Lockheed CL-1250 Twin Engined Fighter (derived from General Dynamics A-2)

[hesham]

Hi,


I can't ID this twin engined superiority fighter of early 1970s,who can help ?;


http://arc.aiaa.org/doi/abs/10.2514/3.59258?journalCode=ja

 

[Antonio]

ATF?

 

[Grey Havoc]

CL-1600?

CL-1600 twin-engined projected development of LANCER to compete against F-16 and F-17, none built

 

[sferrin]

There is a drawing in Jay Miller's "Skunk Works" of the CL-1600 and it does look very similar to this. In the words of Kelly Johnson:

"Some four weeks after that, on March 18,
Johnson made the following log entry, "We
were visited by Lt. Gen. James Stewart, Col.
Cameron, Col. John Boyd, Col. Robert
Parsons, Mr. Fred Wood, Maj. Loh, and Maj.
Gordon England. We discussed our lightweight
fighter and the ability of the Skunk Works to
produce the prototypes. They were on a tour to
visit all bidders who were, besides ourselves,
General Dynamics, Northrop, Boeing, and LTV.
I am sure we answered all their questions well,
but I am greatly concerned about the horrible
situation facing Lockheed with regard to the C-
5A, AH-56, SRAM, and our L-1011 situation. It
seems almost impossible for them to give us a
contract in view of Sen. Proxmire's almost daily
attacks on Lockheed, compounded by the fact
that our design out-performs the F-15 at
approximately 40% of its cost."

. . .

"Between the period of the debriefing and
the present time it has been confirmed to me
from many sources that out CL-1600 was too
good, too honest, too soon, and too cheap.
When you combine these factors with the overall
Lockheed image today, it is easily understood
why we were not a winner. Some interesting
factors developed worthy of note in the
time period stated. Boeing were very mad at
their not placing. Ray Utterstrom from Boeing
came down to see whether or not we could join
together in a joint program to build a fighter
incorporating some of their ideas and some of
ours. When he saw what we had in the CL-
1600 and we compared wind tunnel data,
wherein our wing beat theirs by 20% in lift and
buffet boundary. He went away completely
shaken, saying that we should have won."

 

[hesham]

ATF?

No my dear Pometablava,


the initial work began in 1972,and for my dears Grey and Sferrin,I think it looks like CL-1600
as you mentioned,but differs in some details,the air-intakes has longer road,and the nozzles
is different.

 

[hesham]

Probably CL-1600, just a different iteration of the design.

Maybe that's right my dear Skyblazer.

 

[overscan (PaulMM)]

No.

During the twin-jet tests, the same nozzles were installed in a generalized model of an advanced air superiority fighter having twin buried engines and dual nozzles (Fig. 1). The airframe design was selected from among those developed by General Dynamics under contract with the Air Force Flight Dynamics Laboratory.

The basic test configuration is a modified version of the A-2 twin-jet air superiority fighter design developed by General Dynamics under contract with the Air Force Flight Dynamics Laboratory. The wind-tunnel model is approximately 12 ft in length and has a wing span of 7.9 ft. All testing was conducted over a 0.6 to 2.5 Mach number range in the AEDC (Arnold Engineering Development Center) 16-foot PWT (Propulsion Wind Tunnel).

Please try READING the articles.

 

[hesham]

OK my dear Paul,


and thank you for your explanation

 

[Steve Pace]

Wasn't CL-1600 an advanced version of the X-27 Lancer? -SP

 

[Apophenia]

Just to confuse matter further, another version of this paper only mentions variations on the CL-1600 -- as the Y-1, Y-2, and Y-3 Candidate Turbofan Configurations ... with increasingly spaced apart engines.

Integrated Airframe-Nozzle Performance for Designing Twin-Engine Fighters, E. R. Glasgow and L.D. Miller et al, Lockheed-California Company, Technical Report AFFDL-TR-72-101, October 1972. http://www.dtic.mil/dtic/tr/fulltext/u2/904747.pdf

Three-view drawings of the Y-1/Y-2/Y-3 Candidate Turbofan Configurations are shown on pp-269-275 (pdf pages 293-304).

