Operation Credible Sport
Encyclopedia
Operation Credible Sport was a joint project of the United States military in the second half of 1980 to prepare for a second rescue attempt of the hostages held in Iran
using a Lockheed C-130 Hercules airlifter modified with rocket engine
s. Credible Sport was terminated when the Iranian parliament on 2 November accepted an Algeria
n plan for release of the hostages, followed two days later by the election of Ronald Reagan
as President
.
Its followup project in 1981–82, Credible Sport II, used one of the original aircraft as the YMC-130 prototype for the MC-130H Combat Talon II.
(Operation Eagle Claw), planning for a second mission began in the Pentagon. The first mission failed due to equipment and coordination problems, culminating in the crash, killing eight servicemen, of a RH-53D Sea Stallion helicopter into a parked C-130 Hercules in the Iranian desert.
A new organization, the Joint Test Directorate, was established to assist and support the Office of Secretary of Defense Directorate (OSD) joint planning staff. Under the program name Honey Badger, the JTD conducted a series of large-scale joint-force exercises and projects to develop and validate a variety of capabilities that would be available to OSD when mission requirements were identified. JTD trained a large and diverse force of United States Army
and United States Air Force
special operations
, Ranger
, and aviation units, but the critical factor remained extracting the rescue force and freed hostages from Tehran
. The Credible Sport project, a joint undertaking of the USAF, U.S. Navy
, and Lockheed-Georgia, was created within Honey Badger to develop a reliable extraction capability. Credible Sport was tasked to create a large "Super STOL
" fixed-wing aircraft to extract the rescue team and hostages and overcome the "weak link" in the previous plan, the heavy lift helicopter.
(soccer) across the street from the American Embassy and airlift out Delta Force
and the rescued hostages. The aircraft would then be flown to and landed on an aircraft carrier
for immediate medical treatment of an expected 50 wounded. (A US Marine Corps KC-130 on loan to the US Navy had been previously landed on the aircraft carrier in November 1963 as part of a Naval Air Systems Command demonstration.) Three MC-130 Combat Talon
crews (all Eagle Claw veterans) were assigned to fly the three aircraft, drawn from the 463rd Tactical Airlift Wing, with the concept plan calling for the mission of two aircraft (one primary and one spare) to originate in the United States, reaching Iran by five in flight refuelings
, and penetrate at low altitude in the dark to evade Iranian air defenses.
Auxiliary Field #1 (Wagner Field
), Florida. The contract called for two to be modified to the proposed XFC-130H configuration within 90 days, and the third to be used as a test bed for various rocket packages blistered onto the forward and aft fuselage, which theoretically enabled the planes to land and take off within the confines of the sports arena. (A fourth aircraft, an EC-130 ABCCC, was used as the interior mockup airframe for simulator training.)
After Lockheed was requested on 27 June 1980, to begin preliminary engineering studies on an STOL Hercules, the use of JATO
units was explored, since these had previously been used to power takeoffs. Lockheed reported on 16 July that 58 JATO bottles (more than seven times greater than normal) would be required and that arresting gear would be insufficient to stop the C-130 in the required space. The U.S. Navy's Naval Air Weapons Station China Lake
organization was then brought into the project to provide expertise on existing rocket motor power. Lockheed proceeded with work to structurally reinforce the C-130 airframe to withstand rocket forces and to develop a passenger restraint system for 150 persons.
The resulting XFC-130H aircraft were modified by the installation of 30 rockets in multiple sets: eight forward-pointed ASROC
rocket motors mounted around the forward fuselage to stop the aircraft, eight downward-pointed Shrike
rockets fuselage-mounted above the wheel wells to brake its descent, eight rearward-pointed MK-56 rockets (from the RIM-66 Standard Missile) mounted on the lower rear fuselage for takeoff assist, two Shrikes mounted in pairs on wing pylons to correct yaw
during takeoff transition, and two ASROCs mounted at the rear of the tail to prevent it from striking the ground from over-rotation.
