this is an interesting case where status of the unit matters. since only one model would be grounded, and would be the only model in the unit eligible to be charged, that ONE model could charged. However since there is still other models in the air, the unit is more than 50% flying, and thus wouldn't be able to be charged. Since this case doesn't really appear in 40k, being at its a 30k unit, its really weird. Its not the same as charging a unit when you can see only one model, as long as the unit is in range to be charged and you can see at least one model of it you can charge it. that being said the converse also applies, there is a model in LOS and it can be charged.
Sadly, there is nothing supporting the concept that if 50% of the models of a unit cannot be Charged, the unit cannot be Charged. And yes, it is exactly the same as the concept of being able to see, as the same rule states "reach". All references to "Flying Monstrous Creatures" are singular, not by group. So, we take those rules on a model by model basis. Therefore, that's all we got. If all references to "Flying Monstrous Creatures" refer to the unit, then the whole unit would be Grounded anyway.
There are two ways to simplify this for 40k purposes, 1 the entire unit takes a grounding check, however only the model who took a wound would take a wound from grounding should they fail. This solution would not be a popular one since it is wholly different from the rest of the book, but its just a simplification to try to avoid any disambiguation.
The second, and the most reasonable, is just to say that the unit is unable to be charged based on the status of the unit. There is no "squadron" rule for FMC unlike vehicles.
There is even a third possible outcome that I just thought of while typing all of the above. That option being that the unit can be charged, and any models are currently flying immediately land and take part in the combat.
The third is the one I mentioned at the beginning, and fits with the rules we currently have. We are not required to consider all the model's status when Charging a unit, just so long as we can reach one. We may need to consider a unit's status, but Swooping has yet to be proven to be a unit status.
The second one is not supported by any rules, and is not reasonable. You finally got it to the ground, but can't Charge it because its mate is still in the air? Again, this is like saying I cannot Charge a unit because the rest of the models are out of sight or only accessible across Impassable Terrain.
The first, if we are to consider the unit to be going by the same status at all times, then the entire unit is Grounded, as the same language that we would be justifying not being able to Charge the one Grounded model is the same language being used to Ground that model in the first place.
Either way, the unit can be Charged. It just works better for balance if it is just the one model. The Chargers get their Charge and fight, while the owner limits the models that initially make the Charge move against his unit. Pile Ins would take care of the rest.
Edited by Kristoff, 20 March 2017 - 09:12 PM.