Perhaps the Journal of Aircraft Vol. 11, No. 6 article Hesham linked to is based on a slightly latter version of this paper ? ???

 

[sferrin]

Wasn't CL-1600 an advanced version of the X-27 Lancer? -SP

Completely different design. The X-27 was the CL-1200.

 

[Steve Pace]

There was two versions of the Lancer - the second one being an advanced Lancer. So I was wondering if the second version got the CL-1600 model number. -SP

 

[overscan (PaulMM)]

From Lockheed Skunk Works by Jay Miller

In still another January 12 entry, Johnson recounted, "Reviewed our design efforts to date to obtain optimum performance of the lightweight fighter. I disagreed with Ben and others on shortening the airplane by 6 feet, which would lead to a questionable weight saving, in my view, and very poor flight and buffet characteristics.

After going over all design elements, I set a design empty weight of 13,900 pounds for the long fighter, which does have good flying characteristics and much greater ground attack potential than the one 6 feet shorter.

"We will submit the single-engine airplane with the aerodynamic configuration of the CL- 1200 as our basic bid. We set a new design number for the lightweight fighter, which will be the CL-1600, to divorce it from our prior studies. I called Rus Daniell, Larry Billups, Dick Adair, Ben Rich, Jack Prosser, and Bob Murphy and told them the schedule and approach I want to take on the CL-1600.

Essentially with the Feb. 18, 1972 date for turning in our proposal and following the Air Force statement that they would decide the program in about 45 days. I proposed that if we are one of the two winners, that in June we start tooling the aircraft with part of the $3 million available, and we aim for a flight date of June 1973.

Johnson, in releasing the new design number, had written several of his Skunk Works team members with the following notation:
"It is advisable to change the design number of our Lightweight Fighter from the CL-1200 to another serial. The reason for this is to impress the Air force with the fact this is truly a new aircraft and responsive reaction to their request for bid on the subject aircraft. We have been advised to play down the fact that our Lightweight Fighter is derived from the CL-1200, the X-27, or the F-104. In response to this suggestion, I have obtained the design number CL-1600 for our proposed aircraft. Rationale for this number has to do with our desire to avoid the 1300 and 1500 series for obvious reasons, the latter of course being conflict with the F-15."

 

[overscan (PaulMM)]

So, that PDF makes it all relatively clear. It makes the "CL-1600" designation for the drawing in Skunk Works seem dubious though. I have CL-1600 looking like CL-1200.

Lockheed (Calac) made a generic advanced fighter test model for engine optimisation studies by reworking the AFFDL General Dynamics A-2 model from Project Tailor Mate to more closely resemble their studies (e.g. low to high wing) in configuration.

As discussed in Subsection 2.1.2, the basic test configuration is a modified version of the A-2 twin-jet air superiority fighter design evolved by GD under the AFFDL-sponsored Supersonic Inlet Design and Airframe Inlet Integration Program (Reference 57). This design, designated as the Calac CL-1250, has a high wing, half-axisymmetric inlets mounted on the sides of the fuselage forward of the wing leading edge, and close coupled stabilizers, as illustrated in Figure 139.

 

[overscan (PaulMM)]

Following on we have


Y-1 = CL-1250-9
Y-2 = CL-1250-10
Y-3 = CL-1250-8
Z-1 = CL-1250-11


These drawings need reassembling. They are large, F-15 / Su-27 sized.



CL-1250 spanned a wide range of F-15 type designs, including wing mounted engine versions.

 

[hesham]

Oh my God,


great find my dear Paul,you made my day,

 

[Merv_P]

Following on we have


Y-1 = CL-1250-9
Y-2 = CL-1250-10
Y-3 = CL-1250-8
Z-1 = CL-1250-11


These drawings need reassembling. They are large, F-15 / Su-27 sized.



CL-1250 spanned a wide range of F-15 type designs, including wing mounted engine versions.

Here's a quick cleanup of the Z-1 configuration using the 3-views in the PDF. It's at 1024pix, the original is 5000pix. I'm working over Christmas but can do the others after that unless anyone else wants to; they're not that difficult to clean.

