Lockheed S-3 Viking Variants and Projects

Abraham Gubler

ACCESS: Top Secret
Senior Member
18 March 2008
Reaction score
Does anyone have any information on the design for the enlarged S-3 Viking offered as a carrier onboard delivery (COD) aircraft in competition with the second batch of Grumman Greyhounds? And I don’t mean the US-3 which was just a stripped ASW Viking for high speed COD duties. Apparently this super Viking COD had a new fuselage, engines and seats for up to 30 passengers.

Did not JP Santiago (aka Sentinel Chicken) do some what-iff's of a Viking COD with a longer fuselage?
Yes!!! ;D

[image links broken - Admin]

Note also new main gear!
Maybe JP Santiago / Sentinel Chicken or someone else can give us info, if this concept is based on facts or on fiction.
If fiction, the mods have the right to move this thread over to Scale Modelling, CGI and Profiles forum.
Last edited by a moderator:
Nope, the Vector site article is pretty clear that the Lockheed COD would have a new fuselage and engines and not just a remodelled aft fuselage. It would also have seats for 30 which is quite large.
Hi there

Has anybody got any info or pics on the proposed smaller "mini" or "micro" s-3 viking intended to operate from smaller carriers?

Many thanks
My COD version was purely conjectural on my part. Couldn't find any info at the time on the COD Viking so more or less took a wild-arse guess.
Sentinel Chicken said:
My COD version was purely conjectural on my part. Couldn't find any info at the time on the COD Viking so more or less took a wild-arse guess.

Looks good nonetheless! :)
Greetings All -

I did not find a previous thread looking at AEW variants/proposals of the S-3 so started up this one. This model is in the possession of the Frontiers of Flight Museum at Love Field in Dallas, TX. This is a Vought/LTV proposal for an AEW variant of the S-3. Makes sense coming from Vought as they did the Navy acceptance qualification work for the original S-3 and obviously had far more navair experience than Lockheed. Not bad looking either....

Any other proposals out there to replace the E-2? There's the joined wing Boeing design in another thread but what else might be out there?

Enjoy the Day! Mark


  • xLTV S-3 AEW Variant-1.jpg
    xLTV S-3 AEW Variant-1.jpg
    117.9 KB · Views: 978
  • xLTV S-3 AEW Variant-2.jpg
    xLTV S-3 AEW Variant-2.jpg
    106.8 KB · Views: 917
  • xLTV S-3 AEW Variant-3.jpg
    xLTV S-3 AEW Variant-3.jpg
    112.8 KB · Views: 834
An older thread

Lockheed & Grumman Multiple Purpose Subsonic Naval Aircraft (MPSNA) studies (1986)

As a side note on the E-2 in general, its been said that Vought's E-2 submission was superior to Grumman's but the contract went to Grumman anyway. The more aerodynamic antannae from Vought's proposal found its way into the Hawkeye.
Last edited by a moderator:

proposed S-3A-based CCW/USB STOL aircraft.


  • 1.JPG
    28.5 KB · Views: 880

I am new here, but I have a question? Does anyone here have color pictures or drawings of the S-3 Viking as a AEW&C aircraft or any other new variants that were not used by the US navy before they were retired. I was told that the US Navy tried (unsuccessfully) to sell up dated models of this airframe to Brazil for its new air craft carrier the Sao Paulo when the Brazilian Government bought this ship from France in the late 1990's. Any feed back would be appreciated.
Would Sao Paolo be able to operate and S3 - given the difficulty the French had in intergrating the E2 with C de G?

JohnR said:
Would Sao Paolo be able to operate and S3 - given the difficulty the French had in intergrating the E2 with C de G?



The S-3 has a far more limited take off performance than the E-2, the catapults on the ex-Foch are very limited in capability, Brazil doesn't seem to have the money or resolve to adequately fund its current Skyhawk airgroup, and the remaining Vikings have a limited number of traps left, although they apparently have quite a few flight hours left if operated from land.

