If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#101
|
|||
|
|||
If all midair collisions were eliminated...
On Feb 14, 10:12*pm, brian whatcott wrote:
Darryl Ramm wrote: /snip/ And I forgot to mention Mode S TIS (which is not the same as ADS-B TIS- B). Which is SSR derived traffic position sent over Mode S to each TIS capable aircraft. Only available where there is terminal radar with TIS support. Area radar would update too slowly, so it's limited to terminal radar coverage and then only if that terminal radar facility has the extra smarts to do TIS. The TIS ground processor calculates threats to each aircraft and uplinks that to that aircraft over Mode S. Obviously the threat aircraft need to have Mode C or S transponders and be within coverage of that terminal radar. /snip/ Darryl Which reminds me: I fly out of a civil field in a notch of the zone round a military base - where a digital radar upgrade has recently appeared. * * I notice that with my mode C active, I seem to be able to hear an interrogation as a click as well as see a visual interrogation flash. These days, I don't get a repetitive once a revolution style interrogation, but rather a string of clicks when I am inbound (i.e a threat to military types which do have squitter) in my headset tuned to the CTAF Brian W The click is most likely your transponder replying to an interrogation and likely just coupling though the avionics power supplies, but it might also be RF coupling. Also just FYI on interrogations, each click you hear is likely not a single interrogation. For an radar/ATCRBS (I just wanted to throw in another acronym) interrogator the beam will hit your transponder with an alternating pattern of Mode A and Mode C interrogations at ~few hundred Hz as the beam sweeps over your aircraft. The exact number and pattern depends on the type of radar/ATCRBS system. There is also a remote possibility that what you hear if it is synchronous with a radar antenna rotation (not this case it seems) is RF interference picked up from the high-power primary radar beam. Which is much more powerful than the ATCRBS/transponder interrogator and usually on a quite different frequency than the 1030MHz interrogator - usually a few GHz and up. The 1030Mhz interrogator beam is such low power it's not going to cause interference directly, only by triggering your transponder to fire. If you are hearing clicking of order once per second or so then it is possibly TCAS (and/or TCAD) related. These do a clever Mode C interrogation sequence (the "Whisper-Shout" sequence) at about 1 Hz. Each TCAS equipped aircraft close enough will hit you independently with interrogations each at about 1Hz (and technically each interrogation may fire rapidly several times but you would only hear one click). Another possibility if this is only correlated to changes in military ground infrastructure is that the higher frequency interrogations not correlated with a radar rotation could be from ground based Mode C interrogators that are part of a multilateration (MLAT) systems for surface or airborne tracking. Maybe that got deployed with the new radar (or maybe the new "digital radar" is an MLAT system). And all of these interrogations help paint the position of transponder equipped aircraft for those passive PCAS systems. Darryl |
#102
|
|||
|
|||
If all midair collisions were eliminated...
In article ,
Mxsmanic wrote: Jim Logajan writes: If all GA midair collisions were eliminated, ~99% of GA aircraft fatalities would still happen. If all GA midair collisions were eliminated, 27 people would still be alive, based on your own cited statistics. Is saving lives not a sufficient justification for eliminating midair collisions? Is there are threshold of deaths below which efforts to eliminate midair collisions are not justified? What cost is there in attempting to eliminate midair collisions that offsets the loss of life that they entail? There is the very obvious cost of expending a n dollars to save one life when spending it elsewhere would save more than one life. -- Alan Baker Vancouver, British Columbia http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg |
#103
|
|||
|
|||
If all midair collisions were eliminated...
In article ,
brian whatcott wrote: Mxsmanic wrote: Jim Logajan writes: If all GA midair collisions were eliminated, ~99% of GA aircraft fatalities would still happen. If all GA midair collisions were eliminated, 27 people would still be alive, based on your own cited statistics. Is saving lives not a sufficient justification for eliminating midair collisions? Is there are threshold of deaths below which efforts to eliminate midair collisions are not justified? What cost is there in attempting to eliminate midair collisions that offsets the loss of life that they entail? If the US road speed limit were reduced from 70 to 65 mph, perhaps 30,000 lives would be saved annually. Isn't that worthwhile? We have apparently decided NOT. Because it's utter bull****. -- Alan Baker Vancouver, British Columbia http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg |
#104
|
|||
|
|||
If all midair collisions were eliminated...
