Soldiers in bright yellow flight suits hunch down along the outer rim of the vertical wind tunnel, their headsets and goggles fastened securely to protect them from the wind's velocity and the dizzying drone of the 3,600-horsepower engine creating it.
    In the inner circle, black-suited instructors "fly" above the students' heads, ascending and descending at will within the 24-foot-tall structure that simulates an actual free fall at 120 miles per hour.
    Military free fall is one of several advanced-skills training courses offered to a special group of soldiers who call themselves "the quiet professionals," who "cannot be mass produced." Among their other skills are combat diving and target interdiction.
    Their branch insignia, two crossed arrows, was worn during World War II by soldiers of the famed 1st Special Service Force.
    Collectively, they operate in some 130 countries, speak about 15 different languages and hold higher-level positions than conventional soldiers of the same rank. And unlike most soldiers, their primary mission is not as combatants but as teachers to soldiers and civilians in Third-World nations around the world.
    They are the green berets -- soldiers who make up the Army's elite special forces.
    Becoming one of them takes fortitude and guts, said Capt. Todd Wilcox, recruiting detachment commander for the U.S. Army Special Operations Command at Fort Bragg, N.C.
    Prospective SF enlisted soldiers must be specialists and above, and officers must be promotable first lieutenants and above, before they can volunteer for Special Forces Assessment and Selection, a 23-day exercise in mental and physical stamina and one of several prerequisites for the Special Forces Qualification Course itself.
    Before a soldier attends SFAS, he's briefed -- albeit minimally -- about what to expect. Recruiters at Fort Bragg, and other select Army installations that recruit SF soldiers, explain what they'll do as members of a 12-man SF Operational Detachment-A, or A-team, if they make it through SFAS's three grueling phases and subsequent training.
    The first week includes a variety of psychological and physical evaluations. "A psychologist interviews each soldier to see if he's stable and whether he has lingering problems from the past," Wilcox said.
    The soldier must also meet the Army Physical Fitness Test standard for 17- to 21-year-olds, scoring at least 206 points, completing a 50-meter swim in BDUs and boots and marching about 150 miles carrying a 50-pound rucksack and a weapon.
    Week two includes more walking and marching but adds a 1.5-mile-long obstacle course with vertical obstacles -- 85 percent of which test upper body strength -- and a land navigation course.
    "Some guys need several chances to make it through the challenging land navigation course called 'Star,'" said 1st Sgt. Joe Callahan, who runs the selection program. "They have to move across 18 kilometers of rough terrain with many obstacles, including hills and water. They can't use roads or flashlights, and they have to navigate at night with a heavy rucksack, no matter what the weather."
    It's the longest land navigation course in the armed services that someone has to navigate alone, said Callahan.
    SSgt. John O'Brien, who graduated from the SF Qualification course last May, said, "Star was pretty gnarly. It was really cold and rainy, and we plotted our courses on a map with a protractor. You just know there are a few swamps here and there and you try to stay out of them. There were 120 of us on the first Star exam. About 40 of us made it." Soldiers get three chances.
    Week three of the SFAS focuses on the individual soldier's leadership skills and determines how well he operates in a group. Candidates are separated into 12-man teams that must react to various stress-inducing situations. "This allows instructors to assess how well they problem-solve and implement the ideas of the team," Wilcox said.
    Soldiers are given certain equipment and a mission statement and may have to construct or move something. One test requires the team to move a trailer over roughly 18 kilometers.
    Boards are held after weeks one and three to identify soldiers who will be eliminated from the program. On average, only 50 percent of each class is selected to attend the SF Qualification course.
    "I've been to all the SF courses, and this, in my opinion, is the hardest physically and emotionally," said Callahan. "It will definitely break a man down after three weeks. It's not uncommon for a soldier to lose 30 pounds, despite the fact that we shovel food into him.
    "It's mentally draining because a man will base his whole future in SF. He's giving up another whole career to be SF, and while no one is ever penalized for not completing the program, to go back to your unit if you don't make it is extremely tough," Callahan added.
    "You have to be in the right mindset," O'Brien said. "Every night when you get in you know tomorrow's going to be just as bad, and it keeps coming. You just have to keep telling yourself you can do it."
    "I got smoked at SFAS," said Sgt. Dale Bennett, who left his mechanized infantry unit in Germany to become an SF soldier. "One of the toughest events for me was the 'Sandman.' Two duffel bags filled with sand simulate downed pilots. We had to carry them 10 kilometers. Guys were literally crying at the end of that."
    The soldiers who complete SFAS aren't home free. Enlisted soldiers must also complete airborne school and the Primary Leadership Development Course before attending the SF Qualification course. And those who opt to become special forces communications sergeants must also undergo eight weeks of Morse code training.
    When enlisted applicants finally do make it to the qualification course, they've essentially entered into a basic noncommissioned officer course that is unique, Special Forces BNOC, said BNOC 1st Sgt. Bill Saam.
    The course's 80 hours of common leader training -- together with SF common-task and MOS-specific instruction -- meet the requirements for BNOC in the Army's education system.
     While enlisted soldiers focus on MOS-specific training in Phase Two of the course, officers undergo 15 weeks of instruction in SF doctrine, mission, operations and MOS skills, said Maj. Rod Walden, operations officer for the 1st Battalion, 1st Special Warfare Training Group.
    Enlisted soldiers select from four MOSs: the Special Forces Weapons Sergeant course and SF Engineer Sergeant course, both 13 weeks long; the 21-week SF Communications Sergeant course, or the 45-week SF Medical Sergeant course.