I don't honestly know if the Viking was ever involved in any crossdecking with the MN, but I would guess not.
Then that would explain why the S-3 was not accepted by the Brazilian navy...However were there not attempts to sell these aircraft with different variants of the airframe to foreign customers...and with these possible sales wasn't a SLEP offered? Jemiba, Thanks for the pictures of the S-3 AEW&C aircraft, those were cool!!!! however are there any color drawing available?
A recent issue of Naval History magazine had an article by Norman Polmar about the S-3 Viking. It mentioned the stretched COD version of the aircraft that was proposed in the 1980s. It did not mention a new fuselage or seats for 30, only a fuselage plug of 70 inches.

The vector website is gone. Anybody know what it referred to?
blackstar said:
The vector website is gone. Anybody know what it referred to?
Not gone, the author just hived off the aviation side of his site to a separate URL. The relevant article can now be found here:
Thank you for that. Here is an excerpt:

"One of the interesting derivatives of the "stock" S-3A was a modification for the "carrier on-board delivery (COD)" cargo / personnel transport role. Lockheed initially proposed a major redesign of the Viking for COD operations, featuring a longer and wider fuselage with a rear loading ramp and accommodations for 30 passengers, plus more powerful engines to handle the bigger airframe. The Navy didn't buy the idea, so Lockheed came up with a minimum-change solution, originally given the designation "S-3A(COD)" but then redesignated "US-3A". Combat avionics were removed, with a color navigation radar and a LORAN-Omega navigation beacon receiver installed. The seats for the SENSO and TACCO were removed, though a place was installed for a loadmaster. The US-3A could carry six passengers or up to 2,125 kilograms (4,680 pounds) of cargo internally in a cargo hold with 7.6 cubic meters (10 cubic yards) of usable space. It could be fitted with either an external tank or a cargo pod under each wing, depending on whether the mission demanded range or load.

One of the original YS-3A Viking prototypes was converted as a demonstrator, performing its first flight on 2 July 1976. The Navy was impressed, but decided to standardize on the Grumman C-2A Greyhound instead. However, the Navy did acquire six more US-3A conversions to meet a specialized COD requirement. They provided service during the Gulf War, but were retired in the mid-1990s. One was lost in a crash. The US-3A's cargo pods, known as "blivets", were carried on other Viking variants on rare occasions."

I think that there are actually three COD versions that were proposed or built:
1-the original COD proposal, with a much larger fuselage.
2-the actual US-3A COD that was built, essentially consisting of the standard fuselage with the interior stripped out to serve in the COD role.
3-the COD version mentioned in Polmar's Naval History magazine article, which would have consisted of the basic S-3 airframe with a 70-inch fuselage plug. The article linked above does not refer to that version.
Also AIBF,ultra-STOL concept,fitted with four engines;

To assess the AIBF ultra-STOL performance potential,the experimental data
developed by the NASA/USAF/Lockheed large-scale tests for the AIBF concept
were used for analyzing the deck performance of a typical sea-based aircraft
configuration.Figure 10 depicts this conceptual AIBF ultra-STOL configuration
which had an aspect-ratio 7.73 wing of 68-ft span and a wing area of
598 sq.ft.The power plants were four TF34-GE-2 turbofans. It was assumed
that the TF34/AIBF installation was similar to the AIBF application scheme
shown in Figure 1b and that the flap setting for both takeoff and landing
configurations was 30 degrees.



    42.8 KB · Views: 978
  • AIBF Model.JPG
    AIBF Model.JPG
    61.2 KB · Views: 618



  • CL-1555-text.png
    177.5 KB · Views: 592
  • CL-1555-drawing1.png
    62.8 KB · Views: 654
  • CL-1555-drawing2.png
    82.2 KB · Views: 698
Two images of the Viking AEW concept.

The first is a PK Nagata artists concept of the Viking AEW getting ready to launch
The second is a different scan of the same poor image of a Viking AEW model
Both from Vought Aircraft Historical Foundation archives.



  • xViking-AEW-PK-Nagata-VoughtAircraftHistoricalFoundation.jpg
    64.1 KB · Views: 741
  • xViking-AEW-Model-VoughtAircraftHistoricalFoundation.jpg
    56.2 KB · Views: 495
I also found this graphic for the program.



  • Viking-AEW-Emblem.jpg
    61 KB · Views: 385
Proposed revised version of Viking COD. New fuselage.


