Hercules, Airlifter to The World

Just as the modern generation of fighters developed from specific lessons learned from the Vietnam War, the Hercules was born from the experience gained in Korea and the Berlin Airlift of 1948. Students of both these “moments in history” will remember that the West possessed a worn-out fleet of transports that were merely derivatives of commercial airliners of the day. The C-54, C-56 and C-121 were military versions of the DC4, DC6 and the early Constellations, and while they could transport troops and basic equipment to a war they totally lacked the ability to feed men and machines into the front line.

The experience gained in these theatres revealed the urgent need for a transport plane that did not then exist, a STOL type of weight-lifter with adequate range and less dependent than contemporary types upon ample and highly developed facilities. Three prominent American aircraft manufacturers Boeing, Douglas and Lockheed submitted basic designs. That of Lockheed for a high-wing monoplane was approved; this specified four turboprop engines, a source of power then replacing the piston engine which at the time had reached the end of its technical development. The selected engine, the Allison T-56, has since matched the airframe’s fine record of performance and development.

Two prototype C-130s were built at Burbank, California in August 1954. Production orders were placed and the entire project was transferred to Lockheed’s giant facility at Marietta, Georgia.  Flight testing of the first production C-130A began on April 7, 1955 with deliveries to the Tactical Air Command of USAF, its first operator, commencing on December 9, 1956.

USAF transport pilots who had been bred on the lumbering piston-engined airlifters, and who were jokingly referred to as “truck drivers” by pilots of swifter aircraft, had a real surprise in store for them when slowly their squadrons began converting over to the propjet Hercules. An off-the-cuff quote by a USAF Colonel gives some idea of the impact the new aircraft had at the squadron level. The crews, he said, “developed from transport pilots almost into fighter pilots.

The new planes were so much easier to handle, and their power potential had our crews literally whooping for joy . . . It seemed as if everyone walked straighter, and for sure they were able to fly in a manner they’d never dreamed of. The things we could do with this new bird had everyone buzzing.

.. we could take the ‘130 up to 12,000ft, hold it up with the nose in a steep climb until the aircraft scrabbled for lift. Finally, we’d go into a complete stall. Then, just slam the throttle forward and the aeroplane never changes its altitude. The props chewed their way straight on out and up from that stall”.

If the Hercules had a profound effect on USAF crews then spare a thought for our own RAAF pilots who transitioned from C-47s straight into 130s Australia was the first nation outside the United States to put the C-130 into service in 1958 with the acquisition of twelve C-130As. In 1966 the. RAAF added twelve of the updated long-range C-130Es to its fleet.

The RAAF has achieved what Lockheed believes to be a safety record unmatched by any other operator. Its two Hercules squadrons – 36 Squadron with the original twelve “A”s and now re-equipped with twelve advanced “H” models, and 37 Squadron with its twelve C-130Es – each has _ achieved more than 100,000 accident-free hours of flying. The squadron of “A’s” logged the historic milestone in 1972 and eventually accrued more than 145,000 accident-free hours, while the “E” reached the 100,000-hour flying mark in 1977.

The RAAF allocates two specifically different roles for its two Hercules squadrons. Number 36 Squadron is a Tactical unit that specialises in short to medium-range low-level operations largely indirect “in the field” support of ground troops. Number 37 Squadron, flying the “E” model, flies mainly the longer haul strategic missions.

The new model advanced C-130H has significant structural and systems improvements over the earlier “A” model. Lockheed has boosted the C-130 payload by 26%, its cruise speed by 11%, its range by 52% and virtually doubled its already extensive airframe longevity. If the early-series “A” models withstood twenty years of RAAF service (and were by no means at the end of their true airframe lives when withdrawn from service in 1978) then the “H” will undoubtedly still be wearing RAAF roundels well into the twenty-first century. In fact, many of the crews destined to serve aboard the “H” models currently in service with the 36 Squadron have not even been born yet – a sobering thought, if not a great tribute to this famous aeroplane.

Many of these improvements were achieved with the C- 130E model. But the “H” Hercules incorporates more powerful Allison propjet engines with both higher cruise settings and takeoff ratings which result in shorter airfield performance and increased cruise speeds and altitudes.

The more powerful T56-A-15 engine on the “H” has a takeoff power of 4,508 equivalent shaft horsepower. This compares to 3,750eshp on the “A” and 4,050eshp on the C- 130E. The improvements to the engine provide greater overall reliability and have reduced maintenance and operating costs. In effect, the engines are a flat-rated version of the Allison power plant to be found in the RAAF’s P-3C aircraft. This commonality leads to saving on maintenance costs while flat-rating an engine greatly reduces operating stresses on that engine and effectively extends the Time Between Overhauls by as much as 30%.

When the “A” models were purchased in 1958 they cost around $2. 5 million each with spares. The “H” models, twenty years later, cost around $10 million each with a comprehensive inventory of spares. It is generally felt that while the twenty-year-old “A” models could have been re-engined, propped and updated with new electrical systems and avionics this would have cost $4-5 million per aircraft for what would probably be a 10 to 15-year life extension at reduced per annum flying hours. Therefore at $10 million a copy, the latest-technology C-130H represents first-rate value.

