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OT Call: Military Question Thread

Military History 2004

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#141 tennyson

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Posted 23 August 2006 - 07:15 PM

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Instead of high and low altitudes, is it high and low prices?

High/low references to the prices in both the case of the F-15/F-16 and F-22/F-35. They can both reach about the same altitudes.

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I mean, when they retired the 14 and had nothing left but the 18 to go for air superiority with, their response was to make it bigger, so they must figure bigger=better for air superiority... but given the laws of physics, how could they be unless that long-range issue is practically always at work? Are the small ones not just small, but also underpowered? If a big plane and a little plane had to fight and neither was too far from its base, which would you expect to win?

They made the Super Hornet bigger mainly due to the range issue. The F/A-18A through C was and is notoriously short-ranged and a lot of ordance was lost because they had to jettison it to get home. That was the main reason for the increase in size.
The F-16 is a bit more manuverable than the F-15 but in its original form it didn't have a BVR(Beyond Visual Range) missile at all, just the AIM-9 Sidewinder infrared missile. So the F-15 could kill the F-16 at longer ranges before manuverability become an issue. Then along came AMRAAM, the first American active radar missile that wasn't tied to a single fighter.(The F-14 had the active radar Phoenix missile but it was huge and couldn't be operated by another aircraft. Essentially the F-14 and the Phoenix were designed as one weapons system whose goal was to meet a Soviet attack on our carriers at as long a range from the carriers as possible as part of a three layered defense with the F-14 being the outermost layer.)
Engines have also improved over the years and the fighters themselves are heavier as more has been added to them. The F-15's engines are powerful enough to mostly offset any manuverability issues from wieght.  The F-16 now only has an airframe in common with the original. It's a lot heavier, can carry a massive array of weapons and sensors that weren't available then including a completely different radar and the Lantrin series of ground attack pods and have new engines.
Being larger also means you can mount more powerful, longer-ranged, more capable radar and the current idea in air superiority is to be able to detect and kill the enemy from as far away as possible before they can even detect you. So the smaller fighter is at a disadvantage, especially if it doesn't have a BVR missile like the original F-16.
As for the fight, something like that happened between the Isrealis and the Syrians over the Bekka Valley in Lebanon in 1982. Using good coordination, BVR missiles and AWACS(Air Bourne early warning and control) they downed 82 Syrian fighters of various types with no losses to themselves.

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Is that really the trend, though? I could say I've seen some signs that that's the case, but here we are looking at the next generation and it's still one of each of the two types.

To even be accepted as a design over the last 15 years the fighter has to be multirole. The Mirage 2000, Eurofighter Typhoon, Swedish Grippen, F-22, F-35, Super Hornet, F-15E, all have both ground attack and air to air capability and it has been added to aircraft that previously didn't do it like the F-14, Su-27 and MIG-29 in later variants. The British are even retiring the Tornado Air Defense Variant and replacing it with the Eurofighter because it can't be adapted for the ground attack role.(The Tornado ADV and IDS[Interdiction Strike] have the same fusealage but complettely different engines, weapons fits and sebnsors. The IDS is optimized for ground attack while the ADV is a pure interceptor) Existing fighters have seen thier roles broaden immensely. The F-16 now does literally dozens of missions that weren't on its original role as a cheap air superiority fighter from functioning as a SEAD(Suppression of Enemy Air Defences) aircraft, to close support to interdiction/strike, reconnaissance, and so on.

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Is the range the reason, or is there also something else?
Range is one of the reasons. In its original form the F-16 couldn't designate laser-guided bombs, had no ground attack sensors beyond a mode on its radar and wasn't compatible with a range of guided munitions. When the Isrealis hit Osrik they had to both refuel in flight and hit it with "dumb" unguided freefall iron bombs. It took more than a decade of addons to make the F-16 truly capable of the task. These include a new radar and subsystems that let them use weapons like the HARM antiradiation missile, the mounting of LANTRIN targeting and navigation pods that carry laser desginators, low-light tv cameras and imaging infrared sensors to navigate, see, and designate weapons at the target accurately. The latest F-16E/F variant that the USAF isn't buying even includes builtin additional conformal fuel tanks in addition to the already used drop tanks.
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#142 CJ AEGIS

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Posted 23 August 2006 - 07:40 PM

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Delvo: The fastest, longest-jumping, and such animals, for example, are always the light ones, not the strong, muscular ones. But that would give the 16 or 18 an advantage over the 14 or 15 when the distance they travel to the fight isn't so long, and I've never heard that that would be the case.
The first thing to comment on in my opinion is the nickname of the F-4 Phantom.  “The Miracle of Thrust Over Aerodynamics” was the nickname for the Phantom for two reasons.  The first is that the F-4 looked like it shouldn’t fly and it was a very heavy fighter.  Now the F-4 Phantom found itself in combat against the MiG-17 over Vietnam.  This is the classic example of a heavy fighter against a lighter one.

