Max Q
Topic Author
Posts: 6916
Joined: Wed May 09, 2001 12:40 pm

Conformal tanks on fighters

Tue Nov 27, 2018 6:39 am

I was just reading an article on the F15 and it’s use of conformal tanks


It seems like their use in the USAF over the years has mostly been on the E model and squadrons in Alaska flying the C/D variant


Now they’re being fitted to aircraft with an ANG Squadron and being looked at again for more widespread use, their benefits of
additional range without taking up hard points are prompting a second look at this
capability that always seemed a no brainer to me


Apparently their use incurs a small drag penalty although not as great as external tanks, not sure if their installation limits ‘g’
when full or not



Interestingly this article states that most
fighter pilots were against them as they cant be dropped like external tanks when they are heading into a dogfight



That makes sense but If these tanks are g limiting when full why not just dump this fuel ?
The best contribution to safety is a competent Pilot.
 
User avatar
Dutchy
Posts: 7093
Joined: Sat Nov 03, 2007 1:25 am

Re: Conformal tanks on fighters

Tue Nov 27, 2018 7:52 am

link to the article would be welcome ;-)
Many happy landings, greetings from The Netherlands!
 
Ozair
Posts: 3108
Joined: Mon Jan 31, 2005 8:38 am

Re: Conformal tanks on fighters

Tue Nov 27, 2018 8:37 am

Dutchy wrote:
link to the article would be welcome ;-)

Probably this one.

http://www.thedrive.com/the-war-zone/18 ... fuel-tanks
 
Max Q
Topic Author
Posts: 6916
Joined: Wed May 09, 2001 12:40 pm

Re: Conformal tanks on fighters

Tue Nov 27, 2018 9:22 am

Correct, that is the article
The best contribution to safety is a competent Pilot.
 
User avatar
bikerthai
Posts: 2538
Joined: Wed Apr 28, 2010 1:45 pm

Re: Conformal tanks on fighters

Tue Nov 27, 2018 1:44 pm

Max Q wrote:
That makes sense but If these tanks are g limiting when full why not just dump this fuel ?


No need to dump fuel as by the time they need to dogfight, the fuel in those tanks would likely be used up.

Max Q wrote:
Interestingly this article states that most
fighter pilots were against them as they cant be dropped like external tanks when they are heading into a dogfight


Isn't that what the F-35 supposed to do? I guess if they complain enough, they can get transferred to an F-35 squadron.

Besides, the conformal tanks to not take up additional wing hard point, thus you can carry more missiles/bombs as opposed to carrying drop tanks.

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
YIMBY
Posts: 455
Joined: Tue Sep 20, 2016 4:32 pm

Re: Conformal tanks on fighters

Tue Nov 27, 2018 1:51 pm

bikerthai wrote:

Besides, the conformal tanks to not take up additional wing hard point, thus you can carry more missiles/bombs as opposed to carrying drop tanks.

bt


What about the weight?
 
User avatar
keesje
Posts: 11929
Joined: Thu Apr 12, 2001 2:08 am

Re: Conformal tanks on fighters

Tue Nov 27, 2018 3:01 pm

bikerthai wrote:
Max Q wrote:
Interestingly this article states that most
fighter pilots were against them as they cant be dropped like external tanks when they are heading into a dogfight


Isn't that what the F-35 supposed to do? I guess if they complain enough, they can get transferred to an F-35 squadron.


Coincidently I recently had a sandwich with an eagle driver who said he preferred speed, a mate & two engines above scary places..
"Never mistake motion for action." Ernest Hemingway
 
wingman
Posts: 3537
Joined: Thu May 27, 1999 4:25 am

Re: Conformal tanks on fighters

Tue Nov 27, 2018 3:54 pm

keesje wrote:
Coincidently I recently had a sandwich with an eagle driver who said he preferred speed, a mate & two engines above scary places..


