the link I provided for a non TSO'd unit that would probably interface quiet well with a TCAS and stop the constant harping by people that fail to adhere to the basic laws of VFR in VMC and in CTAF's where a SAAB lands once a day. It wouldn't wash with the Airservices mob though even though RA-Aus can't fly in CTR.
Has anybody the time or inclination to investigate the device and find out a projected price? I couldn't be bothered. Laziness tells me some "expert" wll tell me anyway, some day, and how bad it is compared with some other at a marginally higher price.
A bit like that $1000 phone which does the same as my $150 model when it comes to talking with someone.
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I did have a look Frank, and its possibly going to be a great device. I wonder how the static source is achived, even cabin static is within tolerences in most cases so it should work OK.
There is nothing about price or when it will make it to market though.
Caveat....it was a few days ago I looked at the link so I do not recall everything and I am too lazy to look again
J
There is nothing about price or when it will make it to market though.
Caveat....it was a few days ago I looked at the link so I do not recall everything and I am too lazy to look again
J
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Dependant upon price, I would give guarded support to this gadget.
And yes, apathy is a curse.
But who cares?
And yes, apathy is a curse.
But who cares?
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Slippery_Pete, in my initial post I made the bold assumption that under the prevailing conditions that IAS would damn near equal TAS, shooting from the hip you might say. I enrolled in the Aerodynamics 101 as you suggested and came up with the following.
The Mount Gambier weather report for the time of day.
Temp 11°C
Dew Point 8°C
QNH 1023
Assumptions
Lapse Rate 1.9812°C/1,000'
Pressure Altitude 2,400'
IAS 250K
Will give you a TAS of 257.1759K
So to have a TAS of 270 would have required exceedance of the 250IAS limit.
Without crunching the exact numbers, a TAS of 270 would require an IAS of approx 263.
The Mount Gambier weather report for the time of day.
Temp 11°C
Dew Point 8°C
QNH 1023
Assumptions
Lapse Rate 1.9812°C/1,000'
Pressure Altitude 2,400'
IAS 250K
Will give you a TAS of 257.1759K
So to have a TAS of 270 would have required exceedance of the 250IAS limit.
Without crunching the exact numbers, a TAS of 270 would require an IAS of approx 263.
Last edited by Brian Abraham; 7th Jun 2011 at 18:59. Reason: Data Entry
Descending trough clouds into VFR traffic is one of my biggest fears, especially with the closing speeds of (in my case a twin) compared with VFR aircraft doing local joyflights. For this reason, I start listening to the CTAF a long way out and will make an initial inbound call at maybe 30 nm out.
But I also fly old non-transponder and non-electric aircraft and defend their right to fly without transponder.
In this case I suspect that there are some less than ideal factors on both sides that contributed.
If the Aeromacchi didn't have a functioning TXP, then one would think there was a greater responsibility to have a functioning radio & pay attention to radio traffic. Apparently the radio had a transmit problem, but one might hope that they were on the correct frequency to hear the descent call from the RFDS. So, they are been less than diligent in both this regard and their navigation. 53nm out of Mt Gambier on the Adelaide track (assuming that the RFDS was on-track) puts them about 20nm off track for Mt Gambier - Portee Station. A handheld GPS and VHF would have gone a long way.
The RFDS report doesn't really seem completely straight up and down either. Firstly, anyone who has flown formation would find the notion that a Pilatus will feel any wake from C182 sized aircraft at circa 10m laterally and 20ft vertically is a bit fanciful. Secondly, if the RFDS was at 2400 ft 53nm out from MtGambier this puts them about abeam Robe where the LSALT for the W519 route is 2700 ft. 53nm is way too far out to be positioning for a any of the 3 possible instrument approaches into Mt Gambier. Therefore you must conclude that the RFDS crew consciously transitioned to VFR for the final stage of the flight. I would expect that the PC12 would normally climb to Flight Levels for the 202 nm trip from Adelaide to MtGambier, which makes the non-standard descent even more puzzling. The choice by the crew to depart from the IFR track places a higher responsibility on them to integrate with VFR aircraft (ie see & be seen). The ERC shows gliding based at Millicent, so a similar incident could conceivably occurred a few miles on abeam Millicent. However IF ATC gave them the Aeromacchi as traffic, it was nowhere near where they would have been looking for it.
I can't help but think there is a fair bit of bad luck in this incident. But also I can't help but think that AsA have escaped without mention. The report infers (but does not specify) that there was a submitted plan for the Aeromacchi. Was there more that AsA could have done to alert the Aeromacchi crew that their radio was not working? The RFDS flight would have been the logical one to try and relay a call. And there is the old question about whether Australia really has adequate radar coverage.
At the end of the day, I'm not really sure what the lessons are. We know that our current system has a weakness dealing with VFR traffic under a cloud base and descending IFR traffic. Something that is not helped by ASA's decision to delete VHF boundaries from the PCA chart. It can be hard for VFR aircraft to figure out the correct frequency - and the incident occurred not far away from a frequency boundary.
But I also fly old non-transponder and non-electric aircraft and defend their right to fly without transponder.
In this case I suspect that there are some less than ideal factors on both sides that contributed.
