geoprimsField-grade geospatial math

IFR approach brief

The weather, the holding speed, the entry, the wind-corrected hold, and the visual descent point.

For instrument pilots · 6 steps · each opens with the values filled in

Planning and education aid. Not for primary navigation. The values here are an example; use your own. Full disclaimer

  1. Step 1

    METAR decoder

    Read the weather at the field.

    You should see KBJC is IFR with wind 340° true at 12 kt and visibility 3 SM. The ceiling is 800 ft. Get a current official briefing before flight.

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  2. Step 2

    Maximum holding airspeed

    The most you may fly in the hold at 9,000 ft.

    You should see The maximum holding speed is 230 kt (AIM table 5-3-1, 6,001 ft through 14,000 ft).

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  3. Step 3

    Holding pattern entry

    Arriving on a 150° heading for a hold with a 300° inbound course, right turns.

    You should see Fly a parallel entry. Cross the fix, turn to parallel the outbound course on the non-holding side (120°) for about 1 minute, then turn left back to the fix.

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  4. Step 4

    True and magnetic bearings

    The METAR wind is true; holding courses are magnetic.

    Carries bearing from step 1.

    You should see The converted bearing is 332.4°, using 7.6° E of variation.

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  5. Step 5

    Holding wind correction and timing

    Headings and timing that keep the hold's shape in that wind.

    Carries wind from from step 4, wind speed from step 1.

    You should see Fly 303° inbound and 111° outbound for 51 s.

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  6. Step 6

    Visual descent point

    Where to leave the minimum descent altitude for a 3° path.

    You should see Start down from the MDA 1.38 NM from the threshold. Descend at about 478 ft/min.

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