Dogfighters and much of aerial combat comes down to energy/speed.  Most maneuvers you pull are going to bleed off your speed and your available energy.  You can regain speed by diving this trading your potential energy in the form of altitude into speed.  Ultimately though you can only dive so much before you hit the ground.  Once you run low on energy you become a slow moving target that can’t maneuver for fear of stalling.  So aerial combat comes down to the first guy to make a mistake or the first guy to run out of energy in most cases.  The F-4 against MiG-17s ultimately show one of the important lessons in this type of battle.

F-4 pilots finding themselves in combat with MiG-17s found that if they got themselves into horizontal battles they were at a disadvantage.  The MiG-17 being far lighter was much more agile than the F-4 and was able to dominate it when the F-4 Pilot fought a one dimensional fight against them.  The solution to this was for the F-4 to take advantage of the three dimensional aspect of aerial combat.  The F-4 being a much larger aircraft had more fuel to expend and had larger more powerful engines.  In this type of combat the F-4 went vertical using their more powerful engines to maintain a power advantage over MiG-17.  By turning it into a vertical fight the F-4 could use its sheer thrust as an advantage over the less powerful MiG.  If the MiG-17 tried to stay in a horizontal fight not climbing with the F-4 then the F-4 would control the high ground.  Once the F-4 controlled the high ground it could dive on the MiG gaining a massive energy advantage over the smaller aircraft.  If the MiG tried to climb with the F-4 in many cases they would run out of power before the F-4 forcing them to dive and recover.  During this time the MiG would be vulnerable to having the F-4 dive on them using its speed and energy advantage.  

If a F-4 Phantom found itself being drawn into a horizontal fight with a MiG and couldn’t climb to turn it into a vertical fight due to lack of available energy or some other factor the F-4 still had one advantage.  If all else failed the F-4 could kick in their afterburners and accelerate away at a speed that the MiG couldn’t match.  Again sheer power and available fuel to burn topped the MiG-17.  Once away the F-4 could turn back and engage at will or escape the fight.  The smaller aircraft had no such capability.  Many of these hard learned lessons during the Vietnam War were taught at the Top Gun School and to USAF pilots thus increasing the win ratio of the F-4 against MiGs.  The classic example of this type of fight is the dogfight of Randy “Duke” Cunningham in his fight against a skilled presumed to be ace Vietnamese pilot in a MiG-17.

Though in reality this duality of lighter more nimble aircraft versus larger aircraft goes back even further with it being called dissimilar air combat.  The pilots of the Flying Tigers neutralized the more nimble and faster climbing Zero by taking advantage of the fact that their P-40 Tomahawks could out dive a Zero.  So the P-40s fought by slashing at the Zeroes from high altitude and then speeding away at low altitude before the Zero could react.   So in general the big plane will carry the day if the pilot is well trained enough to not play the smaller planes game and doesn’t make any stupid mistakes.  

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Delvo: Minor sidetrack: the troubles with the 35 project that have been reported lately make me wonder if anybody's trying to make a smaller version of the 22, like they made a bigger version of the 18. If a single design can be modified into both sizes like that, it seems like that could yield us a small plane that would be as much better than other small planes as the 22 is compared to other big planes...
The Super Hornet will a growth and relation to the F/A-18 Hornet doesn’t share extensive commonality with the Hornet.  The most commonality is in the form of avionics and software where the two are very similar.  The airframes and engines of the Hornet and the Super Hornet are very different.  Overall the Super Hornet is the up scaling of a lighter aircraft into a larger one and I have my doubts how well that went.  While the Navy releases a lot of information about how great the Super Hornet is I’ve heard some information indication it doesn’t perform that great and still has many of the flaws of the original Hornet dogging it to a lesser extent.  Overall I think the design requirements for a lighter aircraft and a heavier one are so different that you are better to go for totally different designs rather than trying to downscale or upscale a design.  