  • Viking1.jpg
    200.2 KB · Views: 851
Maybe the results of the X-55 ACCA could be incorporated ?


  • KC-3.gif
    125.2 KB · Views: 627
I wish they had released a better illustration of the aircraft. I am curious as to how they add a larger fuselage to an existing cockpit. Is it just longer or do they increase the width?
My interpretation is an increased length, a higher set wing and maybe
taper of the rear fuselage on a shorter length of the aft fuselage, so
retaining the maximum width on a longer part of the cabin.
Going by the article, both widened and lengthened . They will have some interesting challenges due to "knock-on" effects.

- If they are to keep the wing intact, they are limited as to how much the fuselage can be widened - this is driven by the current engine placement (i.e. you can't move the engines outboard to make room for more fuselage width). As a very rough guess, they can't bump out the fuselage sides more than 9-12 inches on either side. (The reduced clearance could have some aero effects as well as impede maintenance accessibility to the inboard side of the engines.)

- The fuselage outer mold line would probably be bumped out on the sides like that of the 747 Dreamlifter.

- Raising the wing above the "cargo box" of the fuselage means that the empennage group must be raised by roughly the same amount; this driven by the need to have the engine exhaust plume not interact (much) with the horizontal stabilizer.

- Tying in the new fuselage structure to the existing cockpit/nose landing gear structure will be a challenge; the S-3 was designed around a very efficient dual keel beam structure that reacted longitudinal loads all the way from the nose landing gear (cat loads) to the main landing gear, to the tailhook (trap loads). The depth of this structure will have to be greatly diminished in the cargo box to make room for, well, cargo; the transition to the existing structure under the cockpit will be interesting. On the other hand, they won't have to have the gaping [structural] holes in the current upper forward fuselage for the back seaters to eject through.

I would imagine that a lot of the initial groundwork for this was done by Lockheed and Vought in the late 70s/early 80s when last a new COD aircraft was needed. (The customer's solution then was to reprocure the C-2 essentially "off the shelf" rather than engage in a development effort.)

My thoughts anyhow, YMMV.
I think that the COD requirement is to be able to carry an F110 engine without any disassembly. So they need a fuselage that can hold that.

But I agree that eliminating the taper at the back could constitute "widening."
If that is still a requirement, it's an anachronism - F110 powered the F-14D which is long gone. Engines in use by the air wing are F414, F404, J52 (vanishing), T700 and T56 (am I missing any?). I think the driver is probably the number of passengers.

C-2 allows six rows of 2+2 seating plus one row of 2, current S-3 width would give you rows of 1+1 with a slightly wider aisle and seats.


  • S-3A forward .jpg
    S-3A forward .jpg
    159.4 KB · Views: 1,108
  • C-2A.jpg
    228.3 KB · Views: 1,049
I'm guessing the "new" Vikings would be to supplement the C-2's along with freeing up Hornets by taking over more tanking missions. So the passenger factor may not be a big issue. I'm guessing the only reason it's being widened at all is for the ramp at the tail.
aim9xray said:
If that is still a requirement, it's an anachronism - F110 powered the F-14D which is long gone. Engines in use by the air wing are F414, F404, J52 (vanishing), T700 and T56 (am I missing any?).

More likely I misremembered it. But I think the requirement is to carry a spare engine, so pick the biggest engine in carrier use.
Thanks for that. I tried to clean up the image from the AWST article and post it here, but it came out looking lousy, so I quit.

I hope that they release some better imagery. It would be interesting to compare the old and new fuselages. Note the extensions on either side of the bottom of the fuselage. Presumably that is for the landing gear. They would have to move a lot of stuff out of the standard fuselage to get the maximum volume, since the standard S-3 fuselage includes the gear and a weapons bay. Plus, they'd have to beef up the floor. And the tailhook will have to be moved. In other words, it's not simply gutting the fuselage, but completely redesigning it.

Lockheed Martin was doing some experiments with a bizjet fuselage a few years ago. I cannot remember if they were trying to build a composite fuselage or one with standard materials, only trying to speed up the design process. I heard about it during a visit to the Skunk Works in 2011. It was an internal project and they never intended to fly the airframe, but I think that the story got reported.
Top Bottom