Airline pilots can qualify on a new type without ever flying the aircraft, but how far can flight simulators go in training military pilots? Michael Gerzanics / Tampa, Florida

while the military has been at the forefront of technology in many areas, when it comes to synthetic flight training the civil sector has long been the leader. Using Level D full-flight simulators, airlines routinely train aircrew for revenue service without their ever having flown the aircraft.

Now the military is closing the gap, and commercial Level D simulator technology lies at the heart of training systems designed to support airlifters and other transport aircraft. To see how the technology is being applied to military aircrew training, Flight International evaluated the training system being developed by Lockheed Martin and CAE to support the the Italian air force's (IAF's) purchase of 22 C-130J Hercules transports.

The C-130J total training system (TTS) will be installed in the Italian air force's national training centre (NTC) at Pisa AB. Lockheed Martin broke ground for the NTC in September 2000, and the centre is scheduled to open next year. CAE's Military Simulation and Training division, formerly BAE Systems (and before that Reflectone), has developed the key components of the TTS, now undergoing testing at its Tampa, Florida, facility.

The C-130J TTS has four major elements: training management system, computer-based training curriculum, maintenance trainer and operational flight trainer. The training management information system (TMIS) uses a relational database to maintain each student's complete training history and flags overdue training requirements. Both training device and instructor availability are monitored to prevent scheduling conflicts. Simulator maintenance planning is facilitated by the overall view provided by the TMIS and should minimise the impact on daily training operations. The TMIS should help the Italian air force maximise use of its C-130J training assets.

Classic classroom instruction has been supplemented, and in some cases replaced, by computer-based training (CBT) sessions. A structured curriculum has been developed for maintenance personnel as well as pilots. Aircraft system and control panel animations are used to show the effect of various student actions. The pace of instruction is determined by the individual, allowing each student to master each lesson's content before moving on. These CBT simulations provide a near hands-on learning experience in the comfort of an academic training environment.

Getting hands on

The hands-on portion of the training is provided by two different devices, one for maintenance personnel and one for aircrew. Student maintainers use the cockpit avionics part-task trainer (CAPTT). This features a cockpit mockup with an instructor station, and is used to practise ground maintenance tasks such as fault isolation and analysis. The fixed-based device can simulate an aircraft chocked on the ground or raised up on jacks.

Additionally, the CAPTT can simulate the aircraft in flight at a steady airspeed and altitude. The device's open structure allows a group of students to observe as one of their number trains in the cockpit. The CAPTT uses the same 1553 databus, mission computers and software load as the real aircraft. While software emulations of real-world components are often used in training devices to reduce cost, they can introduce inaccuracies. Although undoubtedly more expensive, flightworthy components lend increased authenticity to the learning process.

The heart of the C-130J training system, at least from the pilot's perspective, is the operational flight trainer (OFT). Italy's lone OFT is a Level D-capable full-flight simulator. In the commercial world, Level D devices allow for the training and certification of aircrews with no actual aircraft experience. And while the C-130J OFT will not be certificated to a specific US or European civil training standard, CAE's extensive background in building Level D simulators should ensure certification could be obtained if desired.

Mounted on a six-axis motion system, the simulated flight-deck provides pilot, co-pilot and augmented crewmember stations, as well as an operator/instructor position. The Flight Safety Chroma View panoramic visual system provides a 200¼ horizontal by 40¼ vertical view of the outside world. Looking externally similar to any number of other large commercial aircraft simulators, the C-130J OFT was undergoing initial acceptance trials during Flight International's visit to Tampa, before breakdown and shipment to Pisa. After re-assembly at the NTC, on-site acceptance is slated for May.

The real thing

Having flown the C-130J a few years ago at Lockheed Martin Aeronautics' Marietta, Georgia, facility, I was keen to see how CAE's simulator would compare to the real thing. During a 2h simulator period I was able to evaluate a number of the OFT's capabilities. Normal operations, including take-off, instrument approaches and landings, seemed highly realistic. In general, the simulator felt like the aircraft. Fred Dorr, a Lockheed Martin senior test pilot, assured me the level of fidelity for routine tasks was quite good.

One event I could not accomplish in the real aircraft, due to safety constraints, was engine loss prior to lift-off. In the simulator, Dorr failed the number one engine just after reaching the V1 speed of 95kt (175km/h) for a 50¼ flap configuration. It took a rapid application of almost full right rudder to keep the aircraft pointed down the runway. The subsequent three-engine approach and landing in the simulator was much like the one I had performed in the aircraft, and required constantly changing amounts of rudder to maintain runway centreline on landing rollout.

Having obtained six different type ratings for commercial aircraft in Level Dsimulators, I am confident that within a proper training syllabus the C-130J OFT would allow for type certification of aircrew without actual aircraft experience.

