Does having lead-in lights in-site during an approach that includes them allow for a pilot to descend to 100 feet above the touchdown zone elevation? 14 CFR 91.175 allows a pilot to make such a descent if the approach light system is in-site, but does a lead-in light system qualify?

The approach also states the following:

When visual reference established, fly visual to airport via lead-in lights to Rwy 13L or 13R.


Also worth referencing here is this question about what counts as runway in sight, but this question is specific to lead-in lights and is not answered directly by that question.

  • 1
    $\begingroup$ Possible duplicate of What counts as "runway in sight" when flying an IFR approach to minimums? $\endgroup$
    – TomMcW
    Jul 9, 2018 at 4:34
  • 2
    $\begingroup$ I doubt this is a duplicate, the question essentially asks "Is the lead-in light system considered [a part of] the approach light system?" $\endgroup$
    – Steve V.
    Jul 9, 2018 at 4:40
  • $\begingroup$ This is not a duplicate. The question marked as the answer does not answer the question in reference to lead-in lights. This is a special situation. But I guess there's value in having the reference at the top. $\endgroup$
    – ryan1618
    Jul 11, 2018 at 15:42

2 Answers 2


No, you may not descend below MDA having only the lead-in lights in sight.

Reference FAA Order 6850.2b, "Visual Guidance Lighting Systems", page 1-3 through 1-5.

According to this order, the list of approach lighting systems is as follows:

  1. Medium Intensity Approach Lighting System (MALS).

  2. Medium Intensity Approach Lighting System with Sequenced Flashers (MALSF).

  3. Medium Intensity Approach Lighting System with Runway Alignment Indicator Lights (MALSR).

  4. Simplified Short Approach Lighting System with Runway Alignment Indicator Lights (SSALR).

  5. High Intensity ALS with Sequenced Flashers (ALSF-2).

  6. Omnidirectional Approach Lighting System (ODALS).

The Lead-In Light System is not in this list. Instead, it is found further down the page. Here's the key sentence:

The LDIN may be terminated at any approved approach lighting system, or it may be terminated at a distance from the threshold compatible with authorized visibility minimums permitting visual reference to the runway environment.

The LDIN is not an approach lighting system and so you may not use it to descend below MDA.

  • $\begingroup$ Given that the MAP is 3.6 NM to 13L or 2.6 NM to 13R and the minimums are 800/2nm for Cat A or B it stands to reason that you can continue from the MAP to the runway with only the LDIN in sight. You may not, however, descend below MDA until the runway is in sight. That is how I understand it. $\endgroup$
    – dawg
    Aug 29, 2019 at 1:52

According to the FAR-AIM, RLLS is one of the 9 types of approach light systems. It seems that this would allow you to descend to 100’ under 91.175 guidance.

  • 2
    $\begingroup$ I suspect that the other answer by Steve V. may be correct, but this post raises the valid point that the FAR-AIM lists RLLS alongside the other systems like ALSF-2 and MALSR and so on. If this analysis is wrong, let's find the explanation why, since S.E. policy is to downvote, rather than to delete, incorrect answers. This post was never about raising a new question (though making a point with a rhetorical question can come off as that). $\endgroup$
    – Ralph J
    May 22, 2019 at 3:43

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