The problems with the F-35 project mostly have to do with the fact that they are trying to make it do everything for everyone.  When you have a small airframe or for that matter any airframe you can only have it do so many things before it starts suffering from being overweight or it does the task with less capability.  The F-35 is suffering because the government expects it to do everything and do everything better than existing platforms.  Even the Phablous Phantom for all its multi-service and many roles didn’t fulfill as many roles as the F-35 Lightning II is expected to undertake.
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#143 Delvo

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Posted 23 August 2006 - 08:53 PM

So it's the HMMWV of the air... :lol:

#144 tennyson

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Posted 24 August 2006 - 02:08 AM

No, that would be the C-130 since the HMMWV was designed to move people and things around rather than directly engage in combat ad then later was put into the role.(Much like the C-130 became the AC-130 during the Vietnam War, gaining weapons and armor and sensors and becoming something other than a transport, while most of them still just did thier jobs transporting things.)
"Only an idiot would fight a war on two fronts. Only the heir to the throne of the Kingdom of Idiots would fight a war on twelve fronts."

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#145 D'Monix

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Posted 24 August 2006 - 02:48 AM

View Postoffworlder, on Aug 23 2006, 08:22 PM, said:

it does make like a topsy turvy logic to see a Skyhawk loaded down with bombs and rockets.

Yeah but the veteran navy bomb truckers i've had the pleasure of conversing with get all misty eyed with nostalgia for the 'Scooter.'  It's mongoose aggressor variant (also seen in Top Gun) is a real modification, and made that little attack job into a fighter that regularly embarassed 'Cat jocks in training, especially with the quality of pilots at their controls.

#146 Delvo

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Posted 24 August 2006 - 07:52 AM

View PostCJ AEGIS, on Aug 23 2006, 08:40 PM, said:

By turning it into a vertical fight the F-4 could use its sheer thrust as an advantage over the less powerful MiG.
So my guess was right; the little ones are comparatively underpowered even for their size. (A lighter weight is expected to need less power to move it, but from what you're telling me, the power those planes have is even lower than that, so it's disprotortionate, making for a lower power/weight ratio.) I guess that saved money compared to more powerful engines, which allowed buyers to get more planes. Or the scaling effects I'm used to don't work the same way for planes because so much of their weight is the engine that making the engine more powerful means making a bigger plane anyway, or because the other parts they need to carry don't change as much so a smaller engine still has to carry similar weight in other parts and thus has a worse ratio of engine weight to "other parts" weight...

View PostCJ AEGIS, on Aug 23 2006, 08:40 PM, said:

Overall the Super Hornet is the up scaling of a lighter aircraft into a larger one and I have my doubts how well that went... I’ve heard some information indication it doesn’t perform that great and still has many of the flaws of the original Hornet dogging it to a lesser extent.
What problems did the Hornet have?

View PostCJ AEGIS, on Aug 23 2006, 08:40 PM, said:

The problems with the F-35 project mostly have to do with the fact that they are trying to make it do everything for everyone.  When you have a small airframe or for that matter any airframe you can only have it do so many things before it starts suffering from being overweight or it does the task with less capability.  The F-35 is suffering because the government expects it to do everything and do everything better than existing platforms.
Exactly what goals that people have for the 35 conflict with each other, and how? And I've seen pictures of it, which would normally mean its design is done already. Is it? And if so, then they're arguing over what stuff to put on it, so why not just make different versions of it with that same already-finished body carrying different equipment?

#147 tennyson

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Posted 24 August 2006 - 02:41 PM

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What problems did the Hornet have?

I already mentioned them up thread, range and carrying capacity, especially the ability to bring home unused ordance and still make it back to the carrier.

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So my guess was right; the little ones are comparatively underpowered even for their size.

The MIG-17 was also at least a generation behind the Phantom as well. Differences have evened out since then but thier are still tradeoffs.
"Only an idiot would fight a war on two fronts. Only the heir to the throne of the Kingdom of Idiots would fight a war on twelve fronts."

