What is ...

P

Precision 

As the name implies,

ATC provides Horizontal + Vertical guidance

A

Approach

For Approach use only

-

guidance starts

~ 8 nm from T/D

R

Radar

Need to be in radar contact and have 2-way communication

-

ATC provides guidance by looking on a precise & fast updating radar screen

Usage

  • MOSTLY USED IN EMERGENCY SITUATIONS

     

  • PAR is available at civil and military airports

     

  • DH only upon request by the pilot

     

  • range/dist. Information from touch down is given about once ea. Mile
    (ex: 5mi..., 4mi..., 3mi... from touchdown)

     

  • position updates/corrections are issued every couple of seconds or as required

     

  • missed approach instrument and communication failure will be issued

     

  • PAR usually has a 3 deg. Glide Path unless otherwise noted.

     

  • PAR usually consists of 2 radar units – one sweeps side to side & one that sweeps up and down → both sweep ~ once every second → almost no time delay

COMMON ATC STATEMENTS DURING 
PAR - APPROACH

“coming up + on glide path” - for smaller planes

 

“on course/on glide path”

 

“going left of course/drifting → turn right …. (071)”

 

“going above/below glide path”

 

“slightly above glide path”

 

“going well above glide path”

PAR - Approach Profile

PAR.jpg
PAR2.jpg

Differences between ...

PAR

  • Horizontal + Vertical guidance

  • comparabl to an ILS

  • controller radar screen shows detailed profile of horizontal & vertical (Glide Slope) position of the aircraft.

  • mostly used in Emergency situations

  • the pilot will constantly be advised how to fly/navigate.

ASR

  • Horizontal guidance ONLY

  • pilot is advised when to start descent to MDA (MDA will also be announced)

  • pilot is advised when reaching MAP

  • ATC radar sweep 360 deg./6 sec.

  • (10 rpm) → radar pic updated every 6 sec.

 

During both approaches the Pilot is given position reports relative to the RWY
AND is issued missed approach instruction in case of  2-way radio failure