U.S. Forest Service adaptations of helicopters to fight raging forest fires in 1967 proved to be highly effective in Vietnam.
“Here come the flying fire trucks!”shouted the heat-blasted engineer sergeant, rallying his weary firefighter troops.
Their smoke-reddened eyes picked up a loosely strung-out flight of Chinook helicopters beating through the hazy Vietnam sky toward the large fire surrounding the Army engineer company near Tay Ninh in 1969. Each chopper was part of an airborne bucket brigade towing tandem buckets of water that would be used to douse the raging fires.
“It’s fantastic to watch the helibuckets in action,” MP leader Sergeant Ronald A. Doran said to Stars and Stripes. “A white cloud of steam forms wherever a drop is made, giving a creamlike quality to the flickering red flames and the boiling black smoke. I have nothing but praise for the pilots—those guys get right down on top of it before they release their loads.”
The U.S. Army had brought the “bucket brigade” out of retirement and combined it with the airborne capabilities of helicopters, mainly to help in fighting the numerous fires in and around Saigon in the after math of the 1968 Tet Offensive.“Although the Tet Offensive didn’t last long, Saigon was hit by 40 days of sporadic rocket attacks in the four months that followed, and the specter of mass fire hung on everyone’s mind,” said Craig C. Chandler, the U.S. Forest Service director of Emergency Service, in a 1971 report on the use of air operations in fire services in Vietnam.
In a city designed to hold 500,000 people at the end of World War II, Saigon’s population swelled past 1,700,000 in the late 1960s. Eighty percent of the structures were made of wood, and residential areas were jammed full of wooden and paper shacks with tin roofs, creating fire hazards everywhere.“The Saigon Fire Department was undermanned and poorly equipped, and the city’s water pressure was uncertain,” said Chandler.
Barry R. Flamm, who was serving as chief of the U.S. Forest Service’s Agency for International Development’s (AID) team in Vietnam at the time, pioneered the flying fire truck concept in Vietnam. He knew that helicopters had helped to combat the fires raging out of control across the Pacific Northwest during the summer of 1967, when a small fleet of test choppers had dropped more than 400,000 gallons of water and chemical retardants and had transported more than 51,000 firefighters for ground duty and a million pounds of supplies to support them. In the Sundance Fire in northern Idaho that began on August 23, 1967, 700 aircraft, including transports, tankers, helicopters and reconnaissance planes, helped fight fires on more than 55,000 blazing acres over three weeks.
Flamm had been in Vietnam since early 1967 and had traveled widely throughout the countryside, learning about the needs of forest management and the people. He concluded that forest fire suppression might be aided by the helibuckets that were under development and testing by U.S. Forest Service Research. The Vietnam director of Forest Affairs was interested, as was the U.S. Forest Service. Military Assistance Command, Vietnam (MACV) agreed to provide a chopper to test the buckets, which Flamm obtained through the Forest Service.
“I wanted to use helicopters for fire suppression because of their ability as a stable dispersal platform,” Flamm said. “They were, literally, airmobile and could get right to the fire. Also, the water refill problem was easily solved by available ponds and rivers.”A wild land fire demonstration was planned, which included Vietnamese firefighting ground crews using their local firefighting tools, supported by a chopper making drops. “The demonstration was attended by high-level Vietnamese and U.S. officials and was considered a success,” said Flamm.
Later, in the wake of Tet, with Saigon battling rocket attacks and fires, Flamm saw the great difficulty of fighting the urban fires sparked by warfare and thought that the Forest Service’s helicopter water-dropping techniques might have a place in Saigon firefighting. He drew up a plan for the U.S. Army to use the helibucket system in putting out urban fires, and requested six buckets to test in Vietnam.
Flamm’s proposal sat quietly submerged in official channels, however, until he made a personal appeal to U.S. Ambassador Ellsworth Bunker. The ambassador asked the Pentagon to look into it, and the Pentagon then asked the U.S. Forest Service to send a research and development team to Saigon.
