Boeing F/A-18E/F Super Hornet

[rousseau]

For starting this thread, I want to study this advanced fighter not simply post some interjections.
Now, this fighter seem to be more better than I imaged before, with superior ECM, high T/W rate, CRAET airintakes etc. But right now, I really hope to know is are there other pix which showed not prototype reveal this phenomenon as circled in pic below? Or could you please post other clear pix to show prototype of F-18E that revealed this phenomenon?
Could u tell me what this for? The three missiom you chosen I believe you can do it!

[post edited to include picture as attachment - moderator]

 

[elmayerle]

Er, there was no picture attached so it's a bit difficult to respond.

 

[rousseau]

This is SERECTPROJECT forum, so the thread ought ot be more difficult than other common forum, but just little bit difficult, compare with what I asked in ATS.
I do have some, just ask more.

 

[elmayerle]

Thanks, but I didn't see anything circled. I know they had a few problems early in the flight test program, but as far as I know they've all been corrected.

 

[Sentinel Chicken]

Are you referring to what looks like a small leading edge flap just outboard of the LERX that's hinged down lower than the rest of the leading edge flaps?

 

[rousseau]

Not quite sure, the leading edge flap hinging down I only saw on prototype of F/A-18E, never saw showed on other F/A-18.
I did search alot of big pix of Super Hornet, some pivotal pix show me that flap just a part of LERX not unattached.

 

[elmayerle]

I think that flap may have had something to do with controlling the vortex of the LERX and they managed to find simpler and more effective approaches during the flight test phase.

 

[Sundog]

The biggest problem I heard of on the Super Hornet was a wing drop problem it had at high AOA. However, that was fixed to the best of my knowledge. My understanding is they used a porous material at the hinge to allow the airflow to seep through and apparently re-energize the airflow on top of the wing and either control/stabilize the separation that was occuring or prevent it.

 

[Northax]

Here's a short video of an F-18 Super Hornet during spin-trials (YouTube video):

View: http://www.youtube.com/watch?v=nwYg13DAHq4&eurl=

 

[Griffon]

the hornet you named f/a 18 e super hornet.
i found a similar aircraft known as a f/a 18 f super hornet.

 

[Akaikaze]

Yeah, I heard about the pitch-up problem, too. Someone please explain to me how a 'brand new', computer designed fighter could could have such a flaw? The last time I read about this happening was with aircraft from the 50's. That spells trouble right there. I also heard about less than predicted range and other problems. 'Stupid Hornet' is what I call it. This is a great example of why I won't join the service. Give the Navy back it's Tomcats until they get it right, meaning, get rid of the F/A-18E/F. It'll be a whole lot cheaper and safer in the long run.

 

[elmayerle]

Ah, but CFD doesn't cover every eventuality, that's why you do flight testing. All things considered, it seems to have gone through the flight-testing shakeout fairly well. As to why the F-14 wasn't developed further, there's a lot of bureaucratic politics within the USN behind that. Email or PM me if you want the details.

 

[Sentinel Chicken]

Give the Navy back it's Tomcats until they get it right, meaning, get rid of the F/A-18E/F. It'll be a whole lot cheaper and safer in the long run.

Tomcats are cheaper in the long run? The plane is an immense maintenance hog and that alone costs you in maintenance hours needed per flight hour. Even the newer F-14Ds had their share of maintenance issues. Thankfully the engines were better!

 

[elmayerle]

Give the Navy back it's Tomcats until they get it right, meaning, get rid of the F/A-18E/F. It'll be a whole lot cheaper and safer in the long run.

Tomcats are cheaper in the long run? The plane is an immense maintenance hog and that alone costs you in maintenance hours needed per flight hour. Even the newer F-14Ds had their share of maintenance issues. Thankfully the engines were better!

I think the F-14, if it had been developed further, would have had to go through a major redesign to reduce the maintenance and reliability issues. R&M (Reliability and Maintainability) are a much, much bigger concern these days than when the F-14 was originally designed. Not as extensive, externally, as Hornet --> Super Hornet, but extensively on the internals.

 

[Sundog]

Not to mention, the Super Hornet is actually a totally new airframe that was just "based' off of the Hornet. To me, it was a way for the Navy to get a new fighter while convincing the politicians it was just a new "version" of the Hornet. The only thing I can't understand is why the Navy once again developed an underpowered still too short a range fighter.

At least that mistake won't be repeated on the F-35. The F-35 has an amazing fuel fraction, which I don't know if that was a fall out of the range requirement or a supercruise requirement or both. Most supercruise fighters aim for a fuel fraction of .27 or greater. I think the F-22 actually came in at .25 due to weight growth in development.

 

[Schorsch]

I think that flap may have had something to do with controlling the vortex of the LERX and they managed to find simpler and more effective approaches during the flight test phase.

