Confromal Fuel Tanks Origin

[grss1982]

Lately I have read articles about f-16s and f-15s having this conformal fuel tanks which to a macross fan like me could pass for a FAST Pack in the macross universe.

I was just wondering did the engineers/designers of the tanks get their idea from the macross or what? just curious anyway.

F-16

http://www.defense-update.com/products/c/F-16-CFT.htm

http://www.f-16.net/f-16_photos_album08-page9.html

F-15

http://www.israeli-weapons.com/weapons/air...-15i/F-15I.html

NOTE: mounted on the sides for the eagle, which can also hold extra more bomb/missles.

Edited May 23, 2005 by grss1982

[Gaijin]

Umm...they are called FAST packs in real life.

Fuel

And

Sensor

Tactical

It's the other way around...Macross uses something we'd recognize...or not.

Edited May 23, 2005 by Gaijin

[Graham]

Conformal fuel tanks, called FAST Packs (Fuel And Sensor Tactical) first appeared on the F-15 Eagle nearly 3 decades ago. I'm sure David or some of the other aviation buffs on this site would know the exact year they entered service.

Kawamori got the idea from them, not the other way round.

Graham

[Guest Bromgrev]

Aaw, and here I was thinking the USAF would soon be converting to variable fighters ...

[Pat Payne]

There were conformal fuel tanks long before Kawamori was born. The Germans in WW2 experimented with some over-the-wing fuel tanks they called "slipper tanks" or "doppelreiter" (double riders) which, in theory, were supposed to be more aerodynamic and give greater fuel capacity than the conventional drop tank. It was also part of the German "Mistel" bomber project (basically a fighter would ferry a retired bomber filed with explosives to a military target and then release it to glide to its doom) in the last years of the war. It went nowhere, however, mostly because the tanks, when empty, caused too much instability.

Here's a link to a short history of the tanks and a picture of an FW-190 carrying them.

[F-ZeroOne]

We British also used conformal fuel tanks. They were never very popular, mainly because - unlike later drop tanks - they affected the aircrafts performance and were vunerable in combat. The Germans once tried using them on Bf-110s during a raid in the Battle of Britain and they got slaughtered.

The F-15 was, I think, the first fighter to use FAST packs in their modern sense, but I think a number of jets had experimented with similar concepts before then.

[Noyhauser]

We British also used conformal fuel tanks. They were never very popular, mainly because - unlike later drop tanks - they affected the aircrafts performance and were vunerable in combat.

One major problem I heard about the Spitfire MkV carrying the "slipper tanks" was that they often Jammed on the mounting lugs, which actually decreased the aerodynamics of the fighter, and was often liable to dislodge unpredictably some time later often causing accidents when it hit squadmates.

[grss1982]

Thanks for claering that one out fellow macrossworlders!!! :-)

[HWR MKII]

Actually we who work on the E model just call them CFTs. I have yet to hear anyone call it a fast pack. They are a pain in the butt too. Cause more problems than they are worth with all the leaks and such.

[David Hingtgen]

Yup--FAST was the original name, but nobody uses it anymore. Most everyone says CFT---mainly because that's about all they're used for---the missile and sensor options really fell by the wayside early on.

While the F-15C/D can use them and introduced them, it's extremely rare. AFAIK, only Langley, Kadena, Soesterberg and Elmendorf ever even had them, only Soesterberg used them often.

[Mr March]

I've never seen those top-mounted conformal tanks on an F-16 before. They look very odd in that picture.

[Commander McBride]

They use 'em for bombs on the 15E, though, right? Is it also possible to mount missiles on the F-15 CFTs?

[Graham]

Actually we who work on the E model just call them CFTs. I have yet to hear anyone call it a fast pack. They are a pain in the butt too. Cause more problems than they are worth with all the leaks and such.

That's interesting about the leaks. Never heard that before.

Graham

[Uxi]

Makes sense, though. Most good idea conversions are horrible in the Real World, especially with the "built by the lowest bidder" approach.

