Can you disarm a solar’s Flying Sword?

Question

In 5e D&D, the solar has the ability to release its sword and control it remotely. The description of its Flying Sword action says:

Flying Sword. The solar releases its greatsword to hover magically in an unoccupied space within 5 feet of it. If the solar can see the sword, the solar can mentally command it as a bonus action to fly up to 50 feet and either make one attack against a target or return to the solar's hands. If the hovering sword is targeted by any effect, the solar is considered to be holding it. The hovering sword falls if the solar dies.

What would happen if you attempted to use something like the Battle Master fighter’s Disarming Attack maneuver? I could potentially see a problem in that, for Disarming Attack, the target would be the solar, not the sword.

Answer 1

Not with Disarming Attack

Rules as written, Disarming Attack requires you to hit a creature, then it forces the creature to drop an item it is holding:

Disarming Attack. When you hit a creature with a weapon attack, you can expend one superiority die to attempt to disarm the target, forcing it to drop one item of your choice that it's holding.

The solar which released its sword isn't actually holding it, however, the trait description says that

If the hovering sword is targeted by any effect, the solar is considered to be holding it.

So it would work, if you did target the sword. Unfortunately, according to the feature description, you have to target the solar instead.

You can try another way

The trait description requires the solar to see the sword in order to control it:

If the solar can see the sword, the solar can mentally command it as a bonus action to fly up to 50 feet and either make one attack against a target or return to the solar's hands.

So, if you manage to blind the solar, which released its sword, it loses control on the sword, hence, becomes disarmed. Something like darkness spell should help. (Or an ordinary physical obstacle. Throw your sleeping furs on top of the sword. Thanks @Tommi for the idea)

Answer 2

As RAW....No

According to (DMG p.271), there is an officially suggested contest for disarm attempts (though, to be clear, it is still an optional rule/action that may or may not be present in any given DM's game):

Disarm A creature can use a weapon attack to knock a weapon or another item from a target's grasp. The attacker makes an attack roll contested by the target's Strength (Athletics) check or Dexterity (Acrobatics) check. If the attacker wins the contest, the attack causes no damage or other ill effect, but the defender drops the item.

The attacker has disadvantage on its attack roll if the target is holding the item with two or more hands. The target has advantage on its ability check if it is larger than the attacking creature, or disadvantage if it is smaller.

However since this usually relies on the creature holding onto the weapon with its hands I feel that there is no official RAW for this. Thus if you are playing truly to RAW then No, you cannot

As Homebrew....Maybe

We are now entering the realm of opinion here. If this is something that you wish to do. I would personally look at maybe allowing the Solar to make a Spell Casting Save in order to control the sword. However the questions to consider here are:

• Based on the Solar's Stats compared to the Party, can it fail?
• Do you consider the Sword to be part of the Solar or a separate object?

I unfortunately cannot answer this part for you.