 

[Stargazer]

Fascinating thread, thanks to you all (and mostly to Paul) for sorting out this mess!

 

[Steve Pace]

On page 286 of this amazing pdf it also lists:
X-1 as CL 1250-3
X-2 as CL 1250-4
X-3 as CL 1250-7
X-4 as CL 1250-6
X-5 as CL 1250-6A

 

[overscan (PaulMM)]

Following on we have


Y-1 = CL-1250-9
Y-2 = CL-1250-10
Y-3 = CL-1250-8
Z-1 = CL-1250-11


These drawings need reassembling. They are large, F-15 / Su-27 sized.



CL-1250 spanned a wide range of F-15 type designs, including wing mounted engine versions.

Here's a quick cleanup of the Z-1 configuration using the 3-views in the PDF. It's at 1024pix, the original is 5000pix. I'm working over Christmas but can do the others after that unless anyone else wants to; they're not that difficult to clean.

Thanks! I'd suggest, if you are going to do the work to clean up the scans, you post at 2000+ pixels.

 

[Merv_P]

Thanks! I'd suggest, if you are going to do the work to clean up the scans, you post at 2000+ pixels.

Yes; that image was just testing the waters. Here's a better quality cleanup of the 1250-8 (Y3) version, 2700pix. The rest after Christmas unless someone else wants to have a go.

And thanks to Apophenia for unearthing the PDF.

 

[PlanesPictures]

Nice designs, thanks. Position of fourth rocket is interesting

 

[Apophenia]

... Position of fourth rocket is interesting

Indeed! Nice work on the Y-3 re-assembly Merv_P ... thanks for that.

 

[Steve Pace]

What I've come up with so far:
Configuration, Model, Propulsion System - Comment

X-1 CL 1250-3 P&WA STF371 Turbofanjet – baseline configuration
X-2 CL 1250-4 P&WA STF371 Turbofanjet – baseline configuration
X-3 CL 1250-7 P&WA STF371 Turbofanjet – baseline configuration
X-4 CL 1250-6 P&WA STF371 Turbofanjet – baseline configuration
X-5 CL 1250-6A P&WA STF371 Turbofanjet – baseline configuration
Y-1 CL 1250-9 P&WA STF371 Turbofanjet – candidate configuration
Y-2 CL 1250-10 P&WA STF371 Turbofanjet – candidate configuration
Y-3 CL 1250-8 P&WA STF471 Turbofanjet – candidate configuration
Z-1 CL 1250-11 P&WA STJ353 Turbojet – candidate configuration
Final Report for the Period 1 November 1969 to 31 July 1972 under USAF Contract Number F33657-70-C-0511 for Project Number 668A

 

[Merv_P]

Here are the cleaned-up 3-views from the PDF - almost identical to each other, but fairly straightforward to do. The Y3 image is the same one that I posted as a sampler a few days ago.

 

[hesham]

Excellent Merv_P,many thanks.

 

[Steve Pace]

Very nice Merv_P - Thanks! -SP

Does anyone have images of GD A-1. A-2 aircraft?

 

[Steve Pace]

So what does the General Dynamics A-2 look like? -SP

 

[overscan (PaulMM)]

Project Tailormate here http://www.secretprojects.co.uk/forum/index.php/topic,5429.0.html


The model pics are config B-3 but there are some small drawings of A-2 in there somewhere.

 

[Lascaris]

There is a drawing in Jay Miller's "Skunk Works" of the CL-1600 and it does look very similar to this. In the words of Kelly Johnson:

" It seems almost impossible for them to give us a
contract in view of Sen. Proxmire's almost daily
attacks on Lockheed, compounded by the fact
that our design out-performs the F-15 at
approximately 40% of its cost."

How plausible were the performance claims above?

 

[overscan (PaulMM)]

Found A-2 config (very rough though)


http://www.dtic.mil/dtic/tr/fulltext/u2/744595.pdf

 

[Steve Pace]

Thanks, PaulMM

 

[ivran]

Any drawing. or 3 view of CL-1250-X1 whith twin tail, or CL-1600