In article ,
John Smith wrote: The total accident deaths per year in the US is only around 38,000. Only? One does have to consider how man person-hours are spent driving... -- Alan Baker Vancouver, British Columbia http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg |
#105
|
|||
|
|||
If all midair collisions were eliminated...
Am 16.02.10 00:25, schrieb Alan Baker:
The total accident deaths per year in the US is only around 38,000. Only? One does have to consider how man person-hours are spent driving... No, one does not have to. 38,000 deaths are an awful lot, period. |
#106
|
|||
|
|||
If all midair collisions were eliminated...
In rec.aviation.piloting John Smith wrote:
Am 16.02.10 00:25, schrieb Alan Baker: The total accident deaths per year in the US is only around 38,000. Only? One does have to consider how man person-hours are spent driving... No, one does not have to. 38,000 deaths are an awful lot, period. Yes, one does have to if you want to talk about possible prevention. If you just want to mourn the dead, then 1 death is too many. -- Jim Pennino Remove .spam.sux to reply. |
#107
|
|||
|
|||
If all midair collisions were eliminated...
The total accident deaths per year in the US is only around 38,000.
Only? One does have to consider how man person-hours are spent driving... No, one does not have to. 38,000 deaths are an awful lot, period. Yes, one does have to if you want to talk about possible prevention. If you just want to mourn the dead, then 1 death is too many. Somebody who uses the word "only" when he talks about 38,000 deaths is an idiot, period. There's nothing to relativise here. |
#109
|
|||
|
|||
If all midair collisions were eliminated...
In article ,
says... In article , ple says... The total accident deaths per year in the US is only around 38,000. Only? One does have to consider how man person-hours are spent driving... No, one does not have to. 38,000 deaths are an awful lot, period. Yes, one does have to if you want to talk about possible prevention. If you just want to mourn the dead, then 1 death is too many. Somebody who uses the word "only" when he talks about 38,000 deaths is an idiot, period. There's nothing to relativise here. Of course there is! Put it in terms of a percentage. Or... *if* America had a population of 1,000 - then how does 1 sound? Is that a better number for you? http://en.wikipedia.org/wiki/List_of...es_by_traffic- related_death_rate America looks pretty good indeed. Sorry correction on my typo - 10,000. -- Duncan. |
#110
|
|||
|
|||
If all midair collisions were eliminated...
John Smith wrote:
The total accident deaths per year in the US is only around 38,000. Only? One does have to consider how man person-hours are spent driving... No, one does not have to. 38,000 deaths are an awful lot, period. Yes, one does have to if you want to talk about possible prevention. If you just want to mourn the dead, then 1 death is too many. Somebody who uses the word "only" when he talks about 38,000 deaths is an idiot, period. There's nothing to relativise here. Of course there is, that is a death rate of about 0.01%, which is a trivial rate. And if you want to talk about possible prevention, you have to talk about rates. -- Jim Pennino Remove .spam.sux to reply. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Mid Air Collisions | Sukumar Kirloskar | Soaring | 2 | July 3rd 08 02:42 PM |
FAA Soaring Forecasts being eliminated? | David Neptune | Soaring | 6 | July 15th 06 05:47 AM |
Kids and Aviation records. I thought these were supposed to be eliminated. | Roger Halstead | Piloting | 2 | September 27th 04 07:20 PM |
Mid-Air Collisions | JJ Sinclair | Soaring | 26 | April 19th 04 08:52 AM |
MID AIR COLLISIONS | Vorsanger1 | Soaring | 2 | April 16th 04 04:17 AM |