From what I understand one of the key selling points of the F-35 is taking care of business before arriving at any "scary places", those being defined as ones where your presence is noted. But we'll see. It seems like the real advantage will be in the interconnectivity and perfecting tactics and strategy around more automated or AI controlled air campaigns. Add micro drones to the mix and we should see the first real "Enders Game" type stuff in our lifetime. I'm not terribly excited at the prospect to be honest. On the flip side, that interconnectivity will be the core weak point in the system vs. the stealth in my opinion.
 
User avatar
bikerthai
Posts: 2538
Joined: Wed Apr 28, 2010 1:45 pm

Re: Conformal tanks on fighters

Tue Nov 27, 2018 4:12 pm

YIMBY wrote:
What about the weight?


There's always a trade-off isn't there? With the move toward smaller ordinances such as the SBD, you can increase the quantity of weapons without maxing out the weight.

For a missile truck, weight should not be an issue other than how it affect range and loiter time.

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
Ozair
Posts: 3108
Joined: Mon Jan 31, 2005 8:38 am

Re: Conformal tanks on fighters

Tue Nov 27, 2018 8:49 pm

bikerthai wrote:
YIMBY wrote:
What about the weight?


There's always a trade-off isn't there? With the move toward smaller ordinances such as the SBD, you can increase the quantity of weapons without maxing out the weight.

For a missile truck, weight should not be an issue other than how it affect range and loiter time.

bt

It also depends on which aircraft CFTs we are talking about. The F-16 CFTs weigh approximately 900 pounds but allows for just over 3000 pounds of fuel. A standard 300 gallon F-16 drop tank weighs approximately 200 pounds but holds nearly 2000 pounds of fuel so the external is lighter per pound but carries a greater drag penalty.

Some commentary on the F-16 CFTs from the flight test program,
“The CFTs have very little adverse effect on the F-16’s renowned performance,” said Maj. Timothy S. McDonald, U.S. Air Force project pilot for CFT testing at Eglin. “A set of CFTs carries 50 percent more fuel than the centerline external fuel tank, but has only 12 percent of the drag.” The CFTs are designed for the full F-16 flight envelope – up to 9 g’s, maximum angle of attack and sideslip and maximum roll rate.

https://defense-update.com/20040204_f-16-cft.html

keesje wrote:
Coincidently I recently had a sandwich with an eagle driver who said he preferred speed, a mate & two engines above scary places..

Interesting comment Keesje. My experience is that guys who come from two seat jets prefer two seats while those from single seat aircraft don’t see the issue. The RAAF classic Hornet aircrew (primarily single seat jets) certainly don't have a glowing opinion of RAAF SH aircrew given it is an all twin seat fleet.

Either way the days of two seat fighter jets for the US Military are numbered. The USAF PCA/6th gen will continue the trend of F-22/35 and almost certainly only have a single seat.

bikerthai wrote:
Isn't that what the F-35 supposed to do? I guess if they complain enough, they can get transferred to an F-35 squadron.
bt

Several aircrew who have come from F-15s have stated the F-35A comfortably outranges the F-15 today which shouldn’t be a surprise given the high fuel fraction, single more economical engine and lower drag airframe.
 
Max Q
Topic Author
Posts: 6916
Joined: Wed May 09, 2001 12:40 pm

Re: Conformal tanks on fighters

Wed Nov 28, 2018 6:34 am

Ozair wrote:
bikerthai wrote:
YIMBY wrote:
What about the weight?


There's always a trade-off isn't there? With the move toward smaller ordinances such as the SBD, you can increase the quantity of weapons without maxing out the weight.

For a missile truck, weight should not be an issue other than how it affect range and loiter time.

bt

It also depends on which aircraft CFTs we are talking about. The F-16 CFTs weigh approximately 900 pounds but allows for just over 3000 pounds of fuel. A standard 300 gallon F-16 drop tank weighs approximately 200 pounds but holds nearly 2000 pounds of fuel so the external is lighter per pound but carries a greater drag penalty.

