Northrop goes early with 1-engined F-5?

tomo pauk

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... early meaning that it is made instead of the F-5E/F.
What engine to choose? The J85 was very light, a pair of them were barely above 600 kg. Perhaps soup-up the J52 ASAP, later jump on the F-404? The J65 perchance, it propelled the XF-104 to Mach 2?
 

Archibald

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When ? in 1956 for N156F ? 1961 for F-5A ? or 1969 for F-5E ? In the latter case: J101, the YF-17 engine. And then it becomes a proto-F-20-Tigershark.
 

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I think the J85 was an important part of the F-5 success. Being a glorified supersonic trainer with only the minimum of its customers needs. J85 is simple and cheep. I’m not sure how many contemporary single engines are.
 

H_K

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@tomo pauk Here’s an interesting list of engines that were considered for the BAe Hawk around the same timeframe (1968-70). I assume a reheat could have been added to most.

J85 was considered too thirsty. Not a lot of US alternatives available. From Europe, Adour might have been the best, but unlikely to be available given Jaguar production priority.

https://www.aerosociety.com/media/4842/the-hawk-story.pdf (see pp. 9-11)
 

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BullpupRafale

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I think the J85 was an important part of the F-5 success. Being a glorified supersonic trainer with only the minimum of its customers needs. J85 is simple and cheep. I’m not sure how many contemporary single engines are.
I would not call J85 cheap considering its atrocious fuel efficiency of 1.24 to 1.28 lbs per lbf per hour.

@tomo pauk Here’s an interesting list of engines that were considered for the BAe Hawk around the same timeframe (1968-70). I assume a reheat could have been added to most.

Not a lot of US options available. Adour might have been the best, but unlikely to be available given Jaguar production priority.

https://www.aerosociety.com/media/4842/the-hawk-story.pdf (see pp. 9-11)
But there is always option of licensing which for example Japan acquired for their F1 and T2 jets.
 

Pioneer

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So are we talking F-5E/F Tiger II and not N-156F/F-5A/B to be configured as single-engine?



Regards
Pioneer
 

tomo pauk

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@tomo pauk Here’s an interesting list of engines that were considered for the BAe Hawk around the same timeframe (1968-70). I assume a reheat could have been added to most.

J85 was considered too thirsty. Not a lot of US alternatives available. From Europe, Adour might have been the best, but unlikely to be available given Jaguar production priority.

Thank you for the list and pdf.
A single Adour, even with the reheat, will not add much to the table vs. two J85s. The RB.199 is the best, but I'm not sure about the availability in the early 1970s.
Any European engine has an uphill battle vs. the US engine for an F-5 that is to became single-engined.

So are we talking F-5E/F Tiger II and not N-156F/F-5A/B to be configured as single-engine?

F-5E is made as an 1-engined A/C.
 

zen

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M45-H seems the lowest s.f.c figures for a decent thrust-to-weight ratio.
 

Archibald

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Circa 1969 Sud Aviation in Toulouse takes a F-5E licence to try and piss-off no only Dassault, but also the Gaullists supporting him.
The engine they pick: M45G, orphan of the AFVG. At 5500 kg of thrust it should be more than able to replace the two J85 at 1800 - 2000 kg thrust each.

End result: a proto, French, F-20 Tigershark.
 

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I think the J85 was an important part of the F-5 success. Being a glorified supersonic trainer with only the minimum of its customers needs. J85 is simple and cheep. I’m not sure how many contemporary single engines are.

I'd be hesitant to say as such since twin engines implies doubled maintenance work hours. No one had trouble operating massive quantities of F-104s or A-4 Skyhawks, after all, which had big engines of similar vintage. The J85 was probably just chosen because physically small engines were crummy back then and F-5 was a combatized form of T-38. Less the engine and more the plane picked.

F-5 was supersonic unlike the Skyhawk, and lacked the expensive radars and long range combat capability of the F-104, thus neatly fitting into a nice "day fighter" role that could do more than lug Bullpups around. Like intercept bombers.

The J52 was another good option as I think the T-38 itself competed with a Super Saber-based trainer, and the J52 was cheap enough to be disposable much like the J85, but I don't think the J52 actually existed at the time. But a J52 powered jet would be very different from the F-5 in layout. It might actually fit in a Super Saber though, or a supersonic Skyhawk.

J52 and J57 would both provide similar power to the F-5 over the dual J85 setup, which is all it really needs to do. They're also pretty cheap (enough that Argentina and Israel, both very poor countries at the time, had quite a few them) and J52 would be common with Skyhawk.

