Temora at Easter - RAA + RV homecoming
Joined: Aug 2009
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From: Australia
Blind encoders are usually connected to the same static system as the altimeter, so blind or encoding altimeter makes no difference, or am I missing something that you are trying to say?
(Like X-Boy's shiny glass panel turning into nothing but a make up mirror for his missus.)
Thread Starter
Joined: Feb 2006
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From: Mel-burn
Like X-Boy's shiny glass panel turning into nothing but a make up mirror for his missus
Last edited by VH-XXX; 13th April 2012 at 12:05.
I was having a serious think about the G3X set up for the 10. 2 x G3X, 430, GARMIN intercom, txpndr, sl30.
. Nah, it was just a thought! 
we'll donate your commission to the 'Oshkosh Blind Society'
Joined: Jul 2007
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From: Australia
Yep! What good are these glass panels when the lights go out. Whoever would design and certify an aircraft with only a glass panel and no backup instruments of any kind is beyond me. (Not Cessna obviously - as in, they have done it probably against better judgement, in order to reduce weight)
Joined: Apr 2008
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From: Australia
Dr
it is hard, but not impossible, to prove that you did not infringe controlled airspace, when the radar say otherwise.
That may have been the case pre-GPS but no longer. The GPS log will soon reveal whether or not you stuffed up and I doubt you would have any trouble getting it to stand up in court
Do we need to fly as close to CTA as we can, simply because our gps permits us 10 metre accuracy, or do we need to think about the poor bloke thats now on limited panel flying an archaic approach on the ndb, and give him that extra regulated room to safely manouver, being tracked by the old rotater?
IIRC, the regs/tolerances are written around the worst piece of equipment. Developed in prices that include blood.
Simple crap to make that space, or if you feel the need to cut it fine, get on the mumble box and tell the ATC what you are up to...at least then they don't have to give a call to 'the unidentified at X position' hoping you will answer.
GPS is cool as, but it has to bow down to the lessor accurate equipment.
Joined: Nov 2000
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From: Salt Lake City Utah
The tolerances aren’t just about the accuracy of electronic equipment. It’s also about the accuracy of the means of navigation that people operating under the VFR are qualified and required to use.
If people are going to continue to insist on using uncertified, unapproved GPS and map software as their sole means of navigation when purporting to operate against the VFR, I’d strongly suggest that failure to apply the VFR tolerances to controlled and restricted airspace boundaries will increase the probabilities of being caught and pinged.
The FOIs referred to by Baswell didn’t raise the issue for !!!!!s and giggles.
The avoidance rules are separate from the entry to controlled and restricted airspace rules. Both have been around for decades. It’s not hard.
The airspace boundaries cannot simply be extended to include the tolerances, because the tolerances differ by reference to AGL and day/night. The only other alternative would be to extend the boundaries to cover the greatest potential tolerance – NVFR for the steps below 10,001’ and the highest potential AGL of adjacent aircraft - capturing more airspace than is necessary for many other operations.
If people are going to continue to insist on using uncertified, unapproved GPS and map software as their sole means of navigation when purporting to operate against the VFR, I’d strongly suggest that failure to apply the VFR tolerances to controlled and restricted airspace boundaries will increase the probabilities of being caught and pinged.
The FOIs referred to by Baswell didn’t raise the issue for !!!!!s and giggles.
The avoidance rules are separate from the entry to controlled and restricted airspace rules. Both have been around for decades. It’s not hard.
The airspace boundaries cannot simply be extended to include the tolerances, because the tolerances differ by reference to AGL and day/night. The only other alternative would be to extend the boundaries to cover the greatest potential tolerance – NVFR for the steps below 10,001’ and the highest potential AGL of adjacent aircraft - capturing more airspace than is necessary for many other operations.
Joined: Jul 2001
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From: Australia
Leaddie: I’d be a touch more careful if I were you.
The failure to comply with the quoted requirement in AIP is an offence against CAR 99AA(5) – failure to comply with a direction about the use of Class G airspace.
Entry to controlled airspace without a clearance is a different offence (against CAR 100.)
And in which lane ‘north of Sydney’ can someone fly in Class G airspace at 2,500 AGL, Old Bean?
The failure to comply with the quoted requirement in AIP is an offence against CAR 99AA(5) – failure to comply with a direction about the use of Class G airspace.
Entry to controlled airspace without a clearance is a different offence (against CAR 100.)
And in which lane ‘north of Sydney’ can someone fly in Class G airspace at 2,500 AGL, Old Bean?
I don't agree that infringing the buffer in the AIP constitutes an offense under CAR 99AA(5). I am firmly of the view that the navigation tolerances quoted do NOT constitute a direction as to the final track of an aircraft flying in G, in an area close to a CTA boundary.
Are you aware of any cases where a pilot has been penalized for infringing the "navigational tolerance zone/buffer"? I am certainly aware of two cases (both involving Brisbane area) where the matter was raised and dismissed --- sorry, I can't quote references, it was too long ago.
