Enduring 6 Times Gravity for 20 Seconds: Inside Fighter Pilot Training

"Three, two, one! Head back, brace, and pull!"

"You have to push hard! Harder than now! Harder! Push it out hard!"

These were the urgent words an instructor shouted at this reporter, who was personally experiencing the "G-Tolerance Training" (G-TEST) that Air Force pilots undergo to prepare for extreme maneuvers.

Fighter pilots train to withstand gravitational forces of at least six times their body weight in preparation for sudden maneuvers. Using centrifugal acceleration, they must endure the increased gravity for at least 20 seconds to be eligible to board a fighter jet. On this day, this reporter attempted the "G-Tolerance Training" again after two years.

On the 1st, I visited the "Aerospace Medical Training Center" of the Air Force Aerospace Medical Center, located in Cheongju, North Chungcheong Province — the only place in the country where "flight environment adaptation training," a preliminary gateway to becoming a pilot, can be conducted.

This place is the "hometown" of pilots. Located within the Korea Air Force Academy, it handles education for cadets who have enrolled with dreams of becoming pilots, as well as training for aviation personnel of the Army, Navy and Air Force. Even veteran fighter pilots must visit here once every three years to undergo flight environment adaptation training.

After an introduction to the training center and theoretical education on atmospheric physics, high-altitude physiology theory, oxygen equipment theory, and acceleration training, I immediately received a pilot's training suit and boots and entered full-scale practical training.

The practical exercises covered the flight environments generally encountered, identical to those experienced by prospective fighter pilots. These began with G-Tolerance Enhancement Training (nicknamed G-TEST), followed by spatial disorientation training, emergency ejection training, and high-altitude low-pressure environment training.

The highlight of the day's training was the most painful G-tolerance training. The gravity inside the so-called "gondola" is more than three to four times that of an ordinary roller coaster. During the theoretical education, I learned the "L1 breathing technique," a method for overcoming acceleration. It is a special breathing technique that produces an "Ugh! Khuh" sound.

With the "Ugh" sound, you raise the pressure in your lungs to secure chest space for the heart to function, and quickly make the "Khuh" sound (exhaling on "Kh" and inhaling on "uh") to secure the minimum amount of oxygen. Miss this rhythm and you black out within seconds.

But the moment I sat in the cockpit and grabbed the control stick (joystick) identical to that of an F-15K fighter jet, my confidence dropped — perhaps because I had watched on screen the previous trainees losing consciousness and collapsing one after another. Today's mission was to withstand a force equivalent to six times gravity for 20 seconds.

On the right side of the screen, I could see a gauge reading 1.4G. A moment later, along with the "three, two, one" call came the instructor's order to "pull it straight back." Pressing the trigger on the control stick, I pulled the stick toward my body. The gravitational acceleration rose rapidly.

I put tremendous force into my legs and opened my eyes wide, but as if struck hard on the head, everything went dark before my eyes and my consciousness gradually faded. I had long forgotten the L1 breathing technique. I had even forgotten how to breathe at all. 3G, 4G, 5G, 6G… as the acceleration kept building, my head naturally dropped downward.

Suddenly, I began to lose my vision. This was the "gray out" phenomenon, in which the field of vision narrows. Confused about whether my eyes were open or closed, I only opened them wider. Just as I thought I had failed with "G-LOC" — loss of consciousness caused by gravitational acceleration — the instructor's voice shouting from afar, "You can't lose your mind! Breathe!" made me open my eyes wide again.

Following the instructor's guidance as if it were a revelation, I maintained the L1 breathing technique I had forgotten. "It's all over. Now put the stick down and take a deep breath." The 20 seconds that had felt like an eternity had passed. A moment later came the word "Pass." At first, I thought it was a lie.

Until five seconds before the gondola came to a complete stop, the instructor kept ordering "Breathe" saying it was not yet over. Both my hands were drenched in sweat. As I released the control stick, the gondola slowly came to a stop. As the gondola decelerated at a rate of 1G per second, I felt as if my body was suddenly tilting toward the ground.

