[Ravager]

Okay, these are house rules to try and bring fliers in line with 5th edition rules and the ethos behind them.
They may need a little tweaking.

Deployment
Flyer units are never deployed on the table at the start of the game, instead, they are held in reserve, traveling from a forward base to the battlefield, preparing to make an attack run. When flyer units arrive from reserves they are placed as an outflanking unit, meaning they come on from a short board edge, and must be placed from 24" – 48" from the edge.

Movement
Fliers are incredibly fast, capable of relocating from one end of the battlefield to the other in mere moments. Flyer units have a top speed of 48". However, a flyer must stay moving in order to stay in the air, and thus, flyer units also have a minimum move distance of 24". A Flyer may only pivot once per turn, and must move in a straight line. The movement of flyer type units is never impeded by terrain of any kind. If a flyer moves off the field due to its minimum move distance, it is placed back in to reserve. If it ends the game while off the field, it counts as destroyed.

Shooting
For the purposes of shooting, a Flyer counts as having remained stationary if it moved 24". A Flyer counts as having moved at Combat Speed if it moved further than 24" this turn. Unless firing in to area terrain, all firing by a flyer follows the normal line of sight rules, but inflicts a -1 modifier to all cover saves. Vehicles attacked by a flyer are always hit on their side armour, regardless of the actual facing the flyer is in.

Flyer units may also drop bombs. These are treated as barrage weapons in all respects, and the hit is always assumed to come from the center of the blast marker. Any number of bombs may be dropped in a single turn, but they are one shot weapons. Once a bomb is dropped, it's gone.

Shooting at Flyers
Flyers are incredibly hard to hit due to their great speed. All weapons firing at flyer units add 12" to the distance they are firing, meaning things like pistols and rapid-firing weapons will be unable to hit flyer units. Weapons that do not roll to hit, but are not ordnance, may target flyer units. However, if the shot scatters and misses the flyer, it will not damage nearby units on the ground as the shot is on such an angle that the projectile just keeps flying off in to the distance. Weapons that use the flamer template cannot hit flyer units.

Ordnance weapons are unable to hit flyers unless they are mounted in a turret. If the scatter dice rolls a 'hit' when an ordnance weapon targets a flyer, then it must immediately be re-rolled, to represent the difficulty of such a shot. In addition, even if the central hole of the blast is over the flyer, any ordnance shot counts as half strength, due to the speed of the flyer.

Flyer units get a 2+ cover save from all firing at them, to represent the insane speed they travel at.

Any pintle mounted or one shot optional weapon (Hunter Killer Missile, Seeker Missile, etc) counts as having an Anti-Aircraft mount, and reduces a Flyer's cover save to 4+.

Damage to Flyers
Any Crew – Stunned results count as Crew – Shaken.
If a flyer suffers a Damaged – Immobilised result, roll a D6. On a 1-3 the flyer suffers a Destroyed – Wrecked damage result and is removed from play. On a 4-6 the flyer crashes to the ground 4D6" away in a random direction, and then suffers a Destroyed – Explodes damage result.
If a flyer suffers a Destroyed – Wrecked result at any time it is simply removed from play.
If a flyer suffers a Destroyed – Explodes damage result while still in the air, the explosions will not damage any units on the ground.

[D Black]

All in all not bad need some rewording though the pintle mount is grand but "optional" is open to interpretation what my (optional) lascannon sponsons hit you on 4's, bye bye hellblade

[Ravager]

Originally Posted by D Black

All in all not bad need some rewording though the pintle mount is grand but "optional" is open to interpretation what my (optional) lascannon sponsons hit you on 4's, bye bye hellblade

Clarified it to mean only things like one shot optional weapons, such as Hunter Killers.

[Wargamer]

I think these make Flyers way too powerful; most people hit them on 6s or 7s, and they get a 2+ Cover save. One or the other needs changing.

[Ravager]

Originally Posted by Wargamer

I think these make Flyers way too powerful; most people hit them on 6s or 7s, and they get a 2+ Cover save. One or the other needs changing.

Right, modifier reduced to -1. AA mount ignores modifier.
Now most things will be hitting them on 4s and 5s. Harder to hit than a normal vehicle, certainly, but not stupidly so.

2+ cover remains, to represent the insane speed flyers tear across the field at. Sure, Joe guardsman thinks he hit that Hellblade screaming overhead…

[Wargamer]

Personally, I think you should drop the modifier entirely; give a range modifier (-12" to all weapon ranges, to represent fighting gravity), and let AA weapons reduce the Cover save back down to 4+; this means AA is a much better choice for knocking out flyers, but the speed of the craft ensures it can still potentially run the gauntlet.

Obviously, Flyers receive no penalty to range when firing; they aren't working against gravity.

[Ravager]

Originally Posted by Wargamer

Personally, I think you should drop the modifier entirely; give a range modifier (-12" to all weapon ranges, to represent fighting gravity), and let AA weapons reduce the Cover save back down to 4+; this means AA is a much better choice for knocking out flyers, but the speed of the craft ensures it can still potentially run the gauntlet.

Obviously, Flyers receive no penalty to range when firing; they aren't working against gravity.

Gah, how could I forgot the 12" rule. Thanks Wargamer.
Also added your idea about AA mounts reducing cover saves.

[Animist]

You might need to consider allowing flyers to leave the board, and re-enter along same board edge in a future turn.

This still allows a round of shooting against them, but more of a strafing run feel to them. I would be tempted to make fliers only move in a straight line, and then at the end of their movement make a pivot of up to 45degrees.

Once you go beyond a 6' x 4' table you are into apocalypse rules anyway.

[DELPHEUS]

Where were the original flyer rules? Cause outside the modifier, this looks like what I remember...

[Ravager]

Originally Posted by 3v!L Tak'Ukos

Where were the original flyer rules? Cause outside the modifier, this looks like what I remember...

There are 2 versions.
The proper, official, flyer rules come from the appendices of Imperial Armour Volume X.
The other rules come from Apoc.