Maybe Israel would get super F-5 instead of Mirages who knows.
 
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bobtdwarf

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I think the J85 was an important part of the F-5 success. Being a glorified supersonic trainer with only the minimum of its customers needs. J85 is simple and cheep. I’m not sure how many contemporary single engines are.

I'd be hesitant to say as such since twin engines implies doubled maintenance work hours. No one had trouble operating massive quantities of F-104s or A-4 Skyhawks, after all, which had big engines of similar vintage. The J85 was probably just chosen because physically small engines were crummy back then and F-5 was a combatized form of T-38. Less the engine and more the plane picked.

F-5 was supersonic unlike the Skyhawk, and lacked the expensive radars and long range combat capability of the F-104, thus neatly fitting into a nice "day fighter" role that could do more than lug Bullpups around. Like intercept bombers.

The J52 was another good option as I think the T-38 itself competed with a Super Saber-based trainer, and the J52 was cheap enough to be disposable much like the J85, but I don't think the J52 actually existed at the time. But a J52 powered jet would be very different from the F-5 in layout. It might actually fit in a Super Saber though, or a supersonic Skyhawk.

J52 and J57 would both provide similar power to the F-5 over the dual J85 setup, which is all it really needs to do. They're also pretty cheap (enough that Argentina and Israel, both very poor countries at the time, had quite a few them) and J52 would be common with Skyhawk.

Maybe Israel would get super F-5 instead of Mirages who knows.
J-52 would be my thinking as well and should be "available" post 1957; the Hound dog was deployed in 1960 and designed between '57 and '59. There is nothing stopping putting an A/B on it other than no one called for that application earlier than the JF-17.
 

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An afterburning J52 would be J57 I think, but F-5 probably doesn't need an afterburner at the end of the day as Hound Dog was supersonic.

It might want one to fight MiG-21 but that's why F-20 was made in the first place I guess.
 

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J52 was scaled down from J57. It could have had a scaled down version of the J57 afterburner.
or given the diameter an adapted version of the AB on the J-65.. either way it would be about the size of a J-65, except this one would not SUCK!

Taking a look at it by dividing the wet thrust by the dry thrust to give an idea of how much the AB boosts things... using either of the options gets you about the same 11k wet thrust on the first model of J-52.. if that stays constant over the run then the final 409 model will give you 12k dry and over 17k wet. So very J-79 like performance with a wee bit better SFC and possibly more reliable, no clue if it would be lighter or not.
 
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red admiral

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M45-H seems the lowest s.f.c figures for a decent thrust-to-weight ratio.
Also need to think about physical size of the engine. The higher BPR makes it both big and the intake duct big.

Whereas say RB.199 is not that much bigger than Adour when you consider the accessories too.
 

kaiserbill

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J52 was scaled down from J57. It could have had a scaled down version of the J57 afterburner.
or given the diameter an adapted version of the AB on the J-65.. either way it would be about the size of a J-65, except this one would not SUCK!

Taking a look at it by dividing the wet thrust by the dry thrust to give an idea of how much the AB boosts things... using either of the options gets you about the same 11k wet thrust on the first model of J-52.. if that stays constant over the run then the final 409 model will give you 12k dry and over 17k wet. So very J-79 like performance with a wee bit better SFC and possibly more reliable, no clue if it would be lighter or not.
I have always been amazed an afterburning J-52 never saw the light of day. I guess by that time, turbofans were a thing.
Still, it had a very good pr, SFC, and was compact for the power it produced. It ended up with a better SFC and PR than the J-79, and arguably could have produced as much thrust in a lighter, more compact package.
 
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BullpupRafale

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J52 was scaled down from J57. It could have had a scaled down version of the J57 afterburner.
or given the diameter an adapted version of the AB on the J-65.. either way it would be about the size of a J-65, except this one would not SUCK!

Taking a look at it by dividing the wet thrust by the dry thrust to give an idea of how much the AB boosts things... using either of the options gets you about the same 11k wet thrust on the first model of J-52.. if that stays constant over the run then the final 409 model will give you 12k dry and over 17k wet. So very J-79 like performance with a wee bit better SFC and possibly more reliable, no clue if it would be lighter or not.
I have always been amazed an afterburning J-52 never saw the light of day. I guess by that time, turbofans were a thing.
Still, it had a very good pr, SFC, and was compact for the power it produced. It ended up with a better SFC and PR than the J-79, and arguably could have produced as much thrust in a lighter, more compact package.
Well it was further developed into turbofan and Swedes jammed it in a fighter jet.
 