— Londo, "Ceremonies of Light and Dark" Babylon-5


#148 Delvo

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Posted 16 September 2006 - 05:23 PM

Since there's no visible radar dish on a plane, the radar must be internal (I think I saw a diagram long ago showing it in the nosecone on at least one model). That must mean that at least that part of the plane's hull/skin is made of a radar-transparent substance. What would that be?

* * *

The range of a 16" gun on something like the Missouri was 170 miles; the range of a merely 6" gun on the Zumwalt (prototype of a new "cruiser") is supposed to be 100 miles. That makes the newer little one's range proportionally higher than the older bigger one's (almost 17 miles per inch as opposed to almost 11 miles per inch). Is that difference an inherent issue with scaling, that you're always bound to get diminishing improvement in range from making a gun bigger, or is it because of something new about the little one's technology, like a more explosive propellant?

* * *

How does a government that's unwilling to threaten draftees with torture or death or the torture/death of the draftee's families give an unwilling draftee an incentive not to screw up in training camp in order to get "kicked out" for incompetence?

#149 tennyson

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Posted 17 September 2006 - 02:15 AM

The maximum range of the 16 inch guns on the Iowa class battleships such as the Missouri was not 170 miles, it was 23 miles maximum range. I don't know where you found that 170 miles range figure but it is laughably wrong.
As for the new long range 155mm gun on the Zumwalt class destroyers it achieved this with a combination of technologies, some incremental, some new. It uses new propellants and shell designs as well as rocket assistance combined with Global Positioning System guidance signals to ensure accurate targeting against objects that will be well over the horizon.
I'll have to look up what the nose cone is made of. On some modern aircraft I think it might be a high impact plastic but I'm not entirely sure. Most fighters since the 1950s have had thier radar in a nose cone or other forward projection while aircraft with other duties can have it packaged in a different way like the P-3C Orion's pods or the rotating dome on the E-2C Hawkeye or E-3 Sentry Airbourne Early Warning and Control aircraft.
"Only an idiot would fight a war on two fronts. Only the heir to the throne of the Kingdom of Idiots would fight a war on twelve fronts."

— Londo, "Ceremonies of Light and Dark" Babylon-5


#150 Delvo

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Posted 17 September 2006 - 08:51 AM

I can't find it again at the sites I remember looking at, either, so it must have been from a site that's changed since then (and Wikipedia was one that I was reading) or one that I don't remember the URL or name for. I remember thinking when I saw it that it was shocking, since I hadn't thought it was even as high as 50, but that still just means the new gun on the Zumwalt is still rather shocking... even more so now in comparison; instead of roughly "half again" as many miles per inch, it's gettting alsom twelve times as many! (I even thought of the idea that it might fire rockets instead of just "shells", but thought I should leave the question open instead of throwing out my own crazy imaginative nonsense! :D)

Still, as impressive as the range is, it seems to demonstrate the Navy's diminished interest in guns anyway, since it's small and each ship would only have one or two single-gun turrets. That still makes a big decrease in the total bombarding firepower the ship can deliver unless the new gun's rate of fire and/or explosive power per unit of ammo is also dramaticly higher than those of its predecessors.

If the battleships were still in use, could their big guns be upgraded (or replaced with new guns of equivalent size) with the new technology, or does this technology make a gun's size above 6" irrelevant so this is the size the battleships would get?

* * *

http://en.wikipedia....sto_Upright.jpg

Those things on the front of the "flight deck" top of this amphibious assault ship look like trucks, but clearly this ship can't come close enough to shore to drive them off, even with an extended retracting/folding ramp. Are they trucks, and if so, how do you get them ashore? If they're some kind of watercraft or amphibious craft, how do you get them down to the water? (These ships are extremely tall for their length and width, and I don't see obvious cranes or elevators on them other than the ones along the side that are already holding boats.)

http://www.ss.northr...es/iwo_jima.jpg

Given how bulky and tall the ship is and the fact that an amphibious assault would have to be done with smaller amphibious craft, apparently this ship's role must be to store those smaller craft and transport them to a landing site, where they come out from inside the ship (and pick them up to take them away again later). The middle section of the back wall of the ship's hull looks separate, like it would be a door or ramp that opens up to let the little craft in and out. Is that the deal? If this ship's main role is storing smaller amphibious assault craft, are they stored at various levels/floors/decks/storeies inside the ship and moved up and down with internal elevators? If not, since the thing's so tall, what else is that internal height space used for?

