Slow Flight, the Stall Warning, and the ACS Change That Stopped Us Riding the Horn All the Way Around the Pattern

Under the current Airman Certification Standards (ACS), slow flight is flown at an airspeed where the stall warning stays silent - just fast enough that any further increase in angle of attack, load factor, or reduction in power would trigger it. This is a deliberate change from the pre-2016 standard, which had pilots ride the stall horn continuously at minimum controllable airspeed. The FAA made the switch after the accident record showed too many stall-spin accidents in exactly that regime, and the practical effect is that you now fly just above the warning rather than parked in it.

What Is Slow Flight, Really?

Slow flight isn’t so much a maneuver as a place - the corner of the flight envelope where your airplane spends the most critical seconds of every flight: takeoff and landing.

When you rotate and climb out, you’re slow. When you’re on final fighting a gust and pulling power to idle over the numbers, you’re slow. Down there the controls feel different, the airplane gets mushy, and the margins are thinner.

The entire point of practicing slow flight at altitude is so that when you find yourself slow close to the ground - heart rate up - none of it surprises you.

How Did the Slow Flight Standard Change in 2016?

For decades, slow flight was taught right in the burble. The old Practical Test Standards had you fly at a speed just above the stall, using the stall warning horn as the target. You’d set up with the horn chirping and hold it there - turning, climbing, descending - riding the horn all the way around.

There was a logic to it: teach the pilot to control the airplane at minimum controllable airspeed, that ragged edge where any more back pressure and she quits flying.

But the FAA looked at the accident record and saw pilots stalling and spinning low in the pattern. The unintentional base-to-final stall spin is one of the oldest killers in general aviation, and it’s still with us.

So in 2016, when the FAA rolled the old PTS into the Airman Certification Standards (ACS), they changed the target. Now you establish and maintain an airspeed at which any further increase in angle of attack, any increase in load factor, or any reduction in power would result in a stall warning.

In plain English: fly just fast enough that the horn is quiet, but if you tightened a turn, pulled a hair more, or reduced power, the horn would start. You’re not riding the horn anymore - you’re living just above it.

Why the New Standard Is Better Training

Some instructors argued the change teaches pilots to fear the stall warning and softens the training. But the point of slow flight was never to prove you can tolerate the horn screaming at you.

The point is to develop the feel, the sight picture, and the control coordination to operate at high angles of attack with precision - and you can do all of that just above the warning instead of just below the stall.

This returns the stall warning to what it’s supposed to be: a warning, not a target. When that horn sounds low and slow in the pattern, you should react to it, not sit in it. Training pilots to comfortably ignore the horn for minutes at a time was arguably teaching a habit we didn’t want.

How Do I Fly Slow Flight the ACS Way?

Here’s the maneuver step by step, the way the examiner is looking for it.

1. Clear the area. You’re about to be slow and nose-high with lousy visibility over the cowl. Do two clearing turns and look for traffic, especially below and behind where someone might be climbing at you. Complete these maneuvers no lower than 1,500 feet above the ground.

2. Set up the slowdown. Bring power back toward idle to start decelerating - don’t yank the nose back. As airspeed bleeds off, raise the nose to hold altitude and add flaps in stages as you enter the white arc, if the maneuver calls for landing configuration. In many trainers that means full flaps, gear down if you have it, and a noticeably high pitch attitude.

3. Manage the three things that happen fast. As the airplane slows, control it deliberately while the regime changes under you.

What Changes When the Airplane Gets Slow?

Three things happen down there, and they happen quickly:

Region of reversed command. You need a lot of power just to hold altitude. On the back side of the power curve, slower requires more power, not less, because induced drag climbs steeply. Power controls altitude; pitch controls airspeed - that relationship flips from what feels natural, and the pattern is exactly where it bites people. You add power to climb and to arrest a descent.

Mushy controls. The ailerons feel wrapped in a blanket and the rudder needs real, deliberate pressure. Fly with authority but a light, anticipating touch - big, slow inputs, and lead everything.

