(Israeli F-16 with conformal fuel tanks)
Just something captured from the Internet when considering conformal fuel tanks on any design. In this case the F-16. I knew one of them had to be pulled when you did gun maintenance but this is interesting:
I worked these for awhile in the UAE.The conformals are not difficult to remove and install, thing is they are ALWAYS coming off for maintenance. We had a "conformal crew" and that is pretty much all they did all day long, and we won't even talk about the secondary ECS system for the AN/APG 80 AESA radar. We have CFT's here in Oman on the block 50 but are not flying with them at the moment.
This could also be a consideration when looking at putting them on the Super Hornet design. Don't know what that impact would be on daily maintenance.
The F-15E conformals are slung low on the airframe. They also need to be pulled from time-to-time for various maintenance activity.
10 comments:
Putting CFT's on the Super Hornet can only be a good thing. If they can remove the need for big under-wing EFT's they'll reduce the stress on the wings and have obvious, positive drag implications...
All good things for the Super Hornet.
Ahem!
Under wing EFTs produce a relieving load to the principal wing stressor - wing root bending moment - thus the principal stress on the wing is less.
Being jettisonable means they enable returning the aircraft to a far lower drag index for entering an engagement than conformals which add to the drag of the basic aircraft while increasing wing structural loads and, thus, stress levels.
There are questions I've found as to whether the Super Hornet can support the added weight and drag of the CFTs without seriously impairing its aerodynamic performance.
Boeing officials have previously said that the addition of the CFTs does not add any cruise drag, but they admit that the appliqué fuel tanks would have a negative impact on the aircraft's transonic acceleration because of the increased waved drag. Transonic acceleration has always been a weak spot for the Super Hornet, and many pilots say the aircraft is seriously underpowered compared to other fourth-generation fighters.
http://www.flightglobal.com/news/articles/us-navy-may-add-conformal-fuel-tanks-to-fa-18ef-super-hornet-fleet-383701/
Another Peter -
I'm curious if the Super w/ CFT would have higher negative transonic acceleration penalty, than would Super w/ under-wing toed-out EFT?
I'm assuming Boeing was comparing the drag effects of a clean Super vs a Super w/ CFT? Apples vs Oranges?
Regardless of the wing stress issue though... the CFT would negate need for EFT thus create LESS cruise drag, increase cruise speed and save annual fuel costs in doing so!
Most of all however, it would enable more tactical flexibility of the load-out and mission profile. For one thing, all of a sudden, that fuselage mounted FLIR wouldn't be obstructed in FOV by the EFT. They could leave off the entire pylon, thus saving drag and increasing cruise speed, or add the pylon and load up on an extremely wide mix of ordnance depending on the mission.
Yes? No?
Isnt it amazing how they never design in enough range and always have to design the most bizzare add ons after manufacture.
AFAIK, USAF F-15Cs hardly ever use conformals, but USAF F-15Es always do. Why?
Put on the cft and dump one pylon per wing, space them out properly, and get rid of the cant. The drag on the pylons is more a detriment than anything the extra pylon gives you. Ditch it.
Putting CFT's on the Super Bug will make ultimately make the aircraft slower in acceleration than it already is, which in turn will cause it to be MORE vulnerable to the emerging threats in the Pacific its going to encounter in the future.
Boeing needs to fix the under wing canted-out hard-points which create so much drag, and develop a new hybrid wing to give the Hornet a better mix of dash speed and maneuverability.
In the long run the USN still needs to develop a real air superiority fighter, and ditto for nations like Australia depending the SH for primary air defense.
Put the EPE on it. Should be more than enough to help with the cft drag. Anything is better than canting a drop tank on each inboard.
Until the USAF and USN can get their plans/acts together and develop and practical and shrewd next-gen design, the USAF and USN should likely contemplate and evaluate CFT concepts.
There's a need to add range and un-refueled endurance and there's simply now alternative to CFT concepts. Might there be an additional requirement for upgrading engines too? Perhaps, but that's part of the cost of doing business. There's just no an alternative until improved clean-sheet designs can produced.
With respect to the Super's CFT, I think the Super as a stand-off missile truck already put's it in a subsonic category, so why not take the extra range, add the centerline, and plop on 4x heavy stand-off munitions (AGM-88 and/or JASSM/JSOW) on aligned pylons for the day 1 reqs stuff.
That config would dominate the F-35C's range performance if similarly equipped.
Also, I'd like to see the performance chart of a Super w/ 2 wing EFT and 2 wing-tip AAM accelerating to M1.2, vs a Super w/CFT and 2 wing-tip AAM, all else clean, accelerating to M1.2.
One might be surprised. The CFT config might in fact give faster accel over the draggy EFT-equipped spec.
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