Tragedy in Antarctica

Tag: Feature, Historic, June 2011, Online Content

Due to popularity, we decided to publish this older article online as well. Originally printed in June 2011.

Letters to the Editor about the article are published in the comments. Scroll all the way down to read them.

Skydiver Michael Kearns says, “I think it’s time.” Fourteen years after one of the worst mass-fatality accidents in skydiving history, Kearns and fellow jumper Trond Jacobsen have decided to disclose personal conversations and information about the incident to fellow skydivers. Many news reports at the time were incomplete or incorrect, stating the usual “their parachutes failed to open” explanation.

“Hopefully the families have healed now. I think it’s time to share the story,” says Kearns.

It was a skydiving expedition to the South Pole—one of the highest, driest, coldest places on earth. The skydive onto the southernmost point of the planet would be historical. The year was 1997. Kearns saw the advertisement for a parachuting expedition to the South Pole in a skydiving magazine and signed up. Kearns started jumping in 1976 in the U.S. Air Force, was a military jump instructor and worked in Special Operations. He had jumped in 14 countries and was trying to jump onto every continent on the planet.

Members of the Expedition
A total of six skydivers signed up for the expedition and jump. Most of the skydivers had jumped throughout Europe and the United States and had made several high-altitude jumps.

One of the expedition’s organizers was Steve Mulholland of Seattle, Washington. He was the first person to legally BASE jump Seattle’s Space Needle, doing so in front of a crowd. Also, he was the first person ever to BASE jump in Antarctica. Mulholland had worked in Antarctica as a carpenter at its McMurdo scientific research facility. The other organizer of the expedition was skydiver Ray Miller of Ohio, one of the first skydivers to jump from a 727 jet. Also, he had jumped on the North Pole.

Also on the expedition was Hans Rezac of Austria. Rezac’s proudest skydiving moment was making a jump in temperatures of minus 4 degrees Fahrenheit... in the nude. An Austrian presidential candidate sponsored his expedition to Antarctica.

The fifth and sixth participants, Jacobsen and Morten Halvorsen, were skydivers from Norway. Jacobsen, a tandem instructor, would be taking fellow skydiver Halvorsen on a tandem jump during the expedition. Halvorsen was a trained winter survival instructor. The duo prepared for one-and-a-half years for the jump. Geared up in their tandem rig and student harness, they would go to an ice-cream factory and stand in the freeze chamber at 58 degrees Fahrenheit below zero. They tested each component of their gear to see whether it would break. Norway is home to many explorers, so they consulted with experts on every aspect of the trip and skydive. Upon departure from Norway, they abstained from coffee, tea, alcohol or any other dehydrating food or drink.

The Norwegians wanted to set a unique record by being the first tandem pair to jump onto the South Pole. They had obtained numerous sponsors, including wristwatch, computer, sunglasses, film and glove companies, to name a few.

Be Prepared!
The two organizers exchanged e-mails with the participants regarding critical gear for the trip and jump. They discussed the ideal weight of undergarments and the number of layers and type of clothing required. The organizers informed participants that they could buy custom “polar suits” made by a skydiving equipment manufacturer. They discussed the appropriate gloves, head-and-neck protection and the necessity of jumping in full-face helmets or ski goggles. The South Pole would be extremely bright, so sunglasses or tinted ski goggles were mandatory, even on the ground.

The organizers also encouraged the jumpers to bring large main canopies. Kearns recalls, “I carefully rolled the nose of my canopy I’d be jumping at the South Pole to make sure it would open nice and soft.”

The organizers’ final e-mail read, “Do not underestimate the harshness of conditions on the ice. BE PREPARED!” It stated that the organizers, upon the participants’ arrival in Chile en route to the Pole, would examine all clothing, rigs and any other parachuting equipment.

The six skydivers met each other for the very first time in Chile. They laughed, joked, told stories and became fast friends, as only skydivers know how. It was here that some of the participants learned stunning news from the Norwegians: They would not be the first to skydive into the South Pole as they thought they would be. A Norwegian had already made a parachute jump there in 1992.

