Procedure Turn Timing Calculator (45/180)
The 45-180 course reversal timed out: outbound leg, the 45° offset, the 180 back — each segment's seconds and the protected-airspace check.
A standard-rate 180 takes one minute, during which you traverse a half-circle of diameter GS/60 nm — at 100 kt, 1.7 nm of lateral offset, conveniently close to the 45/180's geometry. 'Remain within 10 nm' is measured from the fix, wind included: time conservatively into a tailwind outbound.
Formula
⚠️ For flight planning and education only — verify with official sources and certified equipment. Not for primary navigation.
The 45-180 course reversal timed out: outbound leg, the 45° offset, the 180 back — each segment's seconds and the protected-airspace check.
About Procedure Turn Timing Calculator (45/180)
The 45/180 procedure turn looks casual on the plate — a barb and a 'remain within 10 nm' — but flying it tidily is segment arithmetic: outbound timing, a 15-second 45° turn, a one-minute leg, a 60-second 180, and the intercept, all drifting with the wind against a protected-airspace boundary. This calculator times each piece at your ground speed and estimates the farthest excursion from the fix, the number the 10-nm limit actually constrains.
How to use Procedure Turn Timing Calculator (45/180)
- 1Enter — sensible defaults are pre-filled so you see a worked result immediately.
- 2Read the live results: .
- 3Check the "With your numbers" line to see the formula segments at GS; standard-rate: 45° = 15 s, 180° = 60 s; half-circle diameter ≈ GS/60 nm substituted step by step.
- 4Adjust inputs (or flip the unit toggle) until the scenario matches yours, then copy or share the result.
Why use Procedure Turn Timing Calculator (45/180)?
- ✓Instant, free and private — every calculation runs in your browser, nothing is uploaded
- ✓Built on the published formula segments at GS; standard-rate: 45° = 15 s, 180° = 60 s; half-circle diameter ≈ GS/60 nm with sources cited on the page
- ✓A standard-rate 180 takes one minute, during which you traverse a half-circle of diameter GS/60 nm — at 100 kt, 1.7 nm of lateral offset, conveniently close to the 45/180's geometry. 'Remain within 10 nm' is measured from the fix, wind included: time conservatively into a tailwind outbound.
- ✓Switch units, tweak any input and watch every result update live
Frequently asked questions
Is the 45/180 the only legal way to fly a charted PT?+
No — where a procedure turn is charted (the barb), the 45/180 is the depicted suggestion, but any maneuver on the protected side within the distance limit satisfies it: the 80/260, a teardrop, even a racetrack. The barb's side and the distance are regulatory; the geometry is pilot's choice. (Where 'NoPT' is charted, no reversal may be flown without clearance.)
How does wind corrupt the textbook timing?+
Two ways: a tailwind outbound carries you farther from the fix per minute (eating the 10-nm budget — shorten the outbound timing), and the wind drifts every turn's ground track. The classic correction: adjust outbound time by the head/tail component's fraction (our wind tools give the component) and crab the straight legs. The protected airspace was designed with wind allowances — for aircraft that make honest corrections.
Why one minute on the 45° leg?+
Geometry that works out: 45° off-course for a minute displaces you laterally about 0.7 × GS/60 nm — at 100 kt, 1.2 nm — which positions the subsequent 180 to roll out comfortably on an intercept back to the inbound course. Longer legs widen the intercept angle's comfort at the cost of distance budget; the one-minute convention balances them for typical approach speeds.
When are procedure turns disappearing from real flying?+
Steadily: RNAV approaches with TAA sectors, radar vectors to final, and HILPT (hold-in-lieu) racetracks have replaced most charted PTs in practice — many instrument pilots fly years between real ones. They persist at non-radar airports and on legacy VOR/NDB procedures, and in every instrument checkride, where the examiner knows precisely how rusty the timing arithmetic gets. This page is the rust remover.
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