Question: Suppose I'm playing a character that has a flying speed (such as a [Variant (Winged) Tiefling](https://www.dndbeyond.com/races/tiefling#VariantTiefling) or an [Aarakocra](https://www.dndbeyond.com/races/aarakocra)) and get critically hit. The DM rolls on the [Lingering Injuries table](https://www.dndbeyond.com/sources/dmg/dungeon-masters-workshop#Injuries) and after rolling a 3 tells me I lose a leg. The table says (emphasis mine):

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> **Lose a Foot or Leg.** Your speed **on foot** is halved, and you must use a cane or crutch to move unless you have a peg leg or other prosthesis. **You fall prone after using the Dash action.** You have disadvantage on Dexterity checks made to balance. Magic such as the regenerate spell can restore the lost appendage.
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If I'm using my flying movement, I know from reading this that my speed isn't reduced (I'm not walking with my feet, I'm flying with my wings). But reading this seems to imply that if I Dash while flying, I still fall prone (and arguably am in worse trouble than if I were trying to run on foot). Is that the case, or am I missing something here?

Answer: 
The rules simply didn't take the flying case into account. You'll notice there is no reference in any of the entries in the table to losing a wing instead of an arm. I think it was simply written before these flying races became playable.

The highlighted text makes perfect sense if you are restricted to using your legs to move around but makes no sense if you are flying and wasn't landing at the end of your movement.
But, rules as written, it says what it says. I would suggest that a DM that makes you fall prone is taking the rules too literally.
By Rules As Written, Probably.
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Out of context, the sentence is unambiguous: *You fall prone after using the Dash action.* Done.

By Rules As Interpreted, Probably Not.
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In context, the sentence derives from the title and preceding sentence about moving *on foot*, hence that modifying clause can be implied, and the effect doesn't necessarily apply to other types of movement.

At my table, Probably.
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Because I would change it to "Lose a Wing or Wingtip" if the damage came from a direction more likely to hit wings than legs.