Had a gear failure my past flight, no controller. Left main gear failed to deploy, but the rest did. So, if there is ATC, am I able to fly by the tower, and will they see all 3 gears down or see it how it is? Sometimes, it’s just the light itself that fails, and while I can obviously go in 3rd person, that is no realism.
At the end, approach went online while I was evacuating the plane, and I literally just logged off and got a contact me message. Goofiest timing.
No they cannot see your aircraft wheels.
In fact, nobody can see your plane. Even your buddy that is flying next to you on VATSIM, (or any other network). They will see a close representation of your plane that is stored on their local hard drive. This means they won’t see your custom livery, gear up or down, just whatever “image” is on their hard drive. I heard (on VATSIM) two friends flying and one guy says to the other “Hey your gear is still down”. The reply was “I’m showing the gear is up”. The first guy was seeing an “image” from his own hard drive (CLS Library folder). Not actually his buddies plane. In this case the “image” had the gear down.
UDATE: This statement is False. I’ve been corrected. See below.
Well, in my experience, since I use FSLTL, The default is the default Asobo aircraft. The generic twin engine, generic quad engine, and then whatever other funny little planes they use. the default Asobo ones can have gear up and down.
Since people will most likely be using some traffic addon like FSLTL to negate confusion of give way instructions, with addons like AIG, FSLTL, etc, does that change it? Or will I still have to commit unrealism 
Previous replies state that ATC cannot see your wheels or whether or not your gear is up/down. One reply even said that other pilots can’t see if your gear is up or down. This is false. ATC and other pilots can indeed see if your gear is up or down. The state of your gear is sent over the network so that other pilot clients (or ATC using visual tower view clients) can see your gear as up or down.
That being said, if the model someone is using to visually represent your plane doesn’t support gear animations, then your gear will appear to be stuck in position. Most models do support gear animation, though.
To answer the original question, no, ATC cannot see individual gear positions. Pilot clients don’t send the state of each gear over the network. They just send a single yes/no value indicating if the gear (all of them) are down or not.
I learn something every day! Thank you for the knowledge! I had no idea. The CLS Library must have two “Images” of each model, one with the gear down and one with the gear up.
I knew about towerview when I wrote my reply, and that and that gear position is transmitted via the simulators, however, I left it out to avoid confusion, the likleyhood of ATC using towerview is quite low.
It’s good to try to minimize confusion, but stating something that is not correct is just creating the potential for confusion in the future. Better to just state the facts.
And tower view is quite common these days, especially since Velocity.
So, is it that then, it sends a signal based off the value triggered from gear input, or by checking if all gear are down?
In other words, if one of the gears is not down, but the other 2 are, will the gear display as up or down?
Depends on the client. With vPilot, it’s based on the position of gear #1, which is typically the nose gear.