Mid - Air @ Caboolture
However, I've just had this scenario described:
The Jab is departing from 29 while the Pawnee, on final for 06, tells the Jab that he'll stop before the intersection. However "a Cessna" then crosses 06/24 ahead of the Pawnee, forcing him to go around and thus collide with the Jabiru. The Jabiru turns through 180 degrees and impacts the ground on the 24 threshold while the Pawnee flies another circuit, lands on 06 and then taxies up to the Jabiru wreckage.
The Jab is departing from 29 while the Pawnee, on final for 06, tells the Jab that he'll stop before the intersection. However "a Cessna" then crosses 06/24 ahead of the Pawnee, forcing him to go around and thus collide with the Jabiru. The Jabiru turns through 180 degrees and impacts the ground on the 24 threshold while the Pawnee flies another circuit, lands on 06 and then taxies up to the Jabiru wreckage.
RIP Dave and Jan
Just prior Covid Dave and I met for a coffee, we hadn’t crossed tracks since 1980
Helped you gain your Class One instrument rating in 77, an excellent student
Very sad
Just prior Covid Dave and I met for a coffee, we hadn’t crossed tracks since 1980
Helped you gain your Class One instrument rating in 77, an excellent student
Very sad
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Quote from #43 "For the amount of flight operations in Australia, mid-airs are over represented, our system is vetted by many third world airspace. ADSB OUT AND IN makes a difference. Having recently avoided 2 different conflicts in short succession due to ADSB IN, I am concerned by the robustness of Aus airspace."
OK, great... Can such claims be backed up by comparable statistics?
What do you mean by over-represented? Per aircraft movements, hours in the air, nautical miles covered?
"Our system is vetted by many third world airspace", that comes across as pejorative.
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OK, great... Can such claims be backed up by comparable statistics?
What do you mean by over-represented? Per aircraft movements, hours in the air, nautical miles covered?
"Our system is vetted by many third world airspace", that comes across as pejorative.
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The demograpically most comparable state to AUS is the USA. Not just because they share the same letters. They have similar see and avoid airspace rules, and have a reasonably comparable operating environment, the USA having some greater elevations, but pretty much the same. Both have many airports that arose from the WW2 training and operations development. The USA has 22 times the hours a year that AUS does, in the GA fleet. The rate of MAC's in AUS however is between 1:500,000FH to 1:1,000,000FH. USA, with ~20 times the density of operations, [1] has a MAC every 3,500,000 FH.[2]
So, with 5% of the activity rate, we get 3.5-7 x the number of MAC's that the USA gets.
Canada may make you happier as a comparison, TSB provides information on their total accidents, and they are operating around 2.7 times the fleet size that Australia does. Their total accidents per year is around 20-30% more than Australia varying over time. Their number of MAC's in the last 13 years, excluding RCAF, is... 0. [3] Canada has a similar level of concentration of population centers, and has similar uncontrolled airspace regs to Aus.
South Korea.... 1 MAC in the last 45 years, but they have a minuscule GA fleet, with massive constraints in operations. And bad weather. And terrain. And trigger happy psycho's near by.
Malaysia.... 1 MAC in the last 45 years, see ROK above...
Indonesia... no data, and minimal GA ops.
Philippines... no midairs since 2010. Modest GA fleet, weather/terrain/comms.
In Europe, France's BEA has good statistics and reports on MAC's. 1-Jan-89-30-Jun-99, 17 midairs. 2x transport category v GA FW, 1x transport category v glider, 3 x light aircraft v glider, 11x light aircraft v light aircraft, [4] The UK, has some 1700 airfield in an area about the same as Victoria, and has a few more aircraft, and operates more hours than Australia. The UK AAIB records 22 MAC events since 1974 to date, or about 1 every 2 years. 2 of those are fast jet on published LL routes. A number are GA FW v glider, and GA FW v GA RW [5] The density of operations in the UK is a bit like France, without the language issues. The complexity of airspace is substantially greater than Australia.