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J52 was scaled down from J57. It could have had a scaled down version of the J57 afterburner.
or given the diameter an adapted version of the AB on the J-65.. either way it would be about the size of a J-65, except this one would not SUCK!

Taking a look at it by dividing the wet thrust by the dry thrust to give an idea of how much the AB boosts things... using either of the options gets you about the same 11k wet thrust on the first model of J-52.. if that stays constant over the run then the final 409 model will give you 12k dry and over 17k wet. So very J-79 like performance with a wee bit better SFC and possibly more reliable, no clue if it would be lighter or not.
I have always been amazed an afterburning J-52 never saw the light of day. I guess by that time, turbofans were a thing.
Still, it had a very good pr, SFC, and was compact for the power it produced. It ended up with a better SFC and PR than the J-79, and arguably could have produced as much thrust in a lighter, more compact package.
it would have been a perfect thing for P&W to offer as an alternative/swappable for GE's J-79.

How many AH's have we all seen where something like "but you would have to fight for/divert production from X,Y or Z? IN this case it would be J-79 production in the early 60's.
 

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How many AH's have we all seen where something like "but you would have to fight for/divert production from X,Y or Z? IN this case it would be J-79 production in the early 60's.

What if the USN busted J79 capability with too many (superb) aircraft ? Vigilante and Phantom and the losers: Super Tiger and Skylancer. AB J-52 for these two would help against the Skyhawk "anti snoopers" for small navies and small carriers.
 

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AB J52 for the blursed supersonic Skyhawk.

Argentina would still lose I think.
 

Michel Van

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A Single Engine F-5 in begin of program would be interesting in long term.
Northrop could bug out the F-5 and adapt it for YF-17 prototype (analog to F-20)
With a F-17 going into productions mid 1970s in USA and Europe

Now This give new question what will be build as F/A-18 ?
Since Navy insist on two engines Aircraft, a Super F-14?
 

tomo pauk

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A Single Engine F-5 in begin of program would be interesting in long term.
Northrop could bug out the F-5 and adapt it for YF-17 prototype (analog to F-20)
With a F-17 going into productions mid 1970s in USA and Europe

Now This give new question what will be build as F/A-18 ?
Since Navy insist on two engines Aircraft, a Super F-14?

Navy gets the F-18, that is a scaled-up F-5A?
 

lancer21

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I would probably start from the N-156F, ok let them use two engines in the T-38, but use the J-65 with AB in the YF-5A prototype, and by the time production is underway in 1962-1963 (probably called C/D) they should be able to use the J-52 with AB of something like what 5000-5500kgf. For the F-5E an improved uprated J-52 of say 6000-6500kgf, then switching to the YJ-101 or F404 when they are available (an earlier F-20 in effect, in OTL it was way too late).

The OTL F-5 was too lame compared to it's contemporaries J-35, Mirage-III, MiG-21 etc. because of the weak engines.
 

Michel Van

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A Single Engine F-5 in begin of program would be interesting in long term.
Northrop could bug out the F-5 and adapt it for YF-17 prototype (analog to F-20)
With a F-17 going into productions mid 1970s in USA and Europe

Now This give new question what will be build as F/A-18 ?
Since Navy insist on two engines Aircraft, a Super F-14?

Navy gets the F-18, that is a scaled-up F-5A?
yes F-18 is scaled up F-5a the twin engine version
but this is about a single engine F-5 and US Navy not wanted single engine aircraft in time the F-18 was build.
and since in this Alternate history F-5 has one big engine like F-20, the US Navy need another aircraft...
 

apparition13

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Northrop was already working on the YF-17 lineage when the F-5E program came along. All they would have to do is decide to simply use one of the engines for the 'not yet YF-17' to get a big performance boost in the new F-5E model. I think the simplest for the OP's timeline is the YJ-101, which pretty much gives you an F-20 with more primitive avionics a decade earlier.

Which would actually make the F-5G/F-20 more viable around 1980, since it would be an avionics upgrade and engine swap rather than a redesign. They could both sell new aircraft and upgrade older, single J101 engined ones.
 

tomo pauk

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yes F-18 is scaled up F-5a the twin engine version
but this is about a single engine F-5 and US Navy not wanted single engine aircraft in time the F-18 was build.
and since in this Alternate history F-5 has one big engine like F-20, the US Navy need another aircraft...

They get the F-18, a twin-engined multi-role aircraft.
 
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