As to the base of YSSY CTA in the area of the light aircraft lane, a small section immediately out of YSBK is 2000'. but the rest of the northbound track, after Pennant Hills, and all of the southbound track come under the 2500' step.
Folks,
Re. using your GPS records as evidence in a matter of infringing a CTL boundary, if it's not a TSOd unit, don't even bother to think about it, unless you have very deep pockets.
Even if it is TSOd, you will still need deep pockets.
In the two cases( not the same two as YBBN) in which I have arranged the expert witnesses for the pilot, in each case, the success was based on showing that the radar plot record, that was the evidence for the alleged offense, was not sufficiently accurate to establish the offense to a criminal standard of proof.
Not commonly known is that the radar derived plan position on an ATC screen, and the actual geographic position of targets can vary, this is not necessarily constant, and has been measured with suitably equipped aircraft. This is not a serious problem re. aircraft separation in controlled airspace, because the relative positions of targets of interest to ATC remain accurate.
Tootle pip !!
Last edited by LeadSled; 14th April 2012 at 04:39.
Joined: Nov 2000
Posts: 3,080
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From: Salt Lake City Utah
Leaddie
Ostensibly small words can often have substantially big differences in reality. The word “final” in the next sentence is an example:
I am firmly of that view, too.
So what? Infringing the buffer isn’t the offence.
The direction requires a tolerance to be applied to the “intended” flight path.
In order to comply with the direction, people must first know the direction exists and what it means.
It means, for example, that if someone intends to go from A to B, VFR by day, at an altitude that will result in the aircraft being at around 4,000’ AGL, the person must check that no point on the line A to B is closer than 2NM from the boundary of controlled or restricted airspace. If the line is at any point closer than 2NM to the boundary, the intended flight path must be changed from, for example, A to C or B to D.
When someone flies a perfect track 0.5NM parallel to the boundary of controlled airspace, the very strong inference is that the person:
- doesn’t know about or hasn’t complied with the direction to apply the required tolerance to the intended flight path; and
- isn’t navigating by visual reference to the ground or water.
In contrast, when someone plans to fly a leg A to B that is 2NM parallel to a boundary, takes off, gets to the leg A to B, gets a visual fix on A, takes up the planned heading to get to B, drifts to a point 1NM from the boundary, takes a visual fix and alters heading to restore the intended track (and therefore required tolerance), the very strong inference is that the person:
- does know about and has complied with the direction to apply the required tolerance to the intended flight path; and
- is navigating by visual reference to the ground or water.
If you want to implicitly assure people that they’ll always be OK provided they’re always just outside controlled or restricted airspace, that’s your risk. But I’d also be urging them to be prepared to:
- show an FOI a flight plan with the intended flight paths that comply with the required tolerances; and
- have a credible explanation as to why the actual tracks were so different.
Ostensibly small words can often have substantially big differences in reality. The word “final” in the next sentence is an example:
I am firmly of the view that the navigation tolerances quoted do NOT constitute a direction as to the final track of an aircraft flying in G, in an area close to a CTA boundary.
So what? Infringing the buffer isn’t the offence.
The direction requires a tolerance to be applied to the “intended” flight path.
In order to comply with the direction, people must first know the direction exists and what it means.
It means, for example, that if someone intends to go from A to B, VFR by day, at an altitude that will result in the aircraft being at around 4,000’ AGL, the person must check that no point on the line A to B is closer than 2NM from the boundary of controlled or restricted airspace. If the line is at any point closer than 2NM to the boundary, the intended flight path must be changed from, for example, A to C or B to D.
When someone flies a perfect track 0.5NM parallel to the boundary of controlled airspace, the very strong inference is that the person:
- doesn’t know about or hasn’t complied with the direction to apply the required tolerance to the intended flight path; and
- isn’t navigating by visual reference to the ground or water.
In contrast, when someone plans to fly a leg A to B that is 2NM parallel to a boundary, takes off, gets to the leg A to B, gets a visual fix on A, takes up the planned heading to get to B, drifts to a point 1NM from the boundary, takes a visual fix and alters heading to restore the intended track (and therefore required tolerance), the very strong inference is that the person:
- does know about and has complied with the direction to apply the required tolerance to the intended flight path; and
- is navigating by visual reference to the ground or water.
If you want to implicitly assure people that they’ll always be OK provided they’re always just outside controlled or restricted airspace, that’s your risk. But I’d also be urging them to be prepared to:
- show an FOI a flight plan with the intended flight paths that comply with the required tolerances; and
- have a credible explanation as to why the actual tracks were so different.
Joined: Dec 2003
Posts: 924
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From: Australia
It would seem to me to be illogical to have a buffer (to allow for navigation tolerances), and then make the buffer edge the boundary.
Surely then you would need a buffer for the buffer (to allow for navigation tolerances)!
John
Surely then you would need a buffer for the buffer (to allow for navigation tolerances)!
John
Last edited by rjtjrt; 14th April 2012 at 13:11.
