Is there any piece of equipment, on board, to assist the crew to identify and avoid clear air turbulence (CAT)?

  • 9
    $\begingroup$ Ahh. The holy grail. Following a huge amount of research over the years, LIDAR seems to be the most promising. See this article from Wired. Realistically, the best piece of equipment today is the VHF comm radio where the poor guy flying through it reports it to ATC and it gets passed to you. $\endgroup$
    – Gerry
    Sep 21, 2017 at 16:26
  • $\begingroup$ Not in terms of sensor equipment. Weather charts obtained prior too flight identify areas of possible CAT. Usually, this data is not accurate enough to make changes to planned altitude/route prior to flight, but at least it increases awareness of what to expect. In flight, pilot reports from other aircraft, relayed by ATC, aid in selecting/changing altitude to an altitude where no turbulence, or less turbulence is expected. $\endgroup$
    – Waked
    Sep 21, 2017 at 16:29
  • $\begingroup$ I think there are experiments with airborne lidar goig on (e.g. DELICAT), else Lidar is used from the ground as CAT contains no water vapor, thus is not detectable using radar wavelengths. See: How does radar detect turbulence and wind speed? $\endgroup$
    – mins
    Sep 21, 2017 at 17:44
  • 3
    $\begingroup$ Possible duplicate of How do pilots foresee turbulence? $\endgroup$
    – Pondlife
    Sep 21, 2017 at 18:57
  • 1
    $\begingroup$ I have asked about CAT, not turbulence. $\endgroup$ Sep 21, 2017 at 22:00

1 Answer 1


Not on board the aircraft as of yet, no (unless, as @Gerry said, you count the radio that lets you hear about the person ahead of you running into CAT).

There are ways of detecting CAT, however, which could become standard aircraft equipment in the future. LIDAR is one possibility, as both @Gerry and @mins mentioned; see also here and here. Interestingly, the idea of using LIDAR to detect clear-air turbulence has been around since at least the late 60s, but, when it was first proposed, they couldn't get the sensitivity high enough; later, when this obstacle was overcome, they faced a different problem, which was that the equipment required was far too heavy, bulky, and power-hungry to be practical, which remained the case until very recently. N-slit interferometry can also be used to detect clear-air turbulence (see here, for instance), and an interferometric (I think; the patent description is remarkable in its unintelligibility) CAT detector was patented in 1978, but the equipment required is far too large to fit on an aircraft; as a result, most work with interferometric CAT detection seems to have been in the area of developing a ground-based clear-air turbulence detector that could monitor runway approaches for dangerous CAT.


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