Showing posts with label AH-1 Cobra. Show all posts
Showing posts with label AH-1 Cobra. Show all posts

19 October 2015

Mike Grimm, Father of the Night Stalkers

Michael Grimm, Father of the Night Stalkers
Conventional wisdom in aviation history points to the tragic debacle at Desert One in Iran during the hostage rescue mission as the watershed moment that culminated in the formation of the US Special Forces Command (SOCOM). While I do think that the story of the failed 1980 Iranian hostage rescue mission should be held near and dear to every military leader of this nation, there was actually someone else who sounded the warning bells three years before that fateful day in 1980. His name is legendary amongst US special forces personnel to this day, but I'd bet hardly any of us enthusiasts had ever heard of his name- Mike Grimm.

Long before he would make his mark on the history of US special forces, Mike Grimm was already a decorated hero of the Vietnam War when as a second lieutenant in 1968, assumed command of his platoon and managed to fight off through the night two entire companies of Vietcong before they could be extracted by helicopter from the battle zone. He stayed on with the US Army after the end of US participation in the war in 1973, eventually becoming a helicopter pilot and stationed in Hawaii in 1975. But serving in Hawaii was boring for Grimm, when the most serious decision they ever had to make was whether he would fly clockwise or counter-clockwise around Oahu. In 1976, the world was electrified with the stunning Israeli raid at Entebbe, Uganda, to rescue the passengers of a hijacked Air France flight. In less than one hour, Israeli commandos stormed the Entebbe Airport, killed nearly all the terrorists, rescued nearly all the hostages and only losing one commando. And they also manged to destroy most of the MiGs of the Ugandan Air Force in the process.

Mike Grimm realized that the United States lacked the capability to do what the Israelis managed to do- project power over 2,000 miles into hostile territory and effect a hostage rescue with minimal losses. Austerity was the key word in the post-Vietnam defense budget and even training exercises were canceled to save money. Once he had become the Divisional operations officer in 1977, he decided to use the Division's entire budget for training on a single exercise. He called it an Emergency Deployment Readiness Exercise (EDRE) and in the training scenario, his men and pilots would have to fly 200 miles to the island of Hawaii where a select group of soldiers playing terrorists were holding hostages. Grimm's men would have rescue those hostages with minimal losses. The tactics he developed for the exercise would be the blueprint for all future missions to come, even to this day.


Men from the First and Fifth Infantry Battalions at Schoefield Barracks on Oahu were selected to be the "raiders." Their helicopter element consisted of 10 Bell UH-1H Hueys and two Bell AH-1G Cobra gunships from A Company of the 25th Aviation Battalion. After an alert and planning period, the men and their helicopters flew from Schoefield Barracks to Hickam AFB to be loaded aboard USAF Lockheed C-141A Starlifters to simulate strategic deployment. The men were flown to Hilo Airport which would function as the "intermediate staging base" for the exercise. On 14 November they arrived in Hilo where the helicopters were readied for flight and they flew onward to Bradshaw AAF in the Pohaku Trainng Area in the center of Hawaii. This would be their "forward operating base" for the mission exercise.

The "hostages" were being held in the fire station of Waimea-Kohala Airport just 30 miles north of their forward operating base. The raid would be carried out at dawn as no night vision equipment was available. At ten miles from the target, the "terrorists" heard the team coming and "executed" the hostages. When Grimm's raiding force landed, they were wiped out to the last man.

The next day at Bradshaw AAF the After Action Review took place and everyone but Mike Grimm thought their Army careers were over when the Division commander, Lieutenant General Willard Scott arrived. He began the debriefing with the statement "This exercise was a really bad idea." As he continued for several minutes on the inappropriateness of using helicopter-borne infantry on anti-terror operations. "Our Army will never enter into this area. This is NOT our role."

At that moment, Mike Grimm stood up and interrupted his commander.

