The Hercules of An Loc

Oct. 1, 2012

The seldom-used runway at the National Museum of the US Air Force at Wright-Patterson AFB, Ohio, opened one day in August 2011 to allow a special aircraft to land. The C-130E, serial No. 62-1787, had served long years on Active Duty and with Air National Guard units. Just before retirement, it had been reassigned to Active Duty with the 19th Airlift Wing at Little Rock AFB, Ark.

Few of the crew or maintainers of this Hercules knew it had flown a heroic but little-heralded mission late in the Vietnam War. Even when it arrived at the museum, few of those who saw it land knew why it had been especially chosen for display there.

This C-130, however, had been one of several pressed into service to save the besieged city of An Loc, South Vietnam, in 1972, after the US had already begun disengaging from the Vietnam War. Indeed, the C-130 had no longer even been configured for combat delivery and was slated to leave the country.

In the spring of 1970 US and South Vietnamese troops entered Cambodia, attacking North Vietnamese sanctuary bases just across the border from South Vietnam’s Tay Ninh province. The North Vietnamese were driven deep into Cambodia and back up the Ho Chi Minh Trail complex into Laos. Once that happened, the war in South Vietnam dropped to a low ebb, with little fighting.

By the spring of 1972, the American presence in South Vietnam had been drastically reduced, as US forces turned over more and more missions to the Vietnamese armed forces, a process called “Vietnamization.” Only a handful of US ground combatants remained in the country and they were being withdrawn. Air Force units in South Vietnam had similarly downsized, including the once-vast tactical airlift apparatus that had served as the primary line of communication between rear area bases and more than a hundred forward airfields.

At the height of the war, the 834th Air Division had just under 100 C-130s temporarily assigned to it, along with a wing each of Fairchild C-123 Providers and de Havilland C-7 Caribous. By April 1972, though, the C-123s and C-7s had been given to South Vietnam, and C-130 strength in Pacific Air Forces had been reduced to one wing, the 374th Tactical Airlift Wing, based at Ching Chuan Kang Air Base, commonly known as CCK, on Taiwan. Another squadron was based at Clark AB, Philippines, but was also in the process of inactivating. Cam Ranh Air Base, once the primary C-130 field, transferred to South Vietnamese control. A detachment from the 374th TAW at Tan Son Nhut Air Base, outside Saigon, controlled the remaining C-130s.

All Hell Broke Loose

The C-130 force that had seen extensive action in 1968 and 1969 spent nearly two years flying basic logistics missions. Consequently, only a handful of crews still maintained tactical proficiency. Pilots and other crew members who had seen heavy action had either retired, been discharged, or moved into new assignments outside the C-130 community. Young men fresh out of training and men coming out of Military Airlift Command C-141s and Strategic Air Command bombers replaced them.

Suddenly, in early April 1972, all hell broke loose.

Loadmasters Sgt. David McAleece (l) and SSgt. Charles Shaub look over a camera some time after the An Loc mission. Both were wounded in that airdrop. (USAF photo)

While the United States was withdrawing from South Vietnam, the North Vietnamese had built up their forces in Laos, despite a massive air campaign there by US fighters and AC-130 gunships based in Thailand. The North Vietnamese were preparing for a large-scale invasion of the South. Allied intelligence discovered in early March three People’s Army of North Vietnam (PAVN) infantry divisions just across the border from Tay Ninh province. They expected the soldiers to make attacks on towns in the region. Instead, the PAVN troops discreetly moved across the border into the adjoining Binh Long province and captured the town and airfield at Loc Ninh. One division blocked Highway 13, the road to Saigon, south of the city of An Loc. Another attacked the city itself. These divisions intended to capture the provincial capital and use it as a base for a drive down Highway 13 against Saigon.

The only obstacle to this plan was the South Vietnamese force defending An Loc. It proved to be more formidable than the PAVN expected. The attack turned into a siege as the PAVN 9th Division surrounded the city, cutting it off from all ground resupply.

Initially, South Vietnamese and US Army helicopters delivered supplies and reinforcements to the city, but as the communists built up their strength around An Loc, they brought in an anti-aircraft regiment equipped with .51-caliber, 23 mm, and 37 mm guns; they kept any further helicopter flights at bay.