Other STOL features included a dorsal and two ventral fins on the rear fuselage, double-slotted flaps
and extended aileron
s, a new radome, a tailhook
for landing aboard an aircraft carrier
, and Combat Talon avionics, including a Terrain Following/Terrain Avoidance radar, a defensive countermeasures suite, and a Doppler radar/GPS tie-in to the aircraft's inertial navigation system
.
), a disused auxiliary airfield at Eglin Air Force Base
, Florida. Between 19 October and 28 October, numerous flights were made testing various aspects, including the double-slotted flaps system, which enabled the C-130 to fly at 85 knots on final approach at a very steep eight-degree glide slope. All aspects worked flawlessly, and a full profile test was scheduled for 29 October.
The takeoff phase of the test was executed flawlessly, setting a number of short takeoff records. The Lockheed test crew then assessed that the computer used to command the firing of the rockets during the landing sequence needed further calibration, and elected to manually input commands. The reverse-mounted (forward-facing) eight ASROC rockets for decelerating the aircraft's forward speed were situated in pairs on the upper curvature of the fuselage behind the cockpit, and at the mid-point of each side of the fuselage beneath the uppers. Testing had determined that the upper pairs, fired sequentially, could be ignited while still airborne (specifically, at 20 feet), but that the lower pairs could only be fired after the aircraft was on the ground, with the descent-braking rockets also firing during the sequence.
The flight engineer, blinded by the firing of the upper deceleration rockets, thought the aircraft was on the runway and fired the lower set early. The descent-braking rockets did not fire at all. Later unofficial disclaimers alleged to have been made by some members of the Lockheed test crew asserted that the lower rockets fired themselves through an undetermined computer or electrical malfunction, which at the same time failed to fire the descent-braking rockets.
As a result, the aircraft's forward flight was immediately reduced to nearly zero, dropping it hard to the runway and tearing off the starboard wing between the third and fourth engines. During rollout the trailing wing ignited a fire, but a medical evacuation helicopter dispersed the flame and crash response teams extinguished the fire within eight seconds of the aircraft stopping, enabling the crew to exit the aircraft without injury. 74-1683 was dismantled and buried on-site for security reasons, but most of its unique systems were salvaged.
74-1686 was nearly ready for delivery, but the defeat of Jimmy Carter
by Ronald Reagan
in the presidential election
on 4 November 1980, and an Algerian-negotiated release plan led to the cancellation of the rescue mission plan. The hostages were subsequently released concurrent with Reagan's inauguration in January 1981.
, Georgia
. There in July 1981 it was designated YMC-130H as the test bed for development of the MC-130 Combat Talon II, under the project name Credible Sport II. Phase I was conducted between 24 August and 11 November 1981, to test minor modifications to improve aerodynamics, satisfy Combat Talon II prototype requirements on STOL performance, handling characteristics, and avionics, and to establish margins of safety. It also identified design deficiencies in the airframe and determined that the Credible Sport configuration was suitable only for its specific mission and did not have the safety margins necessary for peacetime operations.
Phase II testing began 15 June 1982, continued through October 1982, and determined that the final configuration resulted in significant improvements in design, avionics, and equipment, and that the Combat Talon II design was ready for production. The 1st Special Operations Wing attempted to have the test bed transferred to operational duty as an interim Combat Talon II until production models became available, but Headquarters, Tactical Airlift Command disagreed. The cost of de-modifying the YMC-130H to airlift configuration was more than its value, and it never flew again.
In 1988, 74–1686 was placed on display at the Museum of Aviation
at Robins Air Force Base
in Warner Robins, Georgia. As of February 2008, the other surviving Credible Sport aircraft, 74-2065, was assigned to the 317th Airlift Group, 15th Expeditionary Mobility Task Force, at Dyess Air Force Base
, Texas, in gray scheme with blue tail band.
