VISSIM, the UK’s leading military air traffic control training facility at RAF Shawbury in Shropshire has undergone several upgrades since the virtual ATC Tower was set up in 1991.
Military simulation and aviation specialists CAE recently completed their third upgrade of the Central Air Traffic Control School (CATCS) simulator — having won the original competitive bid — and each time they have chosen mission-specific projectors from the catalogue of Christie (formerly Electrohome).
As Flt Lt Dave Harvey, in charge of the base’s VISSIM facility, explained, “There was a requirement for upgrading the projectors, based on feedback received from the instructors. The next logical step after CRT projection was into DLP. We asked CAE to investigate and come up with a solution, and they recommended Christie’s Matrix 2000.”
Fed from five Evans & Sutherland simFUSION image generators, it is not only the task of the five projectors to deliver realism to an unprecedented level but to minimise the downtime.
CAE specialises in providing powerful image generators, rapid database generation tools and optimised display systems, and each time they have upgraded the projection system over the last 15 years they have come closer to meeting those criteria, as CAE Project Manager David Hayes explains.
“Originally we specified the Electrohome ECP 4501 CRT projector and in January 1997 we upgraded — this time to the Marquee 8500; RAF Shawbury had been operating with that until now.”
“Although we are not tied to any particular company — and always recommend according to the appropriate project — it speaks volumes for Christie that we have been able to maintain continuity with them throughout.”
The remit in this instance was for a projection system offering high resolution and high brightness— but with equal regard for the life cycle costing. “In other words, we didn’t want a low-cost projector which would then incur enormous maintenance costs,” points out David Hayes. “This was one of the problems with CRT technology, which was bulky, requiring a two-man lift and then seven hours of recalibration time to correct picture drift when the CRTs had to be replaced.”
He adds that where they would once have needed to replace three tubes per projector, DLP technology reduces this to one simple lamp change. “It means we can get it up and running again during a 30-minute lunch break.” Furthermore, the projectors are being run in economy mode — while still providing sufficient brightness, this extends the lamp life to 4,000 hours, further improving the life cycle costs.
The opening of RAF Shawbury’s VISSIM back in 1991 had freed up the dependence on live aircraft — and associated fuel, pilots and engineering — and provided a guaranteed environment in which to operate.
Since then VISSIM has undergone several enhancements both in software and hardware at the hands of CAE, including a complete rehosting of the software from a mixed SGI/Digital/PC platform environment to a single PC platform environment. The software has also been maintained, having migrated from a mixed C and FORTRAN architectural style to a modern Object Orientated style of implementation.
Today, the simulation is visualised using five 2.7m wide by 2.16 m high projection screens creating a 210-degree panoramic Field-of-View of the airfield. Run in 5:4 aspect ratio, this provides topographic and static features such as runways, taxiways and buildings. The control environment simulates the movement of 3D aircraft and vehicles around the airfield and is able to display visual effects such as fire, explosions and smoke, as well as other emergency situations.
This is generated from CAE’s own 3D simulation database; different weather conditions and daylight settings (such as dusk and night-time scenarios) can be changed during simulation, the sense of realism augmented by the Dolby 3D sound, which was introduced five years ago. With 2000 lumens and SXGA+ resolution, the five compact Christie Matrix 2000’s are pole-mounted in the original positions vacated by the Marquees. With purpose-built simulation features such as RGB colour matching, the Matrix 2000 offers multiple control options and built-in networking with on-board ChristieNET.
Both Flt. Lt Harvey and Wing Cdr Jane Chalmers, the officer in command of the Training Centre, agree that the impressive clarity and brightness levels of the Matrix 2000’s — along with the fact that CAE have provided a digital solution — have proved fundamental to this upgrade. The integrators also carry out VISSIM healthchecks during the quarterly review meetings.
“There’s more realism in the system now — the new Christie projectors bring enhanced clarity and you can pick up more detail. For instance, thanks to the crispness of the display you can see that the wheels are polygon-shaped when taxiing in front of the tower — something you would not have noticed before.”
Designed for RAF and Royal Navy personnel, the training syllabus itself is presided over by Wing Cdr Chalmers, a former air traffic instructor, who has extended the length of the course to 132 days.
Up to 96 students pass through VISSIM each year during their 20 weeks course. The VISSIM stage of their course is spent alternating days working inside the simulator and receiving classroom lessons.
“Air Traffic Control training is about aptitude to do the job,” she explains. “There’s a minimum entry level required for students to start training, but from then on we make decisions whether they can move on to each successive stage of the training course.”
Although the basic training has changed little — and is entirely helicopter-based — RAF Shawbury also has to consider modern aircraft such as the Typhoon. “On top of that, we now have to conform to ESARRs European control safety regulation requirements, which means we have added seven days to the course,” says Wing Cdr Chalmers. In March 2005 they also added further days to give students more consolidation time.
With an 80% pass rate, students will qualify with a military license to control — moving to a standard airfield, where their training will continue on a more specific basis.
The final word comes from the Training Officer herself. “I needed a training tool that delivers, showed the detail and in particular was reliable — since I have no flexibility here and any downtime I experience makes life more difficult. What CAE have given us is an efficient training machine.”