The G20 Heron Gunship is a 'Fanon' Design from the depths of my own imagination, with canon Halo vehicle and weapons systems put together in a way that isn't official, but is considered 'lore friendly'.

The UNSC 'Battle Brick' started life as a D20 Heron Heavy Lift Vehicle that was repurposed into a colony structure long ago, but was abandoned along with the colony. After restoring the vessel into something between 'functional' and 'spaceworthy', it was flown back to friendly forces, and was given a series of overhauls to turn it into the enemy's worst nightmare.

Starting with the hull, the armor was heavily reinforced. It could already withstand direct impacts with space debris (both natural and artificial) for prolonged periods of time. However, plasma rounds would eventually overwhelm the armor with sustained fire, so a series of shield generators were put in place all over the outer hull.

For...ahem...'removing' enemy strongholds, the G20 was given a pair of launch tubes for a stock of six M42 Archer missiles. Each one capable of leaving a city-sized crater behind. They are on nearly every UNSC capital ship, so rearming after an attack run is far from difficult.

For dealing with heavy fortifications, a Mark 2488 Onager was 'aquired' and mounted on the craft's chin. For those who are unfamiliar with Magnetic Accelerator Cannons, they are electromagnetic coilguns that fire ferrous tungsten javelins at hypersonic speeds (this one fires rounds at 30km/s). A bit of overkill never hurt, so it fires in a 3 round burst.

For soft targets or vehicle columns, a pair of firebase defense turrets were modified to fire 30mm Armor Piercing Dual Purpose rounds at an alarming rate. The rounds punch through armor, then detonate inside the unfortunate target vehicle.

I don't mean to state the obvious, but a D20 Heron is NOT a small vehicle. Chances are, you could see this thing break atmosphere with the naked eye (let alone sensors) long before it reaches your position. Due to this reason, a pair of dorsal turrets were added. Each with a stock of 40 AAM-50XR anti-fighter missiles, for a total of 80.

If that still wasn't enough, each of the Heron's eight fusion drives were enhanced, allowing this seven story tall armory with the aerodynamic profile of a literal brick to scream across the skies at over 1,100 mph.

Controls:

Pitch/Roll/Yaw: Standard Control Schemes, (See AG8 for details)

Throttle: Lift Engine Power (around 87% will allow a gentle takeoff)

VTOL: Forward/Reverse Thrust (Overrides lift engine pitch controls regardless of flight mode)

Trim: Manual Gun Elevation

AG1: Toggle MAC Cannon

AG2: Toggle Missiles

AG3: Toggle Gun Turrets

AG8: Switch Flight Mode (Automatically deactivates above 280 MPH)

*AG8 ON: Hover Mode (gyroscopic stabilizer will keep the craft level, Lift engines will swivel with Pitch/Roll/Yaw)

*AG8 OFF: Forward Flight Mode (gyroscopic stabilizer disabled, craft will handle like fixed wing aircraft, lift engines will behave slightly differently due to Mark II Avionics package)

[Mounted Weapons]:

• [M42 Archer]: Tactical nuclear missile without the 'tactical' part. Designed for capital ship use. Deployed from forward launch tubes. Use with caution.
  [6 items total.]

• [Mark 2488 Onager]: Electro-magnetic coilgun originally designed for launching small cargo containers into planetary orbit. Outfitted to fire 150mm ferrous tungsten slugs at 88 (not a typo) times the speed of sound. Modified to fire in a 3 round burst. Chin turret mounted.
  [151 rounds total.]

• [AAM-50XR]: One of three payloads for the Class III hardpoint on F-41 Broadsword fighters. Dorsal turret launch system. Intended for anti-air use.
  [80 items total.]

• [M5 [C] Talos]: Modified M5 Talos firebase defense turret. Anti-Infantry variant equipped with modified targeting scanners for firing on the move and from above the target. Chambered in 30mm, fires High Explosive Dual Purpose rounds for Anti-Vehicle as well as Anti-Infantry roles.
  [Infinite ammunition.]

Additional Notes:

• The engine nacelles will slightly canter outwards when close to the ground with the landing gear raised.

• Avionics require landing gear to be retracted, and altitude to be at least 15 meters above the ground to function properly.

• The Mark II Avionics package will automatically disable the gyro when travelling above 280 mph. (You can still override the system manually.)

• The Mark II Avionics package allows the outboard engine nacelles to move with several combinations of Pitch, Roll, Yaw, and VTOL while in 'fixed wing' flight mode. (Including an alternate movement pattern when using the nacelles as retro thrusters)

• The MAC is gyro stabilized, but can be manually aimed vertically if the automatic systems struggle.

• The MAC fires a single round when first fired, but every time afterwards, the burst function works fine. This also explains the 151 MAC rounds, fire the first shot to clear the chamber, wait for the reload, then BLAST 'EM.

• Similar to the MAC, the M5 [C] Talos turrets are gyro stabilized, and also can be manually aimed vertically.

• You can tell which weapon you have online at a glance. If you have the MAC active, the coils glow. The Archer launch tubes and both types of turrets have targeting scanners that light up depending on which weapon you have currently selected.

• The AAM-50XR Missiles can lock onto ground units as well as their intended purpose of shooting down aircraft.

• The MAC and Talos turrets can target aircraft as well as ground targets. Although sniping a fast moving, nimble fighter with a MAC round might be difficult, it is not impossible, and is VERY satisfying.