Re: [Aus-soaring] 50' obstacle clearance rule
Rules are for the blind obedience of fools and the guidance of wise men... From: aus-soaring-boun...@lists.internode.on.net [mailto:aus-soaring-boun...@lists.internode.on.net] On Behalf Of Future Aviation Sent: Sunday, 21 October 2012 7:31 AM To: 'Discussion of issues relating to Soaring in Australia.' Subject: Re: [Aus-soaring] 50' obstacle clearance rule Hi Terry, hello all A lot has now been said about the 50 ft rule but I'm surprised that no one has pointed out that this can be outright dangerous. Consider the case where a heavy open class glider (touching down at 55 kts) is forced to outland in a rather small paddock. Compared to an average 15 m glider (touching down at 40 kts) more than 2.5 times the energy needs to dissipated. Pilots adhering to the 50 ft rule will get on the ground far too late and most likely find themselves in real trouble with the back fence. In fact, they stand a very good chance of getting a honorary mention next time an accident summary is published. The situation gets even worse when the pilot adheres to the "minimum of a wingspan clearance" rule . It increases the clearance to 80 or even 90 ft which almost certainly guarantees an accident. As others have pointed out COMMON SENSE (rather than a blind following of the rules) is what's needed. No doubt, the 50 ft rule makers had good intentions but . Kind regards to all Bernard From: aus-soaring-boun...@lists.internode.on.net [mailto:aus-soaring-boun...@lists.internode.on.net] On Behalf Of Terry Neumann Sent: Saturday, 20 October 2012 9:50 AM To: Discussion of issues relating to Soaring in Australia. Subject: Re: [Aus-soaring] 50' obstacle clearance rule Surely the important thing here is to clear any ground fixed obstacle on approach by a safe margin. That will vary according to the circumstances and the pilot's experience and competence. This discussion has demonstrated how quickly things can be confused by getting hung up on units of measurement. I think we should maintain the simple concept of a minimum of a wingspan clearance as a guide when training (and for early post solo), and allow competent pilots with experience to vary this in later flying according to the situation they find themselves in. Finally in respect of units of measurement it's worth repeating a story told by Mike Valentine.In an earlier lifetime he found himself sitting in pretty basic military jets training with Indian pilots. (Don't ask - it's complicated).Impressed with one particular pilot's ability to repeatedly do good landings, Mike commented on the fact. The reply was "Oh well, my instructor always advised me to start the round out when at the height of two elephants ." Perhaps we can mandate clearing approach obstacles by the height of ten kangaroos . tn ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
At 06:31 AM 21/10/2012, you wrote: Hi Terry, hello all A lot has now been said about the 50 ft rule but I'm surprised that no one has pointed out that this can be outright dangerous. Alan Wilson pointed that out. Mike Borgelt Instruments - design & manufacture of quality soaring instrumentation since 1978 www.borgeltinstruments.com tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784: int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
Hi Terry, hello all A lot has now been said about the 50 ft rule but I'm surprised that no one has pointed out that this can be outright dangerous. Consider the case where a heavy open class glider (touching down at 55 kts) is forced to outland in a rather small paddock. Compared to an average 15 m glider (touching down at 40 kts) more than 2.5 times the energy needs to dissipated. Pilots adhering to the 50 ft rule will get on the ground far too late and most likely find themselves in real trouble with the back fence. In fact, they stand a very good chance of getting a honorary mention next time an accident summary is published. The situation gets even worse when the pilot adheres to the "minimum of a wingspan clearance" rule . It increases the clearance to 80 or even 90 ft which almost certainly guarantees an accident. As others have pointed out COMMON SENSE (rather than a blind following of the rules) is what's needed. No doubt, the 50 ft rule makers had good intentions but . Kind regards to all Bernard From: aus-soaring-boun...@lists.internode.on.net [mailto:aus-soaring-boun...@lists.internode.on.net] On Behalf Of Terry Neumann Sent: Saturday, 20 October 2012 9:50 AM To: Discussion of issues relating to Soaring in Australia. Subject: Re: [Aus-soaring] 50' obstacle clearance rule Surely the important thing here is to clear any ground fixed obstacle on approach by a safe margin. That will vary according to the circumstances and the pilot's experience and competence. This discussion has demonstrated how quickly things can be confused by getting hung up on units of measurement. I think we should maintain the simple concept of a minimum of a wingspan clearance as a guide when training (and for early post solo), and allow competent pilots with experience to vary this in later flying according to the situation they find themselves in. Finally in respect of units of measurement it's worth repeating a story told by Mike Valentine.In an earlier lifetime he found himself sitting in pretty basic military jets training with Indian pilots. (Don't ask - it's complicated).Impressed with one particular pilot's ability to repeatedly do good landings, Mike commented on the fact. The reply was "Oh well, my instructor always advised me to start the round out when at the height of two elephants ." Perhaps we can mandate clearing approach obstacles by the height of ten kangaroos . tn ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
Surely the important thing here is to clear any ground fixed obstacle on approach by a _safe margin_. That will vary according to the circumstances and the pilot's experience and competence. This discussion has demonstrated how quickly things can be confused by getting hung up on units of measurement. I think we should maintain the simple concept of a minimum of a wingspan clearance as a guide when training (and for early post solo), and allow competent pilots with experience to vary this in later flying according to the situation they find themselves in. Finally in respect of units of measurement it's worth repeating a story told by Mike Valentine.In an earlier lifetime he found himself sitting in pretty basic military jets training with Indian pilots. (Don't ask - it's complicated).Impressed with one particular pilot's ability to repeatedly do good landings, Mike commented on the fact. The reply was "Oh well, my instructor always advised me to start the round out when at the height of two elephants ." Perhaps we can mandate clearing approach obstacles by the height of ten kangaroos . tn ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
It was done a decade or so in the USA. You could log on to DUATS - Direct User Access Terminal Service - and choose "plain language" weather briefing. Unfortunately, plenty of things were "rost in transration", with multiple choices given for their own translations. Really shows how silly the abbreviations are. Currently I can't log on to DUATS for glider flight, as the only aircraft types their new website understands have an engine or so. But I consider that type of weather briefing obsolete with map based gliding weather. NOTAMS need to be checked on a different site or sites (ie graphic TFR map for temporary flight restrictions) Jim http://www.duats.com/index.php From: Al Borowski I wish I had that much power. Given the choice, I'd keep Feet etc, but introduce a "plain English" option to run in parallel with TAFs / NOTAMs etc. ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
On 19/10/2012, tom claffey wrote: > So put your proposal to ICAO. > Tom I wish I had that much power. Given the choice, I'd keep Feet etc, but introduce a "plain English" option to run in parallel with TAFs / NOTAMs etc. Something in a simple table format that takes a student pilot 10 minutes to learn, and is trivial for casual pilots to read. The existing system would be kept as per international standards. While I'm dreaming, I'd also simplfy the recreational licensing situation in Australia. If you want to fly Jabirus, Gliders and Paragliders, there are 3 different bodies to join, each with their own fee and ops manual. It's entirely possible for a pilot to legally fly in controlled airspace in a motorglider, but not in a Jabiru. It's also possible for a pilot to legally fly a Tecnam with numbers on the side, but not if it has letters (even though the one with letters is supposedly better maintained - what's the sense in that?). Come to think of it, I'd be happy with the FAA's rules! cheers, Al ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
