The two thick solid lines on runways at 1,000 ft from the end of the threshold are called "fixed-distance markers" in some documentation, and in others, it is called the "touchdown zone marker".

Are they two different things, is one right and the other wrong, or are they truly interchangeable terms?

Airman Knowledge Testing Supplement for Instrument Rating, page 116 Example of "Fixed distance"

AIM 2-3-1 from FAA.gov Example of "Aiming point"

Both of these above examples are Precision Instrument Runways.

  • 1
    $\begingroup$ I understand the first down-vote because I submitted the question with an incomplete sentence, but why the second today? $\endgroup$ Apr 20, 2019 at 20:24

2 Answers 2


Fixed distance marker et al are old terms. The current official term is aiming point.

In ICAO standards the aiming point changes based on runway dimensions. In the US it is fixed at 1000 feet (hence the fixed in the name).

The US lists this difference from ICAO in its AIP (GEN 1.7). And defines it as 306 meters. The U.S. standard places the aiming point marking 306 meters from the threshold where it replaces one of the pair of three stripe threshold markings. The 306 meters location is used regardless of runway length.

You can find the older term 'fixed distance marker' in more results by searching Google Books. In one of them from the snippet view:

... runways also include runway threshold markings and aiming points (used be called fixed-distance markers...

Since the regulations no longer mention the older terms as pointed out by @JScarry, it can only mean that they forgot to update the training material you found.

(All emphasis mine.)

  • $\begingroup$ The standard in the USA is for the marks to begin 1020 feet from the threshold, if there is a runway intersection that would have aiming-marks overlap then the marks may be displaced, there is a standard for which runway gets displaced.(eg, least used or precise approach) They may also be displaced when the visual slope indicator is moved for reasons like adjusting threshold crossing height. $\endgroup$
    – Max Power
    Oct 21, 2020 at 4:53

First, let’s clear up some terminology. Touchdown zones are only on runways with precision approaches. Aiming Point Markings are at 1,000' in USA (ICAO standard is different and is runway length dependent) and are also on non-precsion and visual runways. If you fly a small GA airplane, you will often land in the first 1,000' using the Aiming Point as a guide. The markings are at a fixed distance (500') from each other so that’s probably why you have heard that term. I have most of the FAA publications and ACs on my computer and the only place that "fixed distance markers" is referenced is in the Chart Supplement for some runways that have non-standard distances for the markers, so I am curious as to where you have read that term. EDIT: Per the edited question, I changed my search to “fixed distance marker“ and found a half dozen references. All of them are in Knowledge Test questions and none in other FAA publications.

AIM 2−3−3. Runway Markings

e. Runway Touchdown Zone Markers. The touchdown zone markings identify the touchdown zone for landing operations and are coded to provide distance information in 500 feet (150m) increments. These markings consist of groups of one, two, and three rectangular bars symmetrically arranged in pairs about the runway centerline, as shown in FIG 2−3−1, Precision Instrument Runway Markings.

Precision Runway Markings

TOUCHDOWN ZONE− The first 3,000 feet of the runway beginning at the threshold. The area is used for determination of Touchdown Zone Elevation in the development of straight-in landing minimums for instrument approaches.

Visual and Non-Precision Runway Markings

  • $\begingroup$ The place I have found it is in the FAA Instrument Testing Supplement. I will add it to the question. $\endgroup$ Apr 19, 2019 at 22:26
  • $\begingroup$ @RyanMortensen I changed my search to "fixed distance marker", singular, and found it in several tests. (ATP, IRA, COM and CFI) but nowhere in the FAA publications. They are at a fixed distance (500') and I have referred to them as such, but apparently the FAA only uses that term on the tests. $\endgroup$
    – JScarry
    Apr 19, 2019 at 22:42
  • $\begingroup$ The test answer for it is 1,000 ft from the beginning of the runway threshold, but 500 ft between it and each TDZ marker. $\endgroup$ Apr 19, 2019 at 22:58
  • $\begingroup$ Aiming points are not required marks on non-precision runways below 4200ft with 3/4mile or greater visibility requirements, or any visual approach runways not serving CAT C&D aircraft and longer than 4200ft. FAA doc 5340-1m table 2-1 $\endgroup$
    – Max Power
    Oct 21, 2020 at 5:02

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