Joined: Nov 2000
Posts: 3,080
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From: Salt Lake City Utah
If someone plans properly and applies the tolerances to the intended flight path, and navigates competently and in accordance with the rules, the person won’t chew into the tolerance that much or very often, and will have more time to avoid inadvertent entry.
On the other hand, lots of things can go wrong, quickly, for the bloke with his head glued to the tablet computer and map software, keeping the wing of the nifty aircraft symbol just next to the boundary of the controlled or restricted airspace.
I’m guessing that that’s why the FOIs to whom Baswell referred raised the issue in the first place.
On the other hand, lots of things can go wrong, quickly, for the bloke with his head glued to the tablet computer and map software, keeping the wing of the nifty aircraft symbol just next to the boundary of the controlled or restricted airspace.
I’m guessing that that’s why the FOIs to whom Baswell referred raised the issue in the first place.
Joined: Aug 2004
Posts: 3,557
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From: moon
I think some people are both right but there is need to understand what the word "Tolerance" actually means in engineering terms because it would shine a light on what the regs say.
A tolerance is actually defined as a range of values around a mean.
A tolerance of 10mm plus or minus one mm means that the intended value is in the range 9mm to 11 mm.
Ideally, the average value is 10 mm.
If CASA directs that a tolerance of Two miles be applied, without specifying any limits, then one could be forgiven for assuming that if your average track misses the control boundary by Two miles, then you are complying.
If you wander all over the sky like me, then you are still complying as long as the closest approach of your average course does not take you closer than Two miles. In other words, your closest approach might be one mile or less provided your course also deviates two miles in the other direction at times.
If CASA or ASA wants to specify that no VFR pilot is permitted to approach within Two miles of the boundary of a control zone then they should effing well say so. As in 2 miles minus zero miles plus whatever miles.
In that case you would plan for a course: Two miles plus another mile or Two (your own expected variance) away from the zone.
To put that another way, the regulations and the courts need to understand what the word "tolerance" actually means otherwise they should be written using the word "limit".
The issue of GPS usage raises another issue - risk shifting. this is planning to use tighter tolerances because you think your GPS is more accurate than Mk1 eyeball. The end result of that is what is called "GPS assisted collision" (eg Brazil).
For example I have had another aircraft flying exactly overhead on a reciprocal course in the Melbourne VFR corridor (sugarloaf to kilmore gap waypoints) - which is one reason I always offset my tracks and "fly all over the sky".
A tolerance is actually defined as a range of values around a mean.
A tolerance of 10mm plus or minus one mm means that the intended value is in the range 9mm to 11 mm.
Ideally, the average value is 10 mm.
If CASA directs that a tolerance of Two miles be applied, without specifying any limits, then one could be forgiven for assuming that if your average track misses the control boundary by Two miles, then you are complying.
If you wander all over the sky like me, then you are still complying as long as the closest approach of your average course does not take you closer than Two miles. In other words, your closest approach might be one mile or less provided your course also deviates two miles in the other direction at times.
If CASA or ASA wants to specify that no VFR pilot is permitted to approach within Two miles of the boundary of a control zone then they should effing well say so. As in 2 miles minus zero miles plus whatever miles.
In that case you would plan for a course: Two miles plus another mile or Two (your own expected variance) away from the zone.
To put that another way, the regulations and the courts need to understand what the word "tolerance" actually means otherwise they should be written using the word "limit".
The issue of GPS usage raises another issue - risk shifting. this is planning to use tighter tolerances because you think your GPS is more accurate than Mk1 eyeball. The end result of that is what is called "GPS assisted collision" (eg Brazil).
For example I have had another aircraft flying exactly overhead on a reciprocal course in the Melbourne VFR corridor (sugarloaf to kilmore gap waypoints) - which is one reason I always offset my tracks and "fly all over the sky".
Thread Starter
Joined: Feb 2006
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From: Mel-burn
I've been flying within .1 nautical miles of control zones for quite a number of years, coincidentally since GPS was invented and nobody has ever said anything to me. Doesn't mean that what I've been doing wasn't wrong, but shows there are some tolerances there, perhaps tolerances within the CTA that we as pilots don't know about.
Joined: Feb 2009
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From: dans un cercle dont le centre est eveywhere et circumfernce n'est nulle part
It would seem to me to be illogical to have a buffer (to allow for navigation tolerances), and then make the buffer edge the boundary.
Surely then you would need a buffer for the buffer (to allow for navigation tolerances)!
Surely then you would need a buffer for the buffer (to allow for navigation tolerances)!
Joined: Aug 2009
Posts: 632
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From: Australia
If people are going to continue to insist on using uncertified, unapproved GPS and map software as their sole means of navigation when purporting to operate against the VFR
Products like OzRunways are different; they show you where you are on the actual official VFR map, which you can then use to compare against what you are seeing out the window to make sure you are where you are supposed to be.
It is the most accurate, reliable and easy to use method of VFR navigation ever, bar none. The only way it could be made better is having the same VFR map display capability on a TSO c145/146 GPS unit.