Proposed ammendments to NVFR
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Proposed ammendments to NVFR
Civil Aviation Safety Authority - Project OS 14/01
Thoughts?
Issue
In response to a recent Australian Transport Safety Bureau (ATSB) investigation report into a visual flight rules (VFR) flight conducted in dark night conditions, the Civil Aviation Safety Authority (CASA) advised the ATSB of a number of safety actions being undertaken, including the clarification of the term 'visibility' in dark night conditions and the provision of further guidance on night VFR flight planning.
Dark night conditions
The ATSB report outlines that dark night visual meteorological conditions (VMC) are effectively the same as instrument meteorological conditions (IMC). "The only real difference is that, if there are lights on the ground, they can be seen in VMC. In remote areas where there are no lights or ambient illumination, there is no difference. Pilots cannot see the ground and have no external cues available to assist with their orientation".
Visibility is defined in regulation 2 of the Civil Aviation Regulations 1988 (CAR 1988) as "visibility means the ability, as determined by atmospheric conditions and expressed in units of distance, to see and identify prominent unlighted objects by day and prominent lighted objects by night."
Flight visibility is defined as "the average range of visibility forward from the cockpit of an aircraft in flight". Further, regulation 174 of CAR 1988 requires that flight visibility shall be determined by the pilot in command from the cockpit of the aircraft while in flight; and the pilot in command of an aircraft operating under the VFR is responsible for determining the visibility for the take-off and landing of the aircraft. In determining visibility for the purposes of these regulations, the pilot in command shall take into account the meteorological conditions, sun-glare and any other condition that may limit his or her effective vision through his or her windscreen; this would include dark night conditions.
In the context of dark night conditions being encountered and the lack of any other lighted objects as outlined by the ATSB above, it would be very difficult for the pilot to determine inflight visibility.
Helicopter night visual flight certification issues
There is a significant difference between a helicopter's certification for VMC and IMC operations, which centres on both the static and dynamic longitudinal stability of the helicopter. Unlike most aeroplanes, in VMC a helicopter can be certified with highly unstable static longitudinal stability characteristics provided it can comply with basic requirements for correct control sense of motion criteria.
However in IMC, where there is reduced external visual cues for orientation, the certification standards provide for further longitudinal stability requirements, both statically and dynamically. This is significant as outlined above, the reduced visual cue environment as experienced in dark night conditions effectively constitutes IMC and to operate a rotorcraft in such an environment would require the rotorcraft to be capable of meeting the additional IMC stability requirements.
Objective
The project will review the NVFR requirements in the current rule set and future CASR definitions to ensure it limits the visual environment to that in which a defined external horizon is available for aircraft attitude control. The project will examine the night VMC requirements for both rotorcraft and aeroplanes. However the outcome of the project may limit the change to the night VMC requirements to rotorcraft only in recognition of the difference in certification requirements between the categories. The project will also amend the guidance provided in CAAP 5.13-2 to emphasise the importance of maintaining a discernible external horizon at night particularly in light of the certification basis for NVFR rotorcraft.
Rules affected
CAR 2, 172, 174
CASR 91
In response to a recent Australian Transport Safety Bureau (ATSB) investigation report into a visual flight rules (VFR) flight conducted in dark night conditions, the Civil Aviation Safety Authority (CASA) advised the ATSB of a number of safety actions being undertaken, including the clarification of the term 'visibility' in dark night conditions and the provision of further guidance on night VFR flight planning.
Dark night conditions
The ATSB report outlines that dark night visual meteorological conditions (VMC) are effectively the same as instrument meteorological conditions (IMC). "The only real difference is that, if there are lights on the ground, they can be seen in VMC. In remote areas where there are no lights or ambient illumination, there is no difference. Pilots cannot see the ground and have no external cues available to assist with their orientation".
Visibility is defined in regulation 2 of the Civil Aviation Regulations 1988 (CAR 1988) as "visibility means the ability, as determined by atmospheric conditions and expressed in units of distance, to see and identify prominent unlighted objects by day and prominent lighted objects by night."
