Certification flight-testing of Lockheed Martin's private-venture C-130J is finally under way.

Graham Warwick/ATLANTA

A "FLAWLESS" FIRST flight, after frustrating delays, has boosted Lockheed Martin's confidence in its upgraded C-130J Hercules II. In fact, after the months following the October 1995 roll out spent on integrating hardware and software, first-flight preparations proceeded faster, than expected.

When the first-flight plan was drawn up at the end of 1995, the company assumed that two weeks of tests would be required, following the completion of integration, to gain sufficient confidence. The first aircraft proved to work so well that the tests were completed within seven days, says Gary Riley, head of the C-130J flight and certification programme.

"We gave ourselves 13 days after stabilisation of the software and installation of the flight LRUs [line-replaceable units]," he says. The first aircraft was "so flawless" that intensive functional testing of the integrated systems were completed in two days, instead of three, engine runs in two days, instead of four, and high-speed taxi runs in just one day, rather than three days.

The 2h 11min first flight on 5 April "...did not push the envelope". The aircraft was flown to 10,500ft (3,500m), the landing gear cycled and the rear cargo-ramp lowered. The latter achievement, unusual for a first flight, clears use of the ramp for emergency egress on future flights.

The first-flight crew is enthusiastic about the responsiveness of the C-130J's digitally controlled Allison AE2100 turbo-props and Dowty six-blade propellers. "As you advance or retard the throttles, the thrust response is smooth, linear and instantaneous," says test pilot Lyle Schaefer. "The aircraft is light and, with 30% more installed power than a C-130H, seemed to leap off the runway," he adds.

The aircraft, the first of 25 stretched C-130J-30s for the Royal Air Force, was grounded following its first flight for the installation of composite flaps. The next flight will be of the first US Air Force standard-length C-130J, due on 30 April. Lockheed Martin hopes to have flown all five test aircraft, three RAF and two USAF versions, by July, says C-130J programme director Bill Mikolowsky.

US Federal Aviation Administration certification, has been pushed back some five months, by the first-flight delays and is now scheduled for May 1997. First deliveries will also be delayed and Lockheed Martin hopes to complete negotiations on new delivery dates by early May. RAF and USAF deliveries will be affected, but Riley believes that the first of 12 Royal Australian Air Force (RAAF) C-130J-30s can still be delivered close to schedule.

"We had a lot of integration problems, driven by the late delivery of equipment," Riley admits. "We can't do total weapon-system integration until all the supplier equipment is available."

Mikolowsky says that the problem was "...enthusiastic, overly optimistic, suppliers. They ran into development problems and that impacted bringing the system together. Almost every supplier failed qualification testing, either vibration or EMI [electro-magnetic interference], or 1553 [databus] chip-set testing."

Lockheed Martin made a mistake Mikolowsky says, in allowing suppliers to make the first batch of production equipment before completing qualification testing. "Units arrived marked 'not flight-worthy' and we've spent the past year repairing failures," he says. The good news, he says, is that there have been virtually no equipment failures on the aircraft.

Despite the integration problems, the company has been able to maintain configuration control - critical for civil certification. "We have a very complete record of the hardware and software," says Riley, adding: "The flight-test configuration-management system has worked splendidly."

Although the engines, avionics and many systems are new, structurally the C-130J is almost unchanged from earlier Hercules. This has added to the configuration-management task "...the painful job of cleaning up a quarter century of things not always done by the numbers." There are 11 parts on the first aircraft, some of them dating from 1957, "...for which we can find no installation-approval paperwork in the system," Riley admits.

All major certification issues are now resolved, says Mikolowsky. Special conditions will cover certification of the Flight Dynamics head-up display (HUD) as the primary flight-instrument, and the automatic thrust-control system. The latter, in the event of an outboard-engine failure, throttles back the opposite outboard engine to minimise asymmetry.

The HUDs have been installed in Lockheed Martin's C-130J development simulator and will be on the flight test aircraft by early June, after which all flying will be performed with the HUDs as the primary displays. To safeguard availability of the head-down displays, Lockheed Martin has placed a second company under contract to produce the large-format, liquid crystal, displays.

Riley sees few reasons for further delays to the certification effort: "With software, when it's together and doing what it's supposed to do, it stays that way," he says. That should be good news for the RAF and RAAF, which, in Riley's own words, "...are placing tremendous reliance on Lockheed Martin getting certification".

Source: Flight International