Difference between PAR and ASR approaches
 

Can anyone explain the differences between an 'Airport Surveillance Radar' approach and a 'Precision Approach Radar' approach?

A PAR includes glideslope guidance, an ASR is a non precision approach with course guidance only. Typical PAR minimums are similar to ILS cat I mins, while an ASR is similar to a VOR or loc only approach.

Mark

So in terms of the pilot and controller interaction, its basically the same, but if the facility is equipt with PAR, they can get you the lower minimums? Am I understanding this correctly?

Thanks

Yes. Different equipment that offers vetical guidance with the lateral. Interaction is basically the same.

In other words a PAR is an ILS, and an ASR is a LOC, only with the controller giving you your guidance instead of the NAV radio.

NOTE: Military PAR's usually go down to 100 and 1/4 mil vis, not the std Cat I mins, and the controller will inform you of DH, and crossing the threshold

Except for single piloted, then the mins are 200-1/2.

USMCFLYR

hmm...so how are the descents given by the controller? On a PAR, are you told to descend at a specific rate/min? Or are they just stepping you down, same as they would on a ASR or LOC for that matter?

You will get on glidepath, above, or below calls. You adjust your descent rate accordingly to get back on path.

There's a really good section of the AIM dedicated to this: AIM 5-4-11. Here's the link.

http://www.faa.gov/airports_airtraff...5/aim0504.html