What is overbanking tendency and why does it occur in steep turns?

Overbanking tendency is the natural inclination of an aircraft to continue rolling toward a steeper bank angle once the bank exceeds approximately 45 degrees. It occurs because the outer wing travels faster than the inner wing through the turn, generating more lift on the outside and creating an uncommanded roll toward the inside of the turn. Pilots must apply a small amount of outside aileron pressure to maintain a constant bank angle. The Pilot's Handbook of Aeronautical Knowledge (PHAK) explains this as a direct result of the differential lift produced across the wingspan during steep, coordinated turns.

How does load factor increase during steep turns and what does that mean for stall speed?

Load factor increases as bank angle increases because the wings must support not only the aircraft's weight but also provide the centripetal force needed to maintain the turn; at a 60-degree bank, load factor reaches 2 Gs. According to the PHAK, stall speed increases with the square root of the load factor, so at 2 Gs the aircraft stalls at approximately 1.41 times its wings-level stall speed. This means a pilot who enters a steep turn too slowly or allows back-pressure to become excessive risks an accelerated stall. Understanding this relationship is essential for safely performing the steep turns maneuver evaluated on the Private Pilot Airplane Airman Certification Standards.

Why do students commonly lose altitude during steep turns and how should an instructor correct it?

Altitude loss in steep turns typically results from insufficient back-pressure to compensate for the increased load factor, or from failure to add power to offset the increased induced drag created by the steeper bank. Students often fixate on maintaining bank angle and forget that back-pressure must be continuously coordinated with it. An instructor should teach the student to establish the bank, simultaneously apply smooth aft elevator pressure, and add a small power increment to maintain both altitude and airspeed. The Aircraft Flying Handbook reinforces that altitude deviations are among the most common errors in steep turns and can be corrected by cross-checking the altimeter and attitude indicator throughout the maneuver.

Steep Turns: Overbanking Tendency, Load Factor, and Altitude Deviations

What Is a Steep Turn?

A steep turn is defined in the Airplane Flying Handbook (FAA-H-8083-3) as a turn performed at a bank angle of 45 degrees or more. For the Private Pilot Airman Certification Standards (ACS), the standard is exactly 45 degrees of bank; for Commercial, 50 degrees. These maneuvers are not just test pieces — they develop the precise coordination, situational awareness, and feel for aerodynamic forces that separate a competent pilot from an average one. As a CFI, your ability to explain the why behind every input is what transforms a student who can mimic the maneuver into one who truly understands it.

Overbanking Tendency: The Hidden Force

When a pilot rolls into a bank, the outer wing travels a longer arc than the inner wing. Because lift is a function of velocity (among other factors), the outer wing — moving faster through the air — generates more lift than the inner wing. In shallow and medium turns, this difference is negligible. But as bank angle increases beyond roughly 30 to 35 degrees, the lift differential becomes significant enough to cause the bank to steepen on its own without any additional aileron input. This is called overbanking tendency.

In practical terms: if a student rolls to 45 degrees and then neutralizes the ailerons, the bank will continue to increase. The airplane wants to steepen the turn by itself. The pilot must apply opposite aileron (the aileron on the high, outer wing) to hold the bank steady. This surprises most students who expect a neutralized control to hold a neutral position — that expectation holds for pitch but not for bank in steep turns.

Instructor Tip: Teaching Overbanking

A simple in-flight demonstration works well here. Establish a 30-degree bank with coordinated rudder and then slowly increase to 45 degrees while calling out the changing aileron pressure required. Let the student feel the airplane trying to roll steeper if they relax aileron pressure. This kinesthetic experience is far more memorable than any ground explanation alone.

Load Factor: The Physics of Turning

Every turn imposes an increased load on the wings because lift must now support the weight of the airplane and provide the centripetal force to curve the flight path. The result is a load factor greater than 1g. Load factor is expressed in g-units and is defined as the ratio of the lift the wings are producing to the actual weight of the airplane.

The relationship between bank angle and load factor is a trigonometric one: load factor = 1 / cosine of the bank angle. Key values every pilot must know:

30 degrees of bank: load factor ≈ 1.15g
45 degrees of bank: load factor ≈ 1.41g
60 degrees of bank: load factor ≈ 2.0g
75 degrees of bank: load factor ≈ 3.86g
90 degrees of bank: load factor = infinite (level flight is mathematically impossible)

At 45 degrees — the Private Pilot standard — the wings are supporting 1.41 times the airplane's weight. This has two critical consequences that students must master: increased stall speed and increased power requirement.

Accelerated Stall Speed

Stall speed increases with the square root of the load factor. At a 45-degree bank (load factor 1.41), stall speed increases by a factor of the square root of 1.41, which is approximately 1.19. If the normal power-off stall speed (VS1) is 50 knots, the stall speed in a 45-degree bank rises to roughly 59 knots. At 60 degrees (2g), stall speed increases by the square root of 2, or about 1.41 — so that same 50-knot airplane now stalls near 71 knots. This is why maintaining adequate airspeed and not over-slowing in steep turns is critical. Students who fixate on the altimeter and unconsciously bleed airspeed while adding back-pressure are moving toward an accelerated stall, possibly with a snap-roll departure.