"Respectfully, sir, that is NOT correct." Here he was, a newly minted major, holding a two-star general to task. "Not only do we need to create this capability, sir, but if we don't, we are going to find ourselves at some point in our history embarrassed as a nation!"
Emblem of the 160th SOAR

Three years later, on the morning of 25 April 1980, in the Iranian desert, that embarrassment took place. The wrecks of five Marine RH-53D Sea Stallions and one USAF C-130 Hercules lay smoldering in the desert with the bodies of eight American servicemen. That year Mike Grimm was the commander of A Company of the 229th Aviation Battalion of the 101st Airborne Division where he was working with a handpicked group of men to transform the Hughes OH-6 "Loach" into what would become the MH-6/AH-6 "Little Bird" for night time special forces missions. On the night of 7 October 1981, Mike Grimm was flying one of the unit's MH-6s at low level over the Cumberland River when he hit the side of a power line tower and was killed instantly. One week later, in memorial to Mike Grimm, the new 160th Aviation Battalion uncased its colors. It was the birth of the Army Special Force's aviation element (Special Operations Aviation Regiment, or SOAR), the "Night Stalkers".

Source: The Night Stalkers: Top Secret Missions of the US Army's Special Operations Aviation Regiment by Michael J. Durant and Steven Hartov. GP Putnam and Sons, 2006, p33-64. Photos: US Army, Wikipedia

17 March 2011

The Bell 207 Sioux Scout- Grand Daddy of the Gunship

The Bell D-245 Warrior set the pattern for gunship designs
With the turbine-powered Bell UH-1 Iroquois "Huey" utility helicopter offering a quantum leap in capability for the US Army over previous, cumbersome, piston-driven rotorcraft, it was a natural progression that the UH-1s would be armed for aerial fires support for the growing conflict in Vietnam. But Bell's engineers in Fort Worth were steps ahead of the military with studies as early as 1958 for a tandem-seat purpose-built helicopter gunship that used the transmission and engine systems of what would become the UH-1. Bell's first offering had the in-house designation D-245 and was named "Warrior" which laid down the standard layout of gunships that followed- a slim fuselage with tandem seating for a pilot and gunner, stub wings for weapons, and nose-mounted gun turret. But despite its potential, the Army had yet to determine operational doctrines for the use of attack helicopters and the D-245 Warrior was quietly shelved. 

Despite official disinterest from the US Army, Bell decided to embark on internally-funded development to further refine the D-245 Warrior design. In June 1962 Bell unveiled the D-255 Iroquois Warrior to the Army at its Fort Worth facility. The D-255 was a bit larger than the earlier D-245 but retained the tandem seating for pilot and gunner in stepped layout with the pilot sitting behind and higher than the gunner in the forward seat. Again, the tail boom, rotor transmission and engines were adapted from the UH-1. While the mixed reaction from the US Army was an improvement over the official disinterest that the earlier D-245 design elicited, it still wasn't enough to get a production contract from the Army. Again the D-255 was quietly shelved, but this still wasn't going to discourage the Bell team from staying ahead of the game. In December 1962 a brainstorming session of the engineering team resulted in a decision to build a flying demonstrator to prove the US Army what Bell's gunship concept could accomplish. 

The Sioux Scout was quite small for a two-seat gunship
Designated the Model 207 and named the Sioux Scout, the demonstrator combined the engine, rotor, and drive systems of the proven Bell OH-13 Sioux (the bubble-cockpit helicopter made famous in the introduction to the TV series M*A*S*H) with its civilian counterpart, the Bell 47. The six-cylinder Lycoming 435 engine of the OH-13/Bell 47 was supercharged to deliver 220 horsepower driving the main rotor system from the OH-13 and the tail rotor/tail boom of the Bell 47. An all-new slim fuselage was created that used box beams to create a rigid structure to which were attached the stub wings that could carry external stores on six hardpoints on each side as well as house an additional 43 gallons of fuel which gave the Sioux Scout a range of 200 miles. At high speeds, the stub wings helped offload the main rotor as well. An Emerson Electric TAT-101 gun turret was installed under the nose (the rigid fuselage structure dampened recoil) housing twin 7.62mm machine guns that were adaptations of the M60 gun. With 1,100 rounds of ammunition, the gunner in the forward seat used a pioneering hand controller to operate the gun turret 100 degrees side to side, 15 degress upward, and 45 degrees downward. Under each stub wing were six round, 2.75 inch rocket launchers on each hardpoint. 