In the end, half-conscious and fumbling, I somehow barely endured the 20 seconds. Even after coming out of the gondola, I felt nauseated and had difficulty catching my breath. My legs were shaking, and with each step, the ground felt as if it were caving in. For a while, I found it hard to stand properly.

As I left the training area, the instructor gave a thumbs-up, saying, "Even the Air Force Academy cadets who come to receive training only pass at a rate of about 50 to 70 percent," and "There have been people who passed out within five seconds at 6G, but about half of the reporters who took part in today's training succeeded." Air Force pilots reportedly must withstand 9G — nine times the earth's gravity — for more than 15 seconds to be able to board a fighter jet.

Next, I boarded the flight illusion training equipment for spatial disorientation training. This training is designed to experience the physical limits of relying on vision and to gain trust in the safety of flying by instruments. It is an important form of training, as even veteran pilots sometimes suffer crash accidents due to flight illusions.

It was conducted in a way that allows one to feel the same environment as when maneuvering a fighter jet in a three-dimensional environment, by sitting in a cockpit with a simulation screen and an environment identical to reality. After adapting my body while turning at a 45-degree angle, I entered the full-scale simulation. In a nighttime (in-cloud) flight situation, the fighter jet attempted to take off from the runway at a 10-degree angle. Then I felt as if my body were surging up at a greater angle. This is a kind of flight illusion.

For example, if you lift off the ground at an ascent angle of about 10 degrees, the pilot inside mistakenly believes he is rising at a greater angle because of the acceleration acting on him. When the instructor asked, "What angle do you feel it is right now?" I answered, "It seems like about 20 to 30 degrees." But when the answer came back that it was actually 10 degrees, I was very bewildered.

I felt dizzy because of the spinning equipment, but soon it felt as if I had regained a level position. With the words "Now, look to the left," I turned my head. My head "spun." It was because I felt my whole body soaring up into the sky on the right. In fact, the equipment was tilted to the left as it turned. All of this is a phenomenon caused by the limits of the body, which maintains about 70 percent of its sense of balance through vision, and by the vestibular organs.

As the simulation was ending, the instructor explained. Among the various ways to overcome such spatial disorientation, the most representative is instrument flight (IFR). Senses sometimes lie, but machines do not, so pilots must learn to fly by trusting their instrument panels above all, though their own senses are also important.

Next, I underwent emergency ejection training to prepare for cases where flying the fighter jet becomes impossible. It is a process to become proficient so that a pilot can open a final path to survival at the crossroads of life and death, such as during a fighter jet crash. The instantaneous shock applied to a pilot when the cockpit is ejected reaches 20G, and this training lets you experience it and practice the correct ejection posture and method.

First, I put on a helmet and climbed onto the ejection training equipment placed on a rail at the height of a two-story building (5.2 meters). Sitting in the seat and looking at the screen while flying freely, the word "EJECT" appeared on the screen.

But taking the proper posture was not as easy as I had thought. After barely pressing my body tightly against the seat and setting my posture, I pulled the ejection handle, and I shot up into the air along the rail. The moment I pulled the ejection handle, my body surged upward.

It is similar to the "Gyro Drop" at an amusement park, but pressure is applied in exactly the opposite direction, making it rougher than the amusement ride. Even though I had braced myself to some extent, I felt a shock as if my spine had been struck hard.

In this training, the body surges upward with a very strong force, so if you set the wrong posture, your neck could break. Even if the ejection succeeds, if the altitude is too low, the parachute may not have time to open, or even if it opens, the descent speed may not slow down enough, and one may die from colliding with the ground — making it essential training for fighter pilots.

Through the news, thoughts crossed my mind of Air Force pilots who, out of a sense of duty not to harm the public, held onto the control stick until the very end to avoid civilian areas and missed the right moment for emergency ejection, dying in the line of duty. I felt proud of how tremendous their patriotism toward the country was, and at the same time my heart was moved.

The final course was high-altitude low-pressure environment training. The fighter