In this answer to the question of why zero-visibility landings are legal and routine but not zero-visibility takeoffs, the poster makes the following point:

When an aircraft lands in near zero visibility, it is a fully automated process that is actually done without input from the pilot. The pilots are only needed to taxi off the runway and park the aircraft. It is called "Autoland" and many of today's aircraft have it.

As of today no manufacturer has designed an aircraft with "Auto Takeoff" but I suppose it is not impossible.

(Emphasis added.)

Which seems odd, given that autolanding with an ILS is a mature technique using mature technology, and autotakeoffing with an ITS (instrument takeoff system) wouldn’t need much more on top of that (just some additional antennae on the aircraft’s tail and a couple new routines for the autopilot) - it’d mostly be pretty much an ILS running in reverse, something like this:

possible instrument takeoff system

What’s the dealbreaker for an autotakeoff-supporting instrument takeoff system?

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    $\begingroup$ A failure, like a tire blowing or engine fire requires pilot intervention immediately. It would be better if the pilot as at the controls when it happened rather than having to disengage the automatic systems and play "catch up" with flying the plane. I'm sure this will get there at some point, but right now it's just better to have your hands on the controls and mind in the game during this critical phase. $\endgroup$
    – Ron Beyer
    Commented Feb 20, 2019 at 5:01
  • $\begingroup$ @RonBeyer: Couldn't an autopilot be programmed to react to a failure like an flaming engine or exploding tyre, and do so more quickly than a human pilot could ever hope to do (like how we already have autospeedbrakedeployment for rejected takeoffs)? $\endgroup$
    – Vikki
    Commented Feb 20, 2019 at 5:06

2 Answers 2


Autoland exists at least in part because a pilot can't safely hit (the right part of) the runway (at the right speed and attitude) without visual references, so a lot of precision electronic guidance equipment is needed, and then even more equipment to ensure the first equipment is working correctly.

In contrast, the sky is much bigger than the runway. It's comparatively easy for the pilot to hit the sky even without visual references (provided vis is good enough to taxi out). So none of that fancy stuff is necessary.

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    $\begingroup$ the sky is much bigger than the runway [citation needed] $\endgroup$
    – Sanchises
    Commented Feb 20, 2019 at 7:53
  • 2
    $\begingroup$ @Sanchises: I can vouch. My window is currently full of sky, and if there is any runway out there I cannot see it. Also, Google Sky vs. Google Runway. $\endgroup$
    – dotancohen
    Commented Feb 20, 2019 at 12:50
  • $\begingroup$ @dotancohen - Clever. Real clever. Highlight of the weekend. $\endgroup$
    – nodapic
    Commented Feb 23, 2019 at 21:59

You don't need the radar altimeter / reverse glide slope system, at all. The energy management required and the trimming are not easy and are in fact unsafe (you need to keep climbing at the best climb rate, in case of say birds). All you need is lateral guidance. Once you are wheels off, you are wheels off, continue the climb via the SID, for example, and be on your way (IFR flying).

Auto land category III B requires a minimum RVR (runway visual range) of 50/75-200 m (depending on the jurisdiction).

What if I told you LVTO (low visibility take-off) is a thing, and can go as low as 75 m RVR – as good as many CAT III B installations.

Here's a nice table from ICAO's Doc 9365 (Manual of All-Weather Operations):

enter image description here

Same as auto land, if you (the carrier and crew) and the plane are certified and current, and the right airport equipment (e.g., RVR transmissometers, runway lights, etc.) and procedures exist, you're good to go – only difference is that it'll be manual flying.

For the lateral guidance, localizers (or GLS) are in fact used for LVTO. (See: How does a HUD track a runway?)

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    $\begingroup$ The RVR/VIS numbers are a bit surprising. Usually the RVR and visibility are equal (300m ≅ 1,000ft, 150m ≅ 500ft) or almost so (500m ≅ 1,640ft, 400m ≅ 1300ft, 200m ≅ 660ft, 125m ≅ 410ft) with the visibility even rounded down, but for the lowest case the visibility is more as 300ft ≅ 90m. $\endgroup$
    – Jan Hudec
    Commented Feb 20, 2019 at 6:34
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    $\begingroup$ Good observation @JanHudec - see here: aviation.stackexchange.com/q/30476/14897 $\endgroup$
    – user14897
    Commented Feb 20, 2019 at 6:52

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