But the Norwegian tandem pair was making history, and the solo jumpers wanted to somehow make skydiving history, too. They quickly came up with a solution: They would be the first to make a 4-way jump at the South Pole.

Base Camp and Arrival at the Pole
The South Pole has only a scientific research facility and does not have public accommodations. Visitors usually fly in for only a few hours, with the remainder of the time spent at a relatively nearby base camp. The skydivers spent two days at Patriot Hills, Antarctica, enjoying the rustic camping conditions and discussing the skydive plan in detail.

On December 6, the six skydivers, a doctor and a guide from camp took the five-hour flight from the base camp to the South Pole. The plane was a red-and-white Twin Otter fitted with four skis for landing at the Pole. The ground consisted of solid ice that was covered with about three inches of powdery snow.

December is the “warm” season in Antarctica, and the sun never sets. The skydivers landed on the South Pole under almost completely blue skies, virtually no wind and temperatures of negative 25 degrees Fahrenheit. The jumpers explored their surroundings, taking in the flat, glaring-white, lunar-like landscape. The silence of the South Pole was profound. Kearns describes the featureless scene as “an ocean of white.”

At the Pole’s exact spot is a red-and-white barber-shop-striped pedestal with a mirrored globe on top. Flags from countries around the world circle the marker. There are several buildings at the Pole’s Amundsen-Scott Research Station, where about 220 scientists and workers live during Antarctica’s summer months. Hearing that something exciting was happening, workers came out of the buildings to watch the skydivers, many taking photos or videos.

Preparing to Jump
Two of the skydivers laid a large, square, orange tarp on the ground to mark their target. The 4-way group made a dirt dive. Before gearing up, they discussed the jump four times: The Otter would climb to 9,000 feet above ground level (AGL). The main organizer would check the spot and call “cut.” Two jumpers would exit together, and the two others in the doorway would dive out after them. They stressed that breakoff would be at 4,000 feet AGL and deployment no lower than 3,500 feet. The tandem pair would exit after the 4-way.

The skydivers geared up. They were joking, laughing and excited. Before gearing up, Kearns opened the reserve flap of his container and turned on his automatic activation device (AAD). The tandem pair also activated its AAD. No one else had an AAD to turn on. Kearns joked, “Hey, this CYPRES works! Wouldn’t it be funny if this thing saved me?”

Kearns’ AAD was relatively new to him. Six months earlier, he was filming a tandem skydive at his home drop zone, and because of clouds the group exited lower than planned. Due to that and other factors, Kearns deployed extremely low. He had time only to pull down his toggles before landing hard. His wife found out about the incident and promptly bought him an automatic activation device.

After gearing up, the jumpers carefully checked each other’s gear and clothing. The 4-way reviewed the details of their exit and jump. Before loading, they reviewed the jump two more times. All six skydivers agreed to watch each other for signs of hypoxia or anything out of the ordinary. If there was any issue that affected safety, they would abort the jump.

Ride to Altitude
Since the Otter they were using was not a jump plane, the door was removed just prior to takeoff. The climbing Otter circled around the target, flying to 8,000 feet, about 1,00 feet lower than originally planned. The six jumpers sat up front, as close to the heat as possible, their breath coming out in huge puffs of steam. One of the organizers had a video-camera helmet. He looked at Kearns and asked, “Do you want to wear the video?”

Kearns was surprised by the question. A videographer offering his camera helmet? The jumper said he didn’t have many video jumps, it was a new camera helmet, and he had had never used it before. He was happy to let someone else wear it. Kearns replied, “No, thanks. I paid $22,000 for this trip, and I want to enjoy the visuals and every part of this!”

Looking back, Kearns and Jacobsen recalled that two of the 4-way team fidgeted with their helmets almost the whole ride to altitude and that the videographer had trouble putting his helmet on over a balaclava.

At 8,000 feet, the lead organizer went to the rear of the Twin Otter and looked out. Kearns recalls, “I was shocked to see that in just the couple of seconds his head was out the door, his face shield was covered in frost.” The organizer yelled, “Cut!” and the 4-way moved to the door. One of the 4-way jumpers then realized he left his gloves up at the front of the plane. He asked the tandem pair to retrieve them. Jacobsen had to unhook his passenger, reach for the gloves and bring them to the jumper. Jacobsen also noticed that one of the jumpers had exposed skin on his face.

