6
$\begingroup$

The FAA IFR Landing Minima Chart has both ceiling and visibility minima regardless of approach type (straight-in or circling). I believe it means that a pilot should meet the both ceiling and visibility minima although he conducts straight-in approach procedure.

But in my country (not USA, we follow ICAO regulations), landing minima for straight-in approach procedure consists of only 'visibility'.

So I guess there is difference on landing minima between ICAO and FAA. But I couldn't find that information.

$\endgroup$
  • $\begingroup$ Could you provide an example of an airport in your country with such an approach? $\endgroup$ – J Walters Jan 23 '16 at 14:51
  • $\begingroup$ I live in Korea and I refer Incheon international airport(RKSI) approach procedure. But i don't know how to attach it. Sorry $\endgroup$ – user12972 Jan 23 '16 at 15:42
7
$\begingroup$

In most cases, FAA approach charts do not provide a requirement for a ceiling as you say, but rather provide the minimum altitude that a pilot may descend to without having the runway environment in sight (the DH/MDA) and the minimum required visibility.1

In fact, as described in the FAA Instrument Procedures Handbook, Page 4-7 and in the AIM, section 5-4-20(e), air carrier pilots, who are restricted from even beginning an approach if the reported weather is below minimums, are only restricted by the visibility and may fly the approach when the reported ceiling is lower than the minimum altitude on the approach plate (note that this does not apply to Part 91 operations).

The main reason for this is that a ceiling does not necessarily cover 100% of the sky over the airport environment, and it is quite possible to see the runway even when there is a reported ceiling.


References

FAA Instrument Procedures Handbook, Page 4-7 says:

14 CFR Part 135, section 135.225 states that pilots may not begin an instrument approach unless the latest weather report indicates that the weather conditions are at or above the authorized IFR landing minimums for that procedure. 14 CFR Part 135, section 135.225 provides relief from this rule if the aircraft has already passed the final approach fix (FAF) when the weather report is received. It should be noted that the controlling factor for determining whether or not the aircraft can proceed is reported visibility. RVR, if available, is the controlling visibility report for determining that the requirements of this section are met. The runway visibility value (RVV), reported in statute miles (SM), takes precedent over prevailing visibility. There is no required timeframe for receiving current weather prior to initiating the approach.

AIM, section 5-4-20(e) says:

e. Published Approach Minimums. Approach minimums are published for different aircraft categories and consist of a minimum altitude (DA, DH, MDA) and required visibility. These minimums are determined by applying the appropriate TERPS criteria. When a fix is incorporated in a nonprecision final segment, two sets of minimums may be published: one for the pilot that is able to identify the fix, and a second for the pilot that cannot. Two sets of minimums may also be published when a second altimeter source is used in the procedure. When a nonprecision procedure incorporates both a stepdown fix in the final segment and a second altimeter source, two sets of minimums are published to account for the stepdown fix and a note addresses minimums for the second altimeter source.


Notes

1 Under relatively rare conditions, TERPS specifies that a ceiling is required for a specific approach, but this will be notated on the approach chart with the words CEILING REQUIRED.

| improve this answer | |
$\endgroup$
  • $\begingroup$ As you can find the FAA chart via googling with the Key word "FAA approach minima", There is both ceiling and visibility minoma. $\endgroup$ – user12972 Jan 23 '16 at 16:07
  • 3
    $\begingroup$ @user12972 There is no ceiling minimum, only the minimum altitude to which you may descend. $\endgroup$ – Lnafziger Jan 23 '16 at 16:28
3
$\begingroup$

The other two answers are good ones & correct as far as they go, although I don't think either entirely addresses the question as posted regarding when a pilot has to have both ceiling and vis, or vis only, and the differences between ICAO and FAA criteria.

All approaches will have PUBLISHED both a ceiling and a visibility minimum. Whether you're required to have both of those in order to begin the approach is a separate question. (Or, in some cases, you don't have to have either one -- FAR Part 91 for instance. Under those rules, you can start the approach having neither one. Maybe you're just flying the approach in order to practice the missed approach, and you're okay with the fact that you almost certainly won't be able to land out of it.)

For circling approaches, every authority I'm aware of that requires having minimum weather in order to begin the approach, requires that you must have both ceiling and vis. For straight-in approaches, some authorities require that you must have both, and other require only the published visibility. In FAA rules, flying a straight-in "Vis Only" is generally allowed; some operators (such as the Air Force's Air Training Command, now the Air Education and Training Command, at least when I went through pilot training) require that their pilots have both in order to begin the approach. Major airlines typically have approval to fly straight-in approaches "Vis only."

The idea is, don't start an approach unless there's a good probability that you can land out of it. (Part 91, as described above, is less restrictive here.)

My understanding is that ICAO does the same thing, in that under ICAO rules generally, straight-in approaches may be flown "Vis Only" and the ceiling disregarded for exactly the reason that LNafzinger mentions -- the reported ceiling may not be perfectly uniform and you may well be able to see the necessary runway/lights/environment at your Decision Altitude even though you're somewhat above the published ceiling value. Some nations may choose a more limiting rule that requires both ceiling and vis -- I think at least one nation in the Caribbean does so, although I don't remember which.

Okay, follow-up question: why publish a ceiling if operators are free to ignore it? Answer: besides those operators who choose to require it, it's also used when considering the requirements for alternates and when an alternate qualifies. Those rules have conditions like "if the ceiling is lower than XXX above the lowest authorized approach's minimum ceiling and/or the visibility is lower than YYY above the lowest authorized approach's minimum visibility, then..." Rules like that can only work when the ILS and PAR approaches have the published ceiling values as Jonathan Walters posted.

| improve this answer | |
$\endgroup$
  • 2
    $\begingroup$ So while I agree with much of your answer, approach plates for the US (falling under FAA rules, whether government or Jeppesen) do not publish a ceiling minimum. Take a look at the charts, nowhere does it say ceiling. It simply shows the minimum altitude to which you may descend on the approach. $\endgroup$ – Lnafziger Jan 23 '16 at 18:04
  • 2
    $\begingroup$ Also, I am not aware of an FAA requirement for a minimum ceiling in order to perform a circling approach. Do you have a reference for that? $\endgroup$ – Lnafziger Jan 23 '16 at 18:05
  • $\begingroup$ You've answered that authority can choose wether they require ceiling or not. But as you can see the FAA standard minima table(which explain what figures mean) There is both vis and ceiling so i believe that the aiport which follows FAA regulation, they require both. And I have failed to find the ICAO standard minima table(which explain what figures mean), and the airport which follows ICAO regulation doesn't require Ceiling minima as far as i know. $\endgroup$ – user12972 Jan 23 '16 at 18:57
  • 1
    $\begingroup$ One last thing, your last paragraph quotes the regulations incorrectly. They do not refer to the "lowest authorized approach's minimum ceiling and/or the visibility..." Instead, to calculate the required ceiling they say things like "Add XXX ft to MDA(H) or DA(H), as applicable" (quoted directly from Ops Spec C055). This is because the chart does not specify a ceiling. :) $\endgroup$ – Lnafziger Jan 23 '16 at 23:03

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.