Some commentary on the F-16 CFTs from the flight test program,
“The CFTs have very little adverse effect on the F-16’s renowned performance,” said Maj. Timothy S. McDonald, U.S. Air Force project pilot for CFT testing at Eglin. “A set of CFTs carries 50 percent more fuel than the centerline external fuel tank, but has only 12 percent of the drag.” The CFTs are designed for the full F-16 flight envelope – up to 9 g’s, maximum angle of attack and sideslip and maximum roll rate.

https://defense-update.com/20040204_f-16-cft.html

keesje wrote:
Coincidently I recently had a sandwich with an eagle driver who said he preferred speed, a mate & two engines above scary places..

Interesting comment Keesje. My experience is that guys who come from two seat jets prefer two seats while those from single seat aircraft don’t see the issue. The RAAF classic Hornet aircrew (primarily single seat jets) certainly don't have a glowing opinion of RAAF SH aircrew given it is an all twin seat fleet.

Either way the days of two seat fighter jets for the US Military are numbered. The USAF PCA/6th gen will continue the trend of F-22/35 and almost certainly only have a single seat.

bikerthai wrote:
Isn't that what the F-35 supposed to do? I guess if they complain enough, they can get transferred to an F-35 squadron.
bt

Several aircrew who have come from F-15s have stated the F-35A comfortably outranges the F-15 today which shouldn’t be a surprise given the high fuel fraction, single more economical engine and lower drag airframe.



These F16 conformal tanks seem like
a very useful addition to the aircrafts capability


I am surprised at their high empty weight, assuming they’re of aluminum construction
I would think that a composite set would save a lot of weight and provide the required strength



Still, overall you don’t see many fighters with CFT’s, wonder why that is


It looks like the US Navy will be adding them to most of their E/F model F18’s
The best contribution to safety is a competent Pilot.
 
User avatar
bikerthai
Posts: 2538
Joined: Wed Apr 28, 2010 1:45 pm

Re: Conformal tanks on fighters

Wed Nov 28, 2018 1:42 pm

Max Q wrote:
I am surprised at their high empty weight, assuming they’re of aluminum construction


With the complex contour of the aircraft, I would be surprised if the tanks shell is aluminum, maybe the frames.
From our school days, the most efficient shape to hold the most volume is a sphere. The more you move away from that, the less efficient it will be.

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
smithbs
Posts: 185
Joined: Wed May 17, 2017 6:09 pm

Re: Conformal tanks on fighters

Thu Nov 29, 2018 7:41 pm

The CFTs are a blessing and curse. You get a lot more gas, but you are also increasing the loading on the airframe and landing gear. The CFT and its load take up payload weight, and might cause the aircraft to go over MTOW after you hang a few more things on it. Either way, you are going to lose payload or range. I think that's why you didn't see CFTs on F-16s until Sufa and Block 60, when the structure and gear was redesigned to boost the MTOW. Then you could fly your longer mission with the additional weight.
 
RJMAZ
Posts: 1013
Joined: Sat Jul 09, 2016 2:54 am

Re: Conformal tanks on fighters

Fri Nov 30, 2018 12:24 am

smithbs wrote:
The CFTs are a blessing and curse. You get a lot more gas, but you are also increasing the loading on the airframe and landing gear. The CFT and its load take up payload weight, and might cause the aircraft to go over MTOW after you hang a few more things on it. Either way, you are going to lose payload or range. I think that's why you didn't see CFTs on F-16s until Sufa and Block 60, when the structure and gear was redesigned to boost the MTOW. Then you could fly your longer mission with the additional weight.

All that added weight without the wing getting bigger.

The block 60 F-16's with conformals wing loading would be much higher, even with the thrust boost agility will be much worse.

It would be interesting to see how much the F-35 beats an F-16 with CFT's. Every measure of agility the F-35 would probably win.
 
smithbs
Posts: 185
Joined: Wed May 17, 2017 6:09 pm

Re: Conformal tanks on fighters

Fri Nov 30, 2018 2:51 am

RJMAZ wrote:
All that added weight without the wing getting bigger.

