Could the Mars helicopter Ingenuity have been test-flown outdoors at JPL just for the heck of it? (not that they would) The Ingenuity helicopter that has flown on Mars is designed for roughly 0.01 bar pressure and a colder atmosphere made of mostly CO2. See links (including video) in this answer to What JPL laboratory is this exactly, and what are the functions of these amazing-looking control panels? in Space SE and sources linked within. For more about Mars' atmosphere see this answer to What could Perseverance listening to Ingenuity reveal? there as well, and sources within.
The counter-propagating rotors (driven by separate motors but synchronized) spin at about 2500 RMP. The propellors are huge by Earth standards compared to the tiny weight that they carry. But we also have to remember that it will weigh more on Earth. See answers to Does Ingenuity rotate via differential rotor speeds or differential angles of attack? and sources within for more on that.
Question: Hypothetically, could the Mars helicopter Ingenuity have been test-flown outdoors at JPL just for the heck of it? Not that they would ever do such a thing (it will have been kept very clean and very very safe at all times) but from a technical stand point would it have flown? What rotor speeds and torques would have been necessary, and would these have been possible with the light-weight motors optimized for Mars flight?
No, Ingenuity was too heavy and underpowered to fly while on Earth.
From 27:30 to 29:00 in the video of a 2021 May 13 press event, one of its designers, Matt Keennon, manually pilots what he called a &quot;terrestrial version of Ingenuity,&quot;  officially named Earth Copter, nicknamed Teri or Terry.  (Reporters have had to guess at the spelling.  The transcript of a 60 minutes segment has Terry, but that neglects I for Ingenuity.)
At 24:45 Matt explains that its only significant hardware differences compared to Ingenuity are that it is lighter (he doesn't say how much), and that its motors are taller, with twice the torque.  Aerovironment hasn't published any hard numbers about Terry, or possibly even any text at all since even its name remains disputed.
But it's clear that they designed Terry to closely mimic how Ingenuity would fly on Mars (see the section &quot;Iterations&quot; in Inside Ingenuity With AeroVironment), so they wouldn't have lightened it and used much more powerful motors for capricious reasons.  It had to actually fly.  A direct quote from Matt at 24:45:

We also reduced the weight of Terry compared to Ingenuity because it's flying in Earth's gravity.

Co-designer Ben Pipenberg also says:

Terry is designed to fly here on Earth, so the motors were redesigned and are more powerful and have a higher torque to handle the denser atmosphere and the higher gravity.