The gunner had an outstanding field of view from the front seat
The Sioux Scout made its first flight from Bell's Fort Worth facility in Hurst on 27 June 1963, in the process becoming the first pure gunship in the world to take flight. Since the demonstrator program was somewhat secret, the helicopter was painted red and white to not so blatantly give away its military purpose. After several weeks of testing with Bell that added up to 65 flight hours, the Sioux Scout was repainted in more Army-like olive drab and began a series of weapons tests at Fort Sill, Oklahoma, northwest of Fort Worth. In November of that year, the Sioux Scout was taken on the road, touring Army bases and being flown by both Army and even NASA test pilots with over 300 flight hours that included firing over 83,000 rounds of ammunition from the chin turret. Finally, in 1964, B Troop, 3rd Squadron, 17th Cavalry of the 11th Air Assault Division spent a month flying the Sioux Scout in operational conditions and in field exercises. At the time, the 11th Air Assault Division was tasked by the Army commanders with experimenting and creating operational doctrines in helicopter assault at Fort Benning, Georgia. 

The Model 209 prototype had retractable landing skids
Other than the Sioux Scout being underpowered and the reliability of the experimental gun turret being less than ideal, Army evaluators were overwhelmingly pleased with the outcome of the 11th Air Assault Division's operational evaluation of the demonstrator. The recommendation was issued that a turbine-powered, more capable version be developed as quickly as possible for operational use. In late 1964 the Secretary of the Army created the Advanced Aerial Fire Support System (AAFSS) with invitations to industry to submit designs. With the quick realization that the AAFSS design would take time to field, the Army decided that an interim design was needed that would field the gap until the AAFSS became operational. Bell dusted off its D-255 Iroquois Warrior design and with further refinements based on the Sioux Scout evaluation, designated it the D-262. However, in 1965 the Army rejected the D-262 design. But, as Bell had done before, they quietly went about refining the design further on company funds- within several months of the rejection of the D-262, the situation in Vietnam worsened and the US commander in Vietnam, General William Westmoreland, advised the Pentagon that either the AAFSS needed to fielded quickly or some interim design was needed as soon as possible. In March 1965 Bell just happened to finish the full-scale mockup of its refined gunship designated the Model 209 and "leaked" to Army commanders what it was up to. Before long, the Army issued a formal requirement for an interim design. Beating out submissions from Sikorsky, Kaman, Piasecki and Boeing Vertol, the Model 209 was selected on 11 March 1966 for production as the AH-1 Cobra.

And the AAFSS? That became the Lockheed AH-56 Cheyenne and was a classic case of wanting too much out of a design. It ended up getting cancelled in August 1972. That same month, the Army created the Advanced Attack Helicopter program (AAH) which became the AH-64 Apache. And what become of the Sioux Scout? The grand daddy of gunships can be seen today in the Army Aviation Museum in Fort Rucker, Alabama. And of course, Bell's interim design is still in production today for the US Marine Corps as the AH-1Z Viper.

Source: Helicopter Gunships: Deadly Combat Weapon Systems by Wayne Mutza. Specialty Press, 2010, p56-60. Images from aviatstar.org

14 February 2011

Operation MARHUK: The Combat Debut of the Marine's AH-1J SeaCobra

Marine SeaCobras took a beating operating at sea
The first US Marine Corps AH-1 Cobra gunships in action were actually AH-1Gs which were ordered by the Marines in 1967- having closely watched the Army development of the Cobra gunship, 72 helicopters were requested for one helicopter attack squadron in each of its three Marine Air Wings. Despite having the approval of the Secretary of the Navy, Defense Secretary McNamara overruled the decision and only allowed the Marines to order 38 of the single-engined AH-1G variant. With the first Marine AH-1Gs going into action in Vietnam in April 1969, reports from the field couldn't have been more salutatory in the effectiveness of the Cobra gunship. Based on that initial experience, the Marines wanted a more powerful Cobra- one with twin engines, Marine avionics, a rotor brake for shipboard operations and a harder-hitting gun in the undernose turret. After overcoming the resistance of an obstinate Secretary McNamara, the AH-1J SeaCobra went into production with the first examples undergoing combat evaluation in South Vietnam in February 1971. With the onset of the Easter invasion by North Vietnam of the south and the American response, Operation Linebacker, the first Marine helicopter attack squadron, HMA-369 based in Okinawa, was called upon shortly after its establishment to conduct offensive operations against North Vietnam. 

