[DamienHollow]

The issue with body is that body doesn't rely purely on size but weight and durability.

[DamienHollow]

Oh, here's one you're going to love. Mill Spec Tech doesn't say how big the Hawker-Siddley Mixcoatl is.

[Mantis]

It is body 3 so somewhere in the range of medium drones. I don't see it as being too terribly big and the picture makes me think it may be along the lines of some of the current large RC helicopters you can get. Maybe like this thing?
https://www.youtube.com/watch?v=wEJYAYX9PJk (go to about 1:30)

[ShockWave]

The only component of the Hawker-Siddley Mixcoatl that should necessitate a bigger size is the Weapon Mount. I think it would be slightly larger than a LMG.

[DamienHollow]

Yeah, that one just came to my attention after I tried to use it on chummer and chummer said it had an Extra Large Vehicle sensor. I know he's not the writer of the rules but he's normally pretty good. Anyways I figured I would go and fix it manually like I did the price on one of the wines. When I looked at the book it said body 3 then listed a whole lot of mods which left me thinking small to large range and no good idea of which.

[Shaidar]

The issue is the Global-Hawk is 47.7 feet long.  While the Predator is 27 feet long with a 48.7 - 55.25 wingspan.

[Mantis]

Yeah, those ones are off. I'd say if drones weren't limited to a max body of 4, they should be much higher. Perhaps just reclassify them as unmanned aircraft? GM common sense should come into play at that point and just say no, you can't jam that thing into your drone rack. Consider it part of the issue of the thing being obsolete. It just won't fit into current racks, or really any rack. Beyond those things based on real world drones, there isn't much else presented that couldn't fit in a drone rack of the right size.
The other thing to ask yourself is whether it is worth while to micro-manage this particular issue in a game where the vehicle system in general is abstracted. Are there games where the players are frequently trying to jam a predator drone into their bulldog van? In my experience I can just show a player a picture of the thing and they go, oh OK, I see how that wouldn't fit. I'll think of something else. Get more reasonable players? 

[DamienHollow]

Ares Air-Supply is a bod 6.

[Mantis]

Actually, looking through This Old Drone, not very many of those drones have the body they should for the category of drone they are. Reaper with a body of 2? Predator with a body of 2? Hell, the Black Knight is body 14. I'd just say most of those drones would have to be taken on a case by case basis of whether they would fit a rack. There doesn't seem to be a rhyme nor reason to how they are statted out.
For the more contemporary drones found in Arsenal and the core book, I'd say they should be able to fit the various rack sizes easily. After all, these are the drones the racks were designed for. Perhaps drones should have had an assembly time stat in addition to everything else to address this issue. You could house rule such a thing using the guideline in the improved assembly time mod but then that means no one will be launching drones from the drone racks without stopping to put the thing together first. Kind of defeats the purpose of the rack.

[Shaidar]

Well RL Carrier Based air craft fold their wings at the flip of the switch.  F-18s wings fold to take up less floor space in the hanger deck.

How about applying their Body score as a number of turns required to prepare for launch.  Once or twice back in the S3 days, I even applied the Concealed Turret modifier to the Drone rack to account for disguised racks.

So how about having the Drone Rack take up more slots if it is concealed/disguised.  The +3 slot increase for a Concealed Visibility Turret seems appropriate.

[Mantis]

Anything that increases the launch time to more than a complex action makes the drone and rack useless. Fights in shadowrun just don't last long enough to have drones prepping to launch over multiple rounds. In some cases, even multiple passes would be too long to make them useful. Since the drone rack mod says they are designed for fast disembarkation and can launch a drone in 1 complex action, adding prep time or whatever really defeats the purpose.

I think the issue here is that some drones just wouldn't realistically fit in a drone rack (predator, reaper, black knight, etc). The concealability of the racks shouldn't be an issue. A turret or weapon mount is only really visible so the weapon can move and track targets. Drones just need some sort of door to open so they can be launched. They aren't tracking anything. The racks also aren't illegal or even restricted so there wouldn't be any legality problems with having them on a vehicle.

That said, if a GM really wants to add a concealability stat to drone racks, sure use the Concealed Visibility mod. This to me seems a bit harsh as drone racks already remove a potential weapon mount, have pretty high slot requirements and are kind of expensive already.

To give an example, a large drone rack is 4 mod slots and 4000¥, counts as a reinforced weapon mount for space and can only be installed on body 15 or higher vehicles. Adding Concealed Visibility mod adds an additional 4000¥, and takes up 3 more mod slots and makes the thing illegal.
Compare that to a heavy weapon mount. The mount is 2 slots, 4000¥, Concealed take 3 more slots and adds another 4000¥. The whole thing is illegal, but you can mount any damn weapon you please in there and install it on anything with a body of 6 or higher.

So the drone rack and weapon mount cost the same in nuyen but the drone rack takes 2 more mod slots (using the suggested rule) and goes from being legal to illegal. Plus you have to have a damn big vehicle to put it in. I think the drone racks are fine as is without modifying them. The real world size of some of the drones is the problem.