By Geoff Fein
To ensure the Marine Corps will be able to rely on the EA-6B Prowler for the service’s electronic attack needs and keep pace with global threats, the Navy has made a number of significant investments in the aircraft, from new electronic systems to improving engine reliability, a Navy official said.
One of the more important modifications has been to replace the Prowler’s analog flight control system with the digital flight control system, Capt. Steven Kochman, EA-6B program manager, told Defense Daily in a recent interview.
The digital flight control system is just being introduced to the fleet now, he said.
Northrop Grumman‘s [NOC] EA-6B has been relying on the ASW-41 analog flight control computer. Kochman said the system has issues with maintainability and obsolescence.
“It is an extremely important component in the airplane, and it is very hard to maintain and very hard to repair,” he said. “It had eight components inside of it. [If] any one of them fails, and you have a bad box, then you have a real problem.”
Kochman said when he first came to PMA-234, it was a focus of his to install the digital flight control system in every Prowler. In September, he got approval to move forward on that plan.
“There is a rule in place that says you can’t modify an airplane if they are going to retire within five years. You can’t make modifications when you know they are going to retire within five years,” he said. “But we got a waiver from Dr. [Delores] Etter (the Navy’s acquisition chief) to modify all of our airplanes with the digital flight control system so that we could take advantage of this as quickly as possible, for as long as possible.”
Etter signed the waiver on Sept. 21, Kochman noted.
“She recognized that we built the case. She understood it and she gave us the authority. It’s the right thing to do,” he said. “It’s not a tremendous dollar investment, but if we don’t do it now, we won’t be able to do it later. We want to have the flexibility so that if somebody makes the decision where we extend the use of these Prowlers, we will have made as many of them as viable as possible for as long as possible.”
The Navy hopes to have Prowlers flying until at least 2012 and as far out as 2018 for the Marine Corps (Defense Daily, Oct. 16). While the Marine Corps will continue to fly the Prowler for another 11 years at least, the Navy will move to the Boeing [BA]-built EA-18G.
The Navy has installed BAE SYSTEMS‘ digital flight control system on two Prowlers, with another four in the process of getting upgraded, Kochman said. “And putting them in at a pretty good rate over the next the next couple of years. It will be out in the fleet and deploying in Navy and Marine squadrons certainly within a year.”
He added the Navy will not be taking aircraft out of operating status to do the upgrade. Instead, the Navy will send contract field teams out to do the work so the service does not have to send a plane to a central location for the modification.
The Navy is also in the process of upgrading BAE’s USQ-113 radio countermeasure set, Kochman said. Last month the Navy began a quick reaction assessment so that they would be able to move forward with the important upgrade to the Prowler that is funded through supplemental funding, and get it out to the fleet as soon as possible, Kochman added.
The upgrade will be called USQ-113 (V4). The first flight test of the new system took place Sept. 26. The new system will go on every Prowler, Kochman noted.
“We did a memorandum for the record. We didn’t need a waiver. It got approval to ensure we could do all those airplanes. Because it is low-cost to modify the airplanes [we] just had to do a memorandum for the record…just tell people we were doing it,” he said.
The Navy is also adding BAE’s Low Band Transmitter (LBT) to the EA-6B. Currently inside of each ALQ-99 jamming pod, there are two transmitters and an exciter, Kochman explained.
“So you carry different transmitters based on what mission you are going to do. Currently we have band 1, band 2 and band 2/3. That will all be replaced by the Low Band Transmitter,” he said. “Instead of having to carry three different transmitters, you will be able to carry just one.”
And instead of carrying those transmitters, made with vacuum tube technology, the new LBT is solid state, which improves reliability, Kochman added.
“We have them deployed currently and we will go into full-rate production (FRP)…we are in low rate initial production right now…and will go into FRP in 2008,” he said. “It will be an important asset for the Growler, too. Not to have to carry the legacy transmitters is really helpful.”
The Prowler is also going to get a new tactical air navigation system. The current system is old and hard to maintain, Kochman said.
The tactical air navigation system tells the pilot where they are relative to the ground station. “That’s how we navigate in addition to using GPS and Inertial Navigation System (INS). [The tactical air navigation system] is an important backup system. [It is] especially important on an aircraft carrier because the aircraft carrier moves, so you can’t use GPS and INS. You have to have something that tells you where [the carrier is, in] real time.”
The Navy has also made strides in getting longer life from the Prowler’s engines.
After two crashes back in 2001 ground the Prowler fleet, the Navy began a examination to figure out what to do, Kochman said.
The initial response from the examination was that the Navy had to do some better inspections of the airplane, he said. “As a result, they took a whole lot of engines out of the inventory, and all of a sudden you have a readiness problem based purely on the engines.
“We took this old engine, this J52 P408 engine that’s really been around in design for a long time. We got Pratt & Whitney guys and said, ‘take a look at this and help us understand what needs to be done with it,'” Kochman said.
The Prowler uses two Pratt & Whitney [UTX] J52-P408 turbojet engines.
The company really focused on a single bearing that the Navy knew failed in both of those crashes, according to Kochman. But Pratt &Whitney also looked at how they could build their engine back to the way it should be built, he added.
Pratt & Whitney began something called a build standard review and Kochman said it is now starting to pay off dividends.
“In late 2006, we reworked that formula for doing analysis and really since then we have seen a very nice steady upsurge in engine reliability. We are getting upward of 500 hours between engine removal right now, which is pretty good for a tactical air platform…really good for an engine this old…and much better than what we had even before we built the standard review,” Kochman said.
In August, the Navy achieved 1,175 hours as the average mean flight hour between engine removal, he added.
“That is the standard metric mean average flight hour between removal…1,175…the best it has ever been in the history of the Prowler,” Kochman said. “That’s an important thing to have that confidence in the engine and to ensure we have those engines for a long time. We are building better engines, building cleaner engines, we are doing a better job analyzing the oil that goes through them, and we are paying dividends for it.”