Lockheed Martin C-130H Hercules: Getting the job done

The iconic Hercules, commonly called a Herk, first flew on August 23, 1954, and its mission was to transport troops and equipment to trouble spots all over the world.

The C–130’s hinged rear door and self-contained loading ramp can accommodate a wide variety of outsized cargo, including utility helicopters, six-wheeled armored vehicles, and 105-millimeter howitzers. Alternatively, it can carry 90 combat troops, 64 battle-equipped paratroops (who exit through a paratroop door behind each wing), or 72 stretchers. In its aerial delivery role, it can drop several pallets containing up to 42,000 pounds of equipment and supplies (when landing strips are unavailable or hostile). The extraordinarily rugged aircraft also has high-flotation landing gear enabling it to operate from mud, sand, and clay surfaces.

Many missions

The role of the Hercules has expanded dramatically during its lengthy career to include operating as a drone controller, a lethal gunship (such as the AC–130 Spectre), an aerial refueling tanker (for helicopters), and an emergency hospital. It also is used for electronic warfare, search and rescue, polar operations (when equipped with skis), weather reconnaissance (including hurricane penetration), maritime patrol, psychological warfare (by broadcasting over the enemy’s radio and television stations), aerial photography and mapping, minelaying, relief operations during natural disasters, reconnaissance and surveillance—and, of course, “special operations.” The Hercules also has been used for firefighting, and commercial operators use civilian versions designated as L–100s.

A familiar C–130T named Fat Albert provides support for the U.S. Navy Blue Angels. Until 2009 it impressed spectators with a rocket-assisted takeoff, 45-degree climb, and zero-G pushover prior to rocket-motor burnout.

One of the most famous C–130 missions was Operation Thunderbolt. On July 4, 1976, the Israeli Air Force flew four Herks 2,000 nautical miles from Israel to Entebbe, Uganda, at night, seldom more than 100 feet agl (to avoid detection). They carried 200 commandos and some ground vehicles that were used on a raid to rescue 94 mostly Jewish passengers, as well as the 12 crewmembers, of an Air France flight that had been hijacked to Entebbe by Palestinian terrorists. (The airplanes were refueled at Nairobi during the return flight.)

In 1963, a C–130 became the largest airplane ever to operate from an aircraft carrier when it made 29 touch-and-go landings, 21 unarrested full-stop landings, and 21 unassisted takeoffs from the USS Forrestal.

The 189th Airlift Wing of the Arkansas Air National Guard is based at Little Rock Air Force Base (aka “the Rock”) and is the formal training unit for the Hercules. Herk pilots from all U.S. military branches, and from 44 allied nations, get their training at the “schoolhouse.” The 189th has the world’s most experienced Hercules crews, who pridefully refer to themselves as the last of the military’s real airplane pilots.

Flying the Herk

During my visit to the Rock, more than 70 C–130s were on the ramp, mostly H models. These were built in the greatest numbers and are the most widely used. Others were the newer C–130J, the Super Hercules, which has more powerful engines, six-blade Dowty composite propellers (instead of four-blade Hamilton Standards), and improved performance. Automated systems and a glass cockpit eliminate both the flight engineer and the navigator. The C–130J-30 is the stretched version. The U.S. military is targeted to have a fleet of 308 Hs and Js.

The H models eventually will be modified with glass cockpits. Most of the older pilots, however, seem to prefer analog gauges while the younger ones prefer glass, a seemingly generational split.

My indoctrination flight was in a 1986 C–130H commanded by Lt. Col. Chris Raymond. Reveille could be heard playing over the base as we assembled for a dawn briefing. Our aircraft, call sign “Hawg 50,” was one of a flight of four. We were to make two cargo drops and then do some low-altitude flying.

You normally enter the Herk through a jettisonable crew door (with airstair) on the forward left side of the fuselage. You obviously can also enter through the aft cargo door.

The Herk has such a wide cockpit that you walk on the outboard side of each pilot’s chair to be seated. The 23 windows and short nose allow for outstanding visibility ahead, below, and to the sides.

The four Allison T-56-A-15 constant-speed turboprop engines (developed specifically for the C–130 and used later on the Lockheed Electra) are started pneumatically, and each produces 4,910 effective shaft horsepower. The geared, constant-speed, reversible propellers turn at only 1,021 rpm.

The rudder pedals are not connected to the nosewheel. A tiller to the left of the aircraft commander’s seat is used to steer the nosewheel for directional control on the ground.

Takeoff from Runway 25 involved lowering the Fowler-type flaps to 50 percent, grabbing a fistful of throttles, and advancing them to a maximum torque setting of 19,600 inch-pounds. The co-pilot pushes forward on the yoke to increase weight on the nosewheel and maximize steering effectiveness until about 40 knots, which is when the rudder becomes effective.

Each main landing gear consists of two wheels in tandem that retract vertically into their wells. Climb speed below 10,000 feet is 180 knots. The airplane has a maximum-allowable takeoff weight of 155,000 pounds (175,000 in wartime) and can carry 9,508 gallons of JP-8 fuel.

Hydraulically boosted flight controls provide the Hercules with delightful handling qualities and make the airplane lighter on the controls than many lightplanes. Not much muscle is needed during 60-degree-bank steep turns, standard fare for Herk pilots.

