AINsight: Spin Cycle

 - September 23, 2022, 10:38 AM
cross-control stall on flight display
The dangerous nature of a skidded turn cross-control stall is often overlooked, according to Aviation Performance Solutions CEO Paul “B.J.” Ransbury. In fact, they are attributed to nearly 60 percent of all approach and landing accidents and are almost always fatal. (Photo: Aviation Performance Solutions)

Decades ago, the FAA removed spin training from the private pilot curriculum. Rather than teach spins, the FAA focused on stall recognition and prevention. This paradox promotes a theory that in the absence of a stall, there would be no spin. The problem is that people continue to die from stall/spin accidents.

Today, only flight instructor candidates are required to do spins. Oddly enough, most CFIs today are required to only have a spin “sign off”—a logbook endorsement—and often do not have the thorough in-depth academic or on-aircraft training required to properly teach a spin. 

Industry professionals engaged in upset prevention and recovery training (UPRT) programs recognize that the chronic risk in spin training is the poorly trained instructor.

Aviation Performance Solutions CEO Paul “B.J.” Ransbury said that “spin training as done today typically skips major knowledge, skills, and awareness development by going from the docile coordinated stalls right into the fully developed spin without comprehensively addressing the stages of escalation of the stall/spin between those extremes. For example, the dangerous nature of a skidded turn cross-control stall is often overlooked.” 

Statistics support Ransbury. According to an AOPA Air Safety Foundation study (the Nall Report), cross-controlled stalls/spins are attributed to nearly 60 percent of all approach and landing accidents and are almost always fatal. 

Furthermore, only aerobatic or utility aircraft approved for intentional spins are certified to recover from developed spins beyond one turn of rotation. This adds to the challenge of conducting robust spin training in the current flight training environment. 

This is a critical point,” Ransbury said. “If a pilot gets into a developed spin beyond the normal-category aircraft standard of one turn of rotation, then they are a test pilot—there is no guarantee of a recovery. The one-turn margin in a normal-category aircraft is primarily built-in for a delayed response to a stall recovery, not a deliberate one-turn spin.”

Part of the problem is how pilots are trained today. Traditional stall training involves a slow deceleration in airspeed with an ever-increasing nose-high attitude and angle of attack to the stall. Most pilots never experience a stall in a nose-low attitude. 

A cross-control stall—slipping or skidding—often involves a nose-low attitude in an uncoordinated turn that have remarkably different post-stall characteristics. According to Ransbury, “The slip is stall-spin resistant, tends to maintain energy state, with a resulting increase in rate of descent, and when the stall occurs, the slip tends to roll towards upright—a favorable response to support the recovery.

The skid is a nasty beast; it is typically energy depleting, pro-stall/spin, and when it stalls it rolls toward the inverted, with natural pilot responses further aggravating the flight condition toward the developed spin.

This scenario plays out over and over again in cross-controlled stall/spin accidents involving a skidded turn, where a pilot attempts to use the inside rudder to correct an “overshoot” from the downwind to base or base-to-final turn. This is a killer. 

Accident data supports a change in the way pilots are trained—or not trained—to understand, recognize, avoid, and recover from a scenario that involves an inadvertent stall and spin. There are far too many fatal stall/spin accidents in the traffic pattern, near the ground. 

Due to the low altitude, early stall recognition and prevention may be the only option to survive an encounter with a stall. In particular, the cross-control skidded turn stall may result in insufficient time and/or altitude to avoid the ground even with a perfectly executed recovery.

Identified hazards to changing the curriculum for primary flight students are a cadre of CFIs that are not properly trained to teach spins and a fleet of training aircraft that provide a slim safety margin if a spin develops beyond one full rotation. The risk of combining today’s flight instructors and training aircraft to train future generations of pilots would be catastrophic—the number of stall/spin training accidents would be unacceptable.  

APS’ Ransbury believes “a fully comprehensive spin awareness, prevention, and recovery training program would include several hours of academics and at least two flights. The flights would address regulatory requirements while comprehensively teaching intervention techniques throughout the entire stall-spin escalation, unintentional slow flight, approach to stall, level and turning stalls, slipping stall, skidding stalls, incipient spins, one-turn spins, and fully developed spins in a spin-approved training airplane.

The target should be to increase pilot awareness of the threat and the knowledge, skills, and disciplines to stop a developing stall/condition as early in the escalation process as possible. Moreover, UPRT is essential—and by design should integrate comprehensive stall/spin awareness and recovery training—yet similarly lacks competent instructors to teach it as intended by ICAO Doc. 10011.”

Ransbury said that “one of two things could happen if the FAA were to require spin training for primary students: the FAA would insert themselves and require much more robust spin training for CFI candidates or there could be an increase in fatal spin training accidents in ab-initio flight training.” 

As suggested, current spin training often does not address the reality of most stall/spin accidents. One solution would be to avoid the decades-old “pro-spin versus anti-spin” argument and adopt a new “spin training done differently” approach. That would include pilots training with highly qualified instructors in aircraft (at altitude) that provide an adequate safety margin to simulate scenarios that are proven killers in aviation, such as the cross-control skidded turn traffic pattern stall in the turn from downwind to base to final.