Increased Power Required

Because induced drag rises with increased angle of attack (which is necessary to produce more lift at the higher load factor), more thrust is needed just to maintain altitude and airspeed. In a 45-degree bank, pilots typically add a small amount of power — the exact amount varies by aircraft, but recognizing this requirement and anticipating it is a mark of good airmanship. Failing to add power is one of the most common reasons students lose altitude in steep turns.

Maintaining Altitude: The Core Skill

Altitude maintenance during a steep turn requires the simultaneous management of three inputs: aileron (to hold the bank angle against overbanking tendency), elevator back-pressure (to increase the angle of attack enough to support the elevated load factor), and power (to counteract the added induced drag). Remove any one of these and a deviation follows immediately.

Why Students Gain Altitude

Altitude gain usually means excessive back-pressure. The student has applied too much elevator, raising the nose above the horizon. Because the bank redirects lift inward, the vertical component of lift still exceeds weight, and the airplane climbs. The correction is to relax back-pressure slightly and, if the bank angle has inadvertently decreased, re-establish the correct bank first, then re-trim the pitch.

Why Students Lose Altitude

Altitude loss is the more common error and typically has one of three causes: (1) insufficient back-pressure, so the vertical component of lift no longer equals weight; (2) insufficient power, causing airspeed decay and a reduction in total lift; or (3) a shallowing bank angle. When students fixate on the instruments inside the cockpit, they often let the bank creep shallower, reducing the centripetal force and allowing the nose to drop. The correction is to re-establish bank angle first, then increase back-pressure to recapture altitude.

The Coordination Requirement

Throughout a steep turn, the ball (slip-skid indicator) must remain centered. Because the turn requires inside rudder to overcome adverse yaw and the induced yaw effects, students must stay coordinated. A skidding turn (too much rudder for the bank) increases the risk of a cross-controlled accelerated stall. A slipping turn (too little rudder) wastes energy and degrades turn performance. Remind students: step on the ball.

Rolling In and Rolling Out

Students commonly make errors at the entry and exit of steep turns, not just during them. On entry, the pilot must apply back-pressure simultaneously with the roll — not after the bank is established. Delay produces an immediate altitude loss as the increasing bank reduces vertical lift. On exit, the pilot must roll out early enough to stop on the target heading. A 45-degree bank produces a rapid turn rate, so a rollout lead of roughly half the bank angle (about 20–22 degrees before the target heading) is a practical rule of thumb. As the bank decreases on rollout, the load factor decreases, so back-pressure must be smoothly reduced to avoid a climb. Failure to reduce back-pressure on rollout is a classic error that causes a nose-high exit and altitude gain.

Completion Standards (ACS Reference)

Under the Private Pilot ACS, steep turns must be performed at 45 degrees of bank, within ±100 feet of the entry altitude, within ±10 knots of the entry airspeed, within ±10 degrees of the rollout heading, and with the bank angle maintained within ±5 degrees. Commercial Pilot standards at 50 degrees of bank use the same heading tolerance as Private, with tolerances of ±100 feet, ±10 knots, ±10 degrees of heading, and ±5 degrees of bank. These tolerances exist because at high bank angles even small deviations compound quickly — emphasize to students that precision comes from anticipation and outside visual reference, not from staring at instruments.

Memory Aid

Use the phrase "Bank, Back, Boost" to remember the three simultaneous inputs when entering a steep turn: Bank — roll to the target angle; Back — apply elevator back-pressure as the bank increases; Boost — add power to maintain airspeed. During rollout, simply reverse the sequence: reduce back-pressure and reduce power as the bank comes out. This three-word sequence gives students a mental checklist they can self-cue in flight.

Common Test Traps

Load factor at 60 degrees is exactly 2g — not 1.7g or 2.5g. The cosine of 60 degrees is 0.5, so 1/0.5 = 2.0. This precise value is a frequent knowledge-test question.
Overbanking tendency requires opposite aileron, not opposite rudder. Students confuse overbanking with adverse yaw; they are separate phenomena requiring different corrections.
Rolling out too late. Students often begin the rollout on the target heading rather than before it, and overshoot. The test evaluator will notice a heading deviation beyond ±10 degrees (Private or Commercial).
Forgetting to reduce back-pressure on rollout. As bank decreases, the load factor drops; holding the same back-pressure causes the nose to pitch up and altitude to increase above the entry altitude.
Assuming power is optional. Some students believe altitude can be maintained by back-pressure alone. In reality, the increased induced drag at high load factors requires a power addition — back-pressure without power merely causes speed decay and moves the airplane closer to an accelerated stall.