Left-turning tendencies come roaring back. High power, high angle of attack, and low airspeed is the recipe for a lot of right rudder. In a single-engine airplane, if you’re not feeding in right rudder, the nose yaws left, the airplane is uncoordinated, and an uncoordinated airplane near the stall is how a wing drops and a spin starts. Keep the ball centered with your feet - your feet are doing more work than your hands down here.

Once established - nose high, power up, flaps out, horn quiet but ready to chirp - the examiner will have you fly straight and level holding altitude within 100 feet, holding heading and airspeed, then turns, then maybe climbs and descents. The whole time you manage that stall-warning line: if the horn starts, relax a touch of back pressure or add a little power and stay on the quiet side of it.

How Does This Prevent a Base-to-Final Stall Spin?

Picture a base-to-final turn at a busy airport. You got turned in tight, you’re high, and you’re slow because you configured early. You start to overshoot the extended centerline, so instinct says: tighten the turn, add bank. You don’t want to descend, so you pull. Uncomfortable with steep bank that low, you hold the bank shallow with aileron and skid the nose around with bottom rudder.

Stop right there. That exact sequence - slow, cross-controlled, pulling - is the classic base-to-final stall spin, and the airplane won’t give you much warning before the low wing lets go with no altitude to recover.

Every second of honest slow flight up at altitude trains you for that moment. You’ll have felt the airplane get mushy, you’ll know what your feet should be doing, and you’ll recognize the sound and the buffet. Instead of fighting it, you’ll do the right thing: go around. Add power, level the wings, fly away, and come back to try again. There’s no trophy for salvaging a bad approach.

How Do I Recover From Slow Flight?

The recovery is smooth and coordinated - you’re not slamming anything.

Add power smoothly, up to full if needed. Reduce the angle of attack by lowering the nose to the horizon to build airspeed. Retract flaps in stages as airspeed comes alive - not all at once, because dumping all your flaps at once dumps a lot of lift and the airplane will settle.

Keep the ball centered the entire time. As speed builds, the controls firm up and you climb away or level off.

What Are the Most Common Slow Flight Mistakes on a Checkride?

• Losing altitude in the turns. When you bank, some of your lift pulls you sideways, so you need a touch more back pressure and power to hold altitude. Pilots forget and sag 50 to 100 feet in every turn.
• Not enough right rudder. The nose wanders left and the ball goes out, and the applicant never notices because they’re staring at the airspeed.
• Getting pitch and power backward. Chasing airspeed with pitch and altitude with power - reversed - leads to porpoising and hunting. Be patient, make small corrections, and let the airplane answer before adding more.
• Parking in the stall warning. Under the current standard, a continuous stall warning is not what the examiner wants. A brief chirp while maneuvering is the edge you’re feeling for, but you should fly just above it.

Why You Should Practice Slow Flight Even When It Isn’t on a Test

Slow flight got easier to pass and more useful to fly when the standard changed - but easier to pass created a quiet problem. Many pilots learned it for the checkride and never went back, and this is a perishable skill. The feel fades, the right-rudder reflex gets lazy, and comfort with a high nose and a mushy airplane leaks away if you don’t top it off.

So next time you’re up on a calm evening with altitude to play with, go do some slow flight - not for a checkride, for you. Clear the area, get down there, and live in that corner of the envelope for a few minutes. Feel the airplane talk to you, do gentle turns, and notice how much rudder your feet are feeding in and how power and pitch trade jobs.

Then bring it home and fly a couple of patterns. Your approaches will be smoother because you’ll have recalibrated your hands and feet for exactly the regime where landings happen.

Everything here lines up with the Airman Certification Standards and the FAA’s Airplane Flying Handbook, and the current slow flight standard is worth pulling up in the FAA’s own words.

Key Takeaways

• Under the current ACS (since 2016), slow flight is flown just above the stall warning - quiet horn, not a continuous horn like the old PTS required.
• Fly the maneuver no lower than 1,500 feet AGL, and hold altitude within 100 feet, along with heading and airspeed.
• Down low you’re on the back side of the power curve: power controls altitude, pitch controls airspeed, and you’ll need lots of right rudder.
• The skill directly guards against the base-to-final stall spin - when in doubt, go around.
• Slow flight is perishable; practice it on your own to keep the feel, sight picture, and rudder reflex sharp.