Initially, the UH-1 helicopters, in plentiful supply all over Vietnam, were slated to be the water haulers. On paper, the UH-1s were rated about the same as the Sikorskys that were used for aerial firefighting in the Pacific Northwest. The Forest Service requested six 450-gallon fiberglass buckets, and the Army put its muscle behind the priority requests, cutting through the red tape so that an Oregon bucket manufacturer could work 24-hour shifts to rush the order. They were flown from the plant to Travis Air Force Base in California, then immediately airlifted to Tan Son Nhut Airbase in Saigon. In addition, the Forest Service sent a three-man team to train chopper pilots to use the new buckets.
By then, the Forest Service began to see problems with using the UH-1. By the book, the UH-1 had an adequate lift capacity to handle a 500-gallon bucket, but in Vietnam the ships were fitted with protective armor and extra weapons.“After adding the weight of the bucket and mounts, the residual sling capacity allowed for about enough water to fill a medium-sized bird bath,” said Chandler.“The UH-1s were out.”
The Forest Service turned to another readily available helicopter, the Sikorsky CH-47A, the“Chinook,”but no one had ever used twin-rotor helicopters for water drops before.“We had to start from scratch and determine the proper height and drop speed requirements that would minimize rotor downwash and still give an effective dispersion patterns of liquid on the ground,” Chandler said.
The Army put the 147th Company of the 222nd Combat Support Aviation Battalion at the Forest Service’s disposal for testing. The 222nd was stationed at the old French resort city of Vung Tau, on the South China Sea, and in late June and early July 1968, testing was conducted on the beach, loading water from the ocean. The question on everyone’s mind was whether the technique would be successful on tinroofed buildings, so prevalent in Saigon. The Forest Service concluded,“The CH-47A helicopter is potentially valuable as a tool for fighting conflagration fires in congested urban areas of light wooden construction.” One engineer officer put it this way, according to Stars and Stripes: “Best damn thing we’ve had out here for knocking down fires! It’s going to make fire control safer and free up men for other duties.”
At a demonstration held to cap off the tests at the U.S.Army Post at Long Binh, attended by several dignitaries and agencies, including Ambassador Bunker and CBS News, everything that could go wrong did go wrong. “The plan for the demonstration was to build a clutch of simulated refugee shacks, set them afire, douse the blaze with the buckets and have a Vietnamese fire crew move in and mop up,” said Chandler. “We had to scratch-train a Vietnamese crew in a hurry. I will never again wonder about the origin of the phrase,‘Just like a Chinese fire drill.’”
The Navy Times reported from Long Binh:
Four of the six buckets now on hand in Vietnam were deployed against a Forest Service set fire near the ammunition supply depot here.
The first chopper either waited too long or had trouble activating the electronic release device, missed the burning “village” almost entirely, and deposited its load on the bystanding fire crew.
The second Chinook was on target but it took a timely rainfall plus Vietnamese firemen to finish the job of putting out the last coals of a test fire.
And on a more serious note, the Navy Times said:
The new bucket brigade concept will most likely receive its all-too-literal baptism of fire in metropolitan Saigon when the expected “third wave” communist offensive strikes the city.
The bucket brigade was used under fire in Saigon and Tay Ninh City in 1969, and “it worked as advertised,” said Chandler. A Chinook carrying two of the 450-gallon fiberglass buckets in tandem could apply 5,400 gallons of water per hour, dropped in patterns and intensities that were controlled from inside the helicopter. Following a Viet Cong rocket attack, it took three choppers just one hour to totally knock down more than three acres of raging fire in a sprawling mass of wooden buildings near a suburban area of Saigon. Three choppers suppressed the worst of the Cholon fires in about two hours, allowing civilian firemen to go into the area almost immediately for mop-up and clean-up operations.Working in the Saigon area, the ships were only minutes from the city’s river, so resupply was quick and simple.
Civilian firemen and military firefighters on the ground praised the program. “Those ships went in and handled the worst of it. It keeps my men out of the danger area until it’s time to go in and mop up the little pockets of fire that escape the dousing,” an Army engineer NCO told Stars and Stripes.