Iran hostage crisis
The Iran hostage crisis was a diplomatic crisis between Iran and the United States where 52 Americans were held hostage for 444 days from November 4, 1979 to January 20, 1981, after a group of Islamist students and militants took over the American Embassy in Tehran in support of the Iranian...
using a Lockheed C-130 Hercules airlifter modified with rocket engine
Rocket engine
A rocket engine, or simply "rocket", is a jet engineRocket Propulsion Elements; 7th edition- chapter 1 that uses only propellant mass for forming its high speed propulsive jet. Rocket engines are reaction engines and obtain thrust in accordance with Newton's third law...
s. Credible Sport was terminated when the Iranian parliament on 2 November accepted an Algeria
Algeria
Algeria , officially the People's Democratic Republic of Algeria , also formally referred to as the Democratic and Popular Republic of Algeria, is a country in the Maghreb region of Northwest Africa with Algiers as its capital.In terms of land area, it is the largest country in Africa and the Arab...
n plan for release of the hostages, followed two days later by the election of Ronald Reagan
Ronald Reagan
Ronald Wilson Reagan was the 40th President of the United States , the 33rd Governor of California and, prior to that, a radio, film and television actor....
as President
President of the United States
The President of the United States of America is the head of state and head of government of the United States. The president leads the executive branch of the federal government and is the commander-in-chief of the United States Armed Forces....
.
Its followup project in 1981–82, Credible Sport II, used one of the original aircraft as the YMC-130 prototype for the MC-130H Combat Talon II.
Background
Within two weeks after the failure of the Iranian hostage crisis rescue missionOperation Eagle Claw
Operation Eagle Claw was an American military operation ordered by President Jimmy Carter to attempt to put an end to the Iran hostage crisis by rescuing 52 Americans held captive at the U.S. Embassy in Tehran, Iran on 24 April 1980...
(Operation Eagle Claw), planning for a second mission began in the Pentagon. The first mission failed due to equipment and coordination problems, culminating in the crash, killing eight servicemen, of a RH-53D Sea Stallion helicopter into a parked C-130 Hercules in the Iranian desert.
A new organization, the Joint Test Directorate, was established to assist and support the Office of Secretary of Defense Directorate (OSD) joint planning staff. Under the program name Honey Badger, the JTD conducted a series of large-scale joint-force exercises and projects to develop and validate a variety of capabilities that would be available to OSD when mission requirements were identified. JTD trained a large and diverse force of United States Army
United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
and United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
special operations
United States Special Operations Forces
United States Special Operations Forces under United States Special Operations Command are active and reserve component forces of U.S. Military...
, Ranger
75th Ranger Regiment (United States)
The 75th Ranger Regiment , also known as Rangers, is a Special Operations light infantry unit of the United States Army. The Regiment is headquartered in Fort Benning, Georgia with battalions in Fort Benning, Hunter Army Airfield and Joint Base Lewis-McChord...
, and aviation units, but the critical factor remained extracting the rescue force and freed hostages from Tehran
Tehran
Tehran , sometimes spelled Teheran, is the capital of Iran and Tehran Province. With an estimated population of 8,429,807; it is also Iran's largest urban area and city, one of the largest cities in Western Asia, and is the world's 19th largest city.In the 20th century, Tehran was subject to...
. The Credible Sport project, a joint undertaking of the USAF, U.S. Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
, and Lockheed-Georgia, was created within Honey Badger to develop a reliable extraction capability. Credible Sport was tasked to create a large "Super STOL
STOL
STOL is an acronym for short take-off and landing, a term used to describe aircraft with very short runway requirements.-Definitions:There is no one accepted definition of STOL and many different definitions have been used by different authorities and nations at various times and for a myriad of...
" fixed-wing aircraft to extract the rescue team and hostages and overcome the "weak link" in the previous plan, the heavy lift helicopter.
Concept
The Credible Sport concept called for a modified C-130 Hercules cargo plane to land in the Amjadien StadiumShahid Shiroudi Stadium
The Shahid Shiroudi Stadium is a sports stadium in Tehran, Iran, currently used only for Athletic competitions. Until 2009 it was used mostly for football matches....