By comparison with US forces, the RAAF flies their Hercules aircraft sparingly. For instance, the twelve C-130As logged 145,000 hours in roughly twenty years of operation, which equates to around 12,800 hours per aircraft or an annual average of 640 flying hours. By comparison, a USMC squadron operating KC-130Fs (“B” versions modified for aerial refuelling) flew their twelve aircraft for only fourteen years to log 160,000 hours.

As a personnel transport, the Hercules can carry 92 fully equipped troops, or 64 paratroopers. When evacuating casualties it can load up to 74 stretd1er cases. The Hercules were virtually the lifeline of Australian servicemen during the Vietnam War. C-130Es of 37 Squadron were used to haul in huge supplies from Australia and specially equipped casevac-rigged Hercules were used to evacuate the wounded servicemen back home.

It has also shown its value in the role of personnel retriever, though largely in USAF operations. Special equipment consisting of an inflatable balloon, a 500ft nylon rope and a special harness is dropped to the subject to be rescued. When the balloon is trailed the Hercules traps the rope while flying at a speed of not more than 140 knots, and reels it in with the retrieved subject attached by a winch at the rear. The jerk at the moment of pick-up is no greater than that experienced in a normal parachute drop and if the total weight is not more than 500lb, two persons can be lifted in a single snatch. Needless to say, this personnel extraction method saved many lives during the Vietnam conflict.

The soundness of the original design is clearly reflected in the military C-130s expanding performance over the years when set against the fact that on no occasion has it been necessary to increase the original basic dimensions. The principal measurements of the C-130H are identical with those of the original C-130A. This may not make aviation history but it stands as a testimonial to a set of careful calculations.

A different situation applied to the civil version of the Hercules. Commercial cargo loads, on average, have a lower density than military ones and some operators of the L-100 (the Lockheed designation for civil registered Hercules) found themselves using up the available cargo space and being left with an unusable margin of weight. To provide commercial operators with a better balance between available volume and weight Lockheed introduced, in 1968, the L-100- 20, with a fuselage lengthened by eight feet. However, this did not solve all the operators’ problems and in 1970 there appeared the L-100-30 with a fuselage another seven feet longer than the L-100-20s.

The latest version of the civil Hercules freighter family is the yet-to-be-produced L-100-50, which features a fuselage stretched by some 35 feet over that of the first L-100 model. Lockheed claims that the Dash 50 will be able to cover a sector of 1000nm using 20 to 30 per cent less fuel than aircraft such as the Boeing 727-200. Maximum operational payload will be 60 OOOlb and total bulk cabin volume will be 8,133 cubic feet. The Dash SO will have a greater cargo capacity than the Boeing 707-320C and will operate more economically than either DC-8 or 707 jet freighters.

Yet another proposed derivative is the Hercules Airliner version. Based on the proven L-100-30 airframe the Airliner is configured with six-abreast seating with two miles. The Airliner is intended for use in the short field environment where noise is a problem for jet aircraft and over-state lengths are uneconomic for jets. Seating 106 passengers the cabin interior measures three feet wider than that of the DC-9. Though at first this particular mission sounded a little far-fetched it does offer real practice in areas suffering from the ill effects of jet noise and overstage lengths more suited to a fuel-stingy turboprop.

Another member of the large Hercules family awaiting the nod is the twin-engined L-400 model. Lockheed head had the L-400 on the back boiler for three years now awaiting a launch customer that would make the initial development costs a secure investment. The L-400 features the same fuselage structure as the four-engined C-130. Power is supplied by two Allison turboprops of 4,591eshp turning 14ft Hamilton Standard four-blade props, these would be six inches longer than those used on the C-130. The L-400 is designed to carry a 22,00lb payload on a 500-stage length and could operate fully laden from 3,500ft runways. If the Twin Herc is put into production it is sure to find acceptance with current operators of its bigger brother due to the crew/parts commonality. The only drawback is that the L-400 rounds out at around three-quarters the flyaway price of the C-130 so in many instances its biggest competitor would be from the same stable!

Since putting the C-130 into production a quarter century ago Lockheed has built more than fifteen hundred Hercules aircraft including seventy of the civil L-100 variant. Production is continuing at three aircraft per month and the aircraft type is operated by no less than 44 nations, an unprecedented level of acceptance for an aircraft that was originally thought to run to 30 units for US services alone.

The Hercules fleet worldwide is currently accumulating flight hours at the rate of 100,000 hours per month, with total flight hours accumulated being an impressive 13 500 000hours covering 5 billion miles. This represents the rough equivalence of more than nine thousand round trips between the earth and the moon!

Historians of the future will declare that Hercules made a timeless debut. It was born of experience gained in Korea and lived to play a massive role in Vietnam where it frequently frustrated enemy action by flying men and equipment to strategic points swiftly and on the scale required. It even served as a bomber, dropping a 30,000lb ‘earthquake’ bomb that resembled more cargo than munition. It served as a heavily armed gunship and brought to bear a destructive weight of fire against enemy targets by night and day.

It is now 1979 and even after 25 years of production the Herc is still selling well and indeed is to be sighted at bases and airfields right around the globe from Antarctica to Gabon.

Would it be that this fabulous airliner will still be in production at the turn of the century, who knows, except that if it was, I for one would definitely not be surprised?