The USMC had the AH-1J built from the start to operate from ships
At the time, Army Cobra gunship were operating in South Vietnam against the invasion thrusts of the North Vietnamese Army. Despite having just received its new AH-1J SeaCobras, Admiral John McCain, Jr, head of the US Pacific Command, wanted to make sure that the blockade of North Vietnam was complete. Even though carrier aircraft had sown mines closing Haiphong Harbor, the North's main port, the North Vietnamese had resorted to having Chinese and Soviet cargo ships anchor offshore various locations and cargo would be offloaded into smaller sampans for transfer to the shore. This way the mined sea lanes could be avoided. Because fixed wing carrier aircraft were urgently needed for Operation Linebacker attacks on North Vietnam, it was decided that the AH-1J SeaCobra would be ideal for the role of maritime interdiction off the coast of North Vietnam. In the entire Pacific theatre, only HMA-369 in Okinawa had suitable helicopters for the job and Operation MARHUK (Marine Hunter-Killer) was born. It would be the Bell AH-1J SeaCobra's baptism of fire and off the coast of the heavily defended North Vietnamese coast, no less. 

HMA-369's "Marhuker" patch

 HMA-369 originally wanted a helicopter carrier to be based on for Operation MARHUK, but the Navy's LPHs were heavily committed else where and the 18 officers, 99 men and seven AH-1J SeaCobras of HMA-369 that were ready to deploy in June 1972 were shoehorned into the amphibious transport ship USS Denver (LPD-9). Marine brass give the squadron officers a blank check to do what ever was necessary to get HMA-369 to the war zone and the nickname "Marhukers" was given to the officers who improvised and bent and possibly broke many rules to make their SeaCobras combat ready. Even 5-inch Zuni rockets were procured, a weapon that had not yet been cleared for use from the AH-1J. The ship and its escorts would be positioned near the Hong La anchorage further south down the coast from Haiphong. Here Chinese and Soviet merchant ships anchored offshore and North Vietnamese sampans offloaded cargo offshore to bring into Hong La. Since the rules of engagement forbade hitting the merchant ships, the SeaCobras stayed at least 500 yards away from the ships and remained overwater the whole time as the North Vietnamese had heavy AAA guns on  the shoreline. The SeaCobras operated in pairs and would sink the sampans with their Zuni rockets and 20mm undernose cannon. The pilots were also trained to call in naval gunfire and air strikes while the gunners in front seats of the AH-1Js focused on the sampans. After several weeks, the shore-based heavy AAA guns learned not to fire on the SeaCobras thanks to the naval fire support and air strikes the pilots would call in. 

In August 1972 HMA-369 moved to the USS Cleveland (LPD 7) and then again to the USS Dubuque (LPD 8). Over the course of Operation MARHUK, the AH-1J SeaCobras were called on to provide air cover for downed aviators in the North as well as functioning as forward air controllers for Navy strike aircraft. Missions ranged from 80 miles north of the DMZ to as far north as 80 miles south of Hanoi inland! When Operation MARHUK ended on 26 January 1973 with the end of Operation Linebacker II, nearly 1,000 sorties had been flown with 123 sampans sunk, further straining the logistics of North Vietnam that eventually drove them to the bargaining table. It was quite a stunning debut for the AH-1J SeaCobra. 

Source: Helicopter Gunships: Deadly Combat Weapon Systems by Wayne Mutza. Specialty Press, 2010, p72-76.

19 March 2010


On 18 January 2003 the over 7,000 Marines of Task Force Tarawa set sail from the United States aboard seven amphibious assault ships with 72 aircraft (and more following them) for the Persian Gulf in the run up to Operation Iraqi Freedom. The Bell AH-1W Super Cobras of Marine Light Attack Helicopter Squadron 269 (HMLA-269 "Gunrunners") from MCAS New River, North Carolina were reinforced with additional gunships from sister unit HMLA-167 for a total of 18 AH-1W Super Cobras and nine Bell UH-1N transports. The reinforced squadron embarked on the USS Saipan (LHA-2) and the USS Ponce (LPD-15) for the sea transit to the Middle East. As Task Force Tarawa transited through the choke points of Gibraltar and the Suez Canal, HMLA-269 would have six Super Cobras on flying alert to protect the task force.

