CASA closes Hervey Bay Airport
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CASA closes Hervey Bay Airport
Apparently CASA closed Hervey Bay airport on Friday due to safety concerns with the recently upgraded runway. The airport was reopened late Friday; however CASA are still concerned that the recent extension to the runway has caused a major safety issue. The issue is, that the runway now contains a rather large hump and this hump makes it almost impossible to see any aircraft that are the threshold of runway 11 from the holding point or from the runway 29 threshold. This hump may preclude jet operations into Hervey Bay, which would make the 11 million dollar upgrade a total waste.
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that the runway now contains a rather large hump and this hump makes it almost impossible to see any aircraft that are the threshold of runway 11 from the holding point or from the runway 29 threshold
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Also sounds like Bathurst.. WHat makes BTH all the more interesting, is that the CTAF is NOT 126.7 ! therefore, some people are just NOT on the right freq..... Blind AND deaf! makes for some interesting times.
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Had a look at Proserpine lately. The hump doesn't seem to be a problem there.
If everyone is communicating on VHF does it really matter if you can see the threshold beyond the hump.
Maybe CASA haven't heard of MBZ procedures.
If everyone is communicating on VHF does it really matter if you can see the threshold beyond the hump.
Maybe CASA haven't heard of MBZ procedures.
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VHF
Guys,
One of the main hazards identified at Broome Int. Airport was the loss of sight at the 10 threshold from the main entering taxiway Charlie. This is mitigated by the CAGRS that has visual and comms over the entire movement areas.
VHF is very unforgiving when extending past line of sight, the simple rule is if you lose line of sight you will lose VHF comms.
CASA would not sit easy with this situation if major RPT traffic is involved and I would support their stance.
One of the main hazards identified at Broome Int. Airport was the loss of sight at the 10 threshold from the main entering taxiway Charlie. This is mitigated by the CAGRS that has visual and comms over the entire movement areas.
VHF is very unforgiving when extending past line of sight, the simple rule is if you lose line of sight you will lose VHF comms.
CASA would not sit easy with this situation if major RPT traffic is involved and I would support their stance.
Maybe CASA haven't heard of MBZ procedures.
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Kalgoorlie also suffers from shielding between the apron and the eastern end of 11/29 (see ERSA). If there are line of sight problems (Can't remember - haven't been recently), shouldn't Kalgoorlie be closed too? The owners of HBY might like to raise this point with CASA!
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Within such a short range such as the confines of the airport perimeter, VHF will not be greatly effected by a "hump" in the runway. There are hundreds of airports around the world where you can't see all the thresholds from one another. I actually think people are more vigilant if there is an obstruction in visibility. Airplanes pull out in front of other airplanes at flat airports on a clear day all the time hump or no hump.
Last edited by 150Aerobat; 3rd May 2005 at 12:20.
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150Aerobat
I think your post is potentially misleading
Firstly, VHF ground communication can be affected by a hump in the runway. The Broome Design Aeronautical Study makes the point that the …there is a hump in the runway such that aircraft/vehicles at one end cannot see other aircraft/vehicles at the other end, nor make direct VHF radio contact. As I understand it, various methods have been tried at Broome to overcome the line-of-sight limitation of VHF, such as VHF radio repeater systems. Despite trying hard to make them work, these have proved unsuccessful.
At Broome, there is risk mitigation against the hump which includes (and again from the Broome report) . . the ground component [of CAGRS] is a significant role and half the radio calls made by the Certified Air/Ground Radio Service are to aircraft and vehicles crossing or entering the runway. The CAGRS vision of the entire runway is also a defence against the site-specific hazards at Broome such as the restrictive hump in the middle of the runway that prevents pilots of aircraft at opposite ends of the runway being able to see each other.
The CAGRO level of risk mitigation is appropriate at Broome for the specific mix and density of traffic. Hervey Bay will have a different mix and density, and different or even nil risk mitigation may be appropriate.