On the exit count, the two outer jumpers left the plane and tumbled out of control. Kearns dove out after them with the fourth jumper right behind him. The first two jumpers regained stability and flew close to each other, looking up at Kearns. Kearns dove down to them, checking his altimeter several times. The fourth jumper was still slightly behind him.

When Kearns checked his altimeter again, he was stunned to see it in the red zone, reading well below 2,000 feet. He made a 180-degree turn, waved one arm and was about to deploy his main when a thought stopped him. “My mind immediately went back to that jump six months ago when I deployed so low, and I remembered how slow my main opened.”

Kearns immediately went for his reserve and pulled. His head was thrown back as his reserve snapped open. He knew right then, with his reserve above him, that his two friends in freefall below him didn’t make it. The jumper behind him... maybe.

“I grabbed the toggles, turned into the wind and landed hard, on my face,” he says. “I landed so hard my helmet and face shield were implanted in the snow, and it took me a while to get up.”

Kearns stood up, surrounded by an unspeakable scene. Indeed, the two friends who were below him in freefall had perished. The other friend, who was behind him, had deployed his main, but Kearns could see that only a small portion of it had left the deployment bag. All three jumpers were still in perfect freefall positions.

The spot had been poor. Kearns was half a mile away from the target and the people at the Pole. He began to walk back, alone.

He was eventually met by people in a couple of snowmobiles who were searching for the missing jumpers. Kearns struggled to talk in the extremely dry air. “My tongue was so dry and swollen, I could barely talk,” he says. He was given a ride back to the station, straight into a nightmare.

Meanwhile
Tandem instructor Jacobsen and his passenger had waited 20 seconds after the 4-way left before they exited. Jacobsen says, “It was extremely cold in freefall. The temperature was about 50 degrees Celsius below zero outside [negative 58 degrees Fahrenheit], and we calculated the effective temperature in freefall was... as low as 130 degrees Celsius below zero [minus 202 degrees Fahrenheit].”

Jacobsen continues, “The tandem jump went just as we had planned it. We faced the Amundsen-Scott base on the ground, to have a reference point on the ground, freefalled down to 5,000 feet AGL and deployed the main parachute. We had a soft and normal opening, and we were under canopy at 4,000 feet.”

At the landing target, the observers spotted a canopy coming toward them. It was the tandem pair, who landed about 400 feet south of the target. The canopy seemed to come out of nowhere, because the Otter had been climbing so far south and downwind from the target.

There was chatter amongst the observers, radio calls and then shouting. With growing alarm, a voice over the radio shouted, “Where are the other chutes? There should be five! There should be five!”

A crowd gathered around the tandem pair, asking where the other jumpers were, if they were still on the Otter. “We then knew that something terribly wrong must have happened,” Jacobsen says. “We told them that the 4-way team had jumped before us and that they had to start looking for them. The day that was supposed to be a happy and celebrated day for all of us had turned into the most tragic day of our lives.”

Aftermath
When Kearns met up with the tandem pair, Jacobsen noticed that Kearns’ reserve ripcord didn’t look right—it was not completely extracted from the housing. Jacobsen lifted Kearns’ RSL-equipped Vector reserve flap and saw that the AAD had fired. The three jumpers looked away from one another, absorbed in their own thoughts.

Then, South Pole staff invited them into the main building to warm up and rest. The three jumpers gathered together, linked their arms over each other’s shoulders and walked into the science dome in silence. Soon, the three skydivers, the doctor, the field guide and the remains of their friends were flown back to base camp at Patriot Hills.

“Less than five hours after their plane arrived, it left our home,” said one of the workers at the South Pole station. Then shock turned to anger. For the remainder of the day, the South Pole workers cried, hugged each other or silently processed the recovery scene when they were asked to help. They repeatedly discussed what could possibly have gone wrong. It affected the whole community. The worker said, “Most people who have heard of this station don’t think of it as someone’s home—it’s a station or a research facility or just a tourist attraction. But we were home, and our home had been hit by tragedy.”

