Operation Frequent Wind - Security and Air Support

Security and Air Support

It was not known whether the PAVN and/or the ARVN would try to disrupt the evacuation and so the planners had to take all possible contingencies into account to ensure the safety and success of the evacuation. The staff of 9th MAB prescribed altitudes, routes, and checkpoints for flight safety for the operation. To avert mid-air collisions, the planners chose altitudes which would not only provide separation of traffic but also a capability to see and avoid the enemy's AAA, SA-2 and SA-7 missile threat (6,500 feet for flights inbound to Saigon and 5,500 feet for those outbound from Saigon to the Navy ships). In addition, these altitudes were high enough to avoid small arms and artillery fire.

In the event that the PAVN or ARVN shot down a helicopter or a mechanical malfunction forced one to make an emergency landing in hostile territory, 2 orbiting CH-46s of MAG-39 each carried 15-man, quick-reaction "Sparrow Hawk" teams of Marines from Company A, 1st Battalion, 9th Marines, ready to land and provide security enabling a search and rescue (SAR) helicopter to pick up the crew. In addition, two CH-46s would provide medical evacuation capabilities while AH-1J Sea-cobras would fly cover for the transport helicopters and for any ground units who requested support. The Sea-cobras could also serve as Tactical Air Coordinators (Airborne) or Forward Air Controllers (Airborne).

The air wings of the USS Enterprise and USS Coral Sea, were ready to provide close air support and anti-aircraft suppression if required with their A-6 and A-7 attack aircraft, and would provide continuous fighter cover the evacuation route including by VF-1 and VF-2, flying from the Enterprise with the first combat deployment of the new F-14 Tomcat. USAF aircraft operating out of Nakhon Phanom Air Base, Korat Air Base and U-Tapao Air Base in Thailand were also overhead for the duration of the helicopter evacuation. A C-130 Airborne Command and Control controlled all US air operations over land. USAF F-4s, F-111s and A-7s provided air cover during daylight, being replaced by AC-130s from the 16th Special Operations Squadron at night. Strategic Air Command KC-135 tankers provided air-to-air refueling.

In fact the evacuation was allowed to proceed without molestation from the PAVN. Aircraft flying air cover for the evacuation reported being tracked with surface to air radar in the vicinity of Bien Hoa Air Base (which had fallen to the NVA on 25 April), but no missile launches took place. The Hanoi leadership, reckoning that completion of the evacuation would lessen the risk of American intervention, had apparently instructed General Dũng not to target the airlift itself. Members of the police in Saigon had been promised evacuation in exchange for protecting the American evacuation buses and control of the crowds in the city during the evacuation. American helicopters were repeatedly hit by small arms fire from disgruntled ARVN troops throughout the evacuation without causing serious damage. Despite receiving AAA fire, no attacks were made by USAF or USN aircraft on AAA or SAM sites during the evacuation.

Despite all the concern over these military threats, the weather presented the gravest danger. At the beginning of the operation, pilots in the first wave reported the weather as 2,000 feet (610 m) scattered, 20,000 feet (6,100 m) overcast with 15 miles (24 km) visibility, except in haze over Saigon, where visibility decreased to one mile. This meant that scattered clouds existed below their flight path while a solid layer of clouds more than two miles above their heads obscured the sun, additionally, the curtain of haze, suspended over Saigon, so altered the diminished daylight that line of sight visibility was only a mile. The weather conditions would deteriorate as the operation continued.