IFR
Holding, DME, and station geometry for instrument flying.
Holding entries, holding speeds and wind correction, DME slant range and arcs, radial fixes and intercepts, and time to a station, for instrument pilots planning or reviewing a procedure. Start with the holding entry tool, which picks direct, teardrop, or parallel from your heading and the hold's inbound course, per AIM 5-3-8. Decide the entry from your heading as you reach the fix, not from where you are when the clearance comes. ATC instructions and the published procedure always govern.
Planning and education aid. Not for primary navigation. Full disclaimer
I want to choose a holding entry
- Holding pattern entry
Which holding entry to fly (direct, teardrop, or parallel) from your heading to the fix, the inbound course, and the turn direction, per AIM 5-3-8, with the headings for each entry.
I want to know the maximum holding airspeed
- Maximum holding airspeed
The maximum holding airspeed for your altitude from the AIM table (200, 230, or 265 KIAS), or a published limit, with a flag when your planned speed is above it.
I want to correct a hold for wind and time the legs
- Holding wind correction and timing
Inbound and outbound headings for the wind, the outbound time that gives a 1-minute inbound leg, and the triple-the-drift rule of thumb beside the exact values.
I want to find the fix on a radial at a distance, with the station's variation
- Fix from a radial and distance
The position on a VOR radial at a distance from the station, using the station's published variation, with a warning when today's magnetic field differs from it by more than 1°.
I want to turn a DME reading into ground distance
- DME slant range to ground distance
The distance over the ground to a DME station from the DME reading and your height above the station, and how much the reading overstates it.
I want to time a bearing change to find the station
- Time and distance to a station
How far and how long to a VOR or NDB from the time a bearing takes to change while you fly square to it, exactly and by the 60-times rule.
I want to find the lead points for a DME arc
- DME arc lead points
Where to start the turn onto a DME arc from a radial, and how many radials early to turn off the arc onto an inbound course, from the arc's DME and your standard-rate turn.
I want to find the heading to intercept a radial
- Heading to intercept a radial
The heading to fly to intercept a VOR radial inbound or outbound from the radial you are on now, with the intercept angle doubled from the angle off course or set by you.
Guides that use these tools
- IFR approach brief: The weather, the holding speed, the entry, the wind-corrected hold, and the visual descent point.