10
$\begingroup$

In my company we have a problem that we cannot understand completely, because we cannot find the answer.

  1. If I don't have the runway in sight at the circle minimum (MDA) on an ILS approach, I must immediately execute a missed approach or can I level off and maintain the circle minimum (MDA) and continue inbound until reach the MAPt by DME or timing block (don't have DME) and missed approach?

  2. If a RVR is published in the chart, normally it is RVR at MAPt right? For ILS (precision approach) it is clear that MAP is at the DA. LOC (Non-precision approach) uses MDA at MAPt by DME or timing but for circling where is a MAPt? Use same Non-precision or use circle minimum (MDA) on glide?

  3. If we fly ILS for circling, is it a precision or non precision approach?

$\endgroup$
10
$\begingroup$

Circling approaches are non-precision, regardless of how you arrive at the MDA. When circling you'll level off at the circling MDA and use the missed approach point depicted for the approach.

If you are looking at a Jeppesen approach plate there should be a level-off and 'M' depicted in the profile view. If you are looking at government plates the level-off and MAP are not depicted in the profile view but are still specified elsewhere. In any case, you'll fly the localizer to the MAP and then go missed. You'll descend either via the GS or step down altitudes to the circling MDA and stay there until either the MAP or you are able to further descend.

RVR probably won't be listed for circling minimums (it isn't published for the chart as a whole) as they will generally be at least 1 mile or more. Whether the visibility requirement is specified in feet (RVR) or miles, this is the visibility you need to descend out of the circling MDA. You have the further restriction that you may not descend out of MDA until you are in a position to land. The same familiar rules in 91.175 still apply.

In summary, fly the approach like you normally would but level off at the non-precision circling MDA and go missed at the non-precision MAP if you have no visual contact with the runway. You do not go missed exactly upon reaching the MDA, just as you wouldn't if you were flying a VOR or LOC approach. You go missed at the missed approach point.

enter image description here

$\endgroup$
  • $\begingroup$ Thanks you Casey Now I can understand completely, as you mentioned. But many people in my company does not believe that it is correct. They ask me for more references. Sir, please help me!! Where I can find more references ? to make them believe that your answer is correct. $\endgroup$ – Poro Sripaew Oct 22 '15 at 6:23
  • $\begingroup$ @PoroSripaew if your coworkers don't understand the non-precision procedures represented by the e.g. S-LOC and Circling procedures in the above plate, I'd turn this around on them. Get them to motivate their positions and refer them to the FSDO for a written interpretation if they aren't satisfied. $\endgroup$ – casey Oct 22 '15 at 16:10
  • $\begingroup$ See FAA Instrument Flying Handbook 2012, especially pages 10-20 and 10-21 for some references. Available here link $\endgroup$ – Ugo Oct 31 '15 at 10:05
  • $\begingroup$ @PoroSripaew And if you are flying in areas where procedures are not designed using US-TERPS but instead use ICAO PANS-OPS, refer to ICAO Flight Procedures (DOC 8168) - Arrival and Approach Procedures. In particular Section 7 - Visual Manoeuvring (circling) area. $\endgroup$ – Ugo Oct 31 '15 at 10:23

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.