The LERX of the F/A-18E is quite huge. I think that during normal AOA operations the LERX is rather useless and undisturbed airflow on the leading edge of the wing is desired. So this "gap" is created, allowing a better flow on the wing. Otherwise a turbulence would emerge and disturb the flow on this important inner wing section. Just guessing, I am not fluent on CFD.

 

[Schorsch]

The biggest problem I heard of on the Super Hornet was a wing drop problem it had at high AOA. However, that was fixed to the best of my knowledge. My understanding is they used a porous material at the hinge to allow the airflow to seep through and apparently re-energize the airflow on top of the wing and either control/stabilize the separation that was occuring or prevent it.

They added a saw-tooth, too. These problems were solved with a variety of measures, for example new control laws for the flaps/slats.

 

[F-14D]

Give the Navy back it's Tomcats until they get it right, meaning, get rid of the F/A-18E/F. It'll be a whole lot cheaper and safer in the long run.

Tomcats are cheaper in the long run? The plane is an immense maintenance hog and that alone costs you in maintenance hours needed per flight hour. Even the newer F-14Ds had their share of maintenance issues. Thankfully the engines were better!

Maintenance numbers quoted for the F-14D are often misleading. As a plane approaches its retirement date, the parts supply dries up, forcing you to repair parts that before would be replaced. Fewer maintenance personnel are available or even being trained and some non-safety things are allowed to slide. At the end of its service, and as part of trying to justify its retirement in favor of the Super Hornet, you saw the figure of 50mmh/fh for a Tomcat being thrown around constantly. This number was accurate but misleading. The numbers were really high for the reasons above (and to make the Hornet look good; also F-14A maintenance figures were thrown into the mix to slew the comparison). However, if you looked at the figures for the F-14D as it was making early deployments the numbers were 17 mmh/fh and trending downward.

An F-14D with the Quickstrike enhancements built at equal production rates would cost about $2 million more per unit than an F/A18E (the delta would be less if an F/A-18F was the point of comparison). The resulting Tomcat would be both a better strike aircraft as well as a better fighter than the Super Bug. The R&D for the Super Bug also cost at least 20 times what the development work on adding all weather strike to the -14D would have cost. The Hornet E/F would cost less to maintain, but in addition to the cost of the E/F's R&D you should add in the cost of all those extra Hornet C/Ds that had to be ordered to keep the product in line "warm" (which were not included in figures detailing the cost of the E/F) until the E/F could enter production.

An excellent case can be made that the Tomcat would have been cheaper overall, but now it's a moot point. It would be impossible to bring the F-14 back.

 

[flateric]

Super Bug WT model for stores configuration tests

 

[Blaze1]

The biggest problem I heard of on the Super Hornet was a wing drop problem it had at high AOA. However, that was fixed to the best of my knowledge. My understanding is they used a porous material at the hinge to allow the airflow to seep through and apparently re-energize the airflow on top of the wing and either control/stabilize the separation that was occuring or prevent it.

They added a saw-tooth, too. These problems were solved with a variety of measures, for example new control laws for the flaps/slats.

My understanding is that the wing drop and wing rock problems were never completely resolved. The reprogramming of the control laws combined with the redesign of the wing fold covers help to mitigate the issues. The final design is apparently much improved but not perfect.

 

[AeroFranz]

Gotta find the precise information, but I remember sitting at a conference paper presentation, and someone was saying that the problem was 'cured' by limiting the angle of attack so that one wing would not drop before the other. Or maybe it was dropping the wing opposite of the wing developing the problem, so that asymmetric conditions were prevented. Either way, that hardly seems a cure to me, because you have capped the turning/lifting performance of the airplane. I'll be grateful if anyone can find more on this

 

[mz]

I read at http://www.aerospaceweb.org/question/planes/q0099.shtml that the original (well, not the prototype which was superflexy but the as-produced) Hornet wing was quite flexible and needed a lot of washout but the super hornet wing is much stiffer.

As for the difference in twist between the earlier F-18 Hornet and newer F-18E/F Super Hornet, you are correct in pointing out that the newer model does indeed have less twist than the original. The twist on the original Hornet is slightly more than 4°, but you are mistaken in stating that the E/F has none. In actuality, the wing twist on the E/F model is about 1.5°.

Also possibly related about lerxes and vortex generators: http://www.aerospaceweb.org/question/planes/q0176.shtml

 

[LowObservable]

Note also that the Growler has a different "soft" leading edge notch and a fence. It was offered for the E/F but declined.

 

[Creative]

Super Hornet upgrades.

http://www.aviationweek.com/aw/blogs/farnborough/?plckController=Blog&plckBlogPage=BlogViewPost&newspaperUserId=af81e61b-7188-4a72-8f39-d3869b7980c2&plckPostId=Blog%3aaf81e61b-7188-4a72-8f39-d3869b7980c2Post%3afeb0685f-4b71-457a-8b95-db6887068567&plckScript=blogScript&plckElementId=blogDest

 

[Triton]

"Strike Fighter Outlook" slide from Boeing presentation at Farnborough International Airshow 2010

Source: http://www.aviationweek.com/aw/blogs/farnborough/?plckController=Blog&plckBlogPage=BlogViewPost&newspaperUserId=af81e61b-7188-4a72-8f39-d3869b7980c2&plckPostId=Blog%3aaf81e61b-7188-4a72-8f39-d3869b7980c2Post%3afeb0685f-4b71-457a-8b95-db6887068567&plckScript=blogScript&plckElementId=blog

 

[flateric]

...

