Two years ago, the author of this article had the unfortunate experience of seeing a jumper cut away very low and deploy the reserve too low to survive. Since then, he has researched how jumpers react during emergency situations and interviewed numerous experienced jumpers about their experiences and opinions. This article is the result of that research.
After reading this article, please let us know how you feel about the five-second rule. Do you agree with the author? Do you have your own experiences to share? Send your comments, opinions or stories to safety@uspa.org. Together, we can make a difference.
—USPA Director of Safety and Training Ron Bell
Skydivers and fighter pilots share a unique characteristic: Both can eject from their aircraft. They also share a common reason for fatal accidents: a delay in the decision to do so. In fact, according to the U.S. Air Force, it’s the single most common cause of fighter pilot fatalities. Similarly, in the past few decades, failure to cut away and pull the reserve ripcord in time has been a major factor in skydiving deaths.
In the U.S., cutaways occur more than 4,000 times annually. USPA statistics show that on average skydivers need to release their main parachutes every 700 to 800 jumps. Since skydivers know that cutaways are almost inevitable, and since main-parachute releases and reserve activation mechanisms almost never fail, why would any jumper delay performing their emergency procedures?
The answer is complex and lies in part in how humans make decisions, particularly in time-constrained, risky or ambiguous situations. In his best-selling book “Thinking Fast and Slow,” Nobel Prize-winning author Daniel Kahneman describes two types of thinking. System 1 thinking is the brain’s fast, almost instinctive decision-making process. System 2 thinking is the slower approach, where a person analyzes a problem or weighs options before deciding.
A successful skydive uses both thought processes. Creating and practicing a jump plan on the ground or calculating the separation on exit requires System 2 thinking. A quick and deep stab on the toggles when the winds suddenly die while flaring for landing is a System 1 process. We use the same thought patterns in an emergency. However, they have their hazards. Acting too quickly (System 1 thinking) or taking too long to decide (System 2 thinking) can lead to injury or death.
During initial skydiving training, jumpers learn to focus on altitude—particularly their decision altitude—during a malfunction. However, skydiving is a time-management sport. In an emergency, jumpers may find themselves unable to positively affect the outcome in the time remaining. Knowing this, it makes sense for jumpers to incorporate their internal time clocks into their emergency protocols.
Unfortunately, humans are subject to temporal distortion, in which they perceive time as either shorter or longer than it is, particularly under stress. Vierdordt’s Law—developed by 19th century scientist Karl von Vierdordt—states that people perceive short durations of time (less than a couple seconds) as longer than they are, and longer durations (say, eight to 20 seconds) as shorter than they are.
This effect can be particularly pernicious for skydivers. A jumper may panic and react too quickly in an emergency—for example, perform emergency procedures out of sequence—when they incorrectly think they’ve spent a long time working on a problem. Conversely, a skydiver may go well below their decision altitude as they work for 15 seconds to clear a malfunction because the time elapsed seems shorter. Both scenarios lead to fatal outcomes in the real world.
Fortunately, von Vierdordt also provides an answer to this dilemma when discussing an “indifference point,” a time range that people judge mostly correctly. Experiments have concluded that this is roughly in the two- to five-second range. Using this information, perhaps skydivers could apply a rule of thumb—what psychologists call a heuristic or a mental shortcut—to assist them with their time management skills? For our sport, jumpers could adopt a five-second rule (easy to remember and in the optimal time-judgment window) when making cutaway decisions.
First let’s consider a moderate-speed malfunction such as a spinning canopy with line twists. Canopy piloting expert Brian Germain, in the opening sequence of his educational video “Malfunctions and Their Solutions,” is under his reserve five seconds after a fully developed spinning-canopy malfunction. This plays out with many expert jumpers, who often correctly assess, decide, execute and complete their emergency procedures properly within five seconds or so after a malfunction begins. This is usually due to their development of error-pattern recognition and decision-matching skills through previous experiences in similar situations. However, in some situations, overconfidence can cause an experienced jumper to overestimate their ability to cope with an emergency situation. Jumpers must fight against complacency for the duration of their jumping careers.
By using a five-second rule, everyone can share successful outcomes, experts and novices alike. Using this rule, jumpers give themselves five seconds (by either consciously counting or by relying on an internal clock) after detecting a malfunction to decide whether to cut away. In the case of a high-speed malfunction of 125 feet per second (85 mph), if main-pin extraction occurs at 3,000 feet and it takes several hundred feet for the bag to extract and the canopy to inflate, a jumper will have only about five seconds to assess the canopy and execute emergency procedures by USPA’s recommended altitude of 1,800 feet.
Using a five-second rule would also focus jumpers on the necessity of being time aware. When humans identify a threat (for skydivers this could be a line-over or spinning malfunction), they tend to focus on that danger alone rather than on identifying new or unfolding threats (altitude loss, G forces, etc.). This is called attentional narrowing or cognitive tunneling. Every additional second spent on managing rather than resolving an emergency drains the jumper’s energy and attention. This deteriorates both spatial and temporal cues. The jumper progressively becomes lost in time and space. It also reduces the time available to prepare for other critical phases of the emergency such as secondary malfunctions or landing priorities.
Of course, not all emergencies require a five-second response. But after five seconds, the jumper must stop and assess whether their situation is:
1. The same or worsening
2. Rapidly and clearly improving
In an improving scenario (e.g., the jumper gets out of line twists) the five-second rule can convert to five-second time blocks. The jumper continues managing the malfunction while staying aware of the time lapse by extending efforts in five-second blocks, assessing the results after each block. Rarely should efforts persist beyond 15 seconds.
However, in identical or worsening scenarios, it makes no sense to delay executing emergency procedures after five seconds elapse. USPA statistics show that no jumper has died in the past 10 years in the U.S. solely as a result of a spinning malfunction after properly executing emergency procedures at or above USPA decision altitude and within five seconds or so of the malfunction (e.g., when the equipment was in good order and no secondary malfunction such as a snag occurred). However, skydivers have paid for delays of a few seconds with their lives.
Using the five-second rule as a time-awareness heuristic will likely reduce injuries and fatalities. Regardless of which method a jumper uses, the five-second rule or the five-second-block method, this time-based approach to malfunctions may allow skydivers to stop their worst but also best human drive—the desire to overcome a challenge or obstacle at all costs—and prevent them from dying in the process.
About the Author
Ben Planche Wallace, B-49228, is a private pilot and novice jumper who enjoys the theoretical study of cognitive behaviors under stress and adaptive responses to emergency situations. In addition to researching emergency responses, Wallace performed extensive interviews of instructors and other highly experienced skydivers for this article.