North American ESO-7618 ("Jet T-28") to spec OS-141 (VTB Basic Jet Trainer)

Mark Nankivil

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...and a few more images...

Enjoy the Day! Mark
 

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Quite an ugly sonovab... but quite a fantastic find too!

The missing link between the Trojan and the Buckeye (Trojeye, sort of ;D ).
 
An all-new fuselage/cockpit mated to the T-28 wing and empennage ?
Looks much slimmer, than the Trojan.
 
Actually, the auction ended, but the model didn't sell. If you missed your chance, expect to see it re-listed soon!
 
North American Aviation T-28 variants, with turbojet (USN OS141) and turboprop (USAF YAT-28E) engines.
 

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CostasTT said:
Conceptual beginnings of the T2J/T-2 Buckeye?

Quite possibly. Truman-era DoD procurement (Korean war period) tended to restrict funding for all-new projects, but gave much more latitude for modifications of existing airframes. That's probably why naming an airplane F-86D gave NAA a better chance than with F-95. There are other examples.

Attached are more-better model photos of the NAA NA-241 / Jet T-28 / OS141 / ESO 7618 (or is it ESO 4028? -- I'm confused...)

The underside hook, ahead of the wing root, is the bridle catapult attachment.

Based on later posts in this topic, this is NOT the NA-241 or ESO 4028. Both these designations belong to the T2J Buckeye.
 

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I'll echo the comments that it looks like Buckeye. On a diet.
 
This is the North American ESO-7618 ("Jet T-28") to Outline Specification 141 "VTB Basic Jet Trainer"


A second design offered to the same spec was the North American ESO-4028 / NA-241 also to OS-141 "VTB Basic Jet Trainer". They are clearly listed separately in the Spangenberg Index.



I'm pretty sure OS-141 led to the T2J Buckeye. Here's one of Lockheed's OS-141 design, a highly upgraded T2V Seastar derivative:

index.php


http://www.secretprojects.co.uk/forum/index.php?topic=18059.0
 
So a quick look confirms the Cessna T-37 was submitted to OS-141.

Lockheed's designs are listed in Spengenberg under "VT Basic Trainer" alongside some others:

Lockheed CL-330/-1 VT Basic Jet Trainer
Lockheed CL-340 VT Basic Jet Trainer
Temco 59 VT Basic Jet Trainer
Stroukoff MS-26 VT Basic Jet Trainer
Fairchild M-236 VT Basic Jet Trainer

So there may be two stages here or two related specs.

Fairchild M-236 is listed in the NASM Fairchild Collection http://airandspace.si.edu/research/arch/findaids/pdf/Fairchild_Finding_Aid.pdf

"Folder 4 Fairchild M-236 Model, photographs"
 
Temco Model 59 may be the TTX, a developed version of the Temco TT-1 Pinto (suggestion by Robunos, I agree it is logical)

index.php


http://www.secretprojects.co.uk/forum/index.php/topic,14954.msg149905.html#msg149905
 
PaulMM (Overscan) said:
This is the North American ESO-7618 ("Jet T-28") to Outline Specification 141 "VTB Basic Jet Trainer"

A second design offered to the same spec was the North American ESO-4028 / NA-241 also to OS-141 "VTB Basic Jet Trainer". They are clearly listed separately in the Spangenberg Index.

I'm pretty sure OS-141 led to the T2J Buckeye.

OK Thank you Overscan, for the Spangenberg distinction.
 
Checking the North American model list confirms North American ESO-4028 / NA-241 is the Buckeye, winning submission to OS-141.

The ESO-7618 ("Jet T-28") is thus a direct contemporary of (and alternative to) the T2J Buckeye, a T-28 derivative for low cost and ease of development but probably partly non-compliant with the OS-141 specs.

If compared to Lockheed CL-330/CL-340 proposals, it would seem to fit a general pattern of probably non-compliant derivatives of existing designs (CL-330 derivative of T2V, ESO-7618 derivative of T-28, Temco Model 59 Pinto derivative) and fully compliant but largely new designs (e.g. CL-340, ESO-4028).
 
Thanks a lot Paul for all this most helpful work.