Hi Tom; There are two problems flowing from the units. One is that the average 20 yo does not know what a foot is (and does not care). The other is the image it presents. Of the two the second is the more important for the future of gliding. As I said try asking around. P.S. I inserted the TIFF reference as an example of the impenetrable language used around the average gliding club. It is a marketing disaster. On Fri, 19 Oct 2012, tom claffey wrote: "Hundreds of thousands" of young people staying away from gliding because of feet and knots? Just how many TIFs does your club do? ;) There are many reasons for low numbers of new pilots but units are not one of them! [old mumbling instructors may be!] Tom From: Peter F Bradshaw To: Discussion of issues relating to Soaring in Australia. Sent: Friday, 19 October 2012 8:14 PM Subject: Re: [Aus-soaring] 50' obstacle clearance rule Hi Tom; I'm not sure what you mean by "second officers" but I'm guessing that you are not talking about glider pilots. In any case the people you need to talk to are the young people who are not taking up gliding in their hundreds of thousands. As you have said young people should deal with it and they have - by staying away. They simply have no interest in a bunch of old guys mumbling incoherently about TIFFs in feet and knots etc. I have actually submitted the suggestion about units to CASA. Are they interested - hell no. But even if they were, by the time the ICAO got around to it gliding will be well and truely dead in this country. On Fri, 19 Oct 2012, tom claffey wrote: > Peter, > I am only 48and can deal with either measurement. > I spend my spare time instructing 14-18 year-olds who also deal with it > quite well. > At work I deal with it with 25-30 year old second officers who have no > issues with it. > As I replied to Al, if you have better ideas then put them to ICAO!! > We could change anything we like but the rest of the world wont change > because of it. > Like it or not we are part of the wider Aviation community. > Tom > >___ _ > From: Peter F Bradshaw > To: Discussion of issues relating to Soaritymuning in Australia. > > Sent: Friday, 19 October 2012 6:30 PM > Subject: Re: [Aus-soaring] 50' obstacle clearance rule > > Hi Tom; > > I am 62 years old so I have no problem dealing with it. But I am not > that old that I do not remember that I was once young. > > Recreational flying - and gliding - have become almost exclusively the > pass times of old men. So when glider pilots start talking about > teaching young kids to drive a bus (the rough equivalent to flying a > plane to a young person) and they want to do it using "feet" and "knots" > then I can see no relief. > > Looking at the date I see that the year is 2012, not 1962. If flying is > not to be abut the future it will become about the past (as it already > has) - deal with it! > > On Thu, 18 Oct 2012, tom claffey wrote: > > > Aviation uses feet for height, metres for horizontal distance and knots > for > > speed - deal with it! > > The teenagers I teach with the AAFC have no problems with it. > > Tom > > >>__________________ _ > _ > > From: Peter F Bradshaw > > To: Discussion of issues relating to Soaring in Australia. > > > > Sent: Friday, 19 October 2012 2:24 AM > > Subject: Re: [Aus-soaring] 50' obstacle clearance rule > > > > Hi; > > > > Irrespective of whether it is 50' or not I find it hard to believe > > that the figure is given in a system which people under 40 have no > > heuristic knowledge of. > > > > On Mon, 15 Oct 2012, Mark Newton wrote: > > > > > > > > Hi folks. > > > > > > My google-fu is failing me, but at least one of you can probably > > > help. > > > > > > I've long accepted that the rule for obstacle clearance is 50'. > > > > > > However, the GFA instructor handbook describes it as a wingspan, > > > and the B certificate oral exam calls 50' a "recommended" minimum, > > > so I'm trying to go back to sources to find the origin of the rule. > > > > > > And I can't seem to find it written down anywhere. > > > > > > I'm beginning to suspect that my long-term acceptance of the 50' > > > rule is wrong, and that the real limit is, shall we say, more > > > "operationally fluid" than that. > > > > > > Wond
Re: [Aus-soaring] 50' obstacle clearance rule
At 07:55 PM 19/10/2012, you wrote: "Hundreds of thousands" of young people staying away from gliding because of feet and knots? Just how many TIFs does your club do? ;) There are many reasons for low numbers of new pilots but units are not one of them! [old mumbling instructors may be!] Tom Well said,Tom. Not that many 18 year olds can probably do simple mental arithmetic for unit conversions, if they know what that is. Mike Borgelt Instruments - design & manufacture of quality soaring instrumentation since 1978 www.borgeltinstruments.com tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784: int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
"Hundreds of thousands" of young people staying away from gliding because of feet and knots? Just how many TIFs does your club do? ;) There are many reasons for low numbers of new pilots but units are not one of them! [old mumbling instructors may be!] Tom From: Peter F Bradshaw To: Discussion of issues relating to Soaring in Australia. Sent: Friday, 19 October 2012 8:14 PM Subject: Re: [Aus-soaring] 50' obstacle clearance rule Hi Tom; I'm not sure what you mean by "second officers" but I'm guessing that you are not talking about glider pilots. In any case the people you need to talk to are the young people who are not taking up gliding in their hundreds of thousands. As you have said young people should deal with it and they have - by staying away. They simply have no interest in a bunch of old guys mumbling incoherently about TIFFs in feet and knots etc. I have actually submitted the suggestion about units to CASA. Are they interested - hell no. But even if they were, by the time the ICAO got around to it gliding will be well and truely dead in this country. On Fri, 19 Oct 2012, tom claffey wrote: > Peter, > I am only 48and can deal with either measurement. > I spend my spare time instructing 14-18 year-olds who also deal with it > quite well. > At work I deal with it with 25-30 year old second officers who have no > issues with it. > As I replied to Al, if you have better ideas then put them to ICAO!! > We could change anything we like but the rest of the world wont change > because of it. > Like it or not we are part of the wider Aviation community. > Tom > > > From: Peter F Bradshaw > To: Discussion of issues relating to Soaritymuning in Australia. > > Sent: Friday, 19 October 2012 6:30 PM > Subject: Re: [Aus-soaring] 50' obstacle clearance rule > > Hi Tom; > > I am 62 years old so I have no problem dealing with it. But I am not > that old that I do not remember that I was once young. > > Recreational flying - and gliding - have become almost exclusively the > pass times of old men. So when glider pilots start talking about > teaching young kids to drive a bus (the rough equivalent to flying a > plane to a young person) and they want to do it using "feet" and "knots" > then I can see no relief. > > Looking at the date I see that the year is 2012, not 1962. If flying is > not to be abut the future it will become about the past (as it already > has) - deal with it! > > On Thu, 18 Oct 2012, tom claffey wrote: > > > Aviation uses feet for height, metres for horizontal distance and knots > for > > speed - deal with it! > > The teenagers I teach with the AAFC have no problems with it. > > Tom > > > >___________________ > _ > > From: Peter F Bradshaw > > To: Discussion of issues relating to Soaring in Australia. > > > > Sent: Friday, 19 October 2012 2:24 AM > > Subject: Re: [Aus-soaring] 50' obstacle clearance rule > > > > Hi; > > > > Irrespective of whether it is 50' or not I find it hard to believe > > that the figure is given in a system which people under 40 have no > > heuristic knowledge of. > > > > On Mon, 15 Oct 2012, Mark Newton wrote: > > > > > > > > Hi folks. > > > > > > My google-fu is failing me, but at least one of you can probably > > > help. > > > > > > I've long accepted that the rule for obstacle clearance is 50'. > > > > > > However, the GFA instructor handbook describes it as a wingspan, > > > and the B certificate oral exam calls 50' a "recommended" minimum, > > > so I'm trying to go back to sources to find the origin of the rule. > > > > > > And I can't seem to find it written down anywhere. > > > > > > I'm beginning to suspect that my long-term acceptance of the 50' > > > rule is wrong, and that the real limit is, shall we say, more > > > "operationally fluid" than that. > > > > > > Wondering if the strict mention of 50' that I've seen at clubs all > > > over Australia is actually more of a tradition, perhaps derived from > > > a misunderstanding of certified light aircraft performance charts > > > which give minimum takeoff distances including clearance of a 50' > > > obstacle. > > > > > > Does anyone have a cite to the regulations? > > > > > > (while you're at it, providing
