UTX/UCX proposals

[hesham]

Hi,


the Lockheed GL-135 was the original design for which later called CL-329 Jet Star.

 

[nugo]

Hi All!
Hi circle-5, where the location of the model and if you can show the model from different angles.
In my opinion this project is not a VTOL configuration and model designation AP-90 is not true.
In my opinion this project---Model AP-8? (eliminate Model AP-85).

 

[circle-5]

Hi All!
Hi circle-5, where the location of the model and if you can show the model from different angles.
In my opinion this project is not a VTOL configuration and model designation AP-90 is not true.
In my opinion this project---Model AP-8? (eliminate Model AP-85).

No, it is not a VTOL aircraft. UTX/UCX did not require VTOL capability. The slipper tanks ahead of the engine stacks are removable on the model, which may have given that impression. Hesham indicated the Republic UCX was AP-90. I do not have data to either confirm or deny this.

 

[Stargazer]

A modern day magazine might write wrong stuff gleaned on the web or from erroneous research, but during the 1950s Air Pictorial was basically of the world's three or four leading aviation publications and had access to reliable information.

If AP gave "AP-90" as the designation for the UTX/UCX contender, and since they couldn't possibly make up such a designation, I can see no reason to doubt that bit of data.

 

[nugo]

Thank You very much circle-5!
My friend Stargazer2006, UCX(C-140) is a Air Force medium-weight, multi-engine utility transport-trainer aircraft and UTX(T-39) is a Air Force twin-jet utility trainer aircraft. Maybe AP-90 is a Air Force utility jet aircraft , maybe another competition, which also included the Lockheed Jetstar and NA Sabreliner.
circle-5, if you can show the model from below.

 

[Jemiba]

Very interesting model ! Without meddling into the discussion about the designation, it's the engine/inlet
configuration, that makes me wonder. As the slipper tanks were removable on the model, they certainly
would have been on the full scale article, too, Without those tanks, I think, the model would look like
having the inlet for the lower engines below and for the upper pair above the wing. Would be quite logical,
but impossible WITH tanks. Then the aircraft need an S-duct for the upper engines. Quite complicated, I think.
Have I overlooked something ?

 

[Stargazer]

UCX and UTX requirements were close enough for the designs to be offered for both (JetStar, Sabreliner, McDonnell 119/220) and so it is likely that Republic's proposal for one was also tendered to the other with minor differences.

 

[hesham]

Hi Circle-5,


I see the Republic AP-90 for this aircraft is a completely right,that's because the
Air Pictorial magazine no need to mention it,if it was just speculative,and may
be they got it from the Republic company itself.

 

[circle-5]

Very interesting model ! Without meddling into the discussion about the designation, it's the engine/inlet
configuration, that makes me wonder. As the slipper tanks were removable on the model, they certainly
would have been on the full scale article, too, Without those tanks, I think, the model would look like
having the inlet for the lower engines below and for the upper pair above the wing. Would be quite logical,
but impossible WITH tanks. Then the aircraft need an S-duct for the upper engines. Quite complicated, I think.
Have I overlooked something ?

The slipper tanks were likely to be removable only on the scale model, to easily swap sizes and shapes. Early jet engines were quite thirsty, so external tanks were often necessary.

As for the air intakes, you are correct: these are underwing intakes with a splitter to feed both engines. It's not all that complicated. An air intake on top of the wing at mid-chord would have starved the engine at high or even moderate AOA. It would have had to be extended forward to the leading edge, requiring a separate wing location for the fuel tank -- meaning more drag and a heavier wing structure. In line with the engine stacks, the slipper tank created minimum drag and may also have served as a wing fence, as on the competing JetStar.

Nobody had yet designed a "business jet" aircraft at that time, so UTX/UCX was the driving force behind a whole new class of aircraft. Republic's proposal, while slightly unconventional, is quite elegant, in my opinion.

 

[lark]

The Air Pictorial AP-90 note mentions a bending tailpipe.
Perhaps for VTOL purposes.

Could the aft engines ends perhaps be tilted down...?

 

[Jemiba]

The Republic UTX proposal, using the two model photos, so source grade 2:
Clues and tips, or additional information welcome !

 

[hesham]

Wow,excellent work my dear Jemiba.

 

[Stargazer]

the Lockheed GL-135 was the original design for which later called CL-329 Jet Star.

Accordin to the Al Mooney Papers, the Lockheed GL-135 was studied in other versions, designated GL-135Q and GL-135 CRT.

 

[hesham]

Great find my dear Skyblazer.

 

[hesham]

Hi,

I suggest that; the Temco proposal was Model-41,which was a jet trainer similar to Model-32
with four wing mounted jet engines.

http://www.secretprojects.co.uk/forum/index.php/topic,14958.msg149850.html#msg149850

 

[Jos Heyman]

You reference is confusing. But there is another topic on the Temco Model 41 Jet Trainer and the drawing there looks like something that could have been entered in the UTX/UCX competition. But we must be a bit careful with drawing conclusions. The Temco 41 proposal is dated 8/3/1954 whilst the UTX/UCX competition was started in March 1956 and concluded in August 1956. This time difference must cast some doubt on Temco 41 status in ITX/UCX although, like the T-39, it could have been resurrected. Perhaps more research is necessary.

 

[hesham]

No my dear Jos,

the Temco Model-41 was appeared after Model-32,only the Model-32 was in 1954,
also we can consider the Temco Model-45,which similar to Model-32 with twin turboprop
engines.

http://www.secretprojects.co.uk/forum/index.php/topic,14954.msg150041.html#msg150041

 

[Jos Heyman]

Not according to Bill S post of 1 February 2016 on the Temco T-41 discussion. He states:
"These images come from drawing 41-9000002 by R. Walper dated 8-3-54."

 

[hesham]

OK my dear Jos,

we can also trace the Model-45 ?.

 

[Boxman]

Stumbled across a (low-resolution) photo of a Sabreliner mock-up at the San Diego Air & Space Museum (SDASM) Archive site on Flickr. This has the wing root-mounted engines and sweptback windscreen of the circa-1956 version, as shown/described by Circle-5.
https://www.flickr.com/photos/sdasmarchives/4589924879/in/photostream/

 

[barbara_em]

I think I remember the UCX being written for a four engine craft, thus the switch in the JetStar from the two larger RR engines to the four smaller engines and the original 119 low slung podded units. From the start, the UTX was for a twin engine design. I'll not be surprised if I remember incorrectly, though.