I think one of the issues that rarely surfaces in the debate about radio use is that there are a couple of very fundamental differences between the operational behaviour of gliders and powered aircraft.
Powered aircraft, to a good first approximation, travel around in straight lines at constant altitude. With this type of operation, radio reporting of position, track and altitude makes a lot of sense because a listener can then infer the likely position and altitude of the aircraft for some time into the future. In the circuit a similar situation arises - powered aircraft can be required and expected to follow set tracks at known altitudes and it makes sense for them to do so. The radio calls they make can supplement or even supplant lookout because the behaviour (as long as they follow the procedures) is highly predictable. Situational awareness is considerably enhanced by effective radio use. This is simply not true for gliders. An en-route position report from a cross-country glider gives minimal information about future position and none about future altitude. It may provide "ops-normal" information, and it may confirm the glider's intended destination, but gliders can and do divert widely from direct tracks, fall into holes, catch huge thermals, land out or join gaggles. No one, including the pilot, can do much more than guess where they will be in 20 minutes time. That's why it is fun :) In the vicinity of the gliding site, local flying is relatively random. Thermals will be taken where thermals are found, gliders may head in any direction to find the next one, and even if position reports are given they do no more than alert the listener to the fact that there is a glider in the air, somewhere near the field. In the circuit things are a bit better. Here at least the chances are that a downwind call means the glider is on downwind and can be expected to land soon. It still doesn't say exactly what will happen next though, because the glider will modify the circuit to suit the circumstances. Maybe it will hit sink and turn in early, or maybe find lift and either extend or (in extreme cases) thermal away. Other radio calls can and probably will be made in these situations but it is still relatively unpredictable behaviour compared to what can be expected from power traffic. It is this more random behaviour that makes lookout far more important than radio procedure to a gliding operation. A radio call from a glider will nearly always impart far less situational awareness than the same call from a powered aircraft. This is not laziness on the part of the glider pilot, and it will not be solved by making glider pilots talk more (or talk more formally) on the radio. It is an inevitable result of what gliders are. Cheers Tim -----Original Message----- From: aus-soaring-boun...@lists.internode.on.net [mailto:aus-soaring-boun...@lists.internode.on.net] On Behalf Of Texler, Michael Sent: Wednesday, 2 June 2010 16:49 To: Discussion of issues relating to Soaring in Australia. Subject: [Aus-soaring] The CAAPs and How would you do a cct entry for itinerant power a/c, straw poll. Putting this all another way: Straw poll: If you were flying a power a/c with a cct speed of 100 knots, into an uncertified aerdorome that had glider ops, how would you manoevure yourself and how would you join the circuit? Michael _______________________________________________ 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 No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.819 / Virus Database: 271.1.1/2890 - Release Date: 06/02/10 04:25:00 _______________________________________________ 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