If the Aeromacchi didn't have a functioning TXP, then one would think there was a greater responsibility to have a functioning radio & pay attention to radio traffic. Apparently the radio had a transmit problem, but one might hope that they were on the correct frequency to hear the descent call from the RFDS. So, they are been less than diligent in both this regard and their navigation. 53nm out of Mt Gambier on the Adelaide track (assuming that the RFDS was on-track) puts them about 20nm off track for Mt Gambier - Portee Station. A handheld GPS and VHF would have gone a long way.
The RFDS report doesn't really seem completely straight up and down either. Firstly, anyone who has flown formation would find the notion that a Pilatus will feel any wake from C182 sized aircraft at circa 10m laterally and 20ft vertically is a bit fanciful. Secondly, if the RFDS was at 2400 ft 53nm out from MtGambier this puts them about abeam Robe where the LSALT for the W519 route is 2700 ft. 53nm is way too far out to be positioning for a any of the 3 possible instrument approaches into Mt Gambier. Therefore you must conclude that the RFDS crew consciously transitioned to VFR for the final stage of the flight. I would expect that the PC12 would normally climb to Flight Levels for the 202 nm trip from Adelaide to MtGambier, which makes the non-standard descent even more puzzling. The choice by the crew to depart from the IFR track places a higher responsibility on them to integrate with VFR aircraft (ie see & be seen). The ERC shows gliding based at Millicent, so a similar incident could conceivably occurred a few miles on abeam Millicent. However IF ATC gave them the Aeromacchi as traffic, it was nowhere near where they would have been looking for it.
I can't help but think there is a fair bit of bad luck in this incident. But also I can't help but think that AsA have escaped without mention. The report infers (but does not specify) that there was a submitted plan for the Aeromacchi. Was there more that AsA could have done to alert the Aeromacchi crew that their radio was not working? The RFDS flight would have been the logical one to try and relay a call. And there is the old question about whether Australia really has adequate radar coverage.
At the end of the day, I'm not really sure what the lessons are. We know that our current system has a weakness dealing with VFR traffic under a cloud base and descending IFR traffic. Something that is not helped by ASA's decision to delete VHF boundaries from the PCA chart. It can be hard for VFR aircraft to figure out the correct frequency - and the incident occurred not far away from a frequency boundary.
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Akro
The 25 mile MSA is 2400, and one can only assume from the info that states at 56km FDK made a broadcast at TOD and would be inside the 25MSA before being below the 2700' LSALT.
If that helps....
The 25 mile MSA is 2400, and one can only assume from the info that states at 56km FDK made a broadcast at TOD and would be inside the 25MSA before being below the 2700' LSALT.
If that helps....
When I wrote my post I could only access the ATSB summary. I've now been able to read the full report and reading the full report its a bit hard to fault the RFDS crew. Its also significant that the full report says the incident occurred 56 km from Mt Gambier not 53nm as was stated in the earlier reports (why the ATSB is using km is a mystery) which changes things as well. Also the incident did not occur on the Adelaide - MtGambier route because the RFDS aircraft was cleared to track direct for the RWY 18 RNAV approach.
The crew of the Aeromacchi could have been sharper in retrospect and the situation would have been improved if they made a call on the area frequency. But, the current system absolutely discourages VFR aircraft from doing this and I've heard pilots reprimanded by ATC for making such calls. The Aeromacchi was flying in class g airspace at the correct hemispherical altitude with adequate clearance to cloud. There is some implied criticism from the ATSB that the Aeromacchi crew were not aware of the Adelaide - Mount Gambier IFR route, but how does a VFR pilot know this?
I think this incident highlights that the IFR & VFR procedures that we have don't play well together. Substitute a private TBM or Aerostar for the RFDS and you have an aeroplane flying the same profile at the same speeds without TCAS. Substitute the Aeromacchi for an antique aircraft, glider or ultralight and you have an aircraft flying at the correct hemispherical altitude, 500ft below a scattered cloud base in a low VFR level legitimately flying along without transponder. The area frequency doesn't reliably work on the ground, so unless the RFDS is listening to the CTAF well before they are required to, or the light aircraft makes a position call on the area frequency after take off (which they are discouraged from doing), then there is no mechanism to alert each aircraft of the presence of the other. I can't recall the coverage in that area, but I wouldn't take it for granted that there is reliable transponder coverage at 2,400 ft around Mt Gambier.
The crew of the Aeromacchi could have been sharper in retrospect and the situation would have been improved if they made a call on the area frequency. But, the current system absolutely discourages VFR aircraft from doing this and I've heard pilots reprimanded by ATC for making such calls. The Aeromacchi was flying in class g airspace at the correct hemispherical altitude with adequate clearance to cloud. There is some implied criticism from the ATSB that the Aeromacchi crew were not aware of the Adelaide - Mount Gambier IFR route, but how does a VFR pilot know this?
I think this incident highlights that the IFR & VFR procedures that we have don't play well together. Substitute a private TBM or Aerostar for the RFDS and you have an aeroplane flying the same profile at the same speeds without TCAS. Substitute the Aeromacchi for an antique aircraft, glider or ultralight and you have an aircraft flying at the correct hemispherical altitude, 500ft below a scattered cloud base in a low VFR level legitimately flying along without transponder. The area frequency doesn't reliably work on the ground, so unless the RFDS is listening to the CTAF well before they are required to, or the light aircraft makes a position call on the area frequency after take off (which they are discouraged from doing), then there is no mechanism to alert each aircraft of the presence of the other. I can't recall the coverage in that area, but I wouldn't take it for granted that there is reliable transponder coverage at 2,400 ft around Mt Gambier.
