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PAR vs ASR vs No-Gyro Approaches: What’s Different for Pilots (and Why You Should Care)

Most instrument approaches you fly are procedure-based: you track a published course and descend using published altitudes. PAR, ASR, and no-gyro approaches are different. They’re radar approaches where ATC actively helps (or outright “talks you down”) using radar surveillance—often used when navigation equipment is degraded, weather is marginal, or you’re operating at facilities that still support ground-controlled approaches.


Here’s how they differ from a pilot’s perspective: what guidance you get, what you’re responsible for, how the comm flow works, and where the traps are.



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1) PAR Approach (Precision Approach Radar): “Controller-provided localizer + glideslope”

What it is

A PAR is the closest thing to an ILS you’ll ever fly without using your own localizer/glideslope. The controller provides both:

  • Azimuth (lateral) guidance, and

  • Elevation (vertical) guidance,


…typically as a continuous “talkdown” with frequent corrections.


What you do as the pilot

You fly headings and descent corrections based on the controller’s calls, while maintaining:

  • Airspeed

  • Configuration

  • Checklist discipline

  • Descent rate changes as instructed

  • Missed approach readiness


How it sounds on the radio

Expect rapid, precise calls like:

  • “Slightly left of course… correcting.”

  • “On course.”

  • “Slightly above glidepath… begin descent.”

  • “At decision height…”


Minima / decision point

PARs are flown to a decision height (like a precision approach conceptually), but the exact minima depend on the facility and authorization. The key operational point is that you’ll get a clear “approaching decision height” type call, and you must be ready to either land with required visual cues or go missed immediately.


Pilot “gotchas”

  • Workload spike: It’s a high-tempo, headset-on, no-distractions approach.

  • Overcontrolling: Corrections are often small. Don’t chase every word with big yanks.

  • Stabilization matters: If you’re not configured and trimmed early, you’ll drown in corrections.


2) ASR Approach (Airport Surveillance Radar): “Controller-provided lateral guidance only”

What it is

An ASR approach provides azimuth guidance only—think “radar vectors on final” with tighter monitoring and frequent course corrections—but no vertical path guidance from radar.


You’re responsible for vertical navigation using:

  • Published step-down altitudes (if provided), or

  • Controller-issued altitudes/descents (depending on how the approach is set up at that facility)


What you do as the pilot

You fly:

  • Headings to stay on the final approach course, based on ATC calls, and

  • Your own vertical profile using assigned/published altitudes,

  • Down to an MDA-style point (conceptually non precision).


How it sounds on the radio

Typically less “glideslope-like” and more like:

  • “Turn left heading 170… on course.”

  • “Slightly right of course… correcting.”

  • “Begin descent to (altitude).”

  • “At (time/distance), execute missed approach if not in sight.”


Pilot “gotchas”

  • Vertical discipline is on you: This is where people bust altitudes.

  • Don’t assume a glidepath: ASR is not “PAR lite”—it’s lateral help plus your own descent planning.

  • Brief the missed early: You may be close-in when you hit the MAP/MDA.


3) No-Gyro Approach: “Radar turns without you using heading/gyro information”

What it is

A no-gyro approach is a technique ATC can use (often with radar) when your heading/gyro information is unreliable—classic partial panel, vacuum failure, bad DG/HSI, etc.


Instead of “turn left heading 180,” you’ll get:

  • “Start turn left.”

  • “Stop turn.”


ATC assumes you’ll make a standard-rate turn (or a specified rate), and they stop you when your track is where it needs to be.


What guidance you get

No-gyro can be combined with:

  • ASR (lateral corrections + your vertical), or

  • In some environments, with PAR-style talkdown methods (facility-dependent)


But the defining feature is turn control by start/stop commands, not heading assignments.


What you do as the pilot

  • Immediately establish a standard-rate turn when told “start turn.”

  • Roll out promptly on “stop turn.”

  • Keep airspeed stable—turn rate depends on airspeed/bank.

  • Fly the vertical profile as assigned/published (unless it’s a full PAR talkdown for vertical).


Pilot “gotchas”

  • Turn rate consistency is everything: If you speed up, your standard-rate bank changes; if you slow down, it changes again. Keep it stable.

  • Lag kills: If you’re late starting/stopping turns, you’ll overshoot and ATC workload increases fast.

  • Trim and configuration: Partial panel + changing configuration can turn into a wrestling match.


Practical pilot tips for all three

  • Brief it like a checkride: Who does what? What are your hard gates (altitudes, config, stabilized criteria)?

  • Stabilize early: Gear/flaps/power/trim set well before the controller starts rapid corrections.

  • Readbacks matter: Especially for altitudes and missed approach instructions.

  • Have the missed approach mentally “armed”: At minimums, you need to decide instantly.

  • Don’t be shy about workload: If you’re behind, say it. “Unable” beats guessing.


Bottom line

  • PAR = controller gives lateral + vertical precision talkdown (closest to an ILS without your own nav signals).

  • ASR = controller gives lateral only; you fly vertical like a non precision approach.

  • No-gyro = ATC controls turns with “start/stop” commands when you can’t reliably use heading/gyro—often layered on top of ASR/PAR methods.



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