Let's apply the "commonsense test" to the hump (this test is not usually referenced in modern textbooks). Is there a real problem with a hump? Commonsense says that a hump will lead to occasions when aircraft take off from both ends simultaneously, and this could lead to an accident. VHF and MBZ don't work because the aircraft can't see each other and can't hear each other. The number of times it happens depends on the amount of traffic and the wind. The problem is a real one. I have personally seen this occur due to a bloody-minded commercial pilot on one occasion, and also to occur as a result of genuine confusion during the period when the wind direction was changing as the sea breeze came in (both the 737 and the other pilot thought they were at the right end for takeoff). This is a particular hazard at a coastal airport where the wind direction can change between an on-shore then an off-shore breeze. As a point of clarity, humps are not usually a problem where one aircraft is landing and one is taking off, because there is line of sight visual and radio communication.
The level or need for risk mitigation against the hump depends on frequency and consequence. Frequency depends on the amount of traffic and the particular local circumstances (wind, runway/taxiway layout, size of hump, etc). The consequence depends on the size of aircraft (number of passengers) and type of operation (voluntary sport aviation vs involuntary RPT). The risk mitigation required is an amalgam of the two. Obviously, the introduction of 100-200 seat RPT aircraft changes the consequence significantly.
It is still some 10-12 months before publication of a mathematical algorithm to do the engineering evaluation of this type of risk problem, which is a pity because Hervey Bay issue is a perfect example of where this could be applied. And as Vref+5 mentions, there are other airports such as Kalgoorlie, which can benefit down the track from an engineering analysis of their site-specific risks. In the meantime, I suspect that an aeronautical study might be on the cards.
I think your post is potentially misleading
Within such a short range such as the confines of the airport perimeter, VHF will not be greatly effected by a "hump" in the runway. There are hundreds of airports around the world where you can't see all the thresholds from one another. I actually think people are more vigilant if there is an obstruction in visibility. Airplanes pull out in front of other airplanes at flat airports on a clear day all the time hump or no hump.
At Broome, there is risk mitigation against the hump which includes (and again from the Broome report) . . the ground component [of CAGRS] is a significant role and half the radio calls made by the Certified Air/Ground Radio Service are to aircraft and vehicles crossing or entering the runway. The CAGRS vision of the entire runway is also a defence against the site-specific hazards at Broome such as the restrictive hump in the middle of the runway that prevents pilots of aircraft at opposite ends of the runway being able to see each other.
The CAGRO level of risk mitigation is appropriate at Broome for the specific mix and density of traffic. Hervey Bay will have a different mix and density, and different or even nil risk mitigation may be appropriate.
Let's apply the "commonsense test" to the hump (this test is not usually referenced in modern textbooks). Is there a real problem with a hump? Commonsense says that a hump will lead to occasions when aircraft take off from both ends simultaneously, and this could lead to an accident. VHF and MBZ don't work because the aircraft can't see each other and can't hear each other. The number of times it happens depends on the amount of traffic and the wind. The problem is a real one. I have personally seen this occur due to a bloody-minded commercial pilot on one occasion, and also to occur as a result of genuine confusion during the period when the wind direction was changing as the sea breeze came in (both the 737 and the other pilot thought they were at the right end for takeoff). This is a particular hazard at a coastal airport where the wind direction can change between an on-shore then an off-shore breeze. As a point of clarity, humps are not usually a problem where one aircraft is landing and one is taking off, because there is line of sight visual and radio communication.
The level or need for risk mitigation against the hump depends on frequency and consequence. Frequency depends on the amount of traffic and the particular local circumstances (wind, runway/taxiway layout, size of hump, etc). The consequence depends on the size of aircraft (number of passengers) and type of operation (voluntary sport aviation vs involuntary RPT). The risk mitigation required is an amalgam of the two. Obviously, the introduction of 100-200 seat RPT aircraft changes the consequence significantly.
It is still some 10-12 months before publication of a mathematical algorithm to do the engineering evaluation of this type of risk problem, which is a pity because Hervey Bay issue is a perfect example of where this could be applied. And as Vref+5 mentions, there are other airports such as Kalgoorlie, which can benefit down the track from an engineering analysis of their site-specific risks. In the meantime, I suspect that an aeronautical study might be on the cards.