 

[Colonial-Marine]

I like the conformal fuel tanks and what looks like a IRST sensor under the nose. I have my doubts over the stealthy weapons pod however, as I do with the bays on the F-15SE.

 

[Raptor_101]

Very intriguing looking upgrade. The only thing I wonder about is that funky looking pod behind the cockpit.

 

[AeroFranz]

Top hemisphere IRST?

 

[Eagle2009]

It believe its the Spherical Laser/Missile Warning system described in the first image from Boeing.

 

[Sundog]

Here's what I don't get about the concept. It has a waepons bay to reduce the RCS by putting missiles in it and then it has missiles on the wingtips. Is this only to reduce RCS by not having the pylons under the wings?

 

[ouroboros]

Here's what I don't get about the concept. It has a waepons bay to reduce the RCS by putting missiles in it and then it has missiles on the wingtips. Is this only to reduce RCS by not having the pylons under the wings?

I'd be surprised if the Quiet Bug's pod did not also have fuel storage capabilities, like the Silent Eagle CFT's. Though I imagine drag reduction is more the goal than RCS reduction.

The more interesting question becomes, is this really just a way to slip in the development work for the stealthy external weapons pod package for the F-22 (though usually illustrated with FB-22 designs...)

 

[donnage99]

...

May i ask where u got these pix?

 

[flateric]

http://www.boeing.com/farnborough2010/presentation/fas_gss.pdf

 

[F-14D]

Here's what I don't get about the concept. It has a waepons bay to reduce the RCS by putting missiles in it and then it has missiles on the wingtips. Is this only to reduce RCS by not having the pylons under the wings?

I'd be surprised if the Quiet Bug's pod did not also have fuel storage capabilities, like the Silent Eagle CFT's. Though I imagine drag reduction is more the goal than RCS reduction.

The more interesting question becomes, is this really just a way to slip in the development work for the stealthy external weapons pod package for the F-22 (though usually illustrated with FB-22 designs...)

It would be simpler and cheaper to just do that up front, and would be more optimized for the Raptor (as virtually everything has to be. Besides, why would Boeing want to do that for Lockheed?

 

[donnage99]

It would be simpler and cheaper to just do that up front, and would be more optimized for the Raptor (as virtually everything has to be. Besides, why would Boeing want to do that for Lockheed?)

He probably thinks it's because Boeing builds parts of the f-22 like the wings and rear fuselage, but then that doesn't mean that Boeing has been awarded to build its upgrades. Regardless, I don't know if the f-18 pod would be ideal for f-22 in term of aerodynamic efficiency.

 

[F-14D]

It would be simpler and cheaper to just do that up front, and would be more optimized for the Raptor (as virtually everything has to be. Besides, why would Boeing want to do that for Lockheed?)

He probably thinks it's because Boeing builds parts of the f-22 like the wings and rear fuselage, but then that doesn't mean that Boeing has been awarded to build its upgrades. Regardless, I don't know if the f-18 pod would be ideal for f-22 in term of aerodynamic efficiency.

It wouldn't be stealthy enough, either.

 

[Trident]

New F-15E/Gripen-style HUD? That's one thing I didn't get with the Block50/52/60 Falcons and the Super Hornet - they reverted back to conventional HUDs even after previous aircraft by the same manufacturers demonstrated wide-angle holographic systems (Block40/42, Strike Eagle). OK, maybe the SH is not that surprising in that many other cockpit instruments were carried over from the Hornet to increase commonality, but with the F-16E/F I really am at a loss.

 

[Sundog]

New F-15E/Gripen-style HUD? That's one thing I didn't get with the Block50/52/60 Falcons and the Super Hornet - they reverted back to conventional HUDs even after previous aircraft by the same manufacturers demonstrated wide-angle holographic systems (Block40/42, Strike Eagle). OK, maybe the SH is not that surprising in that many other cockpit instruments were carried over from the Hornet to increase commonality, but with the F-16E/F I really am at a loss.

My guess is as you said; commonality, with what they already had in service. Also, with new programs in the works like the F-22 and F-35, they don't want to spend too much money on aircraft they're going to replace or make those upgrades so good that people will question why we're buying something new. I'm not saying it's just that, but there is some influence of that in these decisions.

 

[donnage99]

It wouldn't be stealthy enough, either.

Good point. The pod's facets may align with the super hornet but doesn't mean they will align with the raptor's alignment, which would increase additional numbers of RCS spikes. Just because a pod is stealthy for one aircraft doesn't mean it's stealthy for another.

PS. Thanks, Flateric!!