The block 60 F-16's with conformals wing loading would be much higher, even with the thrust boost agility will be much worse.

It would be interesting to see how much the F-35 beats an F-16 with CFT's. Every measure of agility the F-35 would probably win.


Ah, but F-16 CFTs are not for the purpose of dogfighting - not in my mind, at least. You see it on the variants that were worked into F-15E surrogates - long range precision strike, maybe with strategic implications. When I survey the F-16 CFT users, it's not for gunfighting. Think F-16I Sufa, or UAE Block 60.
 
RJMAZ
Posts: 1013
Joined: Sat Jul 09, 2016 2:54 am

Re: Conformal tanks on fighters

Fri Nov 30, 2018 2:23 pm

smithbs wrote:
Ah, but F-16 CFTs are not for the purpose of dogfighting - not in my mind, at least.

Greece and the UAE use the F-16's with conformals as their only fighter. So they will have to dogfight with the conformals.
 
Draken21fx
Posts: 155
Joined: Wed Jun 15, 2016 10:38 am

Re: Conformal tanks on fighters

Fri Nov 30, 2018 4:04 pm

RJMAZ wrote:
smithbs wrote:
Ah, but F-16 CFTs are not for the purpose of dogfighting - not in my mind, at least.

Greece and the UAE use the F-16's with conformals as their only fighter. So they will have to dogfight with the conformals.


True I think the Greek Block 52+ do have conformal tanks and they are actively used for dogfighting on a regular basis. I think sometimes they do add externals as well when the range is needed.
 
EBJ68
Posts: 56
Joined: Mon Sep 10, 2018 10:20 pm

Re: Conformal tanks on fighters

Tue Dec 04, 2018 10:37 pm

For clarification, a set of CFTs on an F-16 weighs 900 lbs, making the individual weight 450 lbs.
 
Max Q
Topic Author
Posts: 6916
Joined: Wed May 09, 2001 12:40 pm

Re: Conformal tanks on fighters

Wed Dec 05, 2018 3:41 am

EBJ68 wrote:
For clarification, a set of CFTs on an F-16 weighs 900 lbs, making the individual weight 450 lbs.



That clarifies things and does make a lot more sense


900 pounds for an empty tank seemed really high, but even 450 could be improved on I would think
The best contribution to safety is a competent Pilot.
 
RetiredWeasel
Posts: 657
Joined: Sat Jul 05, 2014 8:16 pm

Re: Conformal tanks on fighters

Wed Dec 05, 2018 5:10 am

MaxQ: There are other reasons to immediately jettison 4-6000 lbs of fuel if the external tanks are full besides trying to improve performance in air-to-air engagements. Having an engine performance degradation shortly after takeoff calls for immediately reducing weight and the fastest way is to hit the jettison button. You can't do that with cormformals. Not sure if the conformals have their own dump pumps, but wing and belly bags don't. You had to feed the gas into the center tank to dump it and that takes time, so jettison was the solution. I can understand current pilots reservations about the conformals.
 
Max Q
Topic Author
Posts: 6916
Joined: Wed May 09, 2001 12:40 pm

Re: Conformal tanks on fighters

Wed Dec 05, 2018 12:49 pm

RetiredWeasel wrote:
MaxQ: There are other reasons to immediately jettison 4-6000 lbs of fuel if the external tanks are full besides trying to improve performance in air-to-air engagements. Having an engine performance degradation shortly after takeoff calls for immediately reducing weight and the fastest way is to hit the jettison button. You can't do that with cormformals. Not sure if the conformals have their own dump pumps, but wing and belly bags don't. You had to feed the gas into the center tank to dump it and that takes time, so jettison was the solution. I can understand current pilots reservations about the conformals.



Understood and good points.


Other than the engine out case my
question would be, if the conformal tanks allow you to fly as far as the external tanks with less drag (as you can leave them behind) aren’t you better off overall ?
The best contribution to safety is a competent Pilot.

Who is online

Users browsing this forum: No registered users and 8 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos