IFR cross-country planning and regulations



  • FARs

    • Part 91 Subpart B
    • Part 95
  • IFR cross-country planning

    • Weather
    • Enroute charts
    • Nav log preparation
  • Lost communications procedures


  • pen and paper
  • Instrument Flying Handbook and The Pilot's Manual: Instrument Flying
  • NACO enroute and approach charts
  • nav logs
  • laptop with internet access, or iPad with ForeFlight/WingX

Instructor actions

  • Compare and contrast instrument cross-country planning to visual
  • Use FliteStar to show the selection of routes based on departure and arrival procedures
  • Discuss weather information relevant to planning

    • Describe night-before and day-of elements
    • Difference between outlook and standard weather briefing
  • Have the student present their route, with the first four navlog waypoints completed
  • Conclude with an oral quiz, identifying and correcting errors

Student actions

  • Arrive with completed route and navlog, including at least four waypoints
  • Maintain active involvement by responding to questions and taking notes
  • Complete an oral quiz and demonstration of the concepts

Completion Standards

The lesson will be complete when the student can apply their knowledge of instrument flight planning to a cross-country route and identify elements of charts and regulations with minimal instructor guidance.

Teaching outline


"Known icing conditions"

  • Unless the aircraft is approved for flight into "known icing conditions" (note: not known ice), the FAA's stance is very black and white.
  • To quote FAA legal counsel:

    • "Reduced to basic terms, known icing conditions exist where visible moisture or high relative humidity combines with temperatures near or below freezing. Since clouds are a form of visible moisture, flying through clouds at an altitude that is near or below freezing would constitute flight into known icing conditions."
    • "Flight into known icing conditions when the airplane flight manual or pilot operating handbook prohibits such flight would constitute a violation whether the aircraft accretes ice or not."
  • Airframe temperature may be below freezing when OAT is not, causing water droplets to accumulate as rime ice in temperatures above freezing.

§91.121 -- Altimeter settings

  • Altimeter must be set to:

    • reported altimeter setting from a station within 100 nm along the route when below 18,000 ft MSL
    • 29.92" Hg when at or above 18,000 ft MSL

§91.167 -- Fuel requirements for flight in IFR conditions

  • 45 minute fuel reserve should be carried
  • enough fuel to fly to the destination, shoot the approach, and divert to the alternate without dipping into the reserve
  • 1-2-3 rule allows us to eliminate the alternate fuel requirement:

    • For at least 1 hour before, and for 1 hour after the estimated time of arrival, the ceiling will be at least 2,000 feet above the airport elevation and the visibility will be at least 3 statute miles.
    • Required alternates must have approaches other than GPS available at the ETA.

§91.177 -- Minimum altitudes for IFR operations

  • Except when necessary for takeoff or landing, no person may operate an aircraft under IFR below minimum altitudes prescribed in §95 and §97 or, if no minimum altitude designated,

    1. over mountainous areas an altitude of 2,000 feet above the highest obstacle within a horizontal distance of 4 nautical miles from the course to be flown
    2. an altitude of 1,000 feet above the highest obstacle within a horizontal distance of 4 nautical miles from the course to be flown
  • If an MEA and MOCA are established, operations are permitted below the MEA but not below the MOCA when within 22 nm of the station
  • Climb to a higher minimum altitude should begin immediately after passing the point beyond which that minimum altitude applies

    • when ground obstructions are present, the point should be crossed at or above the applicable MCA

§91.179 -- IFR cruising altitude or flight level

  • When in controlled airspace, fly ATC assigned headings and altitudes

    • if VFR on top, fly VFR cruising altitudes
  • When in uncontrolled airspace, below 18,000 ft MSL, and on a course between:

    • 0-179°, fly odd thousands
    • 180-359°, fly even thousands

§91.181 -- Course to be flown

  • Fly the centerline of an airway, or on a direct course between navaids
  • Maneuvering to avoid aircraft or to clear the flight path in VFR is permitted

§95.x -- IFR Altitudes

As defined in §95.1:

  • MAA(maximum authorized altitude) defines the upper limit of an airway
  • MCA(minimum crossing altitude) determines the lowest permitted altitude when crossing the waypoint or fix to a higher altitude segment
  • MEA(minimum enroute altitude) is the lowest altitude permitted on the entire route, airway, or segment
  • MOCA(minimum obstruction clearance altitude) provides safe obstacle clearance along the route or airway, but reception is only guaranteed within 25 nm of the station
  • MRA(minimum reception altitude) is the lowest altitude at which an intersection can be determined using ground stations
  • COP(change-over point) suggests the best point to switch to the next station along an airway, guaranteeing continuous reception between facilities

Mountainous areas are defined by latitude and longitude.

IFR cross-country planning

Materials should include: A/FD, enroute and area charts, departure procedures, STARs, and approach plates for the intended route of flight.


Get an IFR briefing from FSS or a DUAT provider, including:

  • current and forecast conditions for departure, enroute, arrival, and alternate
  • winds aloft
  • ATC flow control
  • NOTAMs

Enroute charts

  • Use FliteStar to show Jeppesen format
  • Compare to approach plates

Nav log preparation

  • Take advantage of the FAA's existing routes:

    • start with a departure procedure
    • find STARs, if available, or the best approach's IAF
    • connect the dots using airways
  • ATC may assign a different route, if traffic is high
  • Factor in any performance considerations

    • climb rates
    • winds aloft
  • Determine cruising altitude using magnetic course and MEA
  • Consider alternates enroute as well as at destination

Lost communications

  • Route mnemonic:

    • Assigned
    • Vectored
    • Expected
    • Filed
  • Altitude mnemonic:

    • Minimum
    • Expected
    • Assigned
© 2022 Eric Gideon  •  archive