I've seen pictures of big civilian yachts that take little speedboats or jet-skis with them and have a door somewhat like that. They need an open hull so the little craft can float on the same water the big ship is floating on, just like at a dock, only it's a moving dock. But, since the smaller craft in an amphibious assault ship are amphibious, and the thing I say looks like a closed-up ramp/door seems to be entirely above the water line, I'm guessing the amphibious assault craft inside this ship are stored in a dry environment and drive into and out of the ship using their land gear instead of their water gear, correct? That would seem to greatly simplify the ship's hull design and propulsion design...

#151 tennyson

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Posted 18 September 2006 - 12:24 AM

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Those things on the front of the "flight deck" top of this amphibious assault ship look like trucks, but clearly this ship can't come close enough to shore to drive them off, even with an extended retracting/folding ramp. Are they trucks, and if so, how do you get them ashore? If they're some kind of watercraft or amphibious craft, how do you get them down to the water? (These ships are extremely tall for their length and width, and I don't see obvious cranes or elevators on them other than the ones along the side that are already holding boats.)

Those look to be a mix of standard 2 and a half ton trucks in the front of the ship with HMMWVs towards the rear.
That's the Italians San Giorgio class Landing Ship Dock(LPD) in US Navy nomenclature. It can carry 3 CH-47 medium lift or 3 SH-3D antisubmarine helicopters or 5 AB 212 transport helicopters.
They carry 3 LCMs(medium landing craft) launched via a docking well in the rear of the ship. Then another 3 LCVPs(Landing Craft Vehicle and Personnel) are carried on deck. They are launched by crane.
Under the helicopter flight deck is a vehicle hangar that has a thirty ton capacity elevator connecting it with the flight deck. The vehicle deck can hold up to 30 amphibous APCs or a mix of other vehicles. There is also a ramp at the front of the ship that the ship can use to beach and offload vehicles from there but it is rarely used.
A more normal operation would be for the CH-47 helicopters to carry smaller vehicles like the HMMVs inland while the LCM carries vehicles out the rear well. Each LCM can carry 80 troops or 30 tons of vehicles while the LCVPs can carry 45 troops or 4.5 tons of cargo. Amphibous APCs could also "swim" out the docking well once it was open on thier own.

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The middle section of the back wall of the ship's hull looks separate, like it would be a door or ramp that opens up to let the little craft in and out. Is that the deal? If this ship's main role is storing smaller amphibious assault craft, are they stored at various levels/floors/decks/storeies inside the ship and moved up and down with internal elevators? If not, since the thing's so tall, what else is that internal height space used for?

Yes, the main role of the amphibous assault ship is to carry smaller craft, landing craft and helicopters and then launch them once they are close to the target area. They are stored in various levels. Both ships you linked to are Landing Ship Docks, they function as mobile docks for amphibous forces. Each carries hundreds of troops, a wide variety of supplies including food, ammunition and spares as well as landing craft, vehicles and helicopters on various levels of the ship that are linked by elevators. It needs to be so tall to accomdate the dock and all  the other levels.

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I'm guessing the amphibious assault craft inside this ship are stored in a dry environment and drive into and out of the ship using their land gear instead of their water gear, correct? That would seem to greatly simplify the ship's hull design and propulsion design...

The smaller craft are stored dry then the door at the rear opens and the dock is flooded to allow them out.

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That still makes a big decrease in the total bombarding firepower the ship can deliver unless the new gun's rate of fire and/or explosive power per unit of ammo is also dramaticly higher than those of its predecessors.

Well, it is supposed to be autoloading but the Navy has generally moved away from the gunfire support role, leaving more and more of it in the hands of aircraft.

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If the battleships were still in use, could their big guns be upgraded (or replaced with new guns of equivalent size) with the new technology, or does this technology make a gun's size above 6" irrelevant so this is the size the battleships would get?

