Reply to TWW1FA

[unixronin]

This post is a response to tww1fa's post concerning fighter technology in science fiction, which I couldn't post inline because it's almost 3K over the 4000-character comment limit.

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Modern fighters already have the capability to engage radar targets with missiles in, if not every direction, then certainly a very wide arc and altitude range.  In practical terms, if it's in the forward 180° hemisphere, you can engage it with a radar-guided missile.  Infra-red homing missiles are a little more problematic, as the target has to be within the field of view of the missile's seeker (which may be as narrow as 45°) for the missile to get a lock on it.

Guns present a more difficult problem, because they're generally fixed in the airframe.  The gun has to be pointed fairly precisely at the spot where the target's going to be by the time the projectile gets there.  Radar assistance can be used here; the Eurofighter Typhoon has a single 27mm Mauser revolver gun with a radar gunsight that can be set in automatic-fire mode.  In this mode, all the pilot needs to is maneuver to bring his sights to bear on the target, and the gun will automatically fire whenever the sight calculates that the position and movement of the aircraft and the target are such that a burst fired at that instant will hit the target.  Naturally, the sight's reflexes are much faster than a human pilot's, and it can react to briefer and more sudden firing solutions.

Turret-mounting guns on fighters actually isn't a new idea.  Britain tried it in World War 2 (a bit after your time, I know [grin]) with the Boulton-Paul Defiant, a fighter built on the basis of precisely this idea.  Airborne radar was in its infancy then, of course, and was not accurate enough for targeting, so the Defiant had a two-man crew, a pilot and a gunner, much like many modern strike aircraft.  The gunner had a power-operated turret housing four Browning .30-caliber machineguns.  The idea was that the pilot could concentrate upon flying the aircraft, while the gunner could concentrate on shooting down enemy aircraft.

In practice, it didn't work that well.  The Defiant was utterly useless as a day fighter; compared to the single-place fighters it was competing with, it was slow, heavy, unmaneuvrable and under-armed.  In addition to that, it had to cope with the fact that the pilot and gunner were two separate people who, by some odd chance, didn't share a single brain; consequently the gunner never knew if the pilot was about to bank hard to evade incoming fire from one direction as the gunner was about to fire in another.  The harsh truth was, in a dogfight, the Defiant was just as much dead meat as the German Me110 that was supposed to sweep the sky clean of RAF fighters (and ended up having to be escorted by Me109s).  It was rapidly relegated to duty as a nightfighter, and wasn't even much damned good at that due to its weak armament (compared to, say, De Haviland Mosquitos or Bristol Beaufighters, both of which packed four 20mm cannon, and had the capacity -- unlike the Defiant -- to carry the early radars of the day).

The truth is, it would work even worse now.  A modern jet fighter isn't equipped with .30-caliber or .50-caliber machineguns; it's equipped with one or more cannon in the 20mm to 30mm range. Frequently, they are rotating multi-barrel cannon such as the US General Electric M20E1 Vulcan gun.  They are big, heavy guns, eight feet long or more, with a big, heavy, bulky ammunition feed mechanism.  All of that has to go into a turret, which makes for a pretty big, heavy turret.  This turret, unless absurdly huge, is going to have four to five feet of perhaps multiple gun barrels protruding, and it's going to have to be strong enough and rigid enough to resist aerodynamic forces on those barrels, and possibly the torque reaction resulting from spinning a 200lb barrel/breech cluster up to 6000rpm in a single second, and slew fast enough to hold the gun on a precisely calculated radar bearing to track a target, all while the fighter it's mounted on is maneuvering and pulling as much as 9G.  And the fighter's airframe is going to have to be made stronger (and therefore heavier) to take all those loads.

To cut a long story short, it's not gonna work.  Sure, you can mount a Phalanx system on a warship and it'll never even notice the weight, but on a fighter, the necessary enlargement and strengthening of the airframe to support the turret will probably, when all is said and done, double the overall weight of the airframe, with corresponding effects on the aircraft's performance and maneuverability.  All this for a gun that's only a backup weapon on a modern fighter anyway?

Extending this to a Star Wars type environment, there's a few things you gain.  Aerodynamic drag ceases to be too much of a problem, and probably so does ammunition feed when you're talking about laser cannon.  You also don't have to be pointing the same direction you're flying (something already observed in Babylon 5, for one instance), and if you have an effective directed-energy weapon, it's probably going to be your principal weapon; a missile may be little faster than your fighter and may take minutes to reach its target, but you can't outrun light.  Indeed, there are examples in SF of fighters with turrets (Space: Above and Beyond springs immediately to mind), but in most cases the turret-mounted weapons were small.  The larger a ship is, the easier it is to give it effective turret-mounted weapons with wide fields of fire.  At the same time, though, the larger a ship is, the heavier and less maneuverable it is.

The smallest, lightest, most maneuverable fighters are always going to be those that have their armament rigidly mounted in the airframe, and don't give up the weight/bulk penalties imposed by a turret.  If you can afford to add weight to your fighter, it's more effective to spend that weight making the fixed armament more powerful -- possibly several times more powerful -- than by putting the existing armament in a turret.  And this, I think, is never going to change as long as there is a tactical need for fast, highly maneuverable single-place fighters, and their primary armament is of non-negligible size compared to the fighter airframe.  Sure, larger gunships are going to have turrets, probably multiple turrets (like Homeworld's multi-gun corvette, for example, with its six fast-tracking turrets); but not the majority of single-place fighters.

Comments

Re: Funny you should say that.

[technoshaman.livejournal.com]

How far have you gotten? If you haven't gotten to the new LAC's, you're in for a treat when you do.

Never underestimate the power of a "snub" fighter. *EG*

Re: Funny you should say that.

[unixronin.livejournal.com]

Oh gods. I don't honestly remember. I know I've read my way up to LACs towing missile pods. I need to get back to Honor. And then the Aldenata series.