Arriving off the coast of Kuwait on 18 March 2003, ten of HMLA-269's Super Cobras were detached to a forward base 23 miles south of the Iraqi border to participate in the squadron's first operational mission, the assault on the Iraqi forward reconnaissance positions at Safwan. The first combat missions by the AH-1Ws of the squadron on 20/21 March were notable, however, for the combat use of what was then-a-classified version of the AGM-114 Hellfire missile, the AGM-114N thermobaric Hellfire.

Thermobaric weapons were first developed in the 1960s by the engineers at the China Lake Naval Weapons Center and were what were then known as fuel-air-explosive weapons. FAEs work by releasing a cloud of volatile vapor which is then detonated, creating a large and destructive pressure wave in the process. A standard blast/fragmentation warhead creates a large pressure spike that decays rapidly. A thermobaric warhead, on the other hand, creates a large sustained pressure wave that propagates through any building or enclosed space, making it ideal for urban warfare. In the late 1990s, the engineers at China Lake had succeeded in creating non-liquid thermobaric explosives using metal particles (such as aluminum or magnesium) instead a liquid. The initial detonation releases the fine particles which then ignite, creating the large and sustained pressure wave. For this the China Lake Naval Weapons Center was awarded a classified US patent.

Marine Corps combat experience prior to OIF had shown that missiles like the TOW or Hellfire with their blast/fragmentation warheads were often unsuitable in urban environments as the pressure spike from the warhead detonation would be attenuated inside enclosed spaces. In addition, the missiles would often pass right through the target building before detonating.

The thermobaric weapons work at China Lake resulted in what was called a metal-augmented charge (MAC) that was the ideal warhead for a new version of the Hellfire missile desired by the Marine Corps. The AGM-114N's thermobaric warhead consists of a layer of fine aluminum powder sandwiched between the warhead casing and the explosive fill in the center. On detonation, the aluminum powder is dispersed and ignites, creating a large and sustained pressure wave. Live fire tests at White Sands and China Lake proved the weapon to be effective.

When HMLA-269 arrived in the Persian Gulf, the squadron's commanding officer, Lt. Col. Jeffrey Hewitt, was one of the few Marine aviators aware of the AGM-114N as his previous posting before taking command of the "Gunrunners" was a senior posting in Marine Corps weapons development working closely on the tests of the thermobaric Hellfire missile. The thermobaric Hellfires used in the development and testing work in the United States prior to OIF were converted from stock AGM-114K Hellfires and Lt. Col. Hewitt knew that there were 60 AGM-114Ns left over from the test program that were in storage. Aware that the Marines of Task Force Tarawa faced many urban threats before even reaching Baghdad, he arranged for those 60 missiles to be shipped out to the squadron. However, the US Navy wouldn't transport them as the missiles were never certified for carriage by ship. Lt. Col. Hewitt then turned to the US Air Force, who were more than happy to fly out the missiles immediately to Kuwait for the squadron.

HMLA-269's original plan was to keep the precious AGM-114Ns until Task Force Tarawa reached Baghdad, but they also wanted to prove that the thermobaric Hellfires worked in actual combat. Several were fired during the assault on Safwan and were highly effective. Interestingly enough, during their use in the assault on Safwan and in HMLA-269's combat missions on the march to Baghdad, the AGM-114N thermobaric Hellfire missiles (called TB Hellfire) were still classified!

Source: International Air Power Review, Volume 12, Spring 2004. "Focus Aircraft: Bell AH-1 Cobra" by Robert Hewson, p56-58.

29 April 2009

When the Bell AH-1 Cobra gunship was being developed, the Army's intent was to name the aircraft after an American Indian tribe as had been its long tradition. However, at the time of the development of the Cobra gunship, the Department of Defense was in a legal battle with Piper Aircraft who also named their aircraft after American Indian tribes.

In Vietnam, UH-1 "Hueys" were called "Slicks" if they were operating unarmed, "Hogs" if they were armed with rockets, and "Cobras" if they were armed with guns. As Bell's main pitch for the procurement for the AH-1 was that it was a low-risk development of the UH-1 Iroquois (to some degree true given that the original gunship proposal was called the Iroquois Warrior and had more in common with the UH-1 than the final AH-1 design), the AH-1 got named "Huey Cobra".

Source: New Vanguard: Huey Cobra Gunships by Chris Bishop. Osprey Publishing, 2006, p6-7.