Re: [Aus-soaring] 50' obstacle clearance rule
Hi Tom; I'm not sure what you mean by "second officers" but I'm guessing that you are not talking about glider pilots. In any case the people you need to talk to are the young people who are not taking up gliding in their hundreds of thousands. As you have said young people should deal with it and they have - by staying away. They simply have no interest in a bunch of old guys mumbling incoherently about TIFFs in feet and knots etc. I have actually submitted the suggestion about units to CASA. Are they interested - hell no. But even if they were, by the time the ICAO got around to it gliding will be well and truely dead in this country. On Fri, 19 Oct 2012, tom claffey wrote: Peter, I am only 48and can deal with either measurement. I spend my spare time instructing 14-18 year-olds who also deal with it quite well. At work I deal with it with 25-30 year old second officers who have no issues with it. As I replied to Al, if you have better ideas then put them to ICAO!! We could change anything we like but the rest of the world wont change because of it. Like it or not we are part of the wider Aviation community. Tom From: Peter F Bradshaw To: Discussion of issues relating to Soaritymuning in Australia. Sent: Friday, 19 October 2012 6:30 PM Subject: Re: [Aus-soaring] 50' obstacle clearance rule Hi Tom; I am 62 years old so I have no problem dealing with it. But I am not that old that I do not remember that I was once young. Recreational flying - and gliding - have become almost exclusively the pass times of old men. So when glider pilots start talking about teaching young kids to drive a bus (the rough equivalent to flying a plane to a young person) and they want to do it using "feet" and "knots" then I can see no relief. Looking at the date I see that the year is 2012, not 1962. If flying is not to be abut the future it will become about the past (as it already has) - deal with it! On Thu, 18 Oct 2012, tom claffey wrote: > Aviation uses feet for height, metres for horizontal distance and knots for > speed - deal with it! > The teenagers I teach with the AAFC have no problems with it. > Tom > >___ _ > From: Peter F Bradshaw > To: Discussion of issues relating to Soaring in Australia. > > Sent: Friday, 19 October 2012 2:24 AM > Subject: Re: [Aus-soaring] 50' obstacle clearance rule > > Hi; > > Irrespective of whether it is 50' or not I find it hard to believe > that the figure is given in a system which people under 40 have no > heuristic knowledge of. > > On Mon, 15 Oct 2012, Mark Newton wrote: > > > > > Hi folks. > > > > My google-fu is failing me, but at least one of you can probably > > help. > > > > I've long accepted that the rule for obstacle clearance is 50'. > > > > However, the GFA instructor handbook describes it as a wingspan, > > and the B certificate oral exam calls 50' a "recommended" minimum, > > so I'm trying to go back to sources to find the origin of the rule. > > > > And I can't seem to find it written down anywhere. > > > > I'm beginning to suspect that my long-term acceptance of the 50' > > rule is wrong, and that the real limit is, shall we say, more > > "operationally fluid" than that. > > > > Wondering if the strict mention of 50' that I've seen at clubs all > > over Australia is actually more of a tradition, perhaps derived from > > a misunderstanding of certified light aircraft performance charts > > which give minimum takeoff distances including clearance of a 50' > > obstacle. > > > > Does anyone have a cite to the regulations? > > > > (while you're at it, providing a cite to a current GFA or non-exempted > > CASA regulation which states what GFA annual check entails, whether > > it's required to be signed out in a logbook, or whether an instructor > > is even required to be present, would help to settle a long-standing > > argument :) > > > > - mark > > Cheers > Cheers Cheers -- Peter F Bradshaw: http://www.exadios.com (public keys avaliable there). Personal site: http://personal.exadios.com "I love truth, and the way the government still uses it occasionally to keep us guessing." - Sam Kekovich.___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
Peter, I am only 48and can deal with either measurement. I spend my spare time instructing 14-18 year-olds who also deal with it quite well. At work I deal with it with 25-30 year old second officers who have no issues with it. As I replied to Al, if you have better ideas then put them to ICAO!! We could change anything we like but the rest of the world wont change because of it. Like it or not we are part of the wider Aviation community. Tom From: Peter F Bradshaw To: Discussion of issues relating to Soaritymuning in Australia. Sent: Friday, 19 October 2012 6:30 PM Subject: Re: [Aus-soaring] 50' obstacle clearance rule Hi Tom; I am 62 years old so I have no problem dealing with it. But I am not that old that I do not remember that I was once young. Recreational flying - and gliding - have become almost exclusively the pass times of old men. So when glider pilots start talking about teaching young kids to drive a bus (the rough equivalent to flying a plane to a young person) and they want to do it using "feet" and "knots" then I can see no relief. Looking at the date I see that the year is 2012, not 1962. If flying is not to be abut the future it will become about the past (as it already has) - deal with it! On Thu, 18 Oct 2012, tom claffey wrote: > Aviation uses feet for height, metres for horizontal distance and knots for > speed - deal with it! > The teenagers I teach with the AAFC have no problems with it. > Tom > > > From: Peter F Bradshaw > To: Discussion of issues relating to Soaring in Australia. > > Sent: Friday, 19 October 2012 2:24 AM > Subject: Re: [Aus-soaring] 50' obstacle clearance rule > > Hi; > > Irrespective of whether it is 50' or not I find it hard to believe > that the figure is given in a system which people under 40 have no > heuristic knowledge of. > > On Mon, 15 Oct 2012, Mark Newton wrote: > > > > > Hi folks. > > > > My google-fu is failing me, but at least one of you can probably > > help. > > > > I've long accepted that the rule for obstacle clearance is 50'. > > > > However, the GFA instructor handbook describes it as a wingspan, > > and the B certificate oral exam calls 50' a "recommended" minimum, > > so I'm trying to go back to sources to find the origin of the rule. > > > > And I can't seem to find it written down anywhere. > > > > I'm beginning to suspect that my long-term acceptance of the 50' > > rule is wrong, and that the real limit is, shall we say, more > > "operationally fluid" than that. > > > > Wondering if the strict mention of 50' that I've seen at clubs all > > over Australia is actually more of a tradition, perhaps derived from > > a misunderstanding of certified light aircraft performance charts > > which give minimum takeoff distances including clearance of a 50' > > obstacle. > > > > Does anyone have a cite to the regulations? > > > > (while you're at it, providing a cite to a current GFA or non-exempted > > CASA regulation which states what GFA annual check entails, whether > > it's required to be signed out in a logbook, or whether an instructor > > is even required to be present, would help to settle a long-standing > > argument :) > > > > - mark > > Cheers > Cheers -- Peter F Bradshaw: http://www.exadios.com (public keys avaliable there). Personal site: http://personal.exadios.com "I love truth, and the way the government still uses it occasionally to keep us guessing." - Sam Kekovich. ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