Flight visibility is defined as "the average range of visibility forward from the cockpit of an aircraft in flight". Further, regulation 174 of CAR 1988 requires that flight visibility shall be determined by the pilot in command from the cockpit of the aircraft while in flight; and the pilot in command of an aircraft operating under the VFR is responsible for determining the visibility for the take-off and landing of the aircraft. In determining visibility for the purposes of these regulations, the pilot in command shall take into account the meteorological conditions, sun-glare and any other condition that may limit his or her effective vision through his or her windscreen; this would include dark night conditions.
In the context of dark night conditions being encountered and the lack of any other lighted objects as outlined by the ATSB above, it would be very difficult for the pilot to determine inflight visibility.
Helicopter night visual flight certification issues
There is a significant difference between a helicopter's certification for VMC and IMC operations, which centres on both the static and dynamic longitudinal stability of the helicopter. Unlike most aeroplanes, in VMC a helicopter can be certified with highly unstable static longitudinal stability characteristics provided it can comply with basic requirements for correct control sense of motion criteria.
However in IMC, where there is reduced external visual cues for orientation, the certification standards provide for further longitudinal stability requirements, both statically and dynamically. This is significant as outlined above, the reduced visual cue environment as experienced in dark night conditions effectively constitutes IMC and to operate a rotorcraft in such an environment would require the rotorcraft to be capable of meeting the additional IMC stability requirements.
Objective
The project will review the NVFR requirements in the current rule set and future CASR definitions to ensure it limits the visual environment to that in which a defined external horizon is available for aircraft attitude control. The project will examine the night VMC requirements for both rotorcraft and aeroplanes. However the outcome of the project may limit the change to the night VMC requirements to rotorcraft only in recognition of the difference in certification requirements between the categories. The project will also amend the guidance provided in CAAP 5.13-2 to emphasise the importance of maintaining a discernible external horizon at night particularly in light of the certification basis for NVFR rotorcraft.
Rules affected
CAR 2, 172, 174
CASR 91
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most of my NVFR training was done in exactly the conditions described above, out west of Sydney, west of the ranges, most black hole approaches. and the longest nav was a new moon night, Bankstown, Bathurst, cowra, then south for about 30 miles, then diversion via Bindook to Camden.. (gets dark west of Bindook)
others navs included Goulburn on a moonless night..
so, is the issue with the rules? or with instructors and school not having the skills to teach NFVR in what is mostly IFR type conditions?
Other NFVR students i have spoken to in Sim sessions from other school only completed their training over the built up areas of Sydney and regions to the north and south...
others navs included Goulburn on a moonless night..
so, is the issue with the rules? or with instructors and school not having the skills to teach NFVR in what is mostly IFR type conditions?
Other NFVR students i have spoken to in Sim sessions from other school only completed their training over the built up areas of Sydney and regions to the north and south...
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Can we now dispense with the mandatory instrument training for the issue of the Class 4, (NVMC), instrument rating. A class 4 (day or night) was once to be competent on navaids and be endorsed on same. Come to think about it, why have any endorsement on navaids if it is VFR, just like DAY, only a bit darker. Probably darker shades of grey that make things colour non perspective . Anyway are there any navaids left?
In the US, if you can see it's VFR. What are they trying to do here?
In the US, if you can see it's VFR. What are they trying to do here?
Last edited by Frank Arouet; 6th Nov 2014 at 07:14. Reason: Where have all the FAR's gone, long time passing...
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There has always been a tacit assumption by pilots that VMC = "attitude control by visual reference."
For day flying, we know that that is not always true. For night flying, it's regularly not true. Likewise, IMC does not always mean "attitude control by instruments" (consider a circling manoeuvre in less-than-VMC conditions).
But we compensate for the increased difficulty of no-horizon flying with extra training and (hopefully) some airmanship masquerading as common sense.
If helicopters are required by design rules to be more stable in IMC than VMC, it makes sense to ensure that pilots are operating in the correct regime of flight - not VMC vs. IMC, but "attitude control by visual reference" vs. "attitude control by instrument reference".
For day flying, we know that that is not always true. For night flying, it's regularly not true. Likewise, IMC does not always mean "attitude control by instruments" (consider a circling manoeuvre in less-than-VMC conditions).