The South Vietnamese turned to airdrop, using US-supplied Fairchild C-119 Flying Boxcars and C-123s. Although the supply effort was valiant, ground fire combined with the tiny drop zone made the airdrops unsuccessful. While South Vietnamese Air Force (VNAF) three-ship formations made some drops at 700 feet, some crews released their loads from 5,000 feet to avoid ground fire. Due to the lack of high-altitude rigging equipment, the drops proved fruitless as the loads drifted aimlessly and most bundles came down in enemy-held territory. All drops took place in daylight, and the threat of ground fire made them deadly missions. After the enemy shot down two VNAF C-123s, the South Vietnamese Air Force suspended daylight drops from low level. High-altitude drops continued but were generally ineffective.

The failure of the VNAF effort led US Military Assistance Command Vietnam to decide to use US Air Force C-130s to resupply the besieged city.

No one had expected the USAF C-130s to return to combat operations; in fact, no proper rigging equipment for the US container delivery system existed in all of South Vietnam, and only a handful of crews were even airdrop-qualified.

Eventually, enough tactically qualified personnel were found among the C-130s on rotation to the 374th TAW detachment to make up three crews for a planned drop on the afternoon of April 14.

Loadmasters scrounged from Vietnamese aerial delivery stocks to find the necessary rigging materials. Not finding everything they needed, they jerry-rigged nonstandard gear.

While the loadmasters figured out how to rig their loads, pilots and navigators attended briefings. They were to approach the drop zone at medium altitude, then descend quickly and level off at 600 feet two minutes away from the release point. The rigging problems delayed the planned takeoff, however, leaving insufficient time to make the drop before dark, so the mission was postponed until the following morning.

A Dreadful Night

Capt. William R. Caldwell was to fly the mission’s third airplane, call sign Spare 617. A 1,900-hour pilot, Caldwell was one of the most experienced C-130 pilots at Tan Son Nhut at the time. His copilot, John Hering, and navigator, Richard A. Lentz, were both first lieutenants. The flight engineer was TSgt. Jon Sanders, experienced, but not in Southeast Asia or in combat. One of the loadmasters, SSgt. Charles L. Shaub, had seen the most combat of anyone on the crew. Shaub was on his second tour at CCK, where he had previously served from 1969 to 1970. The other loadmaster, A1C Dave McAleece, was a first-term airman and although he was tactically qualified, his combat hours consisted of routine flying around South Vietnam.

At 5:30 a.m. April 15, the officers were back in the briefing room while the engineers preflighted the aircraft and the loadmasters checked the drop bundles. The previous night had been dreadful; the crews knew they might not survive the extremely dangerous mission.

William Caldwell retired as a colonel.

To make their drops, each crew would have to approach the drop zone at low altitude and only 150 mph. In Vietnam only helicopter crews operated in such low-and-slow conditions, and they didn’t fly into areas with known anti-aircraft artillery of the magnitude surrounding An Loc. The mission harkened back to that of troop carrier C-47s of World War II. Airlift crews early in the Vietnam War had also sometimes operated under similar conditions, with predictable heavy losses.

The mission called for three C-130s, but instead of following each other into the drop zone in a three-ship, in-trail formation, the plan required each crew to make its run separately. This put them at a disadvantage: The PAVN gunners, alerted by the arrival of the first Hercules, would be ready for the others.

The first crew did indeed make its run and drop without a problem, though tracer fire swarmed it, and it took one hit in the rudder.

The second crew discovered a malfunction in their release gate—caused by the use of nonstandard rigging material—and pulled off so the loadmasters could fix it.

Caldwell was cleared in for the drop, but missed the initial point on his first approach and turned out to come back in again. His C-130 carried a cargo load of 27,000 pounds of howitzer and mortar ammunition.