The rate of MAC events in the UK is low, radar deconfliction helps greatly. In the USA, NEXRAD & ADSB UART helps all comers. The availability of ADSB IN displays that don't cost a fortune and are not complicated by certification inertia does not completely stop MACs, but the rates have decreased in recent times. Having flown biplanes, gliders helicopters and jets VFR and IFR in the US along the way, If I don'yt have ADSB IN, I am not interested in flying any more. My aircraft also have TCAS II ch 7.1, and I still run ADSB IN.
Reliance on comms alone is the subject of an interesting study dating back 15 years or so, it is better than nothing but it is not robust. [6]
Reliance on see and be seen also has its issues, here is the target of a 100kt + 100kt closure, without the additional time values of recognition, pilot response, aircraft response and the potential for an error in the reaction undertaken. Add the latter items together, taking a small aircraft at each end and the latest detection point is around 5-6 seconds depending on how many "g" you can pull.
Are there statistics that show ADSB helps? None yet published, but with ADSB IN my own experience is target detection is much better, whether at 50' or FL450.
There are numerous airports in AUS that have blind spots that impact traffic, be it a hump in the middle of the uncontrolled CTAF airstrip, trees hiding cross runways or otherwise. My own experience with midairs were in formations that went pear-shaped, which is one condition that ADSB IN doesn't help.
None of the above detracts from the general guidance and obligations that exist for collision avoidance in the regulations, however, a rigid belief in the infallibility of the system of CTAF/see and avoid etc may or may not work out always [6]. I'll take every tool that I have available not to have another impact with bits of some other persons aircraft.
P.S.: The depressing findings in ref [6] were based on a simplification that the response of the aircraft involved would instantly avoid collision if there was successful communication. It also considered that every communication was comprehended with respect to identity, location, trajectory and that was instantaneously then perceived as a threat or not, and the aircraft involved immediately and correctly manoeuvred to avoid collision, and that the change in attitude resulted in instantaneous translation in position of both aircraft, both being the correct response. At least TCAS recognises when the response was countered by the other targets actions too, coordinated or not. It also assumes that one or both aircraft actually have performance to alter their trajectory in a meaningful manner, e.g., reject, climb, dive, etc. The most common reaction for a pilot in a conflict is to turn, which is normally the least effective response for avoidance.
[1] AOPA State of General Aviation Report 2019
[2] gajsc 2023 Midair Collision Report
[3] TSB
[4] BEA Report: Mid-Air Collisions 1989-1999
[5] AAIB Reports Data base
[6] Fulton N.L., Westcott, M., Emery, S.; 2010, "Influences of communication structural complexity on operational safety in regional airspace design" Safety Science
Spoiler
Last edited by fdr; 29th Jul 2023 at 22:16. Reason: forgot to add reference... P.S. added
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No-one has mentioned why the Pawnee pilot has landed long. He should have had his wheels on the ground by the intersection even if he was using 24 with its threshold only 350 m distant but for:
(a) excessive float in a quartering tailwind or
(b) deliberately landing long(past the intersection) so as to finish the landing run where the gliders might have been parked due to commercial pressures - an extended final at 70kts being quicker and cheaper than a taxi up to the parked gliders at 10-20kts.
I witnessed a couple of weeks ago the tugs at Boonah doing the same thing, approaching high and landing long so as their roll out finished at the end of the runway in front of the club where the gliders were parked. Of course, there is no cross runway at Boonah.
Also there could be possible confusion due to the renaming of the runway 11/29 from previously 12/30. I don't know when this changed, but it would have been only in the last two years. I checked an old ERSA of mine(17 June 2021) and it still had 12/30 listed. I presume this was done to avoid confusion with Caloundra's runways 12/30.
(a) excessive float in a quartering tailwind or
(b) deliberately landing long(past the intersection) so as to finish the landing run where the gliders might have been parked due to commercial pressures - an extended final at 70kts being quicker and cheaper than a taxi up to the parked gliders at 10-20kts.
