Random Facts to Remember SC

IFR Facts to TRY and Remember


  • Localizer freq 108.1-111.95
  • Localizer reception 18nm out, 1,000ft. Above highest terrain, 4,500ft above antenna site
  • Localizer 3-6 degrees wide, 700ft wide at approach RWY threshold
  • Good for 10 degrees left or right of course out to 18nm, 35 degrees off course 10nm out
  • LDA is not aligned with the runway, straight in mins may apply up to 30 degrees off of RWY heading, otherwise circling mins only
  • SDF may have course width of 6 or 12 degrees
  • Glideslope is 250’ to 650’ to the side of RWY, transmits signal 1.4 degrees wide (vertically)
  • Only guaranteed to provide vertical guidance down to DA/DH
  • Glide path typically intersects MM at 200ft AGL and OM at 1,400 AGL
  • Glideslope generally usable up to 10nm from the station
  • False glide path indications occur when far off of intended path
  • TCH is the height that glideslope antenna on A/C would be when crossing the threshold

Speed Limitsifr speed limit airspace

  • 250 KIAS below 10,000’ msl
  • 250 KIAS inside of Bravo Airspace
  • 200 KIAS underneath the Bravo Airspace
  • 200 KIAS within 4nm of a primary airport in Class C or D airspace when you are within 2,500’ agl of the surface.

Minimum Turning Altitude

  • Designated as a MCA with a flag
  • Text will read “MTA” i.e. MTA V330 E TO V520 W 16000
  • Common in mountainous areas at higher altitudes where high ground speeds of aircraft necessitate wider turns


  • Depicted on Low Charts with Compass Rose for H,L, or none for T
    • H or L is in chart supplement
  • Airways 4nm wide or 4.5 degrees wide when COP more than 51nm from the station
  • Must file the first point as VOR when equipment /U
  • Holding Patterns

    • 0-6,000ft msl 200knots
    • 6,001msl-14,000 msl 230knots
    • 14,001 msl+ 265knots
    • Slow to holding speed 3 mins prior to crossing the holding fix
    • At or below 14,000’ msl 1min
    • Above 14,000’ msl 1.5min

Clearance Limits

  1. If no holding pattern is charted and holding instructions have not been issued, the pilot should ask ATC for holding instructions prior to reaching the fix. If unable to obtain holding instructions prior to reaching the fix (due to frequency congestion, stuck microphone, etc.), hold in a standard pattern on the course on which you approached the fix and request further clearance as soon as possible.
  2. When an aircraft is 3 minutes or less from a clearance limit and a clearance beyond the fix has not been received, the pilot is expected to start a speed reduction so that the aircraft will cross the fix, initially, at or below the maximum holding airspeed.
  3. When no delay is expected, the controller should issue a clearance beyond the fix as soon as possible and, whenever possible, at least 5 minutes before the aircraft reaches the clearance limit.