Michael Kearns immediately flew back to Chile. The accident made international headlines, and the press was hounding Kearns for interviews and information. Instead, he wanted to take care of the first priority: the families. “In the military, if something happens, you immediately take care of the families,” he says.

However, the Chilean government detained Kearns and confiscated his passport. “They wanted to know if I packed their parachutes,” Kearns says. The government was interrogating him and investigating a possible homicide. Fortunately, the expedition company provided two interpreters, and eventually the Chilean government determined it was simply a tragic accident.

Looking Back
What happened? What went so wrong? How could three experienced skydivers not pull? Were they disoriented by their lack of depth perception in the monotonous, white landscape? Were they disabled by the extreme temperatures? When investigators inspected all the equipment, they found that the only item that had not functioned in the extreme cold was the video camera. It froze and ceased working as soon as it hit the wind in the door of the plane.

Before they flew from Patriot Hills, Antarctica, to the Pole, the Norwegian tandem pair tried to confirm that there would be supplemental oxygen on the Twin Otter. “We were told this would probably not be necessary,” recalls Jacobsen. This was unsettling. “We knew that oxygen at jump altitude at the South Pole would be absolutely necessary.”

The South Pole is one of the highest, driest and coldest places on earth. Elevation is approximately 9,300 feet above sea level. So their jump from 8,000 feet above ground level was actually about 17,000 feet above sea level. And due to the density of the cold air, terminal velocity would be 36 percent faster than normal, making their fall rate about 163 mph. Calculating for air density, their altitude was equivalent to about 22,000 feet above sea level.

The Patriot Hills camp was at an altitude of 2,900 feet above sea level. Upon arriving at the South Pole, Jacobsen noticed that the altitude of 9,300 above sea level made it more difficult to breathe. He says that as they helped prepare the Otter for the skydive, “I could feel it was harder to breathe. Just moving around and lifting things made us very tired.” After the jump, he also said that upon deploying his main, “We could now feel the lack of oxygen and felt very tired at this moment, but still we were very happy.” He also said that the toggle pressure was hard: “Both of us had to pull down the toggles to flare.”

Supplemental Oxygen
When the skydivers arrived at the South Pole, Jacobsen took it upon himself to ask again about the availability of oxygen for the ride to altitude. There were no hose connections in the aircraft. “The pilot on the Twin Otter had one oxygen bottle with one oxygen mask connected,” says Jacobsen. “I asked if it was OK to use this in the plane while we were climbing to exit altitude. The pilot agreed to this. We would pass the oxygen mask around the plane.”

Jacobsen reflects with disappointment, “This was not the way it should have been, but it was the second best that we could get. Everybody should, of course, have his own mask.”

Climbing to altitude for their jump, Jacobsen asked the pilots for the oxygen bottle at 4,000 feet. The single bottle was given to him. He turned on the valve, breathed through the mask and passed it to his tandem passenger and the others. The two pilots declined the oxygen. Kearns accepted the oxygen mask and breathed from it. Jacobsen offered the oxygen mask to the other three jumpers several times, but they refused. Kearns recalls one of them saying, “I don’t need no stinkin’ oxygen.”

The tandem pair and Kearns shared the oxygen for the remainder of the climb. Jacobsen recalls of the other jumpers, “It seemed like they were busy preparing the camera helmet.”

Automatic Activation Devices
The three jumpers who died did not have AADs in their rigs. In 1997, a significant portion of the skydiving population did not jump with an AAD. It was only in 1991 that the computer-operated CYPRES came on the market, and it was very expensive. Previous AADs were mechanically based, not as reliable and had to be calibrated by hand before each jump. Also, they were not able to automatically adjust to slight changes in barometric pressure throughout the day.

Many skydivers who were active prior to 1991 had witnessed, or had friends who witnessed, premature AAD deployments during formation dives. It took years for some of these older jumpers to get on a load with anyone who was wearing an AAD.

One of the jumpers who died did have an AAD prior to the South Pole jump, but the battery had expired shortly before his scheduled trip. Rather than order and wait for a new battery, the jumper told his rigger, “Go ahead and just take the whole thing out.” Another of the jumpers chose to take his older rig with him since it had a larger main canopy, leaving his AAD-equipped rig behind.