I witnessed a couple of weeks ago the tugs at Boonah doing the same thing, approaching high and landing long so as their roll out finished at the end of the runway in front of the club where the gliders were parked. Of course, there is no cross runway at Boonah.
Also there could be possible confusion due to the renaming of the runway 11/29 from previously 12/30. I don't know when this changed, but it would have been only in the last two years. I checked an old ERSA of mine(17 June 2021) and it still had 12/30 listed. I presume this was done to avoid confusion with Caloundra's runways 12/30.
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I would have thought that the distance from the highway to the displaced threshold of 06 would be plenty to ensure a trailing tow rope didn’t foul the highway or a fence, but there would be quite a challenge in landing and holding short 11/29, if using 06 and only the advertised runway from the displaced threshold. (‘Piano keys’ of sorts for DTHR 06, circled.)
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I also have a plane based at Caboolture and have had problems with gliders, glider tugs and glider operations, at this particular aerodrome;
- The duty runway clearly being runway 11, it being nominated by pilots but the glider fraternity using runway 06 because they couldn't be bothered towing their rubbish around to runway 11 because runway 06 is a hop, step and jump to their hangar.
- The incredible stupidity of operating on runway 06 whilst other pilots are using runway 11 when there is a forest between the two runways. It is impossible to see aircraft operating from either runway so why do it?
- The incredible stupidity of using runway 06 with a significant displaced threshold, whilst operations are taking place on a safer runway (11), the displaced threshold providing fewer options in the very case that happened in this accident in the event of a last second sighting of an aircraft coming into view.
- There are pilots that heard the radio transmissions or lack there of with this incident THAT KILLED TWO PEOPLE.
- Anyone who states that this is a quiet airport, or that it isn't a high traffic density airport, at times, have not operated there when it is.
- The continual descents of tug aircraft on downwind into the circuit at this and every other airport that has glider operations placing every other aircraft in danger every time they do it.
- The use of a runway with tailwind, why? Yet again because an operation couldn't be bothered towing infrastructure to the other end of the runway.
- The dangerous lack of situational awareness displayed by glider operations, either that or the lack of care, just to save a few bucks in airborne tug time.
- For those of you who would consider this as 'just an accident' **** you. All due to the continual selfish, dangerous and negligent use of a runway configuration to save a few bucks.
A very experienced and professional pilot and his spouse dead, for no reason.
- The duty runway clearly being runway 11, it being nominated by pilots but the glider fraternity using runway 06 because they couldn't be bothered towing their rubbish around to runway 11 because runway 06 is a hop, step and jump to their hangar.
- The incredible stupidity of operating on runway 06 whilst other pilots are using runway 11 when there is a forest between the two runways. It is impossible to see aircraft operating from either runway so why do it?
- The incredible stupidity of using runway 06 with a significant displaced threshold, whilst operations are taking place on a safer runway (11), the displaced threshold providing fewer options in the very case that happened in this accident in the event of a last second sighting of an aircraft coming into view.
- There are pilots that heard the radio transmissions or lack there of with this incident THAT KILLED TWO PEOPLE.
- Anyone who states that this is a quiet airport, or that it isn't a high traffic density airport, at times, have not operated there when it is.
- The continual descents of tug aircraft on downwind into the circuit at this and every other airport that has glider operations placing every other aircraft in danger every time they do it.
- The use of a runway with tailwind, why? Yet again because an operation couldn't be bothered towing infrastructure to the other end of the runway.
- The dangerous lack of situational awareness displayed by glider operations, either that or the lack of care, just to save a few bucks in airborne tug time.
- For those of you who would consider this as 'just an accident' **** you. All due to the continual selfish, dangerous and negligent use of a runway configuration to save a few bucks.
A very experienced and professional pilot and his spouse dead, for no reason.