[David Hingtgen]

CFT's on an F-15 can hold missiles, but only because they cover up the normal mounts on the fuselage. The original plan was to use them to hold ADDITIONAL missiles, likely AIM-82's. (Which never came to be) The F-15E can also mount missiles on its CFT's similar to how the F-15C does, but it does require some rearranging of parts---since there are usually 3 bomb racks on the large inner CFT-mounted pylon, but only 2 missile launchers. Read all about it here: http://www.f-15estrikeeagle.com/weapons/lau106/lau106.htm

Neat mixed config for an F-15E: http://www.f-15estrikeeagle.com/weapons/lo...hics/ods_08.gif

CFT's are an option on the F-16 Block 50+/52+. Note the plus. They are standard on the Block 60.

Edited May 25, 2005 by David Hingtgen

[Guest Bromgrev]

What does 'confromal' mean?

[HWR MKII]

It conforms to the shape of the acft when its attached to reduce drag. Wing mounted drop tanks are not conformal they do not follow the shape of the acft. acft is an acronym for aircraft by the way.(for those who may question)

[Guest Bromgrev]

It conforms to the shape of the acft when its attached to reduce drag. Wing mounted drop tanks are not conformal they do not follow the shape of the acft. acft is an acronym for aircraft by the way.(for those who may question)

Obviously, that's what conformal means. Doesn't answer my original question. Oh, the art of irony - how we mourn your passing ...

[Godzilla]

I thought the CFTs were used on the F-15s for long flights say from US to Europe in the event of a Warsaw Pact invasion.

[David Hingtgen]

The F-15's original design spec was to get to Europe without refuelling, and CFT's were designed to fullfill that requirement. However, much like going Mach 2.5, that never ever happens in real life. Any modern deployment in a known warzone often presumes they'll have to fight their way in, and go in fully armed. Not ultra-sleek and carrying large heavy empty CFT's when you arrive. IIRC, it took 7 mid-air refuellings to do Langley to Saudi Arabia, due to drag/weight from being loaded up for combat. CFT's on a F-15C are basically used when you're in a really desolate area. Alaska, Iceland. When you could easily be REALLY far from a suitable place to land. It's little more than a safety margin/reserve in real life.

The E mainly gets more use from them because it flies at gas-guzzling low level and weighs more with more drag. It uses more fuel to fly the same distance as a C, due to how it flies and what it carries. So it needs more fuel just to have the same range as a C. Plus without the CFT pylons, it can only carry like 1/4 as much ordnance.

Edited May 26, 2005 by David Hingtgen

[Skull Leader]

For the record, I think CFTs on Vipers are just ass ugly (same thing with that enlarged spine that Israeli vipers are known for). I was so glad to hear that Japan wouldn't be subjecting their F-2s to the CFT treatment (they reviewed the concept and decided they didn't need to spend more money on an already way-too-costly fighter.)

[Noyhauser]

The F-15's original design spec was to get to Europe without refuelling, and CFT's were designed to fullfill that requirement.  However, much like going Mach 2.5, that never ever happens in real life.  Any modern deployment in a known warzone often presumes they'll have to fight their way in, and go in fully armed. Not ultra-sleek and carrying large heavy empty CFT's when you arrive.  IIRC, it took 7 mid-air refuellings to do Langley to Saudi Arabia, due to drag/weight from being loaded up for combat.  CFT's on a F-15C are basically used when you're in a really desolate area.  Alaska, Iceland.  When you could easily be REALLY far from a suitable place to land.  It's little more than a safety margin/reserve in real life. 

The E mainly gets more use from them because it flies at gas-guzzling low level and weighs more with more drag.  It uses more fuel to fly the same distance as a C, due to how it flies and what it carries.  So it needs more fuel just to have the same range as a C.  Plus without the CFT pylons, it can only carry like 1/4 as much ordnance.