But we compensate for the increased difficulty of no-horizon flying with extra training and (hopefully) some airmanship masquerading as common sense.
If helicopters are required by design rules to be more stable in IMC than VMC, it makes sense to ensure that pilots are operating in the correct regime of flight - not VMC vs. IMC, but "attitude control by visual reference" vs. "attitude control by instrument reference".
Why do we need a change?
Yes, outback NVFR and Victorian NVFR are two very different beasts, and the accidents prove it.
I worry, however, that CASA and industry will come to a common sensible ground, and that will go the the lawyers and come back into law rewritten with such complexity and legalese that it will end up being a regressive step.
I worry, however, that CASA and industry will come to a common sensible ground, and that will go the the lawyers and come back into law rewritten with such complexity and legalese that it will end up being a regressive step.
Most of the accidents I've heard of recently in Victorian night conditions were nothing more than poor decision making by the PIC. (Let's land on a private strip with no lighting on moon-less night with a car pointed at the approach for "lighting")
You can't legislate for that..
You can't legislate for that..
Good point here that as per ENR 1.10 Para 1.2.4,
As the area forecast is a "worst case scenario", adherence to these rules, and not the illegal "we'll see what it's like when we get up there" misconception would go a long way towards reducing the chance of getting caught in less than ideal (or legal) conditions.
CHTR, AWK and PVT operations under the VFR at night must not be conducted unless the forecast indicates the flight can be conducted in VMC at not less than 1000FT above the highest obstacle located within 10NM either side of track.
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And max 4/8 cloud cover. VFR is the key and says it all really. Rather than increase regulation of the rating, it may be better to concentrate on meteorological skills retention in the BFR.
Cloud cover is not the issue here. Nor is Maverick incompetence. It is to do with operations on a dark, moonless night in the outback with no horizon. You can be VMC and have no external reference. From liftoff, you are in effect flying 100% on instruments, as you would be if you were in cloud.
Hence the intent of the regulatory review as I understand it is to draw a commonality with those conditions (i.e. no external reference) with flying skills required for an instrument rating.
Retention of meteorological skills in a VFR BFR does not an IF skilled pilot make.
The simple solution in my mind is to add in a paragraph into the regs that states, "For NVFR operations, a pilot must have discernible horizon or clear external visual cues to allow the attitude of the aircraft to be immediately determined".
Instead the lawyers will get to it we'll get a list of regs stating "it is an offence to blah blah blah" and take two pages to say the same thing.
Hence the intent of the regulatory review as I understand it is to draw a commonality with those conditions (i.e. no external reference) with flying skills required for an instrument rating.
Retention of meteorological skills in a VFR BFR does not an IF skilled pilot make.
The simple solution in my mind is to add in a paragraph into the regs that states, "For NVFR operations, a pilot must have discernible horizon or clear external visual cues to allow the attitude of the aircraft to be immediately determined".
Instead the lawyers will get to it we'll get a list of regs stating "it is an offence to blah blah blah" and take two pages to say the same thing.
Last edited by compressor stall; 7th Nov 2014 at 21:02.
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A pilot must have the skills to operate at night in VFR conditions which includes the skills for a Class 4 instrument rating/night. There are currency considerations existing as is.
If there is no discernible horizon and pitch black it could be successfully argued that it is not VFR. Similar to fog in daylight and irrespective of cloud.
In the US, VFR is VFR, day or night. You can either see or you can't. Our sky is no different sans regulatory embuggerence.
If there is no discernible horizon and pitch black it could be successfully argued that it is not VFR. Similar to fog in daylight and irrespective of cloud.
In the US, VFR is VFR, day or night. You can either see or you can't. Our sky is no different sans regulatory embuggerence.
includes the skills for a Class 4 instrument rating/night.
The minimum skill required is one
night landing at a dark aerodrome with no horizon. Hardy enough to let people loose on a dark, dark night. And no requirement for a takeoff with no horizon, and that kills a couple of people every few years.
If there is no discernible horizon and pitch black it could be successfully argued that it is not VFR.
Similar to fog in daylight and irrespective of cloud.
