Lockheed Martin is highlighting the suitability of its LM-100J civilian Hercules for the firefighting mission, as well as promoting the four-engine turboprop's application to a wide variety of commercial and government duties, from hauling outsize cargo and equipment to austere strips to ferrying VVIPs in special passenger accommodation.
Two LM-100Js are now flying, with a third nearing completion. They are part of a five-aircraft order for an unnamed customer, with initial deliveries planned for later this year following the expected award of U.S. FAA approval.
The LM-100J differs in several respects from the military C-130J, with military equipment removed. It has a 9g cargo restraint added at the forward cargo hold bulkhead, carbon brakes, Honeywell RDR-4000 series weather radar, and Inmarsat SwiftBroadband satcoms. A GE Aviation flight management system is installed, similar to that fitted in the Boeing 737.
It is also running on the latest Block 8.1 software with datalink that provides for full compliance with future CNS/ATM air traffic requirements. Two military C-130Js are also engaged in operational trials and evaluation of this software iteration.
For firefighting missions, the LM-100J is being proposed with two systems, both of which have roll-on/roll-off internal tanks so that the aircraft can be used for other missions when not engaged in firefighting. The simpler of the two is the modular aerial fire-fighting system (MAFFS) II, which offers a 13,250-liter (3,500-gallon) capacity with retardant ejected by compressed air through a duct that exits through the paratroop door. MAFFS II is already in use on U.S. Air Force C-130Js.
Alternatively, the FireHerc could carry the Coulson Aviation retardant aerial delivery system (RADS) that is certified on the legacy C-130. At 15,140 liters (4,000 gallons) this system has a higher capacity than MAFFS II, and an 18,925-liter (5,000-gallon) development is planned. RADS is a gravity-drop system with variable delivery rates. This system can be used from a higher altitude than the MAFFS II and delivers a more precise coverage pattern. However, the system does require some airframe modifications as it ejects retardant through ports in the lower fuselage.
Legacy Hercules have been flying on firefighting duties for many years. The new-generation LM-100J has a number of attributes that lend it to this challenging mission, including an extended-service-life wing that can handle the high turbulence that is repeatedly encountered close to fires. The aircraft has an advanced stall awareness/warning system that is appreciated by fire crews, as well as a terrain avoidance warning system and windshear detection. The all-digital avionics include a primary flight head-up display that allows the crew to fly “eyes out.”
Above all, the LM-100J is very agile at low level and has a considerable power margin, attributes that are being demonstrated during the airplane's aerial display this week at the Farnborough Airshow. The aircraft’s performance at low level in hot-and-high conditions aligns the LM-100J ideally with the requirements of the firefighting mission.
In the meantime, Lockheed Martin is exploring technologies that would allow the LM-100J to fight fires at night, an activity that is currently not performed by fixed-wing tankers. The company is examining a distributed aperture infrared imaging system with sensors located around the airframe, fused with data from other systems such as millimeter-wave radar that could form a synthetic vision system that gives the crew a wide area of regard on a helmet-mounted display.
Extending the mission into the hours of darkness has significance to fire-fighters beyond just allowing fires to be fought for longer, as fires typically settle down in the nighttime and are easier to bring under control. Moreover, if a fire breaks out at night it can be attended to immediately, rather than having to wait until dawn.
Certification for the Civilian Herc
Lockheed Martin’s two flying LM-100Js are about 80 percent through the certification process, which is due to conclude this fall. As the C-130J design was certified as the L-382J in 1998, the LM-100J is being approved through a Type Design Update (TDU) process, requiring around 200 hours of flight test. The digital nature of the LM-100J allows data to be easily retrieved, although a small amount of additional test equipment is installed.
Certification flying is facilitated by Lockheed Martin’s chief test pilot being an FAA-assigned Designated Engineering Representative (DER), permitting flight tests to be undertaken in line with FAA requirements without the need for agency personnel to be present. The concept allows Lockheed Martin to conduct the necessary tasks on its own and then call in FAA representatives for examination.
As the final part of the TDU process, the FAA itself conducts the function and reliability (F&R) tests that are required for Part 25 approval, in which the agency’s representatives take an aircraft for two to three weeks to conduct whatever flights they deem necessary. F&R campaigns are undertaken by a joint FAA/Lockheed Martin crew.
Attending to other certification issues, mission loads such as palletized seating and specialized cargo systems require supplemental type certificates. Parts intended for the LM-100J have different numbers from their military counterparts, requiring separate storage and documentation. The Marietta, Georgia factory has been an FAA-certified production facility since the first-generation L-100 civilian Hercules were produced there between 1964 and 1992.