Hi Tom; I am 62 years old so I have no problem dealing with it. But I am not that old that I do not remember that I was once young. Recreational flying - and gliding - have become almost exclusively the pass times of old men. So when glider pilots start talking about teaching young kids to drive a bus (the rough equivalent to flying a plane to a young person) and they want to do it using "feet" and "knots" then I can see no relief. Looking at the date I see that the year is 2012, not 1962. If flying is not to be abut the future it will become about the past (as it already has) - deal with it! On Thu, 18 Oct 2012, tom claffey wrote: Aviation uses feet for height, metres for horizontal distance and knots for speed - deal with it! The teenagers I teach with the AAFC have no problems with it. Tom From: Peter F Bradshaw To: Discussion of issues relating to Soaring in Australia. Sent: Friday, 19 October 2012 2:24 AM Subject: Re: [Aus-soaring] 50' obstacle clearance rule Hi; Irrespective of whether it is 50' or not I find it hard to believe that the figure is given in a system which people under 40 have no heuristic knowledge of. On Mon, 15 Oct 2012, Mark Newton wrote: > > Hi folks. > > My google-fu is failing me, but at least one of you can probably > help. > > I've long accepted that the rule for obstacle clearance is 50'. > > However, the GFA instructor handbook describes it as a wingspan, > and the B certificate oral exam calls 50' a "recommended" minimum, > so I'm trying to go back to sources to find the origin of the rule. > > And I can't seem to find it written down anywhere. > > I'm beginning to suspect that my long-term acceptance of the 50' > rule is wrong, and that the real limit is, shall we say, more > "operationally fluid" than that. > > Wondering if the strict mention of 50' that I've seen at clubs all > over Australia is actually more of a tradition, perhaps derived from > a misunderstanding of certified light aircraft performance charts > which give minimum takeoff distances including clearance of a 50' > obstacle. > > Does anyone have a cite to the regulations? > > (while you're at it, providing a cite to a current GFA or non-exempted > CASA regulation which states what GFA annual check entails, whether > it's required to be signed out in a logbook, or whether an instructor > is even required to be present, would help to settle a long-standing > argument :) > > - mark Cheers Cheers -- Peter F Bradshaw: http://www.exadios.com (public keys avaliable there). Personal site: http://personal.exadios.com "I love truth, and the way the government still uses it occasionally to keep us guessing." - Sam Kekovich.___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
So put your proposal to ICAO. Tom From: Al Borowski To: tom claffey ; Discussion of issues relating to Soaring in Australia. Sent: Friday, 19 October 2012 1:53 PM Subject: Re: [Aus-soaring] 50' obstacle clearance rule On 19/10/2012, tom claffey wrote: > Aviation uses feet for height, metres for horizontal distance and knots for > speed - deal with it! > The teenagers I teach with the AAFC have no problems with it. > Tom > The only problem with the "this is the way it's always been done" approach is we end up with weather reports etc that are more suitable for WW2 then 2012. If we're already mixing metric and imperial units, what's the harm in putting a metric equivalent as well? I suspect no-one goes into aviation with an intuitive understanding of what 2000 feet AGL looks like. Everyone has to learn "at height X, the view looks like Y", so the units are irrelevant. The altimeter could read in fractions of a football field and I bet student pilots would cope just as well.. Smaller distances are a different story. It's reasonable for a 20 year old to instantly point to something ~100M away, but I bet they'd be much slower when the unit is specified in feet. Cheers, Al ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
On 19-Oct-12 11:11, Mike Borgelt wrote: At 06:16 AM 19/10/2012, you wrote: But in any event is the rule necessary? We all know the advantages of not hitting the far fence at 5 knots over going through the near fence at 50 knots. Those who don't are not around to tell! So, clear all obstacles is the key, and land as safely as you can. Thanks Alan, lets put that in Caps, Bold SO, CLEAR ALL OBSTACLES IS THE KEY AND LAND AS SAFELY AS YOU CAN. Which is exactly what I was trained to do, learning in the UK, where the paddocks (at least back then) were small. -- Robert Hart ha...@interweft.com.au Darling Downs gliding weather information +61 438 385 533 ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
At 12:53 PM 19/10/2012, you wrote: On 19/10/2012, tom claffey wrote: > Aviation uses feet for height, metres for horizontal distance and knots for > speed - deal with it! > The teenagers I teach with the AAFC have no problems with it. > Tom > The only problem with the "this is the way it's always been done" approach is we end up with weather reports etc that are more suitable for WW2 then 2012. If we're already mixing metric and imperial units, what's the harm in putting a metric equivalent as well? Cos all the aviation charts have ground elevations in feet. You really don't want any confusion here or even the possibility of confusion. It isn't much of a problem for VFR but IFR is a different matter. There's a giant international system where most of the world's aviation and certainly at the top end is done in feet for altitude and nautical miles for distance. Horizontal distances in meters is really bad news IMO. Changing to kilos or litres of fuel from pounds or gallons caused at least one major aircraft accident. Changing units is expensive and fraught with possibilities for error. Yes, its an official stuff up. Mike Borgelt Instruments - design & manufacture of quality soaring instrumentation since 1978 www.borgeltinstruments.com tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784: int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
On 19/10/2012, tom claffey wrote: > Aviation uses feet for height, metres for horizontal distance and knots for > speed - deal with it! > The teenagers I teach with the AAFC have no problems with it. > Tom > The only problem with the "this is the way it's always been done" approach is we end up with weather reports etc that are more suitable for WW2 then 2012. If we're already mixing metric and imperial units, what's the harm in putting a metric equivalent as well? I suspect no-one goes into aviation with an intuitive understanding of what 2000 feet AGL looks like. Everyone has to learn "at height X, the view looks like Y", so the units are irrelevant. The altimeter could read in fractions of a football field and I bet student pilots would cope just as well.. Smaller distances are a different story. It's reasonable for a 20 year old to instantly point to something ~100M away, but I bet they'd be much slower when the unit is specified in feet. Cheers, Al ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
At 06:16 AM 19/10/2012, you wrote: But in any event is the rule necessary? We all know the advantages of not hitting the far fence at 5 knots over going through the near fence at 50 knots. Those who don't are not around to tell! So, clear all obstacles is the key, and land as safely as you can. Thanks Alan, lets put that in Caps, Bold SO, CLEAR ALL OBSTACLES IS THE KEY AND LAND AS SAFELY AS YOU CAN. I'm so sick of blithering idiots who find it necessary to write nit picking rules about everything, describing in unwarranted detail and accuracy, how to achieve an result that is common sense and probably making outcomes less safe in the process. Note: An accident at the approach end is likely to be really bad, at the far end of the landing run likely much less so. HOWEVER there's no need to ever impact the far fence in a glider. Do a ground loop before you get there. This is SOP in the North Island of NZ. You'd never get into any of the paddocks if you went over the fence at 50 feet. Likewise the 1.5 Vs plus plus rule has probably broken as many or more gliders as the 50 foot rule in this country. You wouldn't get into a NZ paddock doing that either. As for the Benalla accident with the power line, we didn't have a problem until some bed wetter in the regulator effectively banned high speed low finishes in contests. The "accident"was quite foreseeable as pilots would game the system. So we turned a gradual using up of the final glide height margin late in the glide close to the airfield resulting in a high speed finish with the inverse, use up the height margin away from the airfield, fly low and decelerate into a low energy situation just as crossing the boundary. I mean, what could possibly go wrong? At least we didn't ban straight in finishes. I shudder to think about the "circuits"that would have been flown then. Not that this matters any more with remote finishes. Laurie, if you think you are more likely to die in a car you are sadly mistaken by at least one order of magnitude (10 times). Nobody is suggesting abolishing rules like keep to one side of the road, give way rules etc. Speed limits are another matter, where a rule can substitute for common sense and reasonable practice. This is the problem. BTW there's a nice discussion on Flight Global's website about the implications of AF447. The NASA publication Mark Newton linked to is worth reading too although one or two of the conclusions are arguable. Mike ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