Prior to leaving for the South Pole expedition, Kearns asked one of the organizers whether he had an AAD in his rig. The organizer said, “Absolutely not,” and stated, “If you can’t deploy your own rig, then you shouldn’t be jumping.”

Behavior in the Plane
The three skydivers who died didn’t appear to be affected by hypoxia. But were they? They obviously were able to get to the door, check the spot, crawl out and leave on the count. Their exit funneled, but they were able to quickly recover and fly their slots.

In the controlled setting of an altitude chamber, it’s possible to watch military or commercial pilots experience hypoxia. The pilots are given a simple task such as picking a card from a deck, holding it up and stating its name. At about 25,000 feet without oxygen, they initially appear to execute the task normally. After several moments in the chamber, the test subjects still execute their tasks—but they begin repeating the same card name. They are slower and uncoordinated. When asked to return to the previous card and verify the card name, they seem to not hear the command and continue to take a card from the deck, hold it up and state the incorrect name. Soon, the test subject will not even take a new card from the deck but will show the same card over and over again. They physically continue the exercise, but something is obviously wrong.

It takes about one minute for a subject to become visibly disabled, although each person reacts and functions differently at low oxygen levels. Factors that can influence hypoxia are the subject’s health or how rapidly he experienced decompression, to name a couple. Hypoxia is different than altitude sickness, though it can be a precursor. Altitude sickness symptoms are nausea, flu-like symptoms and sometimes nose bleeds. Symptoms for hypoxia, on the other hand, can be manifested as euphoria, smiling, giggling, tingling in the fingers or feet, dizziness, disorientation, poor motor control and loss of color vision. Some people equate it to having had a couple of drinks. However, hypoxia is best known for being insidious—most people don’t realize they are experiencing it until after they begin breathing oxygen-rich air again.

During freefall, Kearns recalls one dangerous symptom of hypoxia: “I looked at my altimeter three or four times, but it didn’t mean anything to me.”

Hypoxia is alleviated very quickly as oxygen enters the system. Both Kearns and one of the others attempted to deploy, but terribly low. Most likely, they began to recover quickly from the hypoxia once they were at the lower altitude. Unfortunately, the ground was 9,300 feet above sea level, and the air was still somewhat thin.

SIM Section 6-7
Old-time skydivers say that the Federal Aviation Regulations and USPA’s Basic Safety Requirements are written in blood: Others have paid the price so that we may learn from them.

According to the 2011 Skydiver’s Information Manual (SIM) Section 6-7, oxygen is required for jumps above 15,000 feet mean sea level (MSL), and the system must be turned on and jumpers continually breathing oxygen beginning at 8,000 feet MSL. If the jump plane will fly above 8,000 feet MSL for more than 30 minutes, oxygen must be used starting at 10,000 feet. All aboard a high-altitude flight should breathe oxygen for as long as possible. A backup oxygen system should be available on the aircraft. SIM Section 6-7 also addresses higher-altitude jumps, which require additional safety procedures.

Reflecting
Kearns encourages all skydivers to go through altitude chamber training. “Learning about aerospace physiology and [going through] military altitude-familiarization training gives one an unmatched opportunity to experience hypoxia under medically controlled conditions, and it will leave you with a deep impression,” he says.

As Michael Kearns thinks back to that fateful day, he now clearly sees details that were off. “If those guys were jumping under my supervision in the military, I would have aborted the jump right there,” he says. But Kearns struggles with the situation still, unsure of what he could have done differently. He says that so much of skydiving relies on trusting one another, and it has to.

Jacobsen was completely successful with his precise planning, and he remains the first and only tandem instructor to land at the South Pole. But in looking back, he solemnly wishes he had done something or said something to ensure everyone remained safe. “We [the tandem pair] could of course have said ‘no’ and spent the time on the ground, but that would not have made any difference in this tragedy.” He goes on to say that in the future, “I hope someone will be more brave than us and say ‘stop’ when something isn’t right. This is my wish.”

