In the ARTS IIIA with a transponder failure for any aircraft. The computer would project the track based on stored history. If the aircraft turned it would not show that turn. It would project this track for seven sweeps, CST (coast) would appear in the data block. After the seven sweeps the track data would drop into what they called a Coast/Suspend list. I haven't kept up with all the latest advancements but I believe a primary radar target can now be tracked. Al ----- Original Message ----- From: "RWM" <RWM@xxxxxxxxxx> To: <AIRLINE@xxxxxxxxxxxxxxxxx> Sent: Saturday, December 06, 2003 7:14 AM Subject: Re: Radar > Why do you think the transponder was off? > > In any case, if it failed (or was turned off) subsequent to an IDENT > having taken place, the data tag continues to move with the primary > return. Even if the primary return is lost, the tag would continue to > move with the predicted location based on last computed velocity vector > (for up to three minutes or so, is my recollection). > > - RWM > > Mark Greenwood wrote: > > > > So if a blip is a blip and the transponder was most likely switched off, > > would enroute ATC been given the heads up as to who they were really dealing > > with in order to maintain separation, etc? > > > > Mark > > > > -----Original Message----- > > From: The Airline List [mailto:AIRLINE@xxxxxxxxxxxxxxxxx] On Behalf Of RWM > > Sent: Friday, December 05, 2003 5:36 PM > > To: AIRLINE@xxxxxxxxxxxxxxxxx > > Subject: Re: Radar > > > > Correct, a blip is a blip, but no one is operating with primary radar unless > > the more sophisticated secondary systems fail. When using the secondary > > systems, which is hopefully 100.0% of the time, they are looking at flight > > data tags, essentially "Post It Notes" attached to the primary returns, > > whose data issues from flight plan data (and manually input for pop-up > > traffic). Separation standards are driven by the secondary system, using > > relationships between tagged traffic. > > > > - RWM (7N3) > > -- > > - R.W. Mann & Company, Inc. >> Airline Industry Analysis > > Port Washington, NY 11050 >> tel 516-944-0900, fax -7280 > > mailto:RWM@xxxxxxxxxx >> URL http://www.RWMann.com/ > > > > Floridasky@xxxxxxx wrote: > > > > > > A radar blip looks exactly the same for 747 and single engine Cessna. > > > Believe or not flock of migrating geese will appear like an aircraft. > > > In South Florida controllers call possibel traffic for semi trucks on > > > I 595 on occasion not know for sure what it is. You can observe ships > > > just off the coast on radar at times also. They all look an aircarft > > > hit. > > > > > > Mike (MIA) > > > > --- > > Incoming mail is certified Virus Free. > > Checked by AVG anti-virus system (http://www.grisoft.com). > > Version: 6.0.542 / Virus Database: 336 - Release Date: 18/11/2003 > > > > > > --- > > Outgoing mail is certified Virus Free. > > Checked by AVG anti-virus system (http://www.grisoft.com). > > Version: 6.0.542 / Virus Database: 336 - Release Date: 18/11/2003 > > > > -- > - R.W. Mann & Company, Inc. >> Airline Industry Analysis > Port Washington, NY 11050 >> tel 516-944-0900, fax -7280 > mailto:RWM@xxxxxxxxxx >> URL http://www.RWMann.com/