You need IFR skills to operate at night with no horizon. To fly in those conditions, I believe that one should have the minimum experience as for an IF rating (without the approaches). The PIFR perhaps - I'd have to look at the syllabus.
Last edited by compressor stall; 8th Nov 2014 at 01:24. Reason: Misread Frank about currency.
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Have it your way then. IFR is IFR and VFR is VFR. Currency is within the last 90 days from memory, and you can either see or you can't. But I was wrong before once.
BTW is a class 4 (DAY) now a NVFR rating? Or has this been dispensed with. If I want to fly over 8/8 cloud in VFR DAY, do I need a positive radio navigational fix at whatever intervals? Is a non TSO GPS a suitable aid if I'm not endorsed on it but am on the ADF and VOR and DME? Why is the night air in the US different to the night air in Australia? Why would some pilot fly at night when he can't see when he wouldn't fly in the day with 8/8ths fog and he can't see?
You don't have to answer. I'm with you. Bloody pesky VFR pilots day or night should all be grounded. I'll write CAsA a letter.
BTW is a class 4 (DAY) now a NVFR rating? Or has this been dispensed with. If I want to fly over 8/8 cloud in VFR DAY, do I need a positive radio navigational fix at whatever intervals? Is a non TSO GPS a suitable aid if I'm not endorsed on it but am on the ADF and VOR and DME? Why is the night air in the US different to the night air in Australia? Why would some pilot fly at night when he can't see when he wouldn't fly in the day with 8/8ths fog and he can't see?
You don't have to answer. I'm with you. Bloody pesky VFR pilots day or night should all be grounded. I'll write CAsA a letter.
Last edited by Frank Arouet; 8th Nov 2014 at 00:46. Reason: God.. I'm bored weekends.
You don't have to answer. I'm with you. Bloody pesky VFR pilots day or night should all be grounded. I'll write CAsA a letter.
My position remains that with the current syllabus and required skill the regs should limit NVFR to having a horizon as per my earlier post.
**edit - I just reread your post above - and misread and then misquoted your bit about currency. My reference to the one approach was the minimum amount of training required.
The big thing with NVFR or class 4 instrument rating is currency.
The original intent of the rating was for people to use it to get home just after last light-according to the man from DOTAC(80's name for CASA)when he did my flight test.
ARFOR's at night time are not really accurate for cloud information, what can be obtained from an AWIS or visual observation does not match what is on the other side of the ranges etc.
NVFR flight over Melbourne is fantastic, but a NVFR departure of runway 36 at Mount Gambier on a moonless night in your single AH equipped Cherokee and low on night recency is probably in the risky stakes.
The original intent of the rating was for people to use it to get home just after last light-according to the man from DOTAC(80's name for CASA)when he did my flight test.
ARFOR's at night time are not really accurate for cloud information, what can be obtained from an AWIS or visual observation does not match what is on the other side of the ranges etc.
NVFR flight over Melbourne is fantastic, but a NVFR departure of runway 36 at Mount Gambier on a moonless night in your single AH equipped Cherokee and low on night recency is probably in the risky stakes.
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Isn't this whole thread about reduced longitudinal stability in some helicopters, and the requirement for a visible horizon in order to match the limitations of the pilot's central nervous system feedback loop?
Call me a CASA-phile if you must, but I'm quite happy to have pilots of reduced-stability helicopters required to have a visible horizon.
Now if CASA are talking about stopping me from departing
well that's a different story.
Call me a CASA-phile if you must, but I'm quite happy to have pilots of reduced-stability helicopters required to have a visible horizon.
Now if CASA are talking about stopping me from departing
runway 36 at Mount Gambier on a moonless night in your single AH equipped Cherokee
The original intent of the rating was for people to use it to get home just after last light-according to the man from DOTAC(80's name for CASA)when he did my flight test.
Isn't this whole thread about reduced longitudinal stability in some helicopters, and the requirement for a visible horizon in order to match the limitations of the pilot's central nervous system feedback loop?
project will examine the night VMC requirements for both rotorcraft and aeroplanes
Good point about the dark landing vs no dark take off, Stallie. You don't have to go to Gambier to find black take offs. Any one else recall the Kingair crash at Wondai, QLD? That was a serviceable plane on a black hole take off.