ACS tolerances

The Private Pilot Airplane ACS (FAA-S-ACS-6C, effective May 31, 2024) anchors soft-field-landing tolerances around the stabilized approach (inherited from the normal landing, B), the soft touchdown with no drift, and the continued back-elevator to keep weight off the nose during rollout.

The tolerances at a glance

Parameter	Target	Tolerance	Reference
Approach airspeed	Manufacturer-recommended (or 1.3 V_SO)	±5 KIAS	V.D.S2
Touchdown	Soft, no drift, proper pitch attitude	No hard landing, no drift	V.D.S3
Rollout	Weight off nose, no nose-over	Sustained back pressure	V.D.S4

Plus structural requirements:

• Stabilized approach in the recommended configuration — V.D.S1, S2
• Soft touchdown with no drift in proper landing attitude — V.D.S3
• Weight kept off the nose wheel during rollout — V.D.S4

Approach airspeed ±5 KIAS

Same standard as the normal landing (B). Anchored to manufacturer's recommended approach speed (V_REF) or 1.3 V_SO.

The soft-field landing does not require a slower approach airspeed than the normal landing — the slow-touchdown effect comes from the extended flare, not from approaching slower than V_REF.

Soft touchdown, no drift

V.D.S3 is the maneuver's defining tolerance. The touchdown must be:

• Soft. Minimum sink rate at touchdown — almost imperceptible. A hard touchdown is a bust even if otherwise normal.
• No drift. Wheels track straight at the moment of touchdown. Crosswind correction (per B) must be active.
• Proper pitch attitude. Main gear first, nose well off the runway. A flat or nose-first touchdown is a bust.

The DPE evaluates the touchdown by feel from the right seat: a soft touchdown is heard as a faint contact; a hard touchdown is unmistakable.

Weight off the nose wheel during rollout

V.D.S4 requires continued back-elevator through the rollout to keep the nose wheel off the surface as long as possible. Elevator authority fades with airspeed; the nose will eventually settle, and that's expected — what the standard prohibits is an early nose-down from relaxed back pressure.

The DPE evaluates by watching the elevator from the right seat and watching the pitch attitude of the airplane through the rollout window.

No published touchdown-zone tolerance. Unlike the normal landing (B), which requires touchdown within the first third of the runway, the soft-field landing's touchdown precision isn't specified by a runway-distance tolerance. The maneuver is about touchdown quality, not touchdown precision. The short-field landing (F) is where touchdown-distance precision becomes a tolerance.