Godzilla has a point (and is talking about one of my favorite eras of history)

this requirement never happened because a "surge" deployment was never needed. Not many of us would remember this, but the greatest threat in the 1970s was a rapidly rebuilding Soviet Armed forces, one that it was increasingly becoming apparent would be able to essentially roll over NATO armed forces without resorting to the use of Tactical nuclear weapons. Later on with the Deployment of the SS-20 IRBM, NATO essentially lost what was called their "escalation dominance" or ability to head off the use of force by threatening to escalate the conflict (but thats for another time).

Essentially the US wanted to keep maximum flexibility in its airforces. First there was the diminishing (but not removed threat) of a soviet nuclear bomber offensive against North America. So the US would have to retain some of its fighters as part of the NORAD network. Second There was need for flexibility in deployment. It was assumed that the USAF might have to come to the defence of Japan or other bases in East Asia, so a basing in the US (with long range fuel tanks) would be the best midpoint. Thirdly the there was a belief in surivability of NATO bases in Europe, from not only a tactical nuclear strike, but more likely Russian Spetnaz forces operating in the first days of the war. This was somewhat remedied in the 1980s with a base improvement program with uprgaded security measures and the construction of new hardenend shelters. So the US wanted to base a lot of these fighters in the US to make sure their airdefence wasn't wiped off the face of the earth in the first days of the war. Finally, it was a hell of a lot cheaper to base these fighters in the US then send them over at the time of war. Since tanker aircraft were undoubtedly at a premium, this was a vital requirement.

Also Dave, these fighters would not be expected to molested while ferrying over and therefore just the tanks would be just fine. Fighters would fly into Spain or over the GIUK gap into Europe, and land far away from the front, as the Soviets wouldn't likely have anything that could touch them anyways (if they could penetrate that far into the NATO heartland, there would be far more enticing targets than an unarmed group of F-15s). If a war came the USAF wouldn't have the luxury of having many tanker aircraft available so this was a vital requirement for it to be able to do the transatlantic crossing without aid, even if it had to do so without any weapons.

Edited May 27, 2005 by Noyhauser

[Graham]

Just checked my big F-15 book and it says the F-15's CFTs (FAST Packs) were first tested in prototype form in 1974 and entered service in 1975, long before Macross

Graham

[Graham]

I was so glad to hear that Japan wouldn't be subjecting their F-2s to the CFT treatment (they reviewed the concept and decided they didn't need to spend more money on an already way-too-costly fighter.)

I heard it wasn't a cost issue for the F2, rather Japan's military is supposed to be purely defensive in nature, hence the name 'Self Defence Force'. Putting CFT's or even drop tanks on the F2 would greatly extend it's range making it capable of offensive operations....a big No No.

Graham

[Skull Leader]

I was so glad to hear that Japan wouldn't be subjecting their F-2s to the CFT treatment (they reviewed the concept and decided they didn't need to spend more money on an already way-too-costly fighter.)

I heard it wasn't a cost issue for the F2, rather Japan's military is supposed to be purely defensive in nature, hence the name 'Self Defence Force'. Putting CFT's or even drop tanks on the F2 would greatly extend it's range making it capable of offensive operations....a big No No.

Graham

One of the standard F-2 configurations is a "3-wet" configuration (for those who don't understand, that means 3 droptanks) that gives it enough range to extend well into the chinese mainland. It's already got that capability (and I STILL have yet to figure out if they can mid-air refuel... they've got the doors, but every source I've ever read says that they can't do it)

That WAS a huge part of why they didn't opt to do that upgreade. though.

[Retracting Head Ter Ter]

. Not many of us would remember this, but the greatest threat in the 1970s was a rapidly rebuilding Soviet Armed forces, one that it was increasingly becoming apparent would be able to essentially roll over NATO armed forces without resorting to the use of Tactical nuclear weapons.

Ah! The good old days of the cold war! 50000 Warsaw Pact tanks waiting to roll into West Germany. Tu-95s shadowing the Carrier Battle Groups. Thousands of Mig21s and Mig23s waiting behind the Iron Curtain. Reagan's 600 ship navy.