Some work has been done on this question over the years and it is possible to upgrade the guns. The primary issue is one of cost. The cost of replacing nearly all of the guns' internals and setting up a dedicated production line for ammunition for only four ships. While they were operating the four Iowas were still running on stored World War II era ammunition since all of the production lines for 16 inch gun rounds had closed down decades before the 1980s.
But it would be possible to get truly spectacular range out of them if you were willing to devote the rescources to upgrading and changing them into something like the AGS. For example in the 1980s and 1990s tested were made using surplus 16inch naval gun barrels as space launch platforms for small highly rugged satellites. While thier are issues of scaling that wouldn't make the range increase linear by weapon size a completely upgraded 16 inch gun using those techniques could get truly phenomenal range.
"Only an idiot would fight a war on two fronts. Only the heir to the throne of the Kingdom of Idiots would fight a war on twelve fronts."

— Londo, "Ceremonies of Light and Dark" Babylon-5


#152 Delvo

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Posted 23 December 2006 - 08:36 PM

A brief return to Ex Isle for clarification on one issue about fighter planes...

Earlier in this thread, I asked about the dichotomy of big heavy ones and little light ones; each force seems to want to have one of each. It seemed as if it's generally accepted as fact that the larger ones are more effective and the reason to get smaller ones is the cheaper costs of both initial purchase and continuous operation (which lets you save money or have more planes). In some ways, that's intuitive because a bigger vehicle can carry more stuff (missiles, ammo, fuel, sensors) than a smaller vehicle. In one way, though, it's counterintuitive, because usually smaller vehicles have better speed, acceleration, and maneuverability. So I asked about those items in particular.

The answer was essentially that the bigger engine provides more thrust, which makes the big plane better at engine-power-related things, like running off at high speed or flying upward, and a pilot can use those tricks to overcome a smaller enemy plane's superior nimbleness. To be precise, though, those aren't just about thrust; they're about thrust compared to weight. So if the big planes are generally better at that stuff than the little ones, then they must have not just more thrust but a higher thrust to weight ratio. I left it at that originally, although I still wasn't sure whether this was an inherent scaling effect in jet planes or because the light ones are actually underpowered for their size.

But now I've seen something that contradicts this. A somewhat hidden page at Wikipedia on the "Light Weight Fighter" program (I say hidden because you'd never get to it without already knowing that that was an actual term, unless you noticed while reading about the F-16 that that phrase was linked) says that the LWF program (in which the Air Force picked the F-16 to complement the F-15) was all about making a smaller plane with a higher TWR.

So what's going on here? Does TWR naturally tend to increase, decrease (as I would have expected), or do neither as size increases? If it counterintuitively increases, how--is there a minimum length to be able to include afterburners? If TWR naturally goes down as size goes up, then why would we produce light planes with such weak underpowered engines as to cancel out that advantageous trend and reduce their TWR anyway, thus making the LWF program useless because it didn't test the idea it was supposed to test? Was the F-4's success against concurrent Migs a result of an advantage in general technological sophistication rather than because of its size? If it had higher TWR than the contemporary Mig, was that because of its size or despite its size? How could the LWF program be all about higher TWR but result in planes (F-16s) that are less able to do things that are TWR dependent than their heavier counterparts (F-15s)? And if their TWR is actually higher than the bigger planes' TWR is, then that would mean the bigger planes' overall superiority must be either false or dependent on those other factors I have no trouble understanding (range, sensors, weapon load)... but then in that case, what did the story of the F-4 and the Migs it faced above Vietnam have to do with the modern American fighters? Are you going to tell me the Wikipedia article author got the entire nature of the LWF program all wrong?

#153 offworlder

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Posted 24 December 2006 - 11:39 AM

in some cases it is about thrust to weight ~ the Phantom's success was largely due to its tremendous speed, remember that it was more an interceptor than a dogfighter; it had great success against the Mig17, but the Mig19 was designed directly in response. The Phantom guys would speed into a superior position then fire off missiles before ranges closed to dogfight proximity when a more manoeuverable ship like the Mig17 could excel.

Also look at the success of the Tomcat ~ a truely large plane, but its main role and success were as CAP, the prime defense of carrier groups at sea ~ its speed , combined with its real superiority- the electronic avionics and weapons targeting systems- gave this large heavy ship worldwide superiority in the interceptor role, even though it was also a fair dogfighter; but it could be outmanoeuvered in tight and so they would be 'first on the trigger' like with Phantoms, get the speed in, get the angle, get the lock, and trigger, before the enemy could do those.
:D
The one I'm always confused about, is how that F16 can carry all those bombs when it's smaller than the Tomcat which usually doesn't carry such ! ;)
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#154 tennyson

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Posted 24 December 2006 - 04:45 PM

