Flying Notes

Appearance

Nonprecision Approach ​

This page covers Task A. Nonprecision Instrument Approach (NPA) from the FAA-S-8081-9E Flight Instructor Instrument Practical Test Standards.

Nonprecision Instrument Approach Types ​

  • LNAV
    • See overview section on GPS Approaches
  • LNAV(+V)
  • LP
  • LOC
    • 3-6° beam width
    • 4 times as sensitive as VOR
    • LOC-A, for example (with letter) if approach to runway is too steep (more than 3°)
      • See CBE LOC-A
  • VOR
  • NDB
    • Need to have working ADF onboard unless the approach has a GPS overlay NDB OR GPS
  • LDA
    • Like a localizer, but there is more than a 3° deviation in its alignment with runway heading
    • This offset is noted on the approach chart either in the localizer box, or near it as a note
    • May or may not have a glide slope
    • When it has a glideslope it is an APV procedure
  • SDF
    • Basically extinct
    • Poor man's localizer
    • 6-12° beam width
  • GPS
    • Usually the MAP is a flyover waypoint (4-pointed star with circle around it)
      • Think circle or "O" around the star for "over"
  • ASR
    • This is TRACON approach controller
    • Non-precision version of PAR

Other Approach Types ​

  • Visual approach
    • requires 3 sm visibility and 1000' ceilings
    • May be requested by pilot
    • May be assigned by ATC
  • Contact approach
    • Requires 1 sm visibility and clear of clouds
    • May only be requested by pilot
    • Visual contact with ground or preceding aircraft
    • No assurance of obstacle clearance

Other Non-precision Approach Concepts ​

  • Visual descent points (VDP)
    • Point at which a descent from MDA to runway is made with a 3° angle
    • Published on some non-precision approaches with bold "V" near runway
    • 3° is about 300'/nm descent so that can be used to calculate VDP if it is not on approach plate
    • Should always predetermine a VDP if not published
  • GPS can be used instead of the VOR receiver for a VOR approach if the underlying NAVAID is monitored for course guidance

LDA Approach Plate Examples ​

  • May or may not have a glideslope
KTVL LDA RWY 18.
KSLC LDA RWY 35.

Completion Standards ​

FAA-S-ACS-8C Instrument Rating Airplane Airman Certification Standards

References ​