Circuits/Traffic Pattern

Objectives

Understand safe operation in the traffic pattern at towered and non-towered airports.

Reading

This is the required reading for this lesson. Numbers in [brackets] indicate the starting and ending page in the referenced reading material. Read all the pages and sections referenced.

Summary

The notes below highlight the important parts in the referenced material. Reading the notes without having read the actual referenced material is generally not sufficient to pass the written exam!

PHAK - Chapter 2

  • Contributing factor in many accidents is distraction
    • Keep scanning for traffic outside; monitoring instruments
  • Prepare ahead of time to avoid work overload
    • Listen to the ATIS, ASOS, or AWOS for weather information
    • Listen to ATC before speaking to get an idea of the current traffic

PHAK - Chapter 14

  • Nontowered Airports
    • Always enter at pattern altitude
    • Preferred arrival method: 45 degree entry to midfield downwind
  • Towered Airports
    • ATIS records weather conditions and runways in use
  • Traffic Patterns
    • Pattern altitude
      • Propeller-driven: 600 feet to 1,500 feet above ground level
      • Military turbojet: as high as 2,500 feet above ground level
      • 1,000 feet AGL is the recommended pattern altitude unless otherwise noted in the Chart Supplement.
  • Wake Turbulence
    • Generated by all aircraft; larger aircraft create stronger turbulence.
    • Wake vortices tend to drift with the wind and sink below flight path.
    • Wake vortices begin once aircraft rotates; end once aircraft touches down.
    • Light quartering tailwind is the most dangerous (keeps the turbulence over more of the runway)
    • Avoidance principles:
      Your aircraft Other aircraft Avoidance...
      Landing Departing Land prior to the departing aircraft's rotation point;
      Landing Land beyond the landing aircraft's touchdown point;
      stay at or above its approach path
      Departing Departing Rotate prior to the departing aircraft's rotation point; climb above its flight path; turn clear when able.

AFH - Chapter 7

  • Standard Traffic Pattern
    Left-Hand Traffic Pattern (Turns to the Left)
    Traffic Pattern Altitude (TPA): 1000 feet above ground level (AGL)
    Medium-banked turns (20-30 degrees)
    Departure Straight course aligned with takeoff runway.
    Crosswind 90-degree turn from departure/upwind to crosswind.
    Begin turn once within 300 feet of TPA.
    Downwind 90-degree turn from crosswind to downwind.
    Parallel to runway; opposite direction; ½ - 1 mile from runway.
    Maintain TPA until abeam the approach end of the runway.
    Base 90-degree turn from downwind to base.
    Begin turn once 45-degrees from approach end of runway.
    Final 90-degree turn from base to final.
    Final approach and descent to landing.
    Special legs...
    Upwind Transition from final approach to climb after a go-around.
    Entry 45-degree entry to midfield downwind
    Established at pattern altitude (not climbing/descending)
    Exiting If departing pattern, two options:
    1. Depart straight out;
    2. Exit with a 45-degree turn to the left.
  • Exceptions to standard traffic pattern:
    • Noted in the Chart Supplement (i.e., right turns, higher/lower TPA)
    • ATC may provide exceptions as needed for traffic
  • Entry on opposite side of pattern:
    1. cross 500 feet above TPA, circle to enter downwind on 45, or
    2. cross at TPA direct entry to downwind
  • Right-of-Way Rules:
    • 14 CFR Part 91:
      • Aircraft on final have right-of-way over other aircraft.
      • Aircraft at lower altitude has right-of-way

Sim Pilot Notes

These notes highlight the differences between simulator and real-world flying. These differences are most often due to simulator limitations or specific VATSIM rules.

  • Wake Turbulence: At this point, most simulators do NOT simulate wake turbulence; however some add-on weather program do simulate it. VATSIM ATC will still issue cautions for wake turbulence.
  • Nontowered Airport Frequencies: In the real world, uncontrolled airports have a variety of CTAFs (Common Traffic Advisory Frequencies). This helps avoid radio congestion. As of this document's creation, VATSIM uses a single UNICOM frequency of 122.800 for simplicity.
  • ATC Pattern Instructions: Be aware of the following common instructions while operating in the pattern:
    • "Extend downwind, I'll call your base." This means you should continue flying on the downwind leg. Do not turn base until told to do so by ATC.
      • If you think ATC has forgotten you, ask them.
    • "Make a left/right 360." This means you should make a 360-degree turn in the specified direction. This is used by ATC for traffic flow and spacing.
      • CAREFUL! DO NOT CONFUSE WITH "HEADING 360"!
    • "Follow the traffic…" This means you should follow the traffic pointed out by ATC in the pattern.
    • "Cleared to land, number 2." This means you are the second aircraft on approach, and are cleared to land once the first aircraft is clear of the runway.

Tomas Hansson (This email address is being protected from spambots. You need JavaScript enabled to view it.)
Chief Flight Instructor, VATSTAR
DISCLAIMER: all information contained herein is for flight simulation purposes only.
March 2021

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