Stall recovery is unremarkable if performed at the onset of a buffet—there is no artificial stall-warning indicator—but delaying recovery can require aggressiveness as the aircraft rolls right or left, usually the result of asymmetric engine power.

Our flight of four remained in formation visually, but during instrument conditions or at night, Herk pilots use on-board station-keeping equipment to keep the formation intact.

When nearing the 1,000-by-1,430-yard drop zone, the airplane was depressurized and slowed to 140 knots to open the rear cargo door. With the wing flaps extended to 50 percent, the airplane has a six- to eight-degree nose-up attitude, making it easier for cargo to be rolled out the rear. Ground personnel had secured the drop zone and provided us with the surface wind. The point at which a load is extracted depends on airspeed, wind, altitude (agl), pallet weight, type of parachute used, and where the load is in the aircraft.

Our first drop was made from 650 feet agl and was a gravity drop, so called because the pallet simply rolls out the rear. The second was equipment dropped from 900 feet agl. A parachute let loose in the airstream pulls out this heavier pallet. Once pallets are free of the aircraft, parachutes deploy to control descent. A thickness of crushable, corrugated cardboard on the bottom of each pallet acts as a shock absorber to soften touchdown. Retrieved cargo is then loaded onto a tractor-trailer and returned to base.

High-altitude drops are made by first dropping a radiosonde that radios to the crew the winds aloft at various altitudes during its descent. This data is used to determine at which point to extract cargo, and results in surprisingly accurate drops.

A very low-altitude parachute extraction system allows cargo to be extracted during a low-speed flyby only a foot or so above the ground. Some Herks can drop “smart pallets,” laser-guided pallets released from as high as 20,000 feet that land within a few feet of their targets.

Try to imagine the huge change in center of gravity and aircraft pitch that occurs when tons of weight are first moved rearward and then extracted. The elevator can reach its forward pitch limit as the load moves aft, followed by a sudden and rapid dive entry as the tonnage leaves the aircraft.

During my indoctrination flight I also experienced “earth masking,” a low-altitude operation that takes advantage of geographical features to mask an arrival and avoid enemy detection when flying in a high-threat environment. Our flight of four flew in loose formation at 300 feet agl and cruise airspeed along a military training route (MTR). The Herk’s flight profile undulated with the terrain and exploited valleys and folds in the Earth to avoid radar detection. We streaked below a few low-altitude general aviation aircraft whose pilots might have been surprised by the sight of a formation of Herks passing beneath them at high speed. This reemphasizes the need for lightplane pilots to take MTRs seriously. Ground-hugging Herk pilots also must be alert for birds and obstructions, which is why all eyes on the flight deck were on the lookout for both.

In a C–130H simulator, I was offered an opportunity by my instructor, Maj. Tom Guillebeau, to make an engine-out approach using night-vision goggles (NVGs or “noggs”), not too difficult because of the Herk’s humongous, effective, and powered rudder.

The most fun, though, was using noggs to make a tactical, abeam approach to a 3,000-foot-long, unimproved assault strip at night and as if there was hostile ground fire in the area. The strip was identified by five dim infrared lights. We approached the area at 300 feet agl and 250 knots (airspeed redline is 320 knots). As you cross over the field, the throttles are fully retarded. You then roll rapidly into a 60-degree-bank turn. The incredible drag created by those 13.5-foot-diameter propellers going into flat pitch—they act like giant air brakes—plus doubling the G load is like throwing out an anchor. Bank angle is reduced to 45 degrees, and the gear and flaps are then extended as you continue decelerating in a tight turn onto short final approach.

After touchdown the propellers are brought into reverse and supplement the wheel brakes to provide incredible stopping power. Interestingly, the Herk’s engines are equipped with brakes that bring the propellers to a relatively quick stop after shutdown to prevent endangering ground personnel.

Guillebeau told me about some other unusual procedures approved for Herk pilots. For example, if the starter motor of one engine is inoperative, that engine can be started using a “buddy start.” The problem airplane is placed about 10 feet behind another Hercules. Propeller blast from the forward airplane windmills the ailing engine until sufficient rpm has been attained to facilitate a normal start.

Another solution is the “windmill-taxi start.” You begin a three-engine “takeoff” on a runway at least 7,000 feet long. As the airplane accelerates, so too will the windmilling rpm of the problem engine. When the propeller reaches 40-percent rpm, the engine is started, and the “takeoff” is aborted. Can a Hercules take off on three engines? Yes, as long as the propeller of the inoperative engine is feathered.

The Lockheed Martin C–130 has been in continuous production for more than 60 years, the longest production run of any military aircraft (and getting longer). It currently is competing with the Boeing B–52 Stratofortress for longevity and undoubtedly will win that contest—the Herk will be in service long after the big bomber retires.

The legendary C–130 has landed at both poles and almost everywhere in between; it has reliably performed missions limited only by imagination. It is a shame that the Hercules cannot talk; it would tell some remarkable stories.

The author expresses his gratitude to Col. Robert Ator II, Col. Domenico Sarnataro, Lt. Col. Chris Raymond, Maj. Thomas Guillebeau, Senior Master Sgt. Chris Durney, and the men and women of the 189th Airlift Wing for so graciously sharing their time and expertise.