| Operation Prime Chance | |
|---|---|
| Part of theIran–Iraq War and theTanker War | |
 A U.S. Navy crewman stands atop the cabin of a PB Mark III patrol boat tied up to the oil rig service bargeWimbrown VII in the northern Persian Gulf. From lower to upper right, the barge is armed with a.50-caliberM2 machine gun, an 81 mm Mark 2 mortar, and a 40 mmMk 19 grenade launcher. | |
| Location | |
| Planned by | United States Special Operations Command |
| Date | August 1987 – June 1989 |
| Outcome | Operational success |
| Casualties | 5 Iranian killed, 26 Iranian captured (during raid onIran Ajr only)[1] Other parts of the operation are not included in this number |
Operation Prime Chance (August 1987 – June 1989) was aUnited States Special Operations Command operation intended to protect U.S.-flaggedoil tankers from Iranian attack during theIran–Iraq War. The operation took place roughly at the same time asOperation Earnest Will (July 1987 – September 1988), the largelynaval effort to escort the tankers through thePersian Gulf. The operation was begun after themining of the U.S.-flagged Kuwaiti oil tankerBridgeton.
The two operations were intertwined—United States Army helicopters flew nighttime search-and-destroy missions from Navyfrigates anddestroyers and from two leased barges in the northernPersian Gulf.Navy SEALs andexplosive ordnance disposal operated from the barges as well. But while Earnest Will was the widely publicized reaction toKuwaiti pleas for help, Prime Chance was secret.[2]
The army helicopters flew at night, slipping to and from navy flight decks under cover of darkness. The helicopter pilots often flew some 30 feet (9.1 m) above the water, and became the first to usenight vision goggles andforward looking infrared devices in combat. Tactics included usingMH-6 Little Birds as spotters for the more heavily armedAH-6s for barge-launched missions, and using the warship's radar and that of theirSH-60 Seahawk helicopters for the same purpose on ship-launched efforts.[2]
Planning and preparation for Prime Chance was launched soon after a tanker on the very first Earnest Willconvoy struck a mine, which made it clear that more forces would be necessary to assure the safety of the civilian vessels. TheJoint Chiefs of Staff launched a search for helicopter pilots who could fly at night from navy ships, then set out to train them for the special requirements of the job. Helicopters from the army's160th Special Operations Aviation Regiment (Airborne) reached the navy's command shipLa Salle in the Persian Gulf on 5 August 1987.
The detachment was divided into two teams, with call sign SEABAT and one MH-6 Little Bird, two AH-6s, aircrew, and maintainers. On 8 August, one detachment participated in a convoy escort mission aboardLa Salle. The other flew onto thefrigateKlakring to protectminesweepers operating in the narrow shipping channel west ofFarsi Island. The following day, theLa Salle detachment transferred to the frigateJarrett and escorted the convoy to theGulf of Oman.
Soon afterward, operations began from the barges, dubbed Mobile Sea Bases (MSBs). They were set up asnaval special warfare task units (NSWTU) run by a SEAL commander and answering to the regional naval special warfare task group. Their mission was to stop Iranian forces frommining the Persian Gulf or otherwise attacking shipping. Each mobile sea base had two detachments ofMark III patrol boats, a SEALplatoon, an EOD detachment,3d Low Altitude Air Defense Battalion to provideFIM-92 Stinger Air defense supplementing barge security, army MH-6 and AH-6 Little Bird helicopter gunships andBlack Hawk rescue birds, andair forcecombat controllers.[3]
Mobile Sea BaseHercules was crewed by East Coast naval special warfare units, including Patrol Boats 777 and 758 from Special Boat Unit 20 and Special Boat Unit 24. Mobile Sea BaseWimbrown 7 was crewed by West Coast units, including Patrol Boats 753 and 757 from Special Boat Unit 13 and Patrol Boats 775 and 776 from Special Boat Unit 12.[3]
On 21 September 1987,Iran Ajr, an Iranian ship converted for use as aminelayer, was attacked. Using night-vision devices, Army gunship crews watched the Iranian vessel lay several mines, then swooped in firingminiguns and rockets. A SEAL team boarded the vessel and quickly seized it. During the attack, five Iranians were killed and 26 were captured. Several Iranian sailors were rescued from the waters of the Persian Gulf after jumping overboard during the attack. After collecting intelligence data the SEALs and EODscuttled the vessel the following day.[4]
In January 1988, Task Force 118 arrived withOH-58D Kiowa Warrior helicopters.
Earnest Will ended about five months after the Iran-Iraq ceasefire began in July 1988.Wimbrown 7 soon returned to port, but Prime Chance patrols continued fromHercules until June 1989.[3]
Ships involved in Prime Chance included:
Units involved in Prime Chance included:
