The ILS, the IRS and you

  • Published
  • By Tech. Sgt. Jason Funez
  • 48th Operations Support Squadron
ROYAL AIR FORCE LAKENHEATH, England --  The ILS, the IRS: what's the difference? The answer is known to aircrew, air traffic controllers and airfield technicians and managers who daily monitor and maintain our airport systems. However, pedestrians who drive, walk or work near the airfield should be equally as aware. So what do the Instrument Landing System and the IRS have in common?

The cliché nothing is certain but death and taxes goes hand in hand with landing an aircraft on a rainy, misty, English night. What goes up must come down; preferably along a precise approach path to land squarely on a concrete runway. The IRS is about degrees of taxes and hundreds of dollars, while the ILS is about a 3-degree precision approach in clouds just 200 feet high. No one appreciates the IRS until recession hits the economy; likewise, no one appreciates the ILS until the weather closes the runway.

The ILS is a navigation system which provides course and glide-path information to an aircraft on final approach. By following an ILS signal, without seeing the runway until almost touchdown, a pilot flies an aircraft to a safe landing. Like the under-appreciated IRS, the ILS is a vital system in the Liberty Team's arsenal; it sustains combat capability during adverse weather and remains essential to recovering billions of tax dollars worth of aircraft and our invaluable flight crews.

The ILS equipment emits a precise signal. The area or zone near that signal's source must be protected during inclement weather. This zone, known as the "ILS Critical Area," must be free of vehicles, equipment and personnel to ensure an uninterrupted signal is transmitted to approaching aircraft. This interference principle is similar to the announcement on-board a commercial aircraft requesting you turn off all electronic devices before take-off and landing. If a vehicle enters the ILS critical area while an aircraft is on final approach, the signal may be distorted and provide flawed guidance to the pilot. The potential for disaster is heightened, particularly during extreme weather conditions.

ILS Critical Areas are clearly marked with lines, lights, and signs. When the weather decreases to 800 feet ceilings or two miles visibility, the ILS Critical Area Protection Procedures are in effect. This prompts control tower personnel to switch the traffic lights from green to red indicating that personnel must not precede beyond the instrument hold lines without approval. Control tower personnel then grant or deny entry into and through the critical areas depending on the proximity of the next aircraft.

The success of this system is dependent on skilled aircrews, weather forecasters, airfield systems maintainers, control tower personnel, airfield management specialists, and last but not least, pedestrians who understand the ramifications of violating the ILS Critical Area; in short, YOU!

Initial airfield driver training is conducted by an organization's Unit Airfield Driving Program Manager. This training is specific to RAF Lakenheath and must be conducted regardless of previous airfield driving qualifications at other bases. Once initial training is successfully completed, the airfield driver is issued a license by 48th Operations Support Squadron airfield management. Annual refresher training is required and conducted via computer based training.

In short, the IRS and the ILS both work in degrees and 100's. An error that is off by hundreds of dollars in taxes causes an auditor visit. If an error is off by hundreds of feet in the ILS, the Grim Reaper may visit. So please be wary of the airfield environment and pay special attention to the signals, especially during inclement weather. Do not walk, drive or work in the vicinity of the airfield without understanding and adhering to the rules. The airfield is this wing's largest, most expensive and most protected asset, but that protection relies on you.

If you have questions, please contact your unit airfield driving program manager or RAF Lakenheath's Airfield Driving Program Manager, Tech. Sgt. Jason Funez, at 226-3687.