Aviation uses feet for height, metres for horizontal distance and knots for speed - deal with it! The teenagers I teach with the AAFC have no problems with it. Tom From: Peter F Bradshaw To: Discussion of issues relating to Soaring in Australia. Sent: Friday, 19 October 2012 2:24 AM Subject: Re: [Aus-soaring] 50' obstacle clearance rule Hi; Irrespective of whether it is 50' or not I find it hard to believe that the figure is given in a system which people under 40 have no heuristic knowledge of. On Mon, 15 Oct 2012, Mark Newton wrote: > > Hi folks. > > My google-fu is failing me, but at least one of you can probably > help. > > I've long accepted that the rule for obstacle clearance is 50'. > > However, the GFA instructor handbook describes it as a wingspan, > and the B certificate oral exam calls 50' a "recommended" minimum, > so I'm trying to go back to sources to find the origin of the rule. > > And I can't seem to find it written down anywhere. > > I'm beginning to suspect that my long-term acceptance of the 50' > rule is wrong, and that the real limit is, shall we say, more > "operationally fluid" than that. > > Wondering if the strict mention of 50' that I've seen at clubs all > over Australia is actually more of a tradition, perhaps derived from > a misunderstanding of certified light aircraft performance charts > which give minimum takeoff distances including clearance of a 50' > obstacle. > > Does anyone have a cite to the regulations? > > (while you're at it, providing a cite to a current GFA or non-exempted > CASA regulation which states what GFA annual check entails, whether > it's required to be signed out in a logbook, or whether an instructor > is even required to be present, would help to settle a long-standing > argument :) > > - mark Cheers -- Peter F Bradshaw: http://www.exadios.com (public keys avaliable there). Personal site: http://personal.exadios.com "I love truth, and the way the government still uses it occasionally to keep us guessing." - Sam Kekovich. ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
After over thirty years of instructing, one constant in my observation has been the inability of pilots, including myself, to accurately gauge clearance height over approach obstacles. Self assessments by pilots after landing are typically only either 'well clear' or 'a bit low maybe'. When asked for an estimate of actual clearance, the one constant is a significant over estimate. Any pilot/instructor/observer who berates someone for the sake of it in such a situation does both the observed pilot and themselves a huge injustice. Concerned pilots/instructors/observers will offer genuine feedback on a task that is actually extremely difficult to carry out ie accurate clearance assessment over approach obstacles. At every stage in my gliding I appreciated such feedback and took it on board for subsequent approach planning, as did my peers. Rather than 50', use of the term 'one wingspan' or 'one and a half wingspans' is useful. I'd always thought that the one wingspan term was simply a more useful derivative of the 50' requirement...much easier to visualise. A good technique for giving genuine feedback is the use of the 'box'. If the span of a glider on approach is considered the upper (horizontal) side of a square box shape then the vertical sides of the box to the ground will be the same length. If the box appears a rectangle then the glider's clearance is less than a wingspan. Adequate clearance over approach obstacles is essential for two main reasons. Firstly our ability to identify an over shoot is much great than that of an undershoot. By the time we are well in an undershoot situation significant gain of height is needed to clear obstacles at a time when we are rapidly losing the ability to gain height. Secondly, if I had a choice of going through the far fence at 10kts or hitting a fence/tree/power pole on approach at 60kts, i know which one I'll choose every time. There is wisdom in retaining at least some rules in gliding. Given the strict rules that apply on the road the risk of an accident is still high due to poor judgment by so many drivers. I'm still far more fearful that I'll die in a road accident than in a gliding accident. I'd hate to think of the increased risks I'd face if most of the road rules were abolished. Just my twenty cents worth. Regards Laurie Hoffman From: Alan Wilson To: 'Discussion of issues relating to Soaring in Australia.' Sent: Friday, 19 October 2012 7:16 AM Subject: Re: [Aus-soaring] 50' obstacle clearance rule Ah the 50' rule. It has been around for more years than stated and has been a contributing factor in many a prang I bet. I know of one in the early 70's where the glider pilot had a predilection and acceptance of the 50' rule, landed over that fictitious obstacle and could not fit into the outlanding paddock [at Emu Plains]. There was an option of missing the non-existent obstacle, clear the 4' fence, and land across the diagonal with 40% more landing run! At the time I landed as close as I dared over a fence at Forbes airfield and paced out my touchdown to be 220' from the fence. Critical in a short outlanding, and worse if one adds and unnecessary 50' at 30:1! My google-fu found " Douglas Bader, British WWII air ace). Rules are for the guidance of wise men and the blind obedience of fools. (Solon, the Lawmaker of Athens, d. 559BCE)" ... Some unnecessary rules have been around for millennia. It may come from an instructor who could gauge that clearance of a fence because 50' is a soft conversion of a 15 meter wingspan. Sitting safely on a chair at the pie cart the instructor can visualize that and use it to berate the pilot who considered he had a short landing well under control. But in any event is the rule necessary? We all know the advantages of not hitting the far fence at 5 knots over going through the near fence at 50 knots. Those who don't are not around to tell! So, clear all obstacles is the key, and land as safely as you can. Finally, appreciate that the younger set probably have a good appreciation of metrics, but may not relate to Knots and feet. My 'two bobs' worth, but you can call it 20 cents. Alan Wilson Canberra -Original Message- From: aus-soaring-boun...@lists.internode.on.net [mailto:aus-soaring-boun...@lists.internode.on.net] On Behalf Of Peter F Bradshaw Sent: Friday, 19 October, 2012 2:24 AM To: Discussion of issues relating to Soaring in Australia. Subject: Re: [Aus-soaring] 50' obstacle clearance rule Hi; Irrespective of whether it is 50' or not I find it hard to believe that the figure is given in a system which people under 40 have no heuristic knowledge of. On Mon, 15 Oct 2012, Mark Newton wrote: > > Hi folks. > > My google-fu is failing me
Re: [Aus-soaring] 50' obstacle clearance rule
Ah the 50' rule. It has been around for more years than stated and has been a contributing factor in many a prang I bet. I know of one in the early 70's where the glider pilot had a predilection and acceptance of the 50' rule, landed over that fictitious obstacle and could not fit into the outlanding paddock [at Emu Plains]. There was an option of missing the non-existent obstacle, clear the 4' fence, and land across the diagonal with 40% more landing run! At the time I landed as close as I dared over a fence at Forbes airfield and paced out my touchdown to be 220' from the fence. Critical in a short outlanding, and worse if one adds and unnecessary 50' at 30:1! My google-fu found " Douglas Bader, British WWII air ace). Rules are for the guidance of wise men and the blind obedience of fools. (Solon, the Lawmaker of Athens, d. 559BCE)" ... Some unnecessary rules have been around for millennia. It may come from an instructor who could gauge that clearance of a fence because 50' is a soft conversion of a 15 meter wingspan. Sitting safely on a chair at the pie cart the instructor can visualize that and use it to berate the pilot who considered he had a short landing well under control. But in any event is the rule necessary? We all know the advantages of not hitting the far fence at 5 knots over going through the near fence at 50 knots. Those who don't are not around to tell! So, clear all obstacles is the key, and land as safely as you can. Finally, appreciate that the younger set probably have a good appreciation of metrics, but may not relate to Knots and feet. My 'two bobs' worth, but you can call it 20 cents. Alan Wilson Canberra -Original Message- From: aus-soaring-boun...@lists.internode.on.net [mailto:aus-soaring-boun...