Studebaker to Cadillac: experimental C-130 returns to Wyoming

  • Published
  • By 1st Lt. Christian Venhuizen
  • Wyo. Military Department
For the past six years, one Wyoming Air National Guard C-130 Hercules cargo plane has been the test bed for technological upgrades 60 years in the making. A return to Wyoming signals the final stages of the experimental program, with some of the critical modifications staying in the aircraft.

"We've got a Cadillac instead of a Studebaker," Chief Master Sgt. Randy Wilkison, the Wyoming Air Guard's maintenance quality assurance superintendent, said.

After years of being tied into the Air Force's experimental aircraft program, the "Cadillac," with the yellow-striped tale, returned to its home station in Wyoming, Feb. 24, from its temporary station at Edwards Air Force Base, in California.

The propeller system on that Hercules underwent modifications in September 2005. It began by changing out technology used by C-130s since they first took flight in 1954, specifically the valve housing.

The valve housing, some of which are more than 30 years old and rebuilt 20 times, is a series of valves, fly weights and springs. It is used to control the propellers of most C-130s, Wilkison said. That old propeller control system was replaced by the electronic propeller control system (EPCS).

"It's a quicker turn around, easier to maintain. That's from a maintenance standpoint," said Chief Master Sgt. Wayne Welsh, the Wyoming Air Guard's component repair flight supervisor. He described the EPCS as the "the brains of the propeller."

Time saved could mean a matter of lives saved. In combat, the C-130 transports food, water and ammunition to ground troops isolated by terrain. At home, Wyoming's C-130s are used to fight wildfires, and serve as transports. They can also perform as massive flying ambulances in combat zones and domestically.

"Instead of taking a day, you now have an aircraft back in a matter of hours and get it back into the fight," Wilkison said. The old valve housings on each aircraft normally have a maintenance issue once a week. Wyoming has 12 C-130s.

Moving the aircraft a little faster and quieter to the fight was a part of the next experimental modification.

In 2007, the aircraft had all of its four-bladed propellers removed and replaced with a system of eight-bladed propellers to add thrust and reduce vibration, while improving fuel efficiency. The added result was a smoother and noticeably quieter ride, said Welsh.

The vibrations and noise created by the old propeller system were noticeably muted, he said. Wilkinson added, with the eight blades in motion, he was able to hear other crewmen across the body of the aircraft. Both Welsh and Wilkinson said the reduction of the harmonic noise and the subsequent reduction in vibrations should reduce wear on other systems on the aircraft.

Maintenance on the equipment also improved. Welsh said the old four-bladed system had to be removed completely from the engine to replace one blade. With the experimental system, maintainers could remove or replace just the problem blade.

The modularity of the newer system also makes transporting replacement parts more feasible. While one of the old propellers would take up four pallet loads in the aircraft, four of the new propellers took up just one pallet load, said Wilkison.

However, unlike the EPCS, which will remain indefinitely with the Wyoming C-130, the eight-bladed propellers will not stay with the aircraft. From Feb. 25-27, crews will remove the experimental propellers and replace them with the four-bladed system, and perform scheduled inspections.

Once the aircraft is reconfigured, it will return to Edwards to finish testing. Wilkison said that final testing process will get a baseline for the aircraft to compare with the results from the eight-bladed flights, including completing the fuel efficiency testing. He said the test flights should be complete by June 2011.

The completion of testing will signal the beginning of normal operations for the aircraft, including deployments, and other missions, said Wilkison. That includes making sure Wyoming's "Cadillac" has the replacement parts available for the EPCS and the maintenance crews are trained up on the new technology.