You say that you haven't ever had problems with this operation, but you've taken off on runway 11 and missed aircraft landing or taking off on runway 06 purely by luck. Lucky that you haven't missed calls that may have been made nominating runway 06, or did you miss a call and missed the aircraft by luck? Did you even know that an aircraft landed on that runway because you didn't hear a call?
Do you hear the constant over transmissions on the combined Caloundra, Caboolture CTAF frequency? No, it's not busy at all (sarcasm). So why in gods name when you have everything going against you do you contribute to poor traffic outcomes by using a complex runway configuration?
Do the experts know what aircraft mix uses this aerodrome? Helicopter and GA schools, RAAus schools, warbirds, chutes, experimental, certified. You name it, it fly's in and out of Caboolture.
But the monumentally stupid will promote intersecting runway use that not one ATC would ever dream of using.
Do you hear the constant over transmissions on the combined Caloundra, Caboolture CTAF frequency? No, it's not busy at all (sarcasm). So why in gods name when you have everything going against you do you contribute to poor traffic outcomes by using a complex runway configuration?
Do the experts know what aircraft mix uses this aerodrome? Helicopter and GA schools, RAAus schools, warbirds, chutes, experimental, certified. You name it, it fly's in and out of Caboolture.
But the monumentally stupid will promote intersecting runway use that not one ATC would ever dream of using.
Regular users of this aerodrome have seen near misses that would send chills down your spine.
I'll withdraw my comment that may be taken as alluding to any individual as a clown. I won't withdraw my thoughts of particular operations as a clownshow.
I'll withdraw my comment that may be taken as alluding to any individual as a clown. I won't withdraw my thoughts of particular operations as a clownshow.
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Hoosten:
Clearly you have very different opinions to mine.
Could I suggest that you approach the Club Committee (or either of the Safety Officers) with your concerns?
Clearly you have very different opinions to mine.
Could I suggest that you approach the Club Committee (or either of the Safety Officers) with your concerns?
Back when CASA cared about Air Safety
FDR Thanks for your contribution above which is valuable for its contribution to understanding WHY.
In 2002, CASA carried out an analysis of Mid Air Collisions in Australia for the period 1969 to 2001 and the conclusions support your contention that the mid air rate here per flying hour is greater than in the USA despite the much lower density of air traffic.
In that period there were 22 instances of collisions where the aircraft were not deliberately flown in the same airspace and 36 where they were flown deliberately close.... thermalling, formating, etc.
19 of the 22 were circuit area collisions.
Failúre to implent the USA NAS system and continual invention of weird and complex special Australian traffic advisory systems was then and still is a major contributing factor to our high accident rate.
In 2002, CASA carried out an analysis of Mid Air Collisions in Australia for the period 1969 to 2001 and the conclusions support your contention that the mid air rate here per flying hour is greater than in the USA despite the much lower density of air traffic.
In that period there were 22 instances of collisions where the aircraft were not deliberately flown in the same airspace and 36 where they were flown deliberately close.... thermalling, formating, etc.
19 of the 22 were circuit area collisions.
Failúre to implent the USA NAS system and continual invention of weird and complex special Australian traffic advisory systems was then and still is a major contributing factor to our high accident rate.
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Canada may make you happier as a comparison, TSB provides information on their total accidents, and they are operating around 2.7 times the fleet size that Australia does. Their total accidents per year is around 20-30% more than Australia varying over time. Their number of MAC's in the last 13 years, excluding RCAF, is... 0. [3] Canada has a similar level of concentration of population centers, and has similar uncontrolled airspace regs to Aus.
Spoiler
Is it just me?
The Gympie MAC involved two octogenarian pilots.
This one, two septuagenarian pilots.
I’m in the latter category and I know I’m having to concentrate much, much more I than I used to, just to be situationally aware around busy GA airports. I can honestly say, it is an effort now where once it was a total non event.
It could be that the last 30 years I had been flying the latest and greatest from ILS to ILS, traffic for the most part was handled by ATC and then the miracle of TCAS arrived to make things even easier, thus losing the knack of seeing with my ears.
The Gympie MAC involved two octogenarian pilots.