About the Author
FEATURE20105-10Musika Farnsworth, A-20569, has been jumping since 1992 and has a Bachelor of Arts in social sciences. She lives in Vancouver, Washington.

 

 

 

 

 

References:
Altitude sickness. (n.d.) In Wikipedia. Retrieved February 23, 2011, from http://en.wikipedia.org/wiki/Altitude_sickness

Hypoxia (medical). (n.d.) In Wikipedia. Retrieved February 23, 2011, from http://en.wikipedia.org/wiki/Hypoxia_(medical).

Johnlauriejt. (2007, March 16). “Controlled Hypoxia in Altitude Chamber.” Retrieved from http://www.youtube.com/watch?v=qLQMupV3DLk&feature=related.

Toeppen, Laurell. (1997, December 13). “Tragedy Unveiled.” The Antarctic Sun, p. 15.

Wicke, Tech. Sgt. Russell. (2008, April 28). “Air Force Trains Coast Guard Students in Altitude Chamber.” Retrieved February 28, 2011, from the official web site of the U.S. Air Force: http://www.af.mil/news/story.asp?id=123096069.

NPR-Bob Edwards interviews Michael Kearns in 1998

Live television interview regarding the accident before details were known. Host Bryant Gumbel interviews skydiving and parachute innovator Bill Booth:

Washington DC TV4 news report from April 1998:

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Webmaster
Fri, 08/12/2011 - 13:38

South Pole Correction:

I read with great sadness your well-written article, “Tragedy in Antarctica” (by Musika Farnsworth, Parachutist, June), which was also educational—with the exception of one critical part. The article states that because of the density of the cold air, the exit altitude of 17,000 feet above sea level (MSL) was “equivalent to 22,000 feet.” In reality, density altitude, which describes the altitude it feels to your body like you are at, says that cold air is more dense than warm air, not less. Airplane pilots know the dangers of hot conditions, which can starve the engine of power and the wings of lift. At the pole, the jumpers experienced a density altitude at exit of close to 13,000 feet, not 22,000 feet. This large difference does not disprove the hypothesis that hypoxia was a major factor, but it certainly weakens it; is it possible that disorientation from the extreme cold, lack of visual references and the excitement of the jump were even bigger factors? It is also incorrect to say that the cold would make terminal velocity faster—it would be slower than at the same MSL altitude at normal temperatures due to the thicker air.

This message should be heard for two reasons. First, it calls into question the analysis presented by the article, which strongly implies hypoxia was the primary cause. Second, it is worth taking the opportunity to highlight the concept of density altitude, as few skydivers are familiar with it. Here are two examples of what it can mean to a jumper:

  1. On a hot day at 14,000 feet, you can be at a density altitude of nearly 17,000 feet and at risk of hypoxia. How many jumpers out there would refuse to jump from 17,000 feet without oxygen but would happily jump from 14,000 feet on a hot day?
  2. You usually jump at a sea-level DZ in moderate temperatures. Then you visit another DZ at 1,000 feet elevation. But it’s a hot day (say, 90 degrees Fahrenheit). This means there’s 10 percent less air density than you’re used to, a density altitude half a mile higher than back home. Do you know how much that can affect your swoop? You could be in for a nasty surprise. This summer, watch out for yourself—and others—when you’re “hot and high.”

 —Tom Green | A-33250

San Francisco, California

Webmaster
Fri, 08/12/2011 - 13:39

Editor's Note

The sentences in question read, “And due to the density of the cold air, terminal velocity would be 36 percent faster than normal, making their fall rate about 163 mph. Calculating for air density, their altitude was equivalent to about 22,000 feet above sea level.” The positioning of the word “cold” in the first sentence was regrettable, as while the air was in fact extremely cold (negative 58 degrees Fahrenheit) at the exit altitude (17,000 feet MSL/8,000 feet AGL), the temperature of the air itself was not the cause of the higher freefall speeds—the high altitude was.