Actually in the last ten years of its life the F-14 did become a true fighter bomber, as it gained the ability to first drop iron bombs, then laser-guided and GPS-guided munitions. The Tomcat has about twice the unrefueled combat radius of the F-16 with the same load.
Also, the F-4 Phantom didn't even exist when the MIG-19 went into service and it was not designed in response to it. The MIG-21 was designed in parallel with it and they both came online at about the same time.
Now on to Delvo,

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So what's going on here? Does TWR naturally tend to increase, decrease (as I would have expected), or do neither as size increases? If it counterintuitively increases, how--is there a minimum length to be able to include afterburners? If TWR naturally goes down as size goes up, then why would we produce light planes with such weak underpowered engines as to cancel out that advantageous trend and reduce their TWR anyway, thus making the LWF program useless because it didn't test the idea it was supposed to test?

All fighter design is about balancing out competing goals in a compromise that allows you do as much of your goals as possible while producing a fighter that will work. If you put a massively powerful but fuel hungry engine on a small plane it will be fast but it won't stay in the air long enough to be useful. Assuming the same engine, thrust to wieght ratio does go down as aircraft wieght increases. That's why improved engines are made with more power to overcome this  But while straight line speed does linearly depend upon thrust to weight ratio, the manuverability of the aircraft does not.  So you have interceptor aircraft like the Panavia Tornado or the Mig-25 with good times to altitude and enormous maximum speeds but aren't as good at air combat manuvering.  They have to fight thier own enormous inertia created by the combination of thier wieght and speed to turn and that means they have to slow down enormously if they want to fight in close and they aren't as good at it as a smaller, lighter but similarly powered fighter.  

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Was the F-4's success against concurrent Migs a result of an advantage in general technological sophistication rather than because of its size? If it had higher TWR than the contemporary Mig, was that because of its size or despite its size?

Here are the Thrust to wieght ratios of the F-4 and its main contenders in Vietnam,
F-4 .86
Mig-21 .82
Mig-19 .86
Mig-17 .63
A lot of factors went into and go into success in air combat beyond simple thrust to wieght ratio.  While the F-4 was generally more technologically sophisticated than its opponents with better radar and a more sophisticated weapons load, depending entirely on missiles even so far as to not have an internal gun before the F-4E model but this was not entirely an advantage. While thier Sparrow and Sidewinder missiles had better range than the Vietnamese fighters who mostly relied upon guns, the F-4's missiles were notorious unreliable, with the Sparrow hitting maybe 20 percent of its targets during the war.  Thus once the MIGs had avoided its missiles the F-4 didn't have anything to do but run until it got a gun pod then an internal gun.
Then it became a dogfight where the Migs ability to turn faster(not directly dependent upon TW ratio) tended to work against the F-4s advantages in straight line speed(more dependent on thrust to weight ratio) and range.  Our pilots were better trained and on the average tended to use thier aircraft better and that seems to have been the telling factor range than the technology.


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How could the LWF program be all about higher TWR but result in planes (F-16s) that are less able to do things that are TWR dependent than their heavier counterparts (F-15s)? And if their TWR is actually higher than the bigger planes' TWR is, then that would mean the bigger planes' overall superiority must be either false or dependent on those other factors I have no trouble understanding (range, sensors, weapon load)...
Depending upon thier engine the thrust to weight ratios for the F-15 and F-16 are
F-15, 1.12 or 1.30
F-16 .898 or 1.095
Intially they both used the Pratt and Whitney F100 engine, but the F-16 could only carry one while the F-15 has two, somewhat offsetting its greater weight.
The F-15 does have a higher maximum speed than the F-16 and a greater range and can achieve its maximum altitude faster but the F-16 is still more manuverable. As I mentioned greater weight plus higher speed means the aircraft has more interia that has to be overcome to turn. Also, the F-16, unlike the F-15 is an inherently unstable design, it doesn't have a single fixed moment of interia that it has to pivot around to turn like the F-15. The F-16 constantly wants to depart from a stable constant altitude, unlike the F-15 that will remain in level flight without any control input.  This is how its achieves its incredible manuverability.
Thrust to weight ratio isn't a completely determanistic measure of every facet of aircraft performance.

