Category: This great Nation & Its People
During the 1950s and early 1960s, the Century series of fighter aircraft — the F-100 to F-106 — ruled the skies. The first in the series, the F-100 Super Sabre, also known as the “Hun,” was the first U.S.A.F. Fighter capable of supersonic speed in level flight, and was created as the successor to the F-86 Sabre. The F-86 was the Air Force’s first swept-wing fighter designed for air-to-air combat against the MiG-17 and was considered the best fighter during the Korean War.
The F-100 served in Vietnam as a fighter-bomber and close-air-support aircraft. It later flew as a reconnaissance / forward air controller aircraft during “Misty Fac” missions under the code name Commando Sabre.
Development
In 1953, North American began in-house studies of improving the F-100 for various missions. The U.S.A.F. was looking for a Mach 2 bomber capable of delivering a tactical nuclear weapon. The F-100B featured a recessed weapons bay, in addition to hardpoints under the wings, a single-point refueling capability, and a retractable tail skid. Another feature was the all-moving vertical fin, which, combined with the automated flight control system, allowed the aircraft to roll at supersonic speeds using spoilers.
The most unique feature of the aircraft was the dorsal-mounted variable inlet duct, mounted directly above and behind the cockpit. The inlet automatically controlled the amount of air entering the engine. This early system proved very efficient. The intake was placed on top, as the U.S.A.F. required room on the centerline hardpoint to mount a semi-conformal nuclear weapon. Although the intake limited rear visibility, this was considered a non-issue, as it was assumed that true dogfights were outdated and enemy aircraft would be dealt with by air-to-air missiles at beyond-visual-range.
The J-75 engine would power the new fighter. With 24,500 pounds of thrust, the F-107 had twice as much power as the “Hun.” As the modifications mounted, the U.S.A.F. gave the F-100B the F-107A designation.
In August 1954, the U.S.A.F. signed a contract with North American for three prototypes and six additional airframes. On September 10, 1956, the F-107 made its maiden flight with chief test pilot Bob Baker. The flight went well, reaching a top speed of Mach 1.03. Still, the landing went awry when the brake parachute failed to deploy, resulting in a hot landing and nose-gear collapse. Two months later, in November, the prototype reached Mach 2.
As the program progressed, the aircraft designation was changed to F-107A. While it never received an official name, it was informally known as the “Super Super Sabre” and the “Ultra Sabre”; many North American employees referred to it as the “Maneater” due to the intake above the cockpit.
The Fly Off?
Since the U.S.A.F. had already given the go-ahead for production of the F-105 in March 1956, some 6 months before the first flight of the F-107, many wondered why have a fly-off, as the decision was preordained. The U.S.A.F.’s Tactical Air Command ordered a fly off between the Ultra Sabre and the Republic F-105 Thunderchief.
Both Jets were built for the same mission and were powered by the Pratt & Whitney YJ75 Turbojet engine. While the F-107 had a better rate of climb and a higher ceiling, the internal weapons bay required by the U.S.A.F. for nuclear weapons use had a 14,000-pound capacity, which was 40% larger than the F-107.
Another reason alleged for picking the F-105 was that Republic Aviation required contracts to stay afloat. They were in the final stages of production of their F-84 Thunderjet, with nothing else in the pipeline, while North American was extremely busy working on a plethora of designs.
Another view was that the U.S.A.F. wanted a bomber designed to deliver a nuke — not a fighter that was modified for the mission. U.S.A.F. Gen. Otto Weyland stated that senior U.S.A.F. staff seemed to be obsessed with nuclear weapons.
Ultimately, the F-105 “won” the flyoff and went on to serve as the primary strike aircraft for the first few years of the Vietnam War, until it was replaced by the F-4 Phantom. Still, the big selling point about nuclear capability was moot. The bomb bay was fitted with a 400-gallon fuel tank to extend range, and all ordnance was fitted on external hardpoints.
Testing, Testing
In late 1957, prototypes #1 and #3 were leased to NACA (National Advisory Committee for Aeronautics), which was the predecessor to NASA, for high-speed flight testing. During testing, the variable inlet caused problems. The engineers couldn’t seem to get it dialed in, and ultimately, the intake was fixed into position, limiting top speed to Mach 1.2.