Green is correct in pointing out that the density altitude calculation was off, certainly not 22,000 feet. It was a miscalculation, and we regret the error. Meanwhile, another reader pointed out that atmospheric scientists have found the barometric pressure at the poles is about five percent less at every altitude due to the shape and spin of the earth, and that creates the effect of higher density altitude—thinner air. Putting the calculation of polar density altitude aside, the critical point of the paragraph is that the fall rate was much greater (at least 30 percent) than normally experienced for an equivalent exit altitude above ground level, thereby reducing time from exit to impact by approximately 10 seconds. Disorientation due to extreme cold and the effects of hypoxia, lack of visual references, an exit point that was lower than expected and higher freefall speeds likely all contributed to the deceased skydivers’ failure to pull at a safe altitude.

Green’s discussion about the dangers of hot days and high density altitude is spot-on, and all skydivers should heed it. For a complete discussion, see the Skydiver’s Information Manual Section 5-5, Weather.

Webmaster
Fri, 08/12/2011 - 13:43

If the jump plane had a standard barometric altimeter (and there is every reason to assume it had, and was not using a radar- or GPS based altimeter), and it showed 17,000 feet on jump run, then the density altitude was precisely 17,000 feet, no more, no less. Why? Because the standard barometric altimeter measures air pressure (i.e. density). It then converts it, mechanically or electronically, to feet according to the standard model of the atmosphere. Of course there is a possibility that the standard model did not hold in the conditions which prevailed, which might have resulted in erroneous readings. With the true exit altitude a couple of thousand feet or so lower than the indicated altitude and the ground/ice at 9,000 feet there is a much simpler explanation for the accident: the jumpers thought they had 30 seconds of freefall time when they actually had much less. Lack of ground reference and the onset of hypoxia did the rest. This sequence of events is also in agreement with the testimony of the surviving jumper: he stated that he was "stunned" to see his (barometric) altimeter unwinding so quickly. The Cypres apparently showed the effect, too- it seems to have fired at a lower than normal (true) altitude, which just allowed the jumper to "grab the toggles, turn into the wind, and land".

 —Rudi Albrecht | C-16340

Austria, European Union

Webmaster
Fri, 08/12/2011 - 13:50

2.1. Correction for Low Temperature:
• Use temperature data from the same source as the source of QNH (normally an airport).
• Add 4% per 10 C below standard down to ISA -15 degrees C. For lower temperatures
use correction according to table 1 below.

Table 1. Corrections to be added to altitudes below MSA at low temperature.
Reported OAT Height above AD (ft)
200 300 400 500 600 1000 2000 3000
0°C 20 20 30 30 40 60 120 170
-10°C 20 30 40 50 60 100 200 290
-20°C 30 50 60 70 90 140 280 420
-30°C 40 60 80 100 120 190 380 570
-40°C 50 80 100 120 150 240 480 720
-50°C 60 90 120 150 180 300 590 890

As we can see from this table, it is not possible that the Twin Otter  reached 8000 feet AGL. Depending on ground temperature, they could have been somewhere between 6500 and 7000 feet AGL.

The jumpers internal clock was set for an exit altitude of 8000 feet and 35 seconds of FF time. By exiting from a lower altitude than indicated, and higher free fall speed than usual, (density altitude 17000 feet MSL plus or minus, depending of calculation method)   they have passed through opening altitude much sooner than anticipated.

Leif Hedland | D-646

Sandnes, Norway

Webmaster
Fri, 08/12/2011 - 13:52

A Correction to Tom Green's Letter, "South Pole Correction"

In the August, 2011 issue of Parachutist, Tom Green takes issue with the analysis of the South Pole skydiving mishap.  Mr. Green makes the common mistake of confusing the effects of density altitute with pressure altitude.  Density altitude corrects for local changes in air density.  This is useful for understanding how your canopy will perform under varying conditions, such as on a hot summer day.

Pressure altitude is similar, but there is a crucial difference between the two concepts: pressure altitude, not density altitude, describes "the altitude it feels to your body like you are at."  This is because lung gas exchange is based on the partial pressure of oxygen.  This is also why FAR 91.211 requires crewmembers to determine supplemental oxygen requirements with respect to cabin pressure altitude, not density altitude.

