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While reading the question Why couldn't the CRJ100/200 be equipped with triple-string autoland? I thought the CRJ cannot have autoland because it is not equipped with autothrottles. Somehow I always thought this would be a requirement. However, after doing some research I found that this is not the case:

(a) An automatic landing system must include automatic control of throttles to touchdown unless it can be shown that:

  1. Aeroplane speed can be controlled manually without an excessive workload in conditions for which the system is to be certificated;
  2. With manual control of throttles the touchdown performance limits of CS-AWO 131(c) are achieved; and
  3. The touchdown performance is not critically affected by reasonable errors in speed control.

(EASA Easy Access Rules for All Weather Operations (CS-AWO) 123 Automatic throttle control)

This made me wonder: Is there any aircraft that does not have autothrottles or autothrust, which is certified for autoland?

Note that by autoland, I mean a proper Cat II/III ILS autoland, not something like the Garmin Autoland for GA aircraft.

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    $\begingroup$ You mean a system where the crew has to work the power while the airplane lands itself? $\endgroup$
    – John K
    Commented Sep 25, 2020 at 13:21
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    $\begingroup$ @JohnK Yes. According to the above quote from EASA, such a system should be legal. I'm just not sure if it has ever been done. All aircraft with autoland I know of, also have an autothrottle (or autothrust for Airbus). $\endgroup$
    – Bianfable
    Commented Sep 25, 2020 at 13:30
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    $\begingroup$ Never heard of that kind of system, but you'd think somebody would have done it. $\endgroup$
    – John K
    Commented Sep 25, 2020 at 14:56
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    $\begingroup$ @DJClayworth In general, yes, because it is safer. But not during an autoland: the A/P will use pitch to maintain the glideslope and the A/T will target the approach speed (usually Vref + 5kt). $\endgroup$
    – Bianfable
    Commented Sep 25, 2020 at 16:55
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    $\begingroup$ @DJClayworth On an ILS you don't fly the "normal" way. Because the priority is to maintain a precise slope, you "pitch to path", following up with trim and thrust changes to maintain speed.If the autopilot is doing it, the autopilot is pitching to path and trimming. On an ILS with AP on down to minimums, you just sit there making small thrust tweaks to maintain reference speed with the control column dancing in front of you.If you had an autoland system with manual thrust control, you would need a thrust reduction cue of some kind to tell you to ease off the power as autoland starts to flare. $\endgroup$
    – John K
    Commented Sep 25, 2020 at 19:17

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I'll try to answer, even if it may not be the answer you expect.

To directly answer your question, yes, there are (were) aircraft with autoland system and no autothrottle. Hawker Siddeley Trident 1 is one example: it was the first aircraft to perform autoland (and subsequent versions reached also CAT II) but with no autothrottle.

However, I do not think that the existence of these aircarft is the reason for the rule. Instead, this is probably to allow the use of autoland even if the auto throttle is not working. This is, for instance, the procedures when auto throttle is not functioning in the Minimum Equipment List (MEL) of an A350:

A350 MEL

As you can see, autoland is still available (LAND2) with limited capabilities (cannot land in CAT III). Thus, the regulation may be there to provide the conditions for the definition of MELs in case of autothrottle inoperative.

Side note: the same is impliticly stated in FAA AC 120-118, where auto throttle is required only for CAT III autoland.

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