ALI-50 110mm autocannon

The ALI-50 110mm autocannon is a heavy weapons system employed on the GA-TL1 Longsword series of strikecraft in service within the United Nations Space Command.

Design details
The weapon takes the form of a large autocannon, capable of firing 110mm depleted uranium shells and a high rate of fire.

Usage
The 110mm is employed on the Longsword series of fightercraft (in particular the C709 and C718 variants) - a massive space fighter used for interception and bombing. It was still employed as late as the Fall of Reach in late 2552, where it was regarded as "hopelessly archaic" in comparison to the plasma weaponry employed by the Seraph fighters used by the Covenant.

Production notes
The Longsword's 110mm gun has a dubious canon history within the Halo franchise. It was first referenced in Halo: First Strike as a 110mm weapon affectionately referred to as "the Rotary". A 110mm gun would be larger than even the 90mm cannon equipped on the Scorpion tanks, and would be ludicrous if employed as part of a rotary cannon - something supported by Robert McLees, who described the idea of "110mm rotary cannons in fighter/bombers" (as stated in the Halo Story Bible) as an example of "bad crazy" in the Halo universe.

It is likely that the 110mm rotary cannon established in First Strike was the result of a typographical error (something repeated in other Eric Nylund stories such as the relativistic Magnetic Accelerator Cannons in Halo: The Fall of Reach or the "four-forty" in Halo: Ghosts of Onyx), or may have been intended to refer to the total diameter of the weapon's full assembly rather than the ammunition. However, the number remained unchanged in the 2010 reprint of Halo: First Strike, and its validity is reinforced in Halo: The Essential Visual Guide, which states the C709 variant of the Longsword is equipped with a "heavy rotary cannon".

In the Halo Encyclopedia (2022 edition), the loadout for the Longsword (specifically the C718 variant introduced in the book) was stated to have an ALI-50 110mm autocannon - seemingly a direct reference to the 110mm figure, but now retconned into being a more reasonable autocannon. As such, this article assumes the 2022 Halo Encyclopedia's interpretation of the weapon as an autocannon as canon.

List of appearances

 * Halo: Combat Evolved
 * Halo: First Strike
 * Halo 2
 * Halo: Combat Evolved Anniversary
 * Halo 2 Anniversary