Assuming the jump plane used the South Pole altimeter setting that day of 28.76 inHg, and an outside air temperature of -50 at a true exit altitude of 17,000 feet, the skydivers encountered an equivalent pressure altitude of over 21,000 feet.  (However, if the aircraft altimeter was set to 29.92, as it might have been in the airspace over the South Pole, the pressure altitude would have been equal to the altimeter.  It may not be known today which setting was used.)  Furthermore, the physiological effect of flying off oxygen for several hours from Patriot Hills must not be underestimated, even if only at an altitude of "merely" 13,000 feet.

To further confound the analysis, in severely cold temperatures, a barometric altimeter will erroneously read high.  Under the above assumed conditions, the jump plane's actual altitude might have been 2,360' lower than what was indicated.  This factor alone could have had an enormous impact.

Regardless, the hypoxia hypothesis is not weakened by Mr. Green's calculations.  On the contrary, hypoxia was highly likely to be a major contributor to this tragic mishap.

Sincerely,

Malcolm Schongalla | C-33554
Four years as a Antarctic LC-130 pilot and 4th year medical student

Hanover, New Hampshire

Musika Farnsworth
Sun, 08/14/2011 - 12:15

Thank you everyone for sharing your scientific knowledge. It is interesting, educational... and important. Who ever said skydiving has no redeeming value?!

Eric Geis
Fri, 08/26/2011 - 14:13

I wish to express my thanks to the author for writing such an in depth article and keeping it about the people and not just a litany of dry facts. This tragedy reinforces the adherence to safety rules. As the one jumper stated, "The rules are written in blood". This disaster was clearly an accumulation of mistakes, miscalculations, and deviations from the original plan. None of the mistakes offset any others, i.e., the exit altitude being higher than planned offsetting the higher terminal velocity.

I read the examination of the altitude mistake and appreciate all of the input from our readers. That shows that our readers are reading thoroughly and are not afraid to add their professional opinions.

We all have to hope that we each learn from the mistakes that accumulated to cause such a loss of life.

Condolences to the survivors and thanks to the author,

Eric Geis

Adrian Miller
Fri, 12/07/2012 - 00:57

Ray Miller was my Father. Thank you all for your in-depth analysis and condolences. Both are greatly appreciated.

Thank you Michael Kearns for telling the story publicly, so that people can try to understand what happened, with hopes that other jumpers won't make similar mistakes. And thank you for coming to Ohio and telling that story to the face of a 13 year old boy, 15 years ago.

My heart goes out to the Mulholland and Rezac families.

Sincerely,

-Adrian Miller
Paratrooper, 82nd Airborne Division

Piglet
Tue, 04/02/2013 - 12:03

The article states: "Kearns started jumping in 1976 in the U.S. Air Force, was a military jump instructor and worked in Special Operations." I knew Mike for many years in the Air Force and this description seems a bit at odds with what I remember. Mike enlisted in the Maryland Air National Guard in the late 1970s and served as a loadmaster on C-7A Caribous at Martin State Airport. He joined the AFROTC program at University of Maryland, College Park, in 1980 and at that time the only wings he wore were his enlisted aircrewman wings from his loadmaster days. He was commissioned in 1982 and became an intel officer at Bolling AFB in Washington, DC. By that time I believe he had done some civilian parachuting but had not yet gone to a military jump school. He took part in a veterans jump tour to Israel in 1984 and was honorarily awarded IDF wings for making a C-130 jump, and two years later he did the same in South Africa, making a static line jump from a C-160 Transall. It was in the mid-80s that he attended a two-week static line Airborne course run by the Army Reserve's 12th Special Forces Group (Airborne) at Fort McCoy, WI, and got his US jump wings; however, to my knowledge he was not then, or any at any other time, in a jump slot in a unit that was on jump status, nor am I aware of any time at which he was a military parachuting instructor. Later he was assigned to the USAF Survival School at Fairchild AFB, WA, where he would have crossed paths with those in special operations, but I believe he remained with the Air Force Intelligence Service and was not assigned to any units in the Air Force Special Operations Command. Note: Special Operations Wings, Groups, and Squadrons are typically flying units and their supporting elements typically don't jump. Special Tactics Squadrons include combat controllers and pararescuemen, but I never knew Mike to be a CCT or PJ. If anyone can clarify matters, I'd appreciate it.

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