This one, two septuagenarian pilots.
I’m in the latter category and I know I’m having to concentrate much, much more I than I used to, just to be situationally aware around busy GA airports. I can honestly say, it is an effort now where once it was a total non event.
It could be that the last 30 years I had been flying the latest and greatest from ILS to ILS, traffic for the most part was handled by ATC and then the miracle of TCAS arrived to make things even easier, thus losing the knack of seeing with my ears.
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Originally Posted by Advance
Failúre to implent the USA NAS system and continual invention of weird and complex special Australian traffic advisory systems was then and still is a major contributing factor to our high accident rate.
Many years ago a colleague had a similar situation at YBEV, he was landing on 16 and a glider landed at the same time on 08. They just missed each other. He was on the correct frequency which at the time was Perth Centre (I said it was a long time ago) and the glider was on the "glider frequency". Could this be a contributing factor? I can't understand how two aircraft at an uncontrolled aerodrome (which I note has a CTAF but is not mandatory for carriage of radio) could possibly not be aware of the other unless they were on different frequencies, or not transmitting at all?
I have had a glider tug not on the CTAF at an aerodrome where it is compulsory to carry radio cut in front of me on short final without a word - no idea they were even in the area until he filled up my windscreen and not responding to any radio calls before or after the incident, which was a matter of feet away from a midair, so perhaps on the "glider frequency" again?
I have had a glider tug not on the CTAF at an aerodrome where it is compulsory to carry radio cut in front of me on short final without a word - no idea they were even in the area until he filled up my windscreen and not responding to any radio calls before or after the incident, which was a matter of feet away from a midair, so perhaps on the "glider frequency" again?
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Mid Air collision stats
For many years the statistics here have been way way worse than in the USA just as the CASA study and the FDR post demonstrate.
But having flown in both countries I know which has the safer procedures and ATS systems and over long periods the statistics are reliable.
Many years ago a colleague had a similar situation at YBEV, he was landing on 16 and a glider landed at the same time on 08. They just missed each other. He was on the correct frequency which at the time was Perth Centre (I said it was a long time ago) and the glider was on the "glider frequency". Could this be a contributing factor? I can't understand how two aircraft at an uncontrolled aerodrome (which I note has a CTAF but is not mandatory for carriage of radio) could possibly not be aware of the other unless they were on different frequencies, or not transmitting at all?
I have had a glider tug not on the CTAF at an aerodrome where it is compulsory to carry radio cut in front of me on short final without a word - no idea they were even in the area until he filled up my windscreen and not responding to any radio calls before or after the incident, which was a matter of feet away from a midair, so perhaps on the "glider frequency" again?
I have had a glider tug not on the CTAF at an aerodrome where it is compulsory to carry radio cut in front of me on short final without a word - no idea they were even in the area until he filled up my windscreen and not responding to any radio calls before or after the incident, which was a matter of feet away from a midair, so perhaps on the "glider frequency" again?
Hoosten and Triathlon - do you even operate out of YCAB? I've been there for 25 years and I've never had any concerns about the professionalism of the glider operation there - so, without respect, pull your heads in.
George - my condolences at loosing friends.
One possible factor here is the amount of radio traffic on 125.85; possibly either or both aircraft missed vital calls? This frequency serves two busy airfields (Caboolture and Caloundra) plus it's used for aircraft operating in the Bribie Island training area as well as those transiting out across Morten Bay. Plus you do get clowns with lousy radio discipline; not listening out before transmitting or making incredibly long-winded speeches when a few words would suffice.
George - my condolences at loosing friends.
One possible factor here is the amount of radio traffic on 125.85; possibly either or both aircraft missed vital calls? This frequency serves two busy airfields (Caboolture and Caloundra) plus it's used for aircraft operating in the Bribie Island training area as well as those transiting out across Morten Bay. Plus you do get clowns with lousy radio discipline; not listening out before transmitting or making incredibly long-winded speeches when a few words would suffice.