The operations and instrument procedures required for a specific type rating, however, are only some of the tactical military aviator's skills. In-flight refuelling, air dropping and low-level flying are a few of the additional capabilities needed for combat employment. Some Italian C-130Js are equipped as air-to-air refuelling receivers and tankers. Receiving is accomplished via a probe-and-drogue system. The probe is mounted on the forward upper-left-hand side of the fuselage, its tip clearly visible from the pilot position.

During my flight, a simulated UK Royal Air Force BAC VC10 tanker was placed in an orbit not far from our departure point at Pisa's military airport. The tanker was established in a left-hand racetrack pattern at 10,000ft (3,050m) and 250kt. Rendezvous was easily accomplished using theC-130J's traffic alert and collision avoidance system, which displayed the tanker's altitude, distance and relative bearing. In the simulated daylight conditions I was able to make out details of the tanker aircraft when about 0.8km in trail. Closing to within 0.4km of the tanker, I began to feel wake turbulence from the VC10. Once stabilised I was able to maintain a close in-trail formation position with the tanker, but was unable to "spear" the drogue's basket during several attempts. This was not surprising as I had no previous experience in this type of air-to-air refuelling.

While generally good, I found the visual display's depth cues to be less than adequate for this demanding task. As I had not performed air-to-air refuelling in reality, it is hard to say whether simulation alone would be sufficient to obtain the desired level of proficiency. But I am confident that use of the OFT will measurably reduce the number of refuelling contacts required to achieve proficiency.

Perhaps the most remarkable aspect of the OFT is its presentation of the visual scene. The simulated airports and runways are accurate digital models. However, as with other simulators I have encountered, they tend to be textureless and generic in nature. Where CAE has raised the bar is its depiction of the terrain defined by the "mission region". This includes a large portion of northern Italy, around 96,000km2 (28,000nm2), centred on Pisa. Within this area are 11 rectangular landing/drop zone corridors and two irregularly shaped tactical zones covering about 8,560km2.

Using aerial photographs, a geospecific photo-texture was created and overlayed on terrain elevation data. The result is realistic digital depiction of northern Italy. Roads and features seen in the simulator represented real ones.

The scene is richly textured as each area is unique - gone is the numbing repetition found in so many simulated landscapes. Another benefit of this technique is that features, either geographic or cultural, blend into their surroundings as they do in the real world, and are not as unnaturally noticeable as a generic bridge over a generic river.

As can be imagined, the resulting visual database is quite memory intensive. Terrain resolution in the mission region is a minimum of 7m. In the tactical areas and circular regions around landing/drop zone corridors, it improves to 5m.

Where accurate visual sightings are required, drop zone corridors for example, resolution is 3m. Flying at 250ft and 300kt over the tactical area I found the terrain display to be a reasonable approximation of the view seen while flying low in areal aircraft. The visual display was noticeably more blurry as I flew into the lower-resolution mission region, but still adequate for navigation. Scenes in the landing/drop zone corridors were quite good, but not as good as actual terrain.

Only towns and forests, features with vertical development, lacked realism. They are displayed as cubic structures and are the only obviously digital features in an otherwise strikingly realistic terrain display. Low-level flying in the simulator was not unlike what I had experienced over Georgia in the actual aircraft. I found the visual display provided sufficient texture and depth cues to allow visual terrain- following to be conducted in daylight conditions.

The OFT's cockpit, as in the aircraft, is fully compatible with night-vision goggles (NVGs). The visual display is also NVG-compatible, but I was unable to evaluate this feature of the training system.

I found the basic ground-mapping mode of the simulated radar provided imagery consistent with the terrain depicted by the visual system, a useful feature when low flying at night or in reduced visibility. I did not, however, have an opportunity to evaluate the radar's Doppler beam-sharpened mapping mode, which provides enhanced resolution of significant targets.

Low flying also uncovered another weakness of simulators - their inability to emulate a sustained manoeuvre loading of greater or less than 1g. Aggressive defensive turns in reaction to threats may generate loadings of up to 3g for 10s of seconds. While not a serious deficiency, it does serve to illustrate that reality and virtual reality are two different things.

Virtually there

My exposure to Lockheed Martin's C-130J training system raised a number of points. The lack of a fixed-base avionics/systems trainer for aircrews is one possible shortcoming. Airlines have learned the value of performing systems familiarisation in lower-cost devices, freeing up the expensive full-flight machines for training tasks requiring the fidelity that motion and visual systems provide.

While training crews for only 22 aircraft may allow enough time for the Italian air force's OFT to be used for fixed-based training tasks, if it breaks, things may back up rapidly.

There can be no doubt that the majority, of basic aircraft handling and instrument flight training can be accomplished in the Level D-capable OFT. But while basic tactical skills and procedures may be introduced and practised in the OFT, I feel actual aircraft experience will be necessary to field a combat-ready aircrew.

That said, the Italian air force's NTC represents a significant step forward in cost- effective military training. Flight simulators have become more and more capable, but not yet enough to prevent us from having to slip the bonds of earth from time to time.

Source: Flight International