Another area of testing concerned the use of a right-side-mounted control stick. The side-mounted stick was used to test the system mounted in the North American X-15 rocket-powered aircraft, which was under development. The X-15 had the side stick installed to cradle the pilot’s arm and prevent any unintended control input when the rocket motor ignited. After burnout, the pilot would use the center stick to glide back for landing. Airframe #3 was configured this way.
In September 1959, NACA test pilot Scott Crossfield, who was slated to fly the X-15, was taking off when the plane ground-looped, blowing both main tires and causing a small brake fire. Although the airplane was not badly damaged, it was decided not to invest in repairs, and the prototype was used for firefighter training.
Where Are They Now?
Prototype #1 now resides at the Pima Air and Space Museum, located next to Davis Monthan AFB, aka “The Boneyard.” Prototype #3 is located at the Mecca of Aviation, the National Museum of the United States Air Force in Dayton, Ohio.
Legacy of the Ultra Sabre
The F-107 introduced several design innovations that are in use today. The VAID Variable Area Inlet Duct system is used on several aircraft types to control airflow into the engines. Positioning the inlet on top also minimized aerodynamic interference with the bomb bay, reduced overall drag, and improved shock-wave control at supersonic speeds.
The Ultra Sabre was a prime example of Cold War innovations in supersonic aircraft that influenced aircraft designs to this day.
Robert E. Lee called Pelham “The Gallant Pelham” for his use of light artillery at the Battle of Fredericksburg to delay U.S. soldiers.
Anyone who ever flew an Army helicopter reveres the Loach. Uncle Sam called the bizarre little egg-shaped aircraft the OH-6A Cayuse. Its official classification was Light Observation Helicopter, hence the informal appellation “Loach.” The Loach looks and sounds like a giant, angry bumble bee. It is a simply magnificent machine.
The Loach was used for scouting missions during the Vietnam War. The aircraft was flown without doors at extremely low levels. The typical crew layout was a single pilot on the right with a crew chief sitting just behind on the same side, packing an M60 belt-fed machinegun suspended from a bungee cord. Offsetting the weight on the left was an M-134 minigun in an XM21E1 mount. This electrically-powered 7.62x51mm belt-fed Gatling gun cycled at either 2,000 or 4,000 rounds per minute via a two-stage trigger. It fed from a 2,000-round ammunition magazine. The pilot sighted the minigun via a grease pencil mark on the inside of the Plexiglas canopy.
The Loach operated most commonly as part of a Pink Team. In this configuration, the Loach cruised about down low in the dirt, looking for bad guys, while one or two AH-1G Cobra gunships orbited at altitude, waiting to dive in at the first sign of trouble. The two elements maintained constant radio contact. Experienced Pink Teams were devastating killers on the battlefield. Survival and tactical effectiveness demanded both nerves of steel and exceptional pilotage.
Of all the scout pilots who served in Vietnam, one name percolates above all the rest: Lt. Col. Hugh Mills. He is a legend among Army aviators, even today. A Loach painted as his distinctive “Miss Clawd IV”, dangles proudly from the ceiling at the Army Aviation Museum at Fort Rucker. Among rotary-wing aviators, that is the Army’s highest accolade. Lt. Col. Mills earned every bit of that love.
A Hard Day in Hell
In the summer of 1969, then-Lieutenant High Mills piloted his agile little Loach as the bottom half of a hunter-killer Pink Team. In the back was his regular crew chief, Jim Parker. Mills and Parker had flown together for months and were forged into an exceptionally effective scout team. On this fateful day, they were clearing the route for a supply convoy along a length of highway called Thunder Road.
Without warning, Mills’ Loach was engaged by a well-sited VC .50-caliber machine gun. One of the big thumb-sized rounds punched through the leading edge of one of the Loach’s four rotor blades about four feet from the tip. There resulted a skull-crushing vibration as the hearty Loach clawed to stay in the air.
Mills retained control of the stricken aircraft, but only just. He guided the doomed helicopter to a controlled crash on a nearby flat piece of rice paddy. Parker split his chin on the front sight of his M60, but both aviators were otherwise unhurt. They cleared the aircraft with Parker’s M60 and a seven-foot belt of ammo along with Mills’ CAR-15 and a bandoleer of magazines.