@lists.internode.on.net] On Behalf Of Peter F Bradshaw Sent: Friday, 19 October, 2012 2:24 AM To: Discussion of issues relating to Soaring in Australia. Subject: Re: [Aus-soaring] 50' obstacle clearance rule Hi; Irrespective of whether it is 50' or not I find it hard to believe that the figure is given in a system which people under 40 have no heuristic knowledge of. On Mon, 15 Oct 2012, Mark Newton wrote: > > Hi folks. > > My google-fu is failing me, but at least one of you can probably help. > > I've long accepted that the rule for obstacle clearance is 50'. > > However, the GFA instructor handbook describes it as a wingspan, and > the B certificate oral exam calls 50' a "recommended" minimum, so I'm > trying to go back to sources to find the origin of the rule. > > And I can't seem to find it written down anywhere. > > I'm beginning to suspect that my long-term acceptance of the 50' > rule is wrong, and that the real limit is, shall we say, more > "operationally fluid" than that. > > Wondering if the strict mention of 50' that I've seen at clubs all > over Australia is actually more of a tradition, perhaps derived from a > misunderstanding of certified light aircraft performance charts which > give minimum takeoff distances including clearance of a 50' > obstacle. > > Does anyone have a cite to the regulations? > > (while you're at it, providing a cite to a current GFA or non-exempted > CASA regulation which states what GFA annual check entails, whether > it's required to be signed out in a logbook, or whether an instructor > is even required to be present, would help to settle a long-standing > argument :) > > - mark Cheers -- Peter F Bradshaw: http://www.exadios.com (public keys available there). Personal site: http://personal.exadios.com "I love truth, and the way the government still uses it occasionally to keep us guessing." - Sam Kekovich. ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
Hi; Irrespective of whether it is 50' or not I find it hard to believe that the figure is given in a system which people under 40 have no heuristic knowledge of. On Mon, 15 Oct 2012, Mark Newton wrote: Hi folks. My google-fu is failing me, but at least one of you can probably help. I've long accepted that the rule for obstacle clearance is 50'. However, the GFA instructor handbook describes it as a wingspan, and the B certificate oral exam calls 50' a "recommended" minimum, so I'm trying to go back to sources to find the origin of the rule. And I can't seem to find it written down anywhere. I'm beginning to suspect that my long-term acceptance of the 50' rule is wrong, and that the real limit is, shall we say, more "operationally fluid" than that. Wondering if the strict mention of 50' that I've seen at clubs all over Australia is actually more of a tradition, perhaps derived from a misunderstanding of certified light aircraft performance charts which give minimum takeoff distances including clearance of a 50' obstacle. Does anyone have a cite to the regulations? (while you're at it, providing a cite to a current GFA or non-exempted CASA regulation which states what GFA annual check entails, whether it's required to be signed out in a logbook, or whether an instructor is even required to be present, would help to settle a long-standing argument :) - mark Cheers -- Peter F Bradshaw: http://www.exadios.com (public keys avaliable there). Personal site: http://personal.exadios.com "I love truth, and the way the government still uses it occasionally to keep us guessing." - Sam Kekovich. ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
Thanks Stephen I was going to check my (1974) copy of the Instructors Handbook but you have saved me the trouble. Maybe this is where Mike V and I got the 50' from for the 1986 rule change in the CAO. Wombat - Original Message - From: stephenk To: "Discussion of issues relating to Soaring in Australia." Subject: Re: [Aus-soaring] 50' obstacle clearance rule Date: Thu, 18 Oct 2012 21:09:20 +1030 > OK, > the junk we keep. > > Further digging and I found the inserts of an older > instructors manual. The diagram is not the same, it is > simpler and has no indication of the 50ft clearance but > the equivalent paragraph I referred to below has only > been slightly edited in the 80s version. The sentence > referring to 50ft is word for word identical. The date at > the top of the page is 1 May 1971. So the "approximately > 50ft" rule goes back at least 40 years. > > Regards > SWK > > > On 18/10/2012 8:40 PM, stephenk wrote: > > Mark and Wombat, > > The 50 foot rule predates 1986. I dragged out my old > > instructors manual (the light blue folder one) and that > > shows a diagram with "50 ft over obstacles" on it in > > the circuit appraoch and landing section. Also > reference to it in the text, in the first paragraph after > > the heading "Base turning point" is the sentence "If > > there are obstacles we must ensure that our final > > approach path clears them by approximately 50ft." > > > > I am pretty sure I had this book by January 1984 (my > > assistant instructor course) and may have had it > > earlier. The diagram looks a bit scratchy as if it had > > been copied from an earlier document(s). I would guess > > the older green folder instructors manual (from the 70s) > had the same illustration, and probably wording. > > > Regards > > SWK > > > > On 17/10/2012 6:32 PM, Mike Cleaver wrote: > >> HI Mark > >> > >> I may be able to help re the 50 ft thing. Back in 1986, > at the >> pre-Worlds prior to the Benalla 1987 Worlds, a > French competitor hit >> a power line 4 km from the > airfield flying at or over Vne, removed >> the tailplane > from his glider, and was killed. Between us, the GFA >> > (Mike Valentine RIP) and CASA (myself) devised some > changes to the >> rules for low approaches exemption from > the CAR requiring 500 ft >> above obstacles except in the > course of landing, to say that a glider >> within 5km of > the finish of a race could descend below 500 ft if the >> > flight was in a contest approved by the GFA, with the > proviso that >> the glider was kept in sight of the > finish line, not less than 50 ft >> clear of obstacles, > and with sufficient energy to either make a safe >> > circuit or to land ahead on the airfield. >> > >> That rule has subsequently been changed at least twice, > but may be >> the source of the 50' figure you quote. The > current rule applies to >> any flight away from the > aerodrome and allows a low finish "in >> accordance with > the GFA Ops Regs" and there has been a GFA >> endorsement > for flying a circuit off a low high-energy approach, >> > though nowadays we prefer straight-in approaches to a long > landing >> (leaving room behind for following traffic) > and with enough energy >> for safe obstacle clearance. > >> > >> I was always taught to plan to clear obstacles by > around one and a >> half wingspans, assuming there was no > overriding priority to avoid >> hitting the far fence, > and whilst always remembering that it was >> better to > roll slowly into the far end of the field than to fly >> > through the obstacles at the approach end. It is also far > easier to >> touch down close to the near fence by using > a steep approach with >> adequate clearance than a > shallow one with little in reserve. >> > >> Wombat > >> > >> On 15/10/2012 1:17 PM, Mark Newton wrote: > >>> Hi folks. > >>> > >>> My google-fu is failing me, but at least one of you > can probably >>> help. > >>> > >>> I've long accepted that the rule for obstacle > clearance is 50'. >>> > >>> However, the GFA instructor handbook describes it as a > wingspan, >>> and the B certificate oral exam calls 50' a > "recommended" minimum, >>> so I'm trying to go back to > sources to find the origin of the rule. >>> >
Re: [Aus-soaring] 50' obstacle clearance rule