    SF weapons sergeants students learn to use a variety of U.S. and foreign weapons. They also learn to use the M-16 plotting board, a fire-direction tool used by most Third-World countries instead of the mortar ballistic computers most conventional countries use, said instructor MSgt. Michael Sieradzki.
    Soldiers also learn how to serve as forward observers and run their own fire-direction centers. "When they've completed the course, they know how to run a bare-bones operation" and how to train other soldiers how to do it, Callahan said.
    "What makes us different from conventional units is that we could be operating anywhere and see something suspicious and call for fire on the target," Sieradzki said. "We can do an immediate call-up without going through special channels."
    SF engineer sergeant students train in theater operations construction. They build not only bridges, but 20-by-30-foot structures that "in some countries would be viewed as 4-star hotels," said Callahan. And they learn how to "take out" particular assets by making them inoperable for a given period of time.
    Mine training focuses on the SF soldier's ability to work with and teach demining operations to indigenous personnel and foreign troops. "They learn to arm and disarm some 50 U.S. and foreign mines, with concentration on those most prevalent today," said SFC Stan Ekstrom, primary instructor of the course.
    SF communications sergeant students learn about all Army communications equipment, plus the equipment unique to SF. They learn how to write, encrypt and decrypt messages and use the Emergency Fall-Back System (a message system unique to SF), said SFC Paul C. Petit, chief instructor for the course. Additionally, they learn about satellite communications and digital systems, how to transmit and receive secure data, and to build antennas.
    As a member of an A-team -- responsible for its own communication capability and survival -- the commo sergeant takes everything he needs to communicate with a forward observation base. In a final test, students deploy 1,000 miles from Fort Bragg and must establish a communication link to the installation.
    SF medical sergeant students "are card-carrying paramedics, allowed to walk into hospital emergency rooms and practice medicine when they leave here," said Lt. Col. John Chambers, assistant dean at the Special Operations Medical Training Center and commander of its Medical Training Battalion.
    "In fact, they exceed the standard for paramedics," he continued. "Paramedics don't 'sink' chest tubes or do 'cut downs' -- exposing a vein to administer a needle. Our guys do. Because when they get out with an A-team, they'll find themselves in places where they won't be able to turn to a doctor and ask, 'Should I open the airway with a knife?'
    "They must be able to operate in remote areas for an extended period of time, with a minimum of medical supervision and provide patients the full range of care they'd receive at a mobile Army surgical hospital," Chambers added.
    Training for SF medical sergeants therefore includes four weeks on an ambulance crew in high-trauma-rate cities like New York City and Chicago, plus a four-week internship at a Public Health Service agency.
    While on his hospital rotation, SSgt. Randall Sweeney, a recent graduate of the program, administered oxygen, prepared splints, performed an intubation (throat-tube airway), delivered two babies, assisted in a Cesarean section and performed CPR and defibrillation on two heart-attack victims, as well as performing other duties.
    In the end, all SF candidates have one common experience -- Exercise Robin Sage -- an unconventional warfare field training exercise that puts everything they've collectively learned to the test. When they've successfully completed that, they've earned the green beret.
    And then training continues -- four to six months of language training, depending on the language the soldier studies.
    Specialized training in advanced skills, like military free fall and special operations target interdiction, follows after the soldier has been assigned to a special forces group. The latter teaches SF soldiers about non-standard and foreign sniper weapons.
    "SF snipers learn how to be self-reliant," said SFC Todd Thompson, instructor. "When a standard, conventional sniper runs out of ammo, he's out of it. When these guys complete this course, they'll be able to take Soviet ammunition, break it down and reload it into their own weapons.
    "When I was with the 1st Bn., 10th SFG, in Germany, I did joint-combined training with special operations forces in Israel and Greece," Thompson reflected. "I've experienced glacier-rescue training with Austrian soldiers in the Austrian Alps, performed military free fall with Norwegians and assisted the Turkish government in recovering two downed UH-60 helicopters from a snow-covered mountain."
    Sieradzki, on a sniper team with the 3rd SF Grp. in Kuwait, covered other special operations forces while they cleared the U.S. Embassy there and escorted the U.S. ambassador. Four members of the detachment later went into Iraq with U.S. State Department officials to do a battlefield assessment of the communications sites that had been bombed by the U.S. Air Force during Operation Desert Storm.
    "I deployed to Ghana with a sergeant who gave classes to 45 Ghanians on how to construct buildings and obstacles, blow things up and make improvised grenades," said BNOC instructor Saam. "Another sergeant gave survival classes on how to snare animals and how to make shelters out of what you find in the jungle. An E-7 had the capabilities to be the local veterinarian, doctor and dentist."
     "I went out one day and taught a group of Thai soldiers how to free-fall," added SFC Sean Rundell, a member of the 1st SFG at Fort Lewis, Wash. "Starting out, they can't stay controlled. In three months, you've taught them. You take them 25,000 feet up, give them oxygen and watch them descend over a triple-canopy jungle. I can't explain the feeling of satisfaction that gives me."
    Besides travel advantages and more responsibility than in conventional units, SF soldiers have greater chances for promotion, Wilcox said.
    "Each of our companies has six E-8s; a conventional company has one. And conventional companies are commanded by captains. Ours are led by majors," he said. Proficiency and jump pay, each $110, and a selective re-enlistment bonus that can be as high as $20,000 are other incentives for being SF-qualified.
    "For 1997, our mission is to bring 1,500 enlisted soldiers and 330 officers to SFAS," said Wilcox. About 750 enlisted soldiers and 150 officers will actually complete the requirements for the green beret.