(soccer) across the street from the American Embassy and airlift out Delta Force
Delta Force
1st Special Forces Operational Detachment-Delta is one of the United States' secretive Tier One counter-terrorism and Special Mission Units. Commonly known as Delta Force, Delta, or The Unit, it was formed under the designation 1st SFOD-D, and is officially referred to by the Department of Defense...
and the rescued hostages. The aircraft would then be flown to and landed on an aircraft carrier
Aircraft carrier
An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...
for immediate medical treatment of an expected 50 wounded. (A US Marine Corps KC-130 on loan to the US Navy had been previously landed on the aircraft carrier in November 1963 as part of a Naval Air Systems Command demonstration.) Three MC-130 Combat Talon
MC-130 Combat Talon
The Lockheed MC-130 is the basic designation for a family of special mission aircraft operated by the United States Air Force Special Operations Command , a wing of the Air Education and Training Command, and an AFSOC-gained wing of the Air Force Reserve Command...
crews (all Eagle Claw veterans) were assigned to fly the three aircraft, drawn from the 463rd Tactical Airlift Wing, with the concept plan calling for the mission of two aircraft (one primary and one spare) to originate in the United States, reaching Iran by five in flight refuelings
Aerial refueling
Aerial refueling, also called air refueling, in-flight refueling , air-to-air refueling or tanking, is the process of transferring fuel from one aircraft to another during flight....
, and penetrate at low altitude in the dark to evade Iranian air defenses.
Development
Three C-130s were modified under a top secret project at Eglin Air Force BaseEglin Air Force Base
Eglin Air Force Base is a United States Air Force base located approximately 3 miles southwest of Valparaiso, Florida in Okaloosa County....
Auxiliary Field #1 (Wagner Field
Wagner Field
Wagner Field, Eglin Air Force Base Auxiliary Field #1, is a satellite airfield located northeast of the Main Base in Walton County, Florida. The site is notable as the training location for the Doolittle Raiders, and the test location for the Credible Sport YMC-130H STOL hostage rescue...
), Florida. The contract called for two to be modified to the proposed XFC-130H configuration within 90 days, and the third to be used as a test bed for various rocket packages blistered onto the forward and aft fuselage, which theoretically enabled the planes to land and take off within the confines of the sports arena. (A fourth aircraft, an EC-130 ABCCC, was used as the interior mockup airframe for simulator training.)
After Lockheed was requested on 27 June 1980, to begin preliminary engineering studies on an STOL Hercules, the use of JATO
JATO
JATO is an acronym for jet-fuel assisted take off. It is a system for helping overloaded aircraft into the air by providing additional thrust in the form of small rockets....
units was explored, since these had previously been used to power takeoffs. Lockheed reported on 16 July that 58 JATO bottles (more than seven times greater than normal) would be required and that arresting gear would be insufficient to stop the C-130 in the required space. The U.S. Navy's Naval Air Weapons Station China Lake
Naval Air Weapons Station China Lake
- About : is part of under Commander, Navy Installation Command and is located in the Western Mojave Desert region of California, approximately north of Los Angeles. Occupying three counties – Kern, San Bernardino and Inyo – the installation’s closest neighbors are the cities of Ridgecrest,...
organization was then brought into the project to provide expertise on existing rocket motor power. Lockheed proceeded with work to structurally reinforce the C-130 airframe to withstand rocket forces and to develop a passenger restraint system for 150 persons.
The resulting XFC-130H aircraft were modified by the installation of 30 rockets in multiple sets: eight forward-pointed ASROC
ASROC
ASROC is an all-weather, all sea-conditions anti-submarine missile system. Developed by the United States Navy in the 1950s, it was deployed in the 1960s, updated in the 1990s, and eventually installed on over 200 USN surface ships, specifically cruisers, destroyers, and frigates...
rocket motors mounted around the forward fuselage to stop the aircraft, eight downward-pointed Shrike
AGM-45 Shrike
AGM-45 Shrike is an American anti-radiation missile designed to home in on hostile antiaircraft radars. The Shrike was developed by the Naval Weapons Center at China Lake in 1963 by mating a seeker head to the rocket body of an AIM-7 Sparrow. It was phased out by U.S...
rockets fuselage-mounted above the wheel wells to brake its descent, eight rearward-pointed MK-56 rockets (from the RIM-66 Standard Missile) mounted on the lower rear fuselage for takeoff assist, two Shrikes mounted in pairs on wing pylons to correct yaw
Yaw
The word yaw can refer to:* Yaw angle, one of the Tait-Bryan angles, describing the heading of a vehicle or machine, and some other related elements:**Yaw system, component responsible for the orientation of a wind turbine towards the wind....
during takeoff transition, and two ASROCs mounted at the rear of the tail to prevent it from striking the ground from over-rotation.
