The Helghast Cruiser appears to be modified military versions of the Helghast colony ship (the ships the Helghast used to relocate to Helghan); it is capable of launching Leech Pods to board enemy vessels or, in some cases, SD platforms. It also carries up to six fully loaded dropships on its stern. It is smaller than an ISA Cruiser, but seems to have better performance in a planetary atmosphere than its ISA counterpart, mainly because of the ISA Cruiser's need to deploy vertically in said planet's atmosphere, thus losing most of its superior speed & maneuverability in the process.
The Helghast Cruiser, however, is much weaker than an ISA Cruiser in terms of firepower and defense; a fleet of six defending Helghast Cruisers were shown to have engaged an advancing fleet of ISA Cruisers deployed during the first invasion wave, only to be wiped out without gaining a single kill. During their counter-attack, the helghast launched more than 12 of their cruisers along with fighter support against Battlegroup Mandrake. The Helghast ships immediately took heavy losses, but succeeded in crippling the ISA battlegroup through their use of boarding vessels, and the sheer strength of both numbers and surprise.
Despite its apparent size which can fool one into thinking that the cruiser is over a kilometer long, the comparative size of the onboard Overlord dropships gives the impression that the ship is actually no more than 500 meters long and about 200 meters wide. Given its atmospheric entry abilities, which seem to be achieved via a parabolic, shallow approach angle to avoid burning its out-rigging surfaces through friction, the cruiser is very likely to be equipped with a set of repulsor engines similar to those on the Overlord dropship. The presence of its six, massive engine blocks fed by what seem to be fuel pipes emerging from the midsection is proof that the ship has a conventional rocket engine, much like a space shuttle, due to the fact that the helghast had no access to nuclear technology until the ISA invasion. Whether there are combustion processes involving fuel within the engines is unknown, but the obvious presence of overheated coil aggregates inside the engine blocks is proof that its motion and lift is provided by the same processes that seem to keep it in maneuverable shape in the vacuum of space.
The two hammerhead shaped fins on the cruiser's bow are very likely ailerons which give it the necessary control surfaces in atmospheric flight while its lateral and horizontal motion is possibly ensured by sets of gas thrusters located on the stern and bow. The ship has no visible weapons systems, but the set of pods ahead of the engine blocks very likely serve as long range missile bays while the prominent blister equipment on the ship's topside seems to be either short range missile launchers or naval gunnery mounts. There are likely at least a dozen AA installations dotted around the ship's surface to repel advancing enemy aircraft or provide ground suppression.
Though heavily armored, the cruiser is poorly defended from incoming fire, which is possibly due to either the armor's inadequacy and archaic structure or the ISA missiles' superiority in penetration. The out-rigging superstructure on the ship's topside, located between the engine blocks, is undoubtedly the bridge which appears to have a thin slot of windows and is heavily armored with all of its systems located internally to protect them from incoming fire.
In Killzone 3 the Helghast added a new type of space craft to his fleet. The new ship is a modification of the original cruiser and the changes include a hyperspace jump generator as shown in many illustrations, as well as 4 underbelly mounted petrusite beam cannons, for long range capital ship combat (a deficiency of the original cruisers) and Air-to-Ground bombardment. It has also dramatically lost a good deal of its Leech Pods (in killzone 2 there were 22 total, 11 along each side) were as now there are only 8. This could be due to a tactics shift from brutal frontal assault to long range petrusite bombardment as the previous space has now been taken up, by what appears to be cooling fins for the 4 arc cannons. The newer cruisers are shown to be far more capable at taking on the ISA cruisers and destroying them. Another noticeable change was the loss of 2 of the engines from the side now only being 4 (in the normal cruiser there were 6) as well as the addition of a rudder-like projection to the rear of the ship. The crusier was capiable of firing missiles at ships seen in the mission: interception, as the fleet launches the missiles at stahl's crusier.
Although the numerical strength of the Helghast fleet was increased vastly by Visari, the initial Helghast Cruiser remains similar in strength and performance to its First Extrasolar War ancestor. Whilst this was sufficient to overwhelm the initial ISA fleet, which had been phased out in favour of the Orbital Defence platforms, they were showing their age when deployed against the new breed of ISA Cruiser, which was designed and manufactured with help from the UCA Navy.
While direct combat between the new cruiser of Killzone 3 and the ISA cruisers has never been explicitly shown, it may be assumed that the retrofitted vessels would be much more competent in long-range, air-to-air combat than their predecessors, given their ventral petrusite cannons.
No details have been released regarding specific strengths and weaknesses of the UCA Navy Fleet vessels, but they are believed to be vastly superior to both existing Helghast and ISA vessels. Ingame footage of these ships in atmospheric combat show that they have what appear to be massive autocannons or mass-drivers which complement the petrusite cannons.