OK, the junk we keep. Further digging and I found the inserts of an older instructors manual. The diagram is not the same, it is simpler and has no indication of the 50ft clearance but the equivalent paragraph I referred to below has only been slightly edited in the 80s version. The sentence referring to 50ft is word for word identical. The date at the top of the page is 1 May 1971. So the "approximately 50ft" rule goes back at least 40 years. Regards SWK On 18/10/2012 8:40 PM, stephenk wrote: Mark and Wombat, The 50 foot rule predates 1986. I dragged out my old instructors manual (the light blue folder one) and that shows a diagram with "50 ft over obstacles" on it in the circuit appraoch and landing section. Also reference to it in the text, in the first paragraph after the heading "Base turning point" is the sentence "If there are obstacles we must ensure that our final approach path clears them by approximately 50ft." I am pretty sure I had this book by January 1984 (my assistant instructor course) and may have had it earlier. The diagram looks a bit scratchy as if it had been copied from an earlier document(s). I would guess the older green folder instructors manual (from the 70s) had the same illustration, and probably wording. Regards SWK On 17/10/2012 6:32 PM, Mike Cleaver wrote: HI Mark I may be able to help re the 50 ft thing. Back in 1986, at the pre-Worlds prior to the Benalla 1987 Worlds, a French competitor hit a power line 4 km from the airfield flying at or over Vne, removed the tailplane from his glider, and was killed. Between us, the GFA (Mike Valentine RIP) and CASA (myself) devised some changes to the rules for low approaches exemption from the CAR requiring 500 ft above obstacles except in the course of landing, to say that a glider within 5km of the finish of a race could descend below 500 ft if the flight was in a contest approved by the GFA, with the proviso that the glider was kept in sight of the finish line, not less than 50 ft clear of obstacles, and with sufficient energy to either make a safe circuit or to land ahead on the airfield. That rule has subsequently been changed at least twice, but may be the source of the 50' figure you quote. The current rule applies to any flight away from the aerodrome and allows a low finish "in accordance with the GFA Ops Regs" and there has been a GFA endorsement for flying a circuit off a low high-energy approach, though nowadays we prefer straight-in approaches to a long landing (leaving room behind for following traffic) and with enough energy for safe obstacle clearance. I was always taught to plan to clear obstacles by around one and a half wingspans, assuming there was no overriding priority to avoid hitting the far fence, and whilst always remembering that it was better to roll slowly into the far end of the field than to fly through the obstacles at the approach end. It is also far easier to touch down close to the near fence by using a steep approach with adequate clearance than a shallow one with little in reserve. Wombat On 15/10/2012 1:17 PM, Mark Newton wrote: Hi folks. My google-fu is failing me, but at least one of you can probably help. I've long accepted that the rule for obstacle clearance is 50'. However, the GFA instructor handbook describes it as a wingspan, and the B certificate oral exam calls 50' a "recommended" minimum, so I'm trying to go back to sources to find the origin of the rule. And I can't seem to find it written down anywhere. I'm beginning to suspect that my long-term acceptance of the 50' rule is wrong, and that the real limit is, shall we say, more "operationally fluid" than that. Wondering if the strict mention of 50' that I've seen at clubs all over Australia is actually more of a tradition, perhaps derived from a misunderstanding of certified light aircraft performance charts which give minimum takeoff distances including clearance of a 50' obstacle. Does anyone have a cite to the regulations? (while you're at it, providing a cite to a current GFA or non-exempted CASA regulation which states what GFA annual check entails, whether it's required to be signed out in a logbook, or whether an instructor is even required to be present, would help to settle a long-standing argument :) - mark ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
Mark and Wombat, The 50 foot rule predates 1986. I dragged out my old instructors manual (the light blue folder one) and that shows a diagram with "50 ft over obstacles" on it in the circuit appraoch and landing section. Also reference to it in the text, in the first paragraph after the heading "Base turning point" is the sentence "If there are obstacles we must ensure that our final approach path clears them by approximately 50ft." I am pretty sure I had this book by January 1984 (my assistant instructor course) and may have had it earlier. The diagram looks a bit scratchy as if it had been copied from an earlier document(s). I would guess the older green folder instructors manual (from the 70s) had the same illustration, and probably wording. Regards SWK On 17/10/2012 6:32 PM, Mike Cleaver wrote: HI Mark I may be able to help re the 50 ft thing. Back in 1986, at the pre-Worlds prior to the Benalla 1987 Worlds, a French competitor hit a power line 4 km from the airfield flying at or over Vne, removed the tailplane from his glider, and was killed. Between us, the GFA (Mike Valentine RIP) and CASA (myself) devised some changes to the rules for low approaches exemption from the CAR requiring 500 ft above obstacles except in the course of landing, to say that a glider within 5km of the finish of a race could descend below 500 ft if the flight was in a contest approved by the GFA, with the proviso that the glider was kept in sight of the finish line, not less than 50 ft clear of obstacles, and with sufficient energy to either make a safe circuit or to land ahead on the airfield. That rule has subsequently been changed at least twice, but may be the source of the 50' figure you quote. The current rule applies to any flight away from the aerodrome and allows a low finish "in accordance with the GFA Ops Regs" and there has been a GFA endorsement for flying a circuit off a low high-energy approach, though nowadays we prefer straight-in approaches to a long landing (leaving room behind for following traffic) and with enough energy for safe obstacle clearance. I was always taught to plan to clear obstacles by around one and a half wingspans, assuming there was no overriding priority to avoid hitting the far fence, and whilst always remembering that it was better to roll slowly into the far end of the field than to fly through the obstacles at the approach end. It is also far easier to touch down close to the near fence by using a steep approach with adequate clearance than a shallow one with little in reserve. Wombat On 15/10/2012 1:17 PM, Mark Newton wrote: Hi folks. My google-fu is failing me, but at least one of you can probably help. I've long accepted that the rule for obstacle clearance is 50'. However, the GFA instructor handbook describes it as a wingspan, and the B certificate oral exam calls 50' a "recommended" minimum, so I'm trying to go back to sources to find the origin of the rule. And I can't seem to find it written down anywhere. I'm beginning to suspect that my long-term acceptance of the 50' rule is wrong, and that the real limit is, shall we say, more "operationally fluid" than that. Wondering if the strict mention of 50' that I've seen at clubs all over Australia is actually more of a tradition, perhaps derived from a misunderstanding of certified light aircraft performance charts which give minimum takeoff distances including clearance of a 50' obstacle. Does anyone have a cite to the regulations? (while you're at it, providing a cite to a current GFA or non-exempted CASA regulation which states what GFA annual check entails, whether it's required to be signed out in a logbook, or whether an instructor is even required to be present, would help to settle a long-standing argument :) - mark ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
HI Mark I may be able to help re the 50 ft thing. Back in 1986, at the pre-Worlds prior to the Benalla 1987 Worlds, a French competitor hit a power line 4 km from the airfield flying at or over Vne, removed the tailplane from his glider, and was killed. Between us, the GFA (Mike Valentine RIP) and CASA (myself) devised some changes to the rules for low approaches exemption from the CAR requiring 500 ft above obstacles except in the course of landing, to say that a glider within 5km of the finish of a race could descend below 500 ft if the flight was in a contest approved by the GFA, with the proviso that the glider was kept in sight of the finish line, not less than 50 ft clear of obstacles, and with sufficient energy to either make a safe circuit or to land ahead on the airfield. That rule has subsequently been changed at least twice, but may be the source of the 50' figure you quote. The current rule applies to any flight away from the aerodrome and allows a low finish "in accordance with the GFA Ops Regs" and there has been a GFA endorsement for flying a circuit off a low high-energy approach, though nowadays we prefer straight-in approaches to a long landing (leaving room behind for following traffic) and with enough energy for safe obstacle clearance. I was always taught to plan to clear obstacles by around one and a half wingspans, assuming there was no overriding priority to avoid hitting the far fence, and whilst always remembering that it was better to roll slowly into the far end of the field than to fly through the obstacles at