I understand the puropse of the ILS critical area. But I have never operated at an airport having an ILS critical area. So I do not know when pilots hold outside the critical area but not at the RWY holding position marking.

Do pilots always hold behind ILS holding position marking?

Otherwise, pilots hold behind RWY holding marking and with a particular ATC instruction pilots hold behind ILS holding making?

If so, how will a controller instruct the pilots? I want to know controller’s comments.

enter image description here

enter image description here


2 Answers 2


In the US (and you're looking at an FAA manual, so that implies US rules), this is covered in JO 7110.65, the FAA order covering air traffic control procedures. Flip to page 135 of that PDF (note that the linked version is not yet the currently effective version) for Section 3-7-5:

3−7−5. PRECISION APPROACH CRITICALAREA a.ILS critical area dimensions are described in FAA Order 6750.16, Siting Criteria for Instrument Landing Systems. Aircraft and vehicle access to the ILS critical area must be controlled to ensure the integrity of ILS course signals whenever the official weather observation is a ceiling of less than 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.


It goes on from there to describe further details, including instructions on when to keep the critical area clear and instructions to warn aircraft conducting autoland approaches if the critical area will not be protected.

In short, pilots hold short of the critical area if they're instructed to do so, and controllers tell pilots to do that by simply saying "HOLD SHORT OF (runway) ILS CRITICAL AREA."

  • $\begingroup$ Really appreciate, sir. It is a clear answer and did let me know where I should find if i have further questions. $\endgroup$
    – Hyuk Kim
    Jul 12, 2019 at 15:30

The reason behind this: The radio signals from the ILS (mainly localizer) are slightly disturbed by anything conductive. And this gets more, the closer the aircraft is to the runway. When ILS is for precision approaches this can be too much to accept - so the airplanes will have to hold short a little more off the runway - which is the ILS critical hold...

  • 2
    $\begingroup$ This answer gives the reason for the critical area which seems to be clear to the OP. The question is looking for the procedure including phraseology. $\endgroup$
    – DeltaLima
    Jul 12, 2019 at 8:17
  • $\begingroup$ Thank you, sir for the detailed meaning of the term! $\endgroup$
    – Hyuk Kim
    Jul 12, 2019 at 15:28

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .