Standard vs Half-Standard Rate Comparison
Side-by-side at your TAS: bank, radius, time-around and g for 3°/s versus 1.5°/s — and the speed where procedure design quietly switches.
The crossover lives near 170 kt TAS (where standard rate hits the 25° cap). Above it, your real-world turn rate is set by the bank limit — which is why FMS holding patterns at altitude are enormous and why ATC vectors widen for jets.
Formula
⚠️ For flight planning and education only — verify with official sources and certified equipment. Not for primary navigation.
Side-by-side at your TAS: bank, radius, time-around and g for 3°/s versus 1.5°/s — and the speed where procedure design quietly switches.
About Standard vs Half-Standard Rate Comparison
Somewhere around 170 knots, instrument flying changes gear: the bank that standard rate demands crosses the 25° comfort-and-autopilot cap, and aircraft quietly become bank-limited — turning at whatever rate the capped bank delivers. This comparison tool computes both regimes for your TAS: the banks each rate requires, the rate your actual bank limit produces, and the resulting radius — the geometry behind oversized jet holding patterns and the half-standard convention.
How to use Standard vs Half-Standard Rate Comparison
- 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 bank = atan(V·ω/g) per rate; at a bank cap, achieved rate = g·tan(cap)/V substituted step by step.
- 4Adjust inputs (or flip the unit toggle) until the scenario matches yours, then copy or share the result.
Why use Standard vs Half-Standard Rate Comparison?
- ✓Instant, free and private — every calculation runs in your browser, nothing is uploaded
- ✓Built on the published formula bank = atan(V·ω/g) per rate; at a bank cap, achieved rate = g·tan(cap)/V with sources cited on the page
- ✓The crossover lives near 170 kt TAS (where standard rate hits the 25° cap). Above it, your real-world turn rate is set by the bank limit — which is why FMS holding patterns at altitude are enormous and why ATC vectors widen for jets.
- ✓Switch units, tweak any input and watch every result update live
Frequently asked questions
Who decides whether I fly standard or half-standard rate?+
Physics first, procedure second: PANS-OPS and TERPS design protected airspace assuming the lesser of 3°/s or a fixed bank (25° typically), so flying the bank-capped rate keeps you inside containment by construction. Older turn needles marked '4 min turn' (half-standard) for fast aircraft; modern jet SOPs simply command bank limits and let the rate fall out.
Why cap bank at 25° at all?+
Stacked margins: passenger comfort degrades past ~25°, autopilots certify to bank limits with buffet margin in reserve, and at high altitude the gap between cruise speed and low-speed buffet narrows enough that 30°+ banks genuinely threaten it (load factor raises buffet speed). The cap is where comfort, certification and aerodynamics happen to agree.
How big do holding patterns get for fast aircraft?+
At 250 kt TAS bank-limited to 25°, the turn radius is ~1.9 nm — each 180 sweeps nearly 4 nm of width, before wind drift. That's why holding airspace at altitude is designed in tens of miles, why FMS-computed holds look comically large on the map display, and why slowing to holding speed early is fuel-smart AND containment-smart.
Does my light aircraft ever meet the bank-limited regime?+
Only descending a fast single from altitude (a 200-kt TAS descent wants 28° for standard rate) or in cruise in the speedier singles. Practically, GA instrument flying lives comfortably in the standard-rate world — but understanding the crossover explains the behavior of every jet you share a hold or a vector sequence with, which has tangible spacing consequences behind it.
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