Old bottles of new wine, old trees and new flowers
At the end of September, the U.S. Air Force grounded most C-130H Hercules transport aircraft after a major propeller problem was discovered during maintenance and overhaul of the aircraft.
According to the notice of the US Air Mobility Command (AMC), when the C-130H Hercules was undergoing engine testing after the maintenance overhaul was completed, the maintenance personnel found that the aircraft engine leaked oil during the test, and the problem was eventually located in the crack at the hub of the propeller at the root of its propeller.
This propeller crack is not an isolated case, and the same problem was found in the inspection of two other propellers. As a result, 116 C-130H transport aircraft were grounded and inspected.
The old fault of "Hercules"
The hub assembly is simply the bearing seat on which the blades are mounted. After the power of the engine passes through the reducer assembly, it is transmitted to and drives the propeller to rotate, and its role is extraordinary. The U.S. Air Force attaches great importance to this, immediately conducts on-site visual inspections, removes and then performs stress analysis (from which it can be inferred that cracks are basically caused by mechanical fatigue).
This is the second time in more than three years that the C-130H fleet has been extensively grounded due to propeller problems. Previously, in February 2019, the U.S. Air Force grounded for several weeks 60 C-130Hs, which accounted for nearly a third of the fleet at the time, for several weeks and replaced the blades, fearing possible rupture of propeller blades produced before 1971.
According to the description of the "propeller barrel" in the news report, the crack may be in the outer cylinder part of the hub assembly, and the above picture is the state after removal.
A spokesman for Air Force Air Mobility Command responded to the C-130H grounding, saying that even though most of the C-130H fleet is currently grounded, the Air Force still has enough airlift capacity to meet its transportation needs around the world.
Specifically, the "old fault" of the C-130H in both accidents was the "old" 4-blade propeller it used, the Hamilton Standard 54H60-39 propeller.
In recent years, the "new" C-130H, which has replaced the NP2000 8-blade composite propeller of Collins Aerospace (a subsidiary of Raytheon Technology), and the C-130J using the Doughty R391 six-blade scimitar-shaped composite propeller do not have this problem.
Therefore, news reports are emphasizing that the C-130s grounded are all models equipped with older propellers, including both 100 C-130Hs and special aircraft based on them: 8 MC-130H Combat Claws, 7 EC-130H Compass Pagers and the only TC-130H.
The "new" C-130H has been replaced with an 8-blade composite propeller of the Collins NP2000.
The new generation has rolled off the production line of more than 500 aircraft
Compared with the previous grounding of many models of the US military, this time the C-130H made an "old problem" is actually not surprising, because it comes from the 60s of the last century.
In recent years, while the US military has begun to modernize the C-130H, it is also accelerating the replacement of the old and new "Hercules" family - from the H-type to the new generation of J-type "Super Hercules".
In mid-March, the 500th C-130J rolled off the production line from the Loma Marietta plant and delivered to the Air Force. Today, the C-130J Super Hercules has 273 in the U.S. Air Force, 65 in the U.S. Marine Corps and Navy, and 15 in the U.S. Coast Guard.
The 500th Super Hercules (extended C-130J-30), designated 5934, rolled off the assembly line and was delivered to the McLaughlin Air National Guard in Charleston, West Virginia.
Now, the new generation of Super Hercules is becoming a universal platform for the U.S. Air Force, Marine Corps and Coast Guard.
Its birth originally began with the Royal Air Force "coming to the door" to put forward the demand, Rolls-Royce, Doughty, Lucas and other British aviation manufacturing companies are also widely involved in it, becoming the supplier of Lockheed Martin this project.
Of course, in the early 90s of the 20th century, when the concept of "Super Hercules" was born, Lockheed Martin also needed such a new generation of "Hercules" to take over the baton. After all, at this time, the "Hercules" transport aircraft family has been in service for a long time, with a flight time of nearly 20 million hours.
In 2015, the 2500th C-130 was delivered.
With the "Super Hercules" taking over the baton, the C-130H has been transferred to the US Air Force Reserve and Air National Guard. As a result, they were the most severely affected by the grounding.
According to Lockheed Martin's data as of 2020, the C-130J "Super Hercules" delivered into service in 1999 has been equipped with 26 operating units in 22 countries, and the global C-130J fleet has flown more than 2 million hours, set more than 50 world records, and derived 17 sub-models with the same mission configuration, covering transportation, in-flight refueling, search and rescue, meteorological reconnaissance and firefighting.
Of the 481 Super Hercules currently in service, 26% are used by international customers.
C-130J "Super Hercules" of the Indian Air Force and the Israeli Air Force.
From the "ugly duckling" to the classic transporter
In this way, from "Hercules" to "Super Hercules", the C-130 family has become the world's longest-running military aircraft for more than 60 years. However, in the 50s of the 20th century, no one would have expected such a "great future" for this medium-sized transport opportunity.
The C-130 as a rising star at the time was not favored. The industry's unanimous view is:
How could Lockheed, which produces the P-38 Lightning, C-121 Constellation, P-80 Meteor and U-2 Madame Dragon, design such a slow Ugly Duckling aircraft like a barrel? Even Kelly Johnson, the "soul man" of Lockheed Martin's skunk factory, didn't like it.