One thing though: the Lockheed designs would be dated approximately 1955 and 1956, and the Fairchild M-236 also circa 1956. The Temco 59 was probably the TTX, but I have its date listed as 1958, which seems a little late, isn't it? I also have a "Temco Model 54" which may be a "basic jet trainer proposal" but this would need further confirmation. If confirmed, this could be the earlier proposal.
 
According to the Spangenberg index Model 59 was submitted with CL-330/CL-340 - which is a 1956 design. Therefore Model 59 is 1956 too. The "TTX" Pinto derivative was publicised in 1958, this does not preclude it being the same as Model 59 but we have no proof they are the same.


Temco 58 was publicly revealed in Jan 1956, which fits timelinewise.



OS-141 was awarded to NAA on July 1956.
 
PaulMM (Overscan) said:
So a quick look confirms the Cessna T-37 was submitted to OS-141.

I'm not sure about that. The only BuAer evaluation I have at the moment includes the other airplanes you listed but not the T-37. However, that doesn't mean that it wasn't proposed. I'll have more in a few months.
 
Chances are there must also have been a Carma Weejet proposal, at least in the early stages.
 
Tailspin Turtle said:
PaulMM (Overscan) said:
So a quick look confirms the Cessna T-37 was submitted to OS-141.

I'm not sure about that. The only BuAer evaluation I have at the moment includes the other airplanes you listed but not the T-37. However, that doesn't mean that it wasn't proposed. I'll have more in a few months.


From Spangenberg Index -


Cessna T-37 VTB Basic Jet Trainer OS-141 nd
 
3-view of the "Jet T-28", based on the photos of the model and drawings of the T-28. Special thanks for
the photo of both models, the Jet T-28 and the AT-28, which gave a very good comparison and to my opinion
shows, that the rear fuselage of both are of the same length, allowing for a quite precise calculation of the
uselage length.
 

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It is a great drawing and I can already see the single-seat CAS/COIN version in my mind's eye, perhaps painted in U.S. Army colors as it would have been perfect for the multiple times that the boys in green tried to get into the fixed-wing jet close air support business.
 
Thank you !
I've added some colour, using a standard T-28 as a pattern. Registration, numbers and
names are purely fictional, of course.
 

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FTFY
<edit> image removed, surplus to requirements
 
Thanks Arjen !
And 100 points for Stéphane as the winner of "Who spots the error ?"
Well, that's the result, when making such a lettering like a ransome note ! :-\
 
Thank YOU for the drawing. Excellent as always.
 
Jemiba said:
Thank you !
I've added some colour, using a standard T-28 as a pattern. Registration, numbers and
names are purely fictional, of course.

Love it, thanks. A special request, how about one in U.S. Army colors as a FAC and CAS aircraft, in honor of the U.S. Army evaluations of jet attack aircraft (hotly opposed by the USAF) in 1957 (Cessna T-37A) and 1961 (Douglas A4D-2 Skyhawks, Northrop N-156/early F-5 and Fiat G-91)?

This link shows a B&W image of the trials T-37As if that helps: http://books.google.com/books?id=Cr20MURP3XAC&lpg=PA12&ots=B6FYnqVEoH&dq=cessna%20t-37a%20u.s.%20army%20evaluation%201957&pg=PA12#v=onepage&q=cessna%20t-37a%20u.s.%20army%20evaluation%201957&f=false
 
Why not ? if you can wait some days ... ;)
 
PaulMM (Overscan) said:
Tailspin Turtle said:
PaulMM (Overscan) said:
So a quick look confirms the Cessna T-37 was submitted to OS-141.

I'm not sure about that. The only BuAer evaluation I have at the moment includes the other airplanes you listed but not the T-37. However, that doesn't mean that it wasn't proposed. I'll have more in a few months.

From Spangenberg Index -
Cessna T-37 VTB Basic Jet Trainer OS-141 nd

Strictly speaking, the original handwritten index does not list it as such. It's not even in the same box as the VTB candidates. However, I'll go down to College Park in the early spring and take a look...
 

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Jemiba said:
3-view of the "Jet T-28", based on the photos of the model and drawings of the T-28. Special thanks for
the photo of both models, the Jet T-28 and the AT-28, which gave a very good comparison and to my opinion
shows, that the rear fuselage of both are of the same length, allowing for a quite precise calculation of the
uselage length.

Better late than never...
 

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