Ok, I the examples of crossfire in the rule book are clear about what constitutes that type of attack.

My questions relate more to the use of air units:

Q1: Does crossfire only apply to ground units? Did I miss that declaration?

Q2: If Q1 = No, then it seems like an air unit can use a ground unit as the other side of the crossfire attack. Is that correct?

Q3: If Q2 = Yes, then can two separate aircraft formations perform a crossfire attack?

I think the answers are Q1 = No, Q2 = Yes, and Q3 = Yes, but then it wouldn't be the first time I was incorrect this year  

Cheers,

_________________
Honda

"Remember Taros? We do"

- 23rd Elysian Drop Regiment

Here ya go:

4.1.1 Aerospace Formations
Aerospace units are organised into formations just like
any other unit. However, although aerospace formations
do receive Blast markers, they cannot be broken or
suppressed. In addition, they can’t be assaulted, lend
support to an assault or be used by another formation to
claim a crossfire, etc, while in the air. Once landed, an
aerospace unit may be assaulted and be used in a
crossfire, and is affected by Blast markers normally.

_________________
"EPIC: Total War" Lead Developer

Now living in Boston... any EPIC players want to meet up?

IFAIK, air units can't do a crossfire attack, neither to ground or air units. They are supposed to be constantly moving, is practically impossible for them to cause or be caught in one. Landed ir units can.

And:

4.2.2 Aircraft Attacks
After aircraft have made their approach move they are
allowed to attack. Aircraft carrying out a ground attack
action may attack an enemy ground formation. Aircraft
carrying out an interception mission may attack an enemy
aircraft formation. Aircraft are assumed to be flying high
enough in the air to ignore any terrain that might block
the line of sight when they shoot at any targets, and the
crossfire rule does not apply to aircraft attacks. This aside,
resolve the attack using the normal shooting rules.

_________________
"EPIC: Total War" Lead Developer

Now living in Boston... any EPIC players want to meet up?

I believe the FAQ covered the question of crossfire and aircraft, but I don't have it at hand, sadly.

...aaaaand by the time I posted it this was a thoroughly useless piece of advice  

Chroma has provided the ruling, but it does seem kinda sensible for an air attack to gain Crossfire using available ground formations (not the reverse).

_________________
"Play up and play the game"

Vitai lampada
Sir Hemry Newbolt

As Shermo pointed out, if you are willing to land your aircraft, they then become ground units and follow the ground unit rules.  That includees Crossfire.  Therefore it is possible to land an aircraft and once on the ground claim crossfire to/from it.

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Neal

While landed aircraft can gain crossfire, I was envisaging a bunch of troops in cover from enemy ground fire, being straffed from their rear, which does not count under the rules, but would certainly scare me!

_________________
"Play up and play the game"

Vitai lampada
Sir Hemry Newbolt

I'd agree with you on that. Houserule time!

Fortunately, I've a very sportsmanlike regular opponent, and we fairly often say "Nah, that rule doesn't work" and change it there and then (regardless of who it helps, so long as it adds to realism, fun or both).

I'll bet that if either of us tried strafing already occupied troops as you described, we'd get the crossfire bonus.

_________________
Honda

"Remember Taros? We do"

- 23rd Elysian Drop Regiment

I imagine the reason Air operations don't benefit from crossfire is because of the ease with which planes can get into crossfiring positions compared to ground based formations.

_________________
http://www.troublemakergames.co.uk/
Epic: Hive Development Thread

Air units are supposed to be up in the air (More than 45cms apart from the other unit to claim a crossfire).