The hostile setting, however, posed great danger to the choppers and crews. The unarmed, heavily laden Chinooks were easy targets for Viet Cong ground fire, so they were always accompanied into combat zones by Hueys with a variety of armaments.
“Our purpose [in the forest program] was to save lives and property,”Flamm said.“Our armed buddies made that a lot easier and safer. I do not recall missions [with gunships] where our Chinooks took hits.”
A nearby water source is the only requirement of this aerial firefighting system. The buckets can be filled two ways. In an in-flight “tow fill,” the helicopter drags its bucket into a river or large lake and then sweeps up and away with the load of water. In a “hover fill,” the ship hovers over a pond, lake or river and dips the bucket down into the water.
In addition to this efficient refill method, the flying fire trucks have other advantages over traditional airdrop firefighting methods. The molded, conical tanks are highly stable in flight, so they don’t restrict flying speed and maneuverability—a vastly important consideration in combat situations. The discharge system is selective, allowing the pilot or observer to use a range of release patterns and amounts. Versatility is complete, because myriad equipment options enable the system to be used with most existing military helicopters.
“Along with this operational versatility, the helicopter is a more effective firefighter than fixed-wing aircraft,” Flamm said.“Because of the chopper’s relatively slow flight capability, the pilot has better visibility and is able to make a more accurate aerial drop at slower speeds and lower altitudes than he would in a traditional aircraft.”A helicopter’s ability to hover also made it a more stable platform for drops. And in the event of enemy ground fire, the aircraft could jettison the bucket and quickly escape.
By the end of 1970, there were three flying fire truck systems in Vietnam. According to Army Aviation Officer Brig. Gen. George Putnam Jr., all of the systems were in the III Corps Tactical Zone and employed by the 11th Combat Aviation Battalion at Phu Loi. The Army also used a smaller 140-gallon bucket hauled by Hueys. The larger 450-gallon bucket— 4,000 pounds when full—was hauled by the Sikorsky S-58 as well as the Chinook. Tandem loads of two of the big buckets were carried by the Sikorsky S-61, the CH-47A and the CH-34 “Choctaw.”
Though the helibucket system received minimal fanfare for extinguishing combat-related fires in Vietnam, the flying fire trucks proved to be a godsend in fighting accidental fires and those caused by arson and sabotage in rural and agricultural areas. “In one instance, the brigade aided ground forces after a fire started when a kerosene stove overturned [in Saigon] near the rice mill,” Army Public Affairs Specialist Denis Camire told Stars and Stripes. “Twenty-four homes burned before the fire was put out. Much more would have been lost without our flying fire trucks.”At a naval warehouse fire, two Chinooks made some 25 passes in 21/2 hours and helped keep flames from spreading to other buildings, which, according to both military and civilian officials, prevented a wholesale civilian disaster.
The performance of the helibuckets in Vietnam greatly influenced future development of airborne firefighting. In 1970, the Marine Corps adopted the flying bucket brigade system for all their bases in Okinawa. Aviation design specialist Teagle Fleming proclaimed in 1971,“Design and use of larger bucket payloads is soon to be a reality as the tremendous success of the flying fire trucks in Vietnam has been a great boost to the continued research into this concept.”
Since the early 1970s, the helicopter water bucket has been used extensively worldwide for wildland and urban fire suppression around the world. In March 2011, following an 8.9 magnitude earthquake in Japan, the world anxiously watched as Japanese Air-Defense Force CH-47s, equipped with helibuckets, collected water from the ocean to drop on the severely damaged and overheated reactors at the Fukushima Daiichi nuclear power plant.
Aerial firefighting had come a long way since the Army first tested a converted de Havilland DH-4 bomber for that role in 1921. The Vietnam War innovation of the Army’s helicopter-powered flying fire trucks forming an airborne bucket brigade proved that the best ideas are not always the newest ones.
Army veteran J. David Truby, a former editor for National News Service, was a founder of the Indiana University of Pennsylvania Department of Journalism and has authored more than 30 books.
Originally published in the June 2012 issue of Vietnam Magazine. To subscribe, click here.