depends on the airfield layout. at the airport i'm at right now, there is no way to get into the critical area without first getting an ATC clearance into the movement area and thus getting into the critical area. it's up to ATC to know the weather and issue an instruction to keep a vehicle out of the area. it's not the vehicle operators responsibility to know the official weather and when u have an aircraft inside the OM.So, assuming the WX is such that the ILS markers need to be observed, would crossing into one without clearance by ATC be considered an incursion? Or just a case of a plane/vehicle not being where it's supposed to?
u only need to protect it inside the OM (or fix used in lieu of the OM) when the weather is less than 800 or 2. u also protect the area regardless of the weather if an aircraft is doing a Cat III ILS, autoland, or coupled approach.
that's all i remember off the top of my head.
that is correct. no vehicles/airplanes/etc inside the ILS critical area when an aircraft is within the OM (or fix used in lieu of the OM) and the criteria is met.Not quite sure what you mean by "protect it", but what I'm thinking you meant was keep the area sterile or not have any aircraft or vehicles past the ILS hold short line while an aircraft is on the approach inside the OM.
our regulations don't call for a Cat II ILS to be protected. just a Cat III, autoland, or coupled approach regardless of weather. when the weather is below ceiling 800 and/or visibility below 2 miles then you protect ALL ILS approaches.Practice approaches for Cat II & III will also need the ILS area open. If a vehicle or aircraft gets in the way, we (pilots) have to write the approach up as Unsat.
3-7-5. PRECISION APPROACH CRITICAL AREA
a. ILS critical area dimensions are described in FAAO 6750.16, Siting Criteria for Instrument Landing Systems. Aircraft and vehicle access to the ILS/MLS critical area must be controlled to ensure the integrity of ILS/MLS course signals whenever conditions are less than reported ceiling 800 feet or visibility less than 2 miles. Do not authorize vehicles/aircraft to operate in or over the critical area, except as specified in subpara a1, whenever an arriving aircraft is inside the ILS outer marker (OM) or the fix used in lieu of the OM unless the arriving aircraft has reported the runway in sight or is circling to land on another runway.
HOLD SHORT OF (runway) ILS/MLS CRITICAL AREA.
1. LOCALIZER CRITICAL AREA
(a) Do not authorize vehicle or aircraft operations in or over the area when an arriving aircraft is inside the ILS OM or the fix used in lieu of the OM when conditions are less than reported ceiling 800 feet or visibility less than 2 miles, except:
(1) A preceding arriving aircraft on the same or another runway that passes over or through the area while landing or exiting the runway.
(2) A preceding departing aircraft or missed approach on the same or another runway that passes through or over the area.
(b) In addition to subpara a1(a), do not authorize vehicles or aircraft operations in or over the area when an arriving aircraft is inside the middle marker when conditions are less than reported ceiling 200 feet or RVR 2,000 feet.
2. GLIDESLOPE CRITICAL AREA. Do not authorize vehicles or aircraft operations in or over the area when an arriving aircraft is inside the ILS OM or the fix used in lieu of the OM unless the arriving aircraft has reported the runway in sight or is circling to land on another runway when conditions are less than reported ceiling 800 feet or visibility less than 2 miles.
b. Air carriers commonly conduct ?coupled? or ?autoland? operations to satisfy maintenance, training, or reliability program requirements. Promptly issue an advisory if the critical area will not be protected when an arriving aircraft advises that a ?coupled,? ?CATIII,? ?autoland,? or similar type approach will be conducted and the weather is reported ceiling of 800 feet or more, and the visibility is 2 miles or more.
ILS/MLS CRITICAL AREA NOT PROTECTED.
c. The Department of Defense (DOD) is authorized to define criteria for protection of precision approach critical areas at military controlled airports. This protection is provided to all aircraft operating at that military controlled airport. Waiver authority for DOD precision approach critical area criteria rests with the appropriate military authority.
Signs and markings are installed by the airport operator to define the ILS/MLS critical area. No point along the longitudinal axis of the aircraft is permitted past the hold line for holding purposes. The operator is responsible to properly position the aircraft, vehicle, or equipment at the appropriate hold line/sign or designated point. The requirements in para 3-1-12, Visually Scanning Runways, remain valid as appropriate.
AC150/5340-1, Standards for Airport Markings.
so are you saying that "coupled" is ALWAYS a Cat II ILS? a Cat II ILS describes the ILS equipment, not whatever is going on in the cockpit. Is this correct?Coupled is Cat II as well. When I tell approach we are doing a "coupled approach" that means we are doing a Cat II. (My airline is only certified to Cat II mins)
Coupled means we will be keeping the aircraft autopilot on and coupled to the flight director which is recieving input from the loc and gs. For Cat II ops, we will be using the AP all the way down to 80ft above the runway.
i see what your saying. i guess it's just different on our end. our rules don't take into account everything you guys are doing in the cockpit. unless you say a few magic words, like "coupled" or "autoland" then our response is the same on a Cat II ILS. which is basically business as normal.At my airline (Pinnacle) coupled will always mean Cat II. Other airlines, it may mean Cat II or III depending on the aircraft and crew qualifications.
For example, the weather is clear but the aircraft needs a Cat II approach flown to maintain its currency, I'll tell approach that we are doing a "coupled approach". They will pass that on to tower and hopefully the ILS Crit area will remain clear so the Cat II approach can be completed successfully. There is a whole laundry list of things that need to be complied with in order for the test approach to be considered SAT.
For a Cat II approach we are doing things differently in the cockpit. The ILS is the same, our procedures are different. The normal Cat I approach is flown to wx mins of 200 & 1/2. Cat II allows us to go down to 1200rvr with an indefinite ceiling, this changes how we fly the approach and what we are doing in the cockpit.
In the real world when the wx is at mins on a Cat II or III coupled approach, we have mere seconds to decide to land or not IF we see the runway vs. a Cat 1 appch where we break out at 200ft agl and have 10-15 seconds to see the runway and land.
Clear as mud?