Mills spotted a pair of VC soldiers shooting at them with AK-47s from about 175 yards away. He fired a burst from his CAR-15 as Parker sprayed the area with his M60. Both enemy soldiers fell, but they just kicked over the anthill.
A substantial VC force began slathering the crash site with fire and moving toward the two trapped aviators. Parker returned to the crashed aircraft to retrieve more M60 ammo as Mills covered him with his CAR-15. Meanwhile, the high-cover Snake pummeled the tree line with 2.75″ rockets and minigun fire. However, the Cobra soon ran out of ammo.
Just when it seemed like all was lost, a nearby Infantry Brigade commander in a command-and-control aircraft dropped down to make an emergency extraction. Parker and Mills clambered aboard the hovering Huey and made their escape before the remaining VC could stop them.
Turning an NVA Pot into a Colander
During that same summer, Mills and Parker were tearing along in their Loach on a routine trip into Dau Tieng for a briefing. They had a G-model Cobra flying top cover. As they pitched over a ridgeline, Mills surprised an NVA heavy weapons platoon on the march. Without hesitation, he opened up with his minigun at close range as Parker unlimbered his M60. The NVA troops answered with a fusillade of AK-47 fire.
A pair of NVA soldiers tore off down a paddy dike toward the wood line and cover. The nearer of the two enemy soldiers carried a big cooking pot that flapped against his back as he ran. Mills quickly pivoted his nimble little aircraft, lined up the grease pencil mark on his canopy and triggered a quick squirt from his minigun. His burst passed through the nearest NVA soldier and into his buddy, killing them both.
Mills chased the remaining NVA troops around the paddy until both he and Parker ran out of ammo. Parker then unlimbered both his M16 as well as a 12-gauge pump shotgun. Meanwhile, Mills steadied the collective lever with his knee and emptied six rounds left-handed from his personal .357 Magnum revolver at the fleeing enemy troops. Once completely out of ammunition, Mills rolled clear so the orbiting Snake could pulverize the area with 2.75″ rockets packing flechette warheads.
In two minutes of unfettered combat, their Loach had been hit 25 times. The airspeed indicator and altimeter were both blown away, and the armor plate underneath Parker’s seat had caught two rounds. Mills’ seat armor stopped several more. Five rounds shattered the Plexiglas canopy, two hit the tail boom, and another three struck the rotor blades. One AK round transited the engine compartment but missed anything significant. Another shot the op rod off of Parker’s M60.
Supporting ARP (Aero Rifle Platoon) grunts subsequently inserted and swept the area. They cataloged 26 KIA and seized a pair of POWs along with a large number of AK-47 rifles, an SGM heavy machinegun, a 60mm mortar and a pair of Russian pistols. When they returned to base, the infantry troops presented Lt. Col. Mills with a cooking pot sporting 24 bullet holes.
The Rest of the Story
While serving three combat tours in Vietnam, Lt. Col. Hugh Mills earned three Silver Stars, three Bronze Stars, four Distinguished Flying Crosses, and the Legion of Merit. He was shot down an amazing 16 times and was wounded three times in combat. He ultimately flew 3,300 combat hours in OH-6A and AH-1G helicopters. His record as a combat aviator will never be bested.
The OH-6A was tragically replaced by the Bell OH-58 in Army service. Both aircraft shared a common engine, but in my opinion the Loach was a massively better aircraft. I flew OH-58’s myself, and we all mourned the passing of the Loach. However, that was not the last Uncle Sam saw of this extraordinary little machine.
The Task Force 160 SOAR (Special Operations Aviation Regiment), better known as the Night Stalkers, adopted the OH-6 in an upgraded form as the MH-6 Little Bird. They call it the “Killer Egg.” These immensely capable machines feature an upgraded powertrain along with a more efficient five-bladed rotor system. The Night Stalkers use both an armed gunship version of the aircraft as well as slick-sided variant designed for covert insertion of special operators in places where stealth and speed are of the essence. If ever I win the lottery, my first call will be to my wife. My second will be to Boeing to pick up an MH-6 of my own.
Lt. Col. Mills penned a book about his exploits in Vietnam titled Low Level Hell. It is an amazing read that is just packed with action along with plenty of cool commentary about small arms. It is available on Amazon.