Slow Flight

HASELL Checks

Before practicing any slow flight or stalling exercise, you must complete the HASELL check. This ensures you are in a safe environment to explore the edges of the flight envelope.

H — Height

Sufficient altitude to recover safely. Minimum 3,000 feet AGL for training exercises.

A — Airframe

Configuration appropriate for the exercise: flaps as required, landing gear (if retractable), brakes off, trim set.

S — Security

Harnesses tight, loose articles stowed, hatches and doors secure.

E — Engine

Temperatures and pressures in the green, fuel on fullest tank, mixture set, carburetor heat as required.

L — Location (ABCC)

Away from controlled airspace, Built-up areas, Clouds, and Congested traffic areas. Choose a practice area with clear terrain below.

L — Lookout

Complete a clearing turn (180° or two 90° turns) to ensure the area is free of other traffic above, below, and all around.

Entering Slow Flight

The procedure for controlled deceleration to critically slow airspeed follows the Power-Attitude-Trim sequence:

Step 1 — POWER: Reduce

• Smoothly reduce power toward idle (or a low power setting as briefed)
• The airplane will begin to decelerate

Step 2 — ATTITUDE: Pitch Up to Maintain Level Flight

• As the airspeed decreases, progressively raise the nose to maintain altitude
• The pitch attitude will be noticeably higher than cruise — this is normal
• As speed continues to decrease, you will need to add power to maintain altitude (speed-unstable region)

Step 3 — TRIM

• Trim to relieve control pressure as you stabilize at the target speed
• Target: approximately 5 knots above V_S1 (or V_S0 if flaps are extended)

Maneuvering in Slow Flight

Once stabilized in slow flight, practice:

• Maintaining altitude and heading — notice how much attention it requires
• Gentle turns (15 degrees bank maximum) — add a touch of power to compensate for the increased load factor
• Climbing and descending using power changes while maintaining slow airspeed

Recovery to Normal Flight

Recovery from slow flight to normal cruise uses a positive, sequential procedure:

Step 1 — POWER: Steadily Increase to Full

• Apply power smoothly and progressively — avoid slamming the throttle open, which can cause a yaw to the left
• Maintain balanced flight with right rudder as power increases

Step 2 — ATTITUDE: Maintain Altitude Until Airspeed Increases

• Hold altitude — the nose will need to come down slightly as speed builds
• Once airspeed reaches normal climb speed (V_Y), pitch to the climb attitude if a climb is desired
• Or maintain level flight as speed increases toward cruise

Step 3 — TRIM

• Re-trim for the new flight condition (climb or cruise)
• Retract flaps in stages once safely above V_S1