[Insert: Early reading, such a new "delivery room" of aviation black technology, spending a huge amount of money on Luoma will also be built! ] 】
On August 23, 1954, a prototype YC-130 (No. 53-3397) took off from Lockheed Air Station in Burbank, California, USA. Later the production of the Hercules was transferred from Burbank to the Lockheed Marietta plant.
The 3-bladed propeller and nose radome shape on the prototype were significantly different from the later Hercules.
In the fall of 1954, Lockheed held a naming contest for the new aircraft, and the most popular name among nearly 10,000 proposals was "Griffin" (aka "Gripen", a winged monster with a griff's head, for which Szaab's JAS39 aircraft was nicknamed). But in the end, Lockheed management, with a high vote of 160 votes, decided to name it as the Greek mythological "Hercules" (Hercules, literally translated as "Hercules").
Although Hercules was developed for the needs of the U.S. Air Force in the Korean battlefield in the 50s of the 20th century, it missed that war, and its fate belonged to the lushness of Indochina - the Hercules family proved itself through high-intensity and high-intensity missions on the Vietnamese battlefield, and also gave birth to Hercules' armed gunboat aircraft AC-130.
In more than 60 years of continuous upgrades to "new wine in old bottles," the C-130 has been suffixed from A to J.
This is reflected in changes in aircraft shape, including propellers from the 3-blade Curtis-Wright propeller in the prototype stage, to the final Hamilton-standard 4-blade propeller, to the Doughty 6-blade propeller on the C-130J and the Collins 8-blade propeller in the C-130H upgrade; In the nose radome shape, from the "eagle hook nose" on the early A model to the "Pinocchio nose".
In addition, the Super Hercules' elongated C-130J-30 lengthens the length by 15 feet (4.57 meters) by inserting a two-segment fuselage.
Size comparison of the "Super Hercules" normal version with the extended C-130J-30.
The French Air Force is armed with the C-130J "Super Hercules".
At the same time, in addition to the familiar appearance, the C-130 family is already a completely different aircraft.
The interior changes are concentrated in the cockpit, and there are few designs from the 50s of the 20th century, and under the concept of "vitrified cockpit" are large and small LCD displays. Along with the traditional instrument panel, the C-130 was also "invited" by the flight engineers and navigators of the former crew - now the C-130 crew is directly reduced to 2 pilots and 1 stevedore.
In terms of power, switching from the Allison T56 to the more powerful Allison AE2100 engine, the C-130J Super Hercules has a 50% longer range and a maximum takeoff weight of 25% more than the original A. In addition, the maximum flight speed has been increased and the take-off distance has been shortened.
The C-130 transport aircraft is currently the world's longest-running military aircraft.
An American story of a Vietnamese man and "Hercules"
In the history of "Hercules", there is also a very American story. This story has been repeatedly told by the Smithsonian Institution, the US Air Force and other institutions in the "Hercules" 60th anniversary report article and other materials.
On April 29, 1975, in Saigon, Vietnam, 24-year-old Tinh Nguyen (Nguyen) squeezed into the last C-130A transport plane to take off. He then settled in a resettlement camp at Eglin Air Force Base in Florida, where he worked during the day and studied hard at night before attending the University of Alabama.
After graduating from college he applied for a job at Lockheed , but after being rejected he switched to Gulfstream Aerospace. In 1983, he submitted his resume to Lockheed again. This time, Nguyen finally got his wish and got a job at the Marietta factory.
Tinh Nguyen with the C-130J. The AN/ALE-40 chaff jammer launcher in the SATIN unit is placed on the side paratrooper door of the C-130.
Nguyen's first job at Lockheed was to participate in the development of a prototype of a transport aircraft defense system, which later became the Transport Aircraft Survivability Enhancement Device (SATIN). As for the purpose of SATIN and the role it can play, he naturally understands it after experiencing the Vietnam War and seeing too many fighters shot down. Nguyen's final solution was:
AN/ALR-69 radar warning receiver, AN/ALQ-156 missile warning receiver radar and AN/ALE-40 chaff jamming missile launcher.
Later, the system was successfully transplanted to the C-5 Galaxy strategic transport fuselage according to the needs of the US Air Force.
When the American media played up Nguyen's "wonderful fate" with "Hercules", they also emphasized that his birthday was August 23, and the first flight date of the YC-130 prototype in 1954 was also this day.
Grounded, the US Air Force is going to "cry poverty" again?
Although the legend of Nguyen and "Hercules" is gradually drifting away in the telling of it again and again, similar to Nguyen's time, when the US military withdrew from Kabul in 2021, a large number of local people still crowded into the US military transport plane. Only, will the United States wait for the Afghan who can contribute wisdom to the US military industry in a few years?
However, it is certain that after the US military grounded the C-130H, whether it is the Pentagon or members of both houses, there is another case on hand that can argue that military spending is not enough and the US Air Force equipment is under great pressure. And companies such as Lockheed Martin and Raytheon Technologies, as military-industrial complexes, are happy to see it:
Whether it's expanding the procurement of the C-130J Super Hercules or accelerating the replacement of the NP2000 propeller, it means winning for them.
As for the C-130 transport aircraft, the protagonist of this early reading, the story that belongs to it should continue into the second half of the century.