After my games today and talking with the other local Tau player, we got to talking about Tau Air power and what could be done with it.  It could certainly be turned down a notch.
I looked up some ideas that have been shared in the past by TRC and Hena and I think they are on the right track.
http://www.tacticalwargames.net/forums....y272307http://www.tacticalwargames.net/forums....y277006The Forge World Tau Aircraft all follow the same basic pattern which makes things easy.  They seem to have:
Fixed-Forward Main Weapon
Fixed-Forward Missile Pod
Defensive Burst Cannons
and an optional payload of Seeker Missiles
This pattern seems to hold even through to the Manta, although it has a secondary weapon system as well. ÂÂ
The current (4.4.3) list has the Missile Pod listed as Interceptor Missiles, does anyone happen to know the why of this?  It also upgrades the strength of the Seekers progressively, although I am not sure that the firepower increase is necessary.
Here is my take on the various roles for these craft:
Barracuda - Intercept and ground attack
TigerShark - Ground Attack and Drone Delivery  (Does anyone know why this is a Fighter-Bomber?  I don't recall them being used for Intercept/CAP.  Is there somewhere in IA3 where they are used as fighters?)
TigerShark AX-1-0 - War Engine Hunting
Moray - Long Range Fire Support???  -  Not sure here really.  Other opinions?
Manta - Long Range Fire Support and Troop Transport (although not necessarily in that order)
I think if we look at the basic framework it can be fit to these roles.  How about something like?
Barracuda
Fighter-bomber
Save 6+
Ion Cannon 45cm, AP4+/AT5+,  Fixed Forward Arc
Burst Cannons 15cm, AP4+/AA6+
Missile Pod 30cm AP5+/AT6+/AA5+ Fixed Forward Arc
2 for 175 with +1 for 75 points
This gives it 2 AA and pretty good firepower at strafing infantry.  I chose to drop the Seekers from the Barracuda to keep the firepower down on them which keeps the cost a bit lower, also the basic Tigershark has a nearly identical loadout giving it Seeker Missiles will help give them more distinct flavor.  This starts to set a pattern for what other Tau aircraft would look like.  I think the firepower of this is pretty comparable to a Thunderbolt, which was my goal.
Next up is the Basic TigerShark.  This one is interesting.  In 40k, the toughness of this thing is pretty identical to a Marauder, but in order for it to be a transport for Drone formations it has to be a War Engine, so it ends up being tougher than a Marauder in Epic.  I think they would be better represented not as War Engines, especially as it forces the other TigerShark variants to be War Engines too.  How many people actually use these as Drone Transports?  Would it be a huge loss if the transport ability was dropped?
TigerShark
Bomber
Save 4+
Twin-Linked Ion Cannon 45cm, AP3+/AT4+  Fixed Forward Arc
Burst Cannons 15cm, AP4+/AA6+
Twin-Linked Missile Pod 30cm AP4+/AT5+/AA5+ Fixed Forward Arc
Seeker Missiles  45cm  2x AT5+  Fixed Forward Arc, Guided Missile
It gets much better ground attack firepower than the Barracuda and it not being a War Engine brings it in line with the Bombers of every other army.  I think it also makes the AX-1-0 variant easier if it is not a WE.
TigerShark AX-1-0
Bomber
Save 4+
Twin-Linked Railcannon 45cm, MW3+  Fixed Forward Arc, Titan Killer (D3)
Burst Cannons 15cm, AP4+/AA6+
Twin-Linked Missile Pod 30cm AP4+/AT5+/AA5+ Fixed Forward Arc
Seeker Missiles  45cm  2x AT5+  Fixed Forward Arc, Guided Missile
So, this is similar to the current incarnation, with the loss of WE.  Not being a WE will make it easier for an opponent to counter them, which is I think important for a flying Titan Killer.  Also, in not being WEs, it would be possible to force them to be bought in pairs, which will make it easier to limit the numbers.  I would think that 350 points for a pair would be a good price and limit them to 4 per 3000 points.