Other STOL features included a dorsal and two ventral fins on the rear fuselage, double-slotted flaps
Flap (aircraft)
Flaps are normally hinged surfaces mounted on the trailing edges of the wings of a fixed-wing aircraft to reduce the speed an aircraft can be safely flown at and to increase the angle of descent for landing without increasing air speed. They shorten takeoff and landing distances as well as...
and extended aileron
Aileron
Ailerons are hinged flight control surfaces attached to the trailing edge of the wing of a fixed-wing aircraft. The ailerons are used to control the aircraft in roll, which results in a change in heading due to the tilting of the lift vector...
s, a new radome, a tailhook
Tailhook
A tailhook, also arresting hook or arrester hook, is a device attached to the empennage of some military fixed wing aircraft...
for landing aboard an aircraft carrier
Aircraft carrier
An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...
, and Combat Talon avionics, including a Terrain Following/Terrain Avoidance radar, a defensive countermeasures suite, and a Doppler radar/GPS tie-in to the aircraft's inertial navigation system
Inertial navigation system
An inertial navigation system is a navigation aid that uses a computer, motion sensors and rotation sensors to continuously calculate via dead reckoning the position, orientation, and velocity of a moving object without the need for external references...
.
Testing
The test bed aircraft (AF serial 74-2065) was ready for its first test flight on 18 September 1980, just three weeks after the project was initiated. The first fully modified aircraft (74–1683) was delivered on 17 October to TAB 1 (Wagner Field/Eglin AF No. 1Wagner Field
Wagner Field, Eglin Air Force Base Auxiliary Field #1, is a satellite airfield located northeast of the Main Base in Walton County, Florida. The site is notable as the training location for the Doolittle Raiders, and the test location for the Credible Sport YMC-130H STOL hostage rescue...
), a disused auxiliary airfield at Eglin Air Force Base
Eglin Air Force Base
Eglin Air Force Base is a United States Air Force base located approximately 3 miles southwest of Valparaiso, Florida in Okaloosa County....
, Florida. Between 19 October and 28 October, numerous flights were made testing various aspects, including the double-slotted flaps system, which enabled the C-130 to fly at 85 knots on final approach at a very steep eight-degree glide slope. All aspects worked flawlessly, and a full profile test was scheduled for 29 October.
The takeoff phase of the test was executed flawlessly, setting a number of short takeoff records. The Lockheed test crew then assessed that the computer used to command the firing of the rockets during the landing sequence needed further calibration, and elected to manually input commands. The reverse-mounted (forward-facing) eight ASROC rockets for decelerating the aircraft's forward speed were situated in pairs on the upper curvature of the fuselage behind the cockpit, and at the mid-point of each side of the fuselage beneath the uppers. Testing had determined that the upper pairs, fired sequentially, could be ignited while still airborne (specifically, at 20 feet), but that the lower pairs could only be fired after the aircraft was on the ground, with the descent-braking rockets also firing during the sequence.
The flight engineer, blinded by the firing of the upper deceleration rockets, thought the aircraft was on the runway and fired the lower set early. The descent-braking rockets did not fire at all. Later unofficial disclaimers alleged to have been made by some members of the Lockheed test crew asserted that the lower rockets fired themselves through an undetermined computer or electrical malfunction, which at the same time failed to fire the descent-braking rockets.
As a result, the aircraft's forward flight was immediately reduced to nearly zero, dropping it hard to the runway and tearing off the starboard wing between the third and fourth engines. During rollout the trailing wing ignited a fire, but a medical evacuation helicopter dispersed the flame and crash response teams extinguished the fire within eight seconds of the aircraft stopping, enabling the crew to exit the aircraft without injury. 74-1683 was dismantled and buried on-site for security reasons, but most of its unique systems were salvaged.
