ACS tolerances

The Private Pilot Airplane ACS (FAA-S-ACS-6C, effective May 31, 2024) sets two numerical tolerances, one bank-range requirement, and two structural requirements for turns around a point. The numerical tolerances anchor to entry values the DPE writes down before you begin.

The tolerances at a glance

Parameter	Target	Tolerance	Reference
Altitude	Entry altitude (600–1,000 ft AGL)	±100 ft	V.D.S4
Airspeed	Entry airspeed	±10 KIAS	V.D.S4
Bank range	30°–45° (varies with groundspeed)	Stay in band	V.D.S3

Plus two structural requirements:

• Constant-radius track around the reference point — V.D.S2
• Downwind entry at the appropriate distance — V.D.S1

Altitude ±100 ft

Anchored to the entry altitude. Two failure windows:

• Steepest portion (downwind): load factor at 45° bank requires noticeably more back pressure; under-pulling sinks the airplane.
• Bank transitions: as bank shallows through the upwind half, pilots sometimes ease off back pressure too much and balloon up.

Airspeed ±10 KIAS

Anchored to entry airspeed. Over-pulling on the elevator during the steep downwind portion is the typical cause of airspeed bleed.

Bank range 30°–45°

The bank must stay within the 30°–45° band throughout the maneuver. If the steepest point requires more than 45° to hold the radius, you entered too close to the point. If the shallowest point requires less than 30°, you entered too far away or the wind is too light to matter.

Picking radius matters. Choose an entry distance such that the steepest required bank is around 40°. That gives you headroom in both directions — 5° steeper if needed downwind, 10° shallower upwind. Entering too close makes the maneuver impossible to fly within bank tolerances.

Constant-radius track

The DPE evaluates the ground track from above: does it trace a clean circle around the point, or does it spiral or oval? Common bust modes are documented in pa.v.d.err.mdx.

The reference point itself is a visual cue — it should appear to stay at the same angle relative to your wingtip (or at the same offset across the windshield) throughout the turn.

Downwind entry

V.D.S1 requires entering at the appropriate distance on a downwind heading. Entering upwind or crosswind is an automatic S1 failure. Identify wind direction and verbalize the planned tangent point to the DPE before you commit.