By the end of 2007 the Marine Corps will begin the first of two tests on the CH-53 engine that the service hopes will add another 800 hours of operation time before an engine overhaul is required, according to a Marine Corps official.
Although engine tests are not typically big news, the accelerated simulation mission endurance test (ASMET) will be the first detailed test of the General Electric [GE] T64 engine done in quite some time, Capt. Rick Muldoon, CH-53 program manager, told sister publication Defense Daily in a recent interview.
The test and a second one planned for spring 2008 will condense 15 years of operations into six months of testing, Muldoon added.
Part of the cyclic damage the Marine Corps will try to replicate will require the engine to be turned on, run at full power over a two to three hour time block, and then turned off, Stoney MacAdams, heavy-lift helicopters deputy program manager for propulsion, told Defense Daily during the same interview. While the goal is to stretch the operational hours before engine overhaul from 2,400 to 3,200, Muldoon added, “We may find other things fail during that test that we can take care of now instead of waiting.”
“This is an old engine and there hasn’t been a detailed test done on it in quite some time,” he said. “So we are going to run it through its paces…and take a look at it, then use that data to increase our operating time on the engines.”
ASMET is a piece of the larger Engine Reliability Improvement Program (ERIP) for the Sikorsky [UTX] CH-53E, Muldoon noted.
ERIP is an extensive long-term plan to procure and install engine and air frame changes related to the engines, and increase maintenance and support, Muldoon added.
Since 2003, fleet operators have been complaining about the reliability of the 53D and E engines, he said. In 2003, time on wing was 350 hours. In Iraq, it fell to less than 200 hours, he said.
“Something needed to be done. This program was initiated to correct the problem and bring us up to…the end goal is 100 hours [more hours on] average time on wing,” Muldoon said.
Since initiating the ERIP effort, the current average for time on wing has increased to 630 hours. That’s a 12-month rolling average, Muldoon noted. The Marine Corps has been up as high as 700. Some of the engines had a lot of perturbations, he added.
“We’ve actually had engines go over 2,000 hours in theater and the current high time in theater is between 1,500 and 1,600 [hours], so it is clearly working,” Muldoon said. “The last time I asked an operational commander what his…thought about the engines, he said, ‘I don’t think about the engines anymore,’ which is a good thing.”
Improving time on wing also drives down maintenance man hours if engines are not having to be pulled off and new ones put on or if maintenance personnel are not constantly having to tweak or work with the engines, he added.
“Back in this earlier time frame, the ’03…’04 time frame, we were up 43 to 46 maintenance man hours per flight hour,” Muldoon said. “Now we are in the mid to low 30s. So that’s substantial.”
A lot of the processes used in the repair and overhaul process have been revamped and improved to increase first pass yield on test cells, Muldoon said. “We were having a problem with first pass yield on the engines. Now we are not having any problems. It was a combination of materials and process.”
Right now, the Marine Corps has a plan to keep the CH-53E in operation until 2025. The CH-53E’s replacement, the CH-53K, will go to initial operational capability in 2015, Muldoon added.
“We recognize this [the CH-53E] is going to be a key platform well into the future. We’ve got at least 17 to 18 years left on this platform. That’s why we feel it’s imperative to keep it current,” he said.
Another aspect of ERIP is dealing with parts obsolescence, MacAdams said.
“A lot of the parts that were in the original configuration from 30-plus years ago have become obsolete,” he said. “What you see ERIP doing is two things: Making the part more reliable for the base configuration, but also getting past that obsolescence issue. You see a lot of that in the internal pieces–seals and gaskets–where the materials that may have been used in the manufacturing methods that we used are just no longer in place.”
That’s not necessarily a bad thing, MacAdams added, because the Marine Corps is updating parts anyway to increase time on wing.
While, often times, obsolescence is a result of a company no longer in business, the companies making parts for the CH-53E engine are still around, MacAdams said.
“They just don’t want to make the parts they were making 30 years ago. They want to get out of the old business. They want to posture themselves to making more capable parts, better materials, better manufacturing methods,” he said. “A lot of what the legacy systems have to deal with is just an industrial base that just does not want to make these old parts out of old materials and old processes.”
Muldoon added the Marine Corps is also working on some possible improvements to high-hot performance for the CH-53E engines. For example, if the Pentagon decides to move the Marine Corps to Afghanistan again, the Navy will want to go for better performance at altitude, Muldoon said. “So there is a whole program Stoney MacAdams is doing to improve high-hot performance.”
“What can we do to that to give the E and D better high-hot performance? We are looking for money to do that,” Muldoon said. “I am confident we will get some supplemental to provide that capability to the fleet.”