74-1686 was nearly ready for delivery, but the defeat of Jimmy Carter
Jimmy Carter
James Earl "Jimmy" Carter, Jr. is an American politician who served as the 39th President of the United States and was the recipient of the 2002 Nobel Peace Prize, the only U.S. President to have received the Prize after leaving office...
by Ronald Reagan
Ronald Reagan
Ronald Wilson Reagan was the 40th President of the United States , the 33rd Governor of California and, prior to that, a radio, film and television actor....
in the presidential election
Presidential election
A presidential election is the election of any head of state whose official title is president.- United States :The United States has elections on the state and local levels...
on 4 November 1980, and an Algerian-negotiated release plan led to the cancellation of the rescue mission plan. The hostages were subsequently released concurrent with Reagan's inauguration in January 1981.
Credible Sport II
The remaining airframes were stripped of their rocket modifications and 74-2065 returned to regular airlift duties. 74-1686, however, retained its other Credible Sport STOL modifications and was sent to Robins Air Force BaseRobins Air Force Base
Robins Air Force Base is a major United States Air Force base located in Houston County, Georgia, United States. The base is located just east of and adjacent to the city of Warner Robins, Georgia, SSE of Macon, Georgia, and about SSE of Atlanta, Georgia...
, Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
. There in July 1981 it was designated YMC-130H as the test bed for development of the MC-130 Combat Talon II, under the project name Credible Sport II. Phase I was conducted between 24 August and 11 November 1981, to test minor modifications to improve aerodynamics, satisfy Combat Talon II prototype requirements on STOL performance, handling characteristics, and avionics, and to establish margins of safety. It also identified design deficiencies in the airframe and determined that the Credible Sport configuration was suitable only for its specific mission and did not have the safety margins necessary for peacetime operations.
Phase II testing began 15 June 1982, continued through October 1982, and determined that the final configuration resulted in significant improvements in design, avionics, and equipment, and that the Combat Talon II design was ready for production. The 1st Special Operations Wing attempted to have the test bed transferred to operational duty as an interim Combat Talon II until production models became available, but Headquarters, Tactical Airlift Command disagreed. The cost of de-modifying the YMC-130H to airlift configuration was more than its value, and it never flew again.
In 1988, 74–1686 was placed on display at the Museum of Aviation
Museum of Aviation
The Museum of Aviation is the second-largest aerospace museum of the United States Air Force. The museum is located just outside Warner Robins, Georgia, and near Robins Air Force Base. It has a total of five different buildings containing 93 different aircraft on . The SR-71A Blackbird on display...
at Robins Air Force Base
Robins Air Force Base
Robins Air Force Base is a major United States Air Force base located in Houston County, Georgia, United States. The base is located just east of and adjacent to the city of Warner Robins, Georgia, SSE of Macon, Georgia, and about SSE of Atlanta, Georgia...
in Warner Robins, Georgia. As of February 2008, the other surviving Credible Sport aircraft, 74-2065, was assigned to the 317th Airlift Group, 15th Expeditionary Mobility Task Force, at Dyess Air Force Base
Dyess Air Force Base
Dyess Air Force Base is a United States Air Force base located approximately southwest of Abilene, Texas.The host unit at Dyess is the 7th Bomb Wing assigned to the Air Combat Command Twelfth Air Force...
, Texas, in gray scheme with blue tail band.
Sources
- The Praetorian Starship: The Untold Story of the Combat Talon. Jerry L. Thigpen, Air University Press, Maxwell Air Force Base, Alabama, December 2001.
- Lockheed-Martin Employee Association Flying Club quarterly newsletter, "FLYPAPER," August 2000.
External links
- Abandoned and Little-Known Airfields: Florida, Eglin Area. Wagner Field entry has diagram of test area layout and an overhead of XFC-130H 74-1683 after its crash.
- YMC-130H Page on Museum of Aviation Website
- The Praetorian STARShip : the untold story of the Combat Talon By Jerry L Thigpen