the approach end. It is also far easier to touch down close to the near fence by using a steep approach with adequate clearance than a shallow one with little in reserve. Wombat On 15/10/2012 1:17 PM, Mark Newton wrote: Hi folks. My google-fu is failing me, but at least one of you can probably help. I've long accepted that the rule for obstacle clearance is 50'. However, the GFA instructor handbook describes it as a wingspan, and the B certificate oral exam calls 50' a "recommended" minimum, so I'm trying to go back to sources to find the origin of the rule. And I can't seem to find it written down anywhere. I'm beginning to suspect that my long-term acceptance of the 50' rule is wrong, and that the real limit is, shall we say, more "operationally fluid" than that. Wondering if the strict mention of 50' that I've seen at clubs all over Australia is actually more of a tradition, perhaps derived from a misunderstanding of certified light aircraft performance charts which give minimum takeoff distances including clearance of a 50' obstacle. Does anyone have a cite to the regulations? (while you're at it, providing a cite to a current GFA or non-exempted CASA regulation which states what GFA annual check entails, whether it's required to be signed out in a logbook, or whether an instructor is even required to be present, would help to settle a long-standing argument :) - mark ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
*So I *think* it's true that there's a widespread believe within GFA that there's a rule which mandates a 50' obstacle clearance minimum, and I'm trying to find out why :)* If the rule called for somehting less than 50', say 5', there would be no room left for pilots to break the rule! *Kevin Roden* On 15 October 2012 13:05, Mark Newton wrote: > > > On 15/10/2012, at 13:12, Tim Shirley wrote: > > > As a general comment, making mandatory rules for obstacle clearance for > aircraft without a throttle lever seems a bit silly. > > Agreed! Nevertheless, my received training and my experiences at various > gliding operations have lead me to believe that that's what someone > actually did, and I'm trying to get to the bottom of it. > > For instance, at a comp where I listened to a CD giving a briefing to the > assembled multitudes in the day before the competition finish OD, saying, > "I'm a very poor judge of 50 feet, but I'm an excellent judge of safety." > That CD clearly believed there was a 50' rule too, otherwise he'd not have > worded his comment the way he did. > > So I *think* it's true that there's a widespread believe within GFA that > there's a rule which mandates a 50' obstacle clearance minimum, and I'm > trying to find out why :) > >- mark > > > ___ > Aus-soaring mailing list > Aus-soaring@lists.internode.on.net > To check or change subscription details, visit: > http://lists.internode.on.net/mailman/listinfo/aus-soaring > ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
On 15/10/2012, at 13:12, Tim Shirley wrote: > As a general comment, making mandatory rules for obstacle clearance for > aircraft without a throttle lever seems a bit silly. Agreed! Nevertheless, my received training and my experiences at various gliding operations have lead me to believe that that's what someone actually did, and I'm trying to get to the bottom of it. For instance, at a comp where I listened to a CD giving a briefing to the assembled multitudes in the day before the competition finish OD, saying, "I'm a very poor judge of 50 feet, but I'm an excellent judge of safety." That CD clearly believed there was a 50' rule too, otherwise he'd not have worded his comment the way he did. So I *think* it's true that there's a widespread believe within GFA that there's a rule which mandates a 50' obstacle clearance minimum, and I'm trying to find out why :) - mark ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
Hi Mark, As a general comment, making mandatory rules for obstacle clearance for aircraft without a throttle lever seems a bit silly. If I'm faced with missing a tree by less than a wingspan or hitting the fence at the end of the paddock I know which one I will be choosing. And why would an ASH25 need twice the clearance that a Sparrowhawk does? Oh yes, the 90 deg banked turn onto final. Of course, leaving distance between yourself and the trees is good practice. It's not something for the rule book though. Untitled Document Cheers /Tim/ /tra dire e fare c'è mezzo il mare/ On 15/10/2012 13:17, Mark Newton wrote: Hi folks. My google-fu is failing me, but at least one of you can probably help. I've long accepted that the rule for obstacle clearance is 50'. However, the GFA instructor handbook describes it as a wingspan, and the B certificate oral exam calls 50' a "recommended" minimum, so I'm trying to go back to sources to find the origin of the rule. And I can't seem to find it written down anywhere. I'm beginning to suspect that my long-term acceptance of the 50' rule is wrong, and that the real limit is, shall we say, more "operationally fluid" than that. Wondering if the strict mention of 50' that I've seen at clubs all over Australia is actually more of a tradition, perhaps derived from a misunderstanding of certified light aircraft performance charts which give minimum takeoff distances including clearance of a 50' obstacle. Does anyone have a cite to the regulations? (while you're at it, providing a cite to a current GFA or non-exempted CASA regulation which states what GFA annual check entails, whether it's required to be signed out in a logbook, or whether an instructor is even required to be present, would help to settle a long-standing argument :) - mark ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] 50' obstacle clearance rule
Great pickup.and for a 15 Metre aircraft the two are one and the same; and possibly this is where the history lies as documents were edited by different authors; it obviously requires clarification. SDF On 15/10/2012, at 13:17, Mark Newton wrote: > > Hi folks. > > My google-fu is failing me, but at least one of you can probably > help. > > I've long accepted that the rule for obstacle clearance is 50'. > > However, the GFA instructor handbook describes it as a wingspan, > and the B certificate oral exam calls 50' a "recommended" minimum, > so I'm trying to go back to sources to find the origin of the rule. > > And I can't seem to find it written down anywhere. > > I'm beginning to suspect that my long-term acceptance of the 50' > rule is wrong, and that the real limit is, shall we say, more > "operationally fluid" than that. > > Wondering if the strict mention of 50' that I've seen at clubs all > over Australia is actually more of a tradition, perhaps derived from > a misunderstanding of certified light aircraft performance charts > which give minimum takeoff distances including clearance of a 50' > obstacle. > > Does anyone have a cite to the regulations? > > (while you're at it, providing a cite to a current GFA or non-exempted > CASA regulation which states what GFA annual check entails, whether > it's required to be signed out in a logbook, or whether an instructor > is even required to be present, would help to settle a long-standing > argument :) > > - mark > ___ > Aus-soaring mailing list > Aus-soaring@lists.internode.on.net > To check or change subscription details, visit: > http://lists.internode.on.net/mailman/listinfo/aus-soaring ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
[Aus-soaring] 50' obstacle clearance rule
Hi folks. My google-fu is failing me, but at least one of you can probably help. I've long accepted that the rule for obstacle clearance is 50'. However, the GFA instructor handbook describes it as a wingspan, and the B certificate oral exam calls 50' a "recommended" minimum, so I'm trying to go back to sources to find the origin of the rule. And I can't seem to find it written down anywhere. I'm beginning to suspect that my long-term acceptance of the 50' rule is wrong, and that the real limit is, shall we say, more "operationally fluid" than that. Wondering if the strict mention of 50' that I've seen at clubs all over Australia is actually more of a tradition, perhaps derived from a misunderstanding of certified light aircraft performance charts which give minimum takeoff distances including clearance of a 50' obstacle. Does anyone have a cite to the regulations? (while you're at it, providing a cite to a current GFA or non-exempted CASA regulation which states what GFA annual check entails, whether it's required to be signed out in a logbook, or whether an instructor is even required to be present, would help to settle a long-standing argument :) - mark ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