I am going to skip the Moray for now and talk about the Manta next.  The Manta is a Space Bomber and Troop Transport that is also used by the Tau for groundside fire support.  It is a Heavy Troop Transport, differing from the Orca in the scale of what it can carry.  I do not think that it is an Assault Transport like the Thunderhawk, although it can operate in that capacity, it does not seemed designed for that task.  Despite its size and capabilities the Manta seems to follow the same basic weapons layout as the Barracuda and Tigershark.
From a fire support standpoint, it is described as being similar to a titan.  Up to this point it has been represented as being on the Warlord scale.  Which I think has a lot to do with the size of the model.  However, this has caused it to be a bit over represented and to have a very high cost.  It is a beautiful model and I think a cost reduction would help it to hit the table a bit more often.  So, following the suggestions of others, I would like to see it somewhere in the range of the Reaver Titan in terms of firepower and survivability.  That would allow it to cost in the 700 point range which would be much more playable.
So, first lets look at the Reaver.  It has 3 weapon systems and takes 28 AT hits, 16 MW hits or 10 TK hits o kill in one turn on average rolling.  Given that the Manta is much larger than a Reaver, I think it is fair to give it a higher DC rating.  Also, given the need to be lighter for spaceflight and skimmer movement, lighter armor seems fair also.  So, with 5+ RA and the 5+ Tau Defelctor you get:
DC8 - 27AT Hits, 18MW hits, or 12TK hits
Which would make it slightly less tough against normal fire and tougher against MW and TK weapons.  Seems good to me.
So then you could have a Manta that looks like:
Manta
20cm Skimmer
Save 5+
Twin-Linked Railcannon  105cm, MW2+  Fixed Forward Arc, Titan Killer (D3)
3x Twin-Linked, Long-Barreled Ion Cannon 90cm, AP3+/AT4+  Fixed Forward Arc
4x Twin-Linked, Long-Barreled Burst Cannons 30cm, AP4+/AA6+
Twin-Linked Missile Pod 45cm AP4+/AT5+ Fixed Forward Arc
DC 8, Reinforced Armour, 5+ Tau Deflector, Always Popped Up, Transport (unchanged), Planetfall
Critical: The Tau Deflector is disabled and is unavailable for the rest of the game, further criticals add 1 point of damage.
Comparing the Weapons to the Reaver, the Railcannon is better, the Ion Cannon/Missile Pod is about equivalent to a Turbo Laser, and the Burst cannons are worse, although with the benefit of AA fire.  I have left off any guided missiles as I wanted to keep the firepower down.  Which, I think makes it roughly equivalent in firepower to a Reaver, possibly a little worse really.  So, the Manta then adds transport capacity and planetfall, while the Reaver can get its shields back and benefits from +1 Initiative.  The Manta is better there, so I think a price of 700 points would be fair.
The Moray is an air caste fire support craft that fills a role somewhere in between the Tigersharks and the Manta. In suppose it fills a role similar to a SHT or a scout titan. Although, if it has shields it is more like a small titan. If we assume it follows the same basic pattern as the rest of the Air Caste units it might look something like:
Moray
20cm Skimmer
Save 5+
Twin-Linked Railcannon 75cm, MW3+ Fixed Forward Arc, Titan Killer (D3)
OR4x Twin-Linked Ion Cannon 60cm, AP3+/AT4+ Fixed Forward Arc
2x Twin-Linked, Long-Barreled Burst Cannons 30cm, AP4+/AA6+
Twin-Linked Missile Pod 45cm AP4+/AT5+ Fixed Forward Arc
2x Seeker Missile AT5+ Guided Missile
DC 3, Reinforced Armour, 5+ Tau Deflector, Always Popped Up, Planetfall
Critical: The Tau Deflector is disabled and is unavailable for the rest of the game, further criticals add 1 point of damage.
The Moray may be armed with a Railcannon or Ion Cannons, not both.
From a firepower standpoint, I think that fits between the Tigersharks and the Manta, but I would like some feedback on that. Part of me thinks that the Moray should only have the Ion attack to distinguish it from the AX-1-0, but I doubt that would be very popular.
The Orca is fine the way it is although I think it could lose the GM attack as has been suggested. Back in the early Tau lists they were a transport choice for Cadres rather than an Air Caste unit. If Orcas don't see much play, switching them back to that might help out.