Thirty seconds from the release point, Caldwell’s airplane began taking hits. A shell burst near the cockpit, shattering the windows on the pilot’s side, wounding the copilot and killing Sanders, the engineer. Both loadmasters received shrapnel wounds. The worst damage came from a shell that knocked out a section of the bleed air line on the left side of the cargo compartment. When the line ruptured, hot bleed air poured into the cargo compartment and was sucked into the cockpit. The intense heat set two of the ammunition-laden bundles in the cargo area on fire. Fire also broke out on the left side of the airplane, in the area of the wheel well. Shrapnel hit both engines on the left side; they soon caught fire.

An Loc Was Saved

The crew’s most immediate problem was to get rid of the load. The loadmasters called for the pilot to jettison it, but the electronic release failed. Shaub decided to use the manual release handle in the cargo compartment. Seconds after falling free of the airplane, the two burning bundles exploded.

C-130 Spare 617 arrives at the National Museum of the US Air Force in Dayton, Ohio. Two of her crew members, Caldwell and Shaub, were awarded Air Force Crosses for actions performed during the seige of An Loc. (USAF photo by Jeff Fisher)

Shaub next turned his attention to fighting the fire. He grabbed one of the fire extinguishers from the wall, even though the metal was red hot from the wash of hot bleed air. He severely burned his hands. Meanwhile, Caldwell closed the bleed air valves on the engines on the right side and shut down the two engines on the left side. With the flow of bleed air halted, Shaub was able to extinguish the fire, saving the airplane a second time.

Caldwell next thought about finding a field to put the airplane down. He also considered ordering the crew to bail out, but decided some were too severely injured.

Although his airspeed bled off considerably while he took care of the emergency, he managed to get it back up. He realized the airplane was still flyable, so he decided to return to Tan Son Nhut, some 60 miles away.

With both left engines shut off, the airplane had lost secondary hydraulics. This meant cranking down the landing gear manually. Shaub’s hands were too badly burned to handle the crank. McAleece was able to turn it, although he had been wounded. He cranked the gear down and it locked into place while the C-130 was in the traffic pattern. The airplane was flying on two engines, and while it was in the approach pattern, power on one of the two remaining engines rolled back to 80 percent. Other than that, the landing was uneventful.

The medics who rushed into the airplane declared Sanders dead.

Drops at An Loc continued into May, with only limited success. The enemy shot down three more C-130s, along with several Vietnamese C-123s. A barrage of anti-aircraft fire hit the C-130 commanded by Capt. Don B. Jensen on April 18. Army helicopter crews saw the airplane crash-land in a swamp and rescued the crew. The other two crews, on April 25 and May 3, were lost.

In early May a two-man team arrived in Saigon. TSgt. John F. Limbach from the Tactical Air Warfare Center at Eglin AFB, Fla., and Maj. Myles A. Rohrlick from Tactical Air Command headquarters corrected problems in the rigging methods used on high-altitude parachutes. A new method of dropping the loads used slotted extraction parachutes to stabilize the loads and permitted using ground radar to guide the drops from well above the range of the anti-aircraft guns. An Loc was saved.

For their roles in the April 15 mission, Caldwell and Shaub each received the Air Force Cross. Shaub, who was promoted to technical sergeant soon after the incident, also received the Air Force Sergeants Association’s 1972 William H. Pitsenbarger Award for heroism.

Caldwell retired from the Air Force as a colonel. Shaub retired and returned to his home near Portland, Tenn. He died in Gallatin, Tenn., in 1996.

The C-130 on that mission was repaired and returned to service. It was eventually assigned to the 314th Tactical Airlift Wing at Little Rock, Ark., and went to the West Virginia Air Guard. It later transferred to the Arkansas Air Guard at Little Rock where members of the ground crew discovered the airplane’s historic past and notified their commander, who then contacted the Air Force museum. The C-130 had been scheduled to retire in Fiscal 2013 but wing cracks pushed up the retirement date.

The airplane that saw so much heroism as Spare 617 now awaits public display at the museum at Wright-Patterson.

Sam McGowan served 12 years in aircraft maintenance and as an aircraft loadmaster in Military Airlift Command, Pacific Air Forces, and Tactical Air Command. He is a Vietnam veteran, a retired corporate pilot, and freelance writer who resides in Missouri City, Tex. His last article for Air Force Magazine, “Loadmaster Evolution,” appeared in December 2011.