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but then in that case, what did the story of the F-4 and the Migs it faced above Vietnam have to do with the modern American fighters?
It shows that a host of others factors rather than raw technical sophistication or straight line performance go into victory in air combat.
I think I may have left out something in there, that was a lot of questions and if you need clarification please keep posting.
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#155 Delvo

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Posted 24 December 2006 - 07:35 PM

View Posttennyson, on Dec 24 2006, 04:45 PM, said:

Assuming the same engine, thrust to wieght ratio does go down as aircraft wieght increases...
OK, so the natural scaling effect is as I expected, and a smaller plane with a lower TWR than a big one would have to deviate from that natural trend by having less of an engine for its size. But that still doesn't explain how such a plane could result from a program that was supposed to be for the creation of a small plane with a high TWR as the Wikipedia article on the subject says. That's like setting out to make a new coupe and somehow ending up with a sedan.

#156 tennyson

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Posted 24 December 2006 - 08:49 PM

Sorry I think I used a term inprecisely. The higher the raw number is then the better the thrust to weight ratio. So the Tornado has a thrust to weight ratio of 0.14 and the MIG-25 0.42 but the F-15 and F-16 have ratios higher than one, meaning they produce more thrust than thier own weight, something that had never been done before.
So the goal was achieved and intially both planes had the same engine, the then new F100, just that the F-15 could fit two giving it a better thrust to weight ratio even though it was more massive. Thus giving it a better straight line speed and rate of climb. But the F-16 still had a better thrust to weight ratio than any aircraft of its type before it and it was more manuverable than any operational aircraft had ever been.
"Only an idiot would fight a war on two fronts. Only the heir to the throne of the Kingdom of Idiots would fight a war on twelve fronts."

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#157 Delvo

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Posted 24 December 2006 - 10:24 PM

View Posttennyson, on Dec 24 2006, 08:49 PM, said:

So the Tornado has a thrust to weight ratio of 0.14 and the MIG-25 0.42 but the F-15 and F-16 have ratios higher than one, meaning they produce more thrust than thier own weight, something that had never been done before.
So the goal was achieved and intially both planes had the same engine, the then new F100, just that the F-15 could fit two...
That makes it sound as if the F-15 was a beneficiary of the F-16's engine, rather than the F-16 being developed after the F-15 as an alternative to it.

#158 Talkie Toaster

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Posted 18 January 2007 - 06:38 PM

View Posttennyson, on Dec 25 2006, 01:49 AM, said:

Sorry I think I used a term inprecisely. The higher the raw number is then the better the thrust to weight ratio. So the Tornado has a thrust to weight ratio of 0.14 and the MIG-25 0.42 but the F-15 and F-16 have ratios higher than one, meaning they produce more thrust than thier own weight, something that had never been done before.
So the goal was achieved and intially both planes had the same engine, the then new F100, just that the F-15 could fit two giving it a better thrust to weight ratio even though it was more massive. Thus giving it a better straight line speed and rate of climb. But the F-16 still had a better thrust to weight ratio than any aircraft of its type before it and it was more manuverable than any operational aircraft had ever been.

Several varients of the English Electric Lightning had a thrust to weight ratio higher than one.
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#159 CJ AEGIS

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Posted 18 January 2007 - 07:36 PM

View PostTalkie Toaster, on Jan 18 2007, 06:38 PM, said:

Several varients of the English Electric Lightning had a thrust to weight ratio higher than one.
If I remember to get that figure they were stripped down and had to be empty along with having to be in afterburner.  With the active service Lightnings I think they were well below a 1 in the terms of TTW ratio.  The Lightning was good for its time period but totally outmatched by the F-16 or F-15.  Its comparing a second generation fighter to a 4th generation.  Even against a third generation bird like the F-4 Phantom I wouldn't put my money on the Lightning.  It might be able to out climb the F-4 and have a few other performance advantages when it isn't carrying a combat load but the avionics and weapons on the F-4 would far outmatch it.
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#160 Talkie Toaster

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Posted 19 January 2007 - 10:29 AM

I don't know about the inital Lightnings but later models (in combat configurations, btw) definately had TTW ratios above 1. This really shouldn't be suprising- the Lightning had supercruise abilities decades before any general USAF fighter and held time-to-height records that only fell during the 90s. Not bad for such an old aeroplane.

Edited by Talkie Toaster, 19 January 2007 - 10:30 AM.

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