Drawing the Profile of the F-14 ST21

[Lemniscus 1]

For awhile now, I have considered attempting to make my own profile of the F-14 Super Tomcat 21. However, after making a profile of the F-14D as a base to build from, and doing some reading on the Tomcat 21 itself... I realize I am woefully under-equipped to understand how the changes would have physically altered the appearance of the F-14D aside from the modified Wing Gloves (Which in turn I am experiencing perspective issues on how to imply the changed shape). My biggest problem comes from understanding how to enlarge the engine housing for the F110-GE-429's. Can anyone help illustrate to me how I make those changes?

For reference, here's the profile of the F-14D I am working from (based directly on Hasegawa's F-14D kits) attached below.

 

[Foo Fighter]

PNG.

 

[F-14D]

I know this is very late, I just stumbled across this. If you're still working on this, you don't need to change the housings. The F-14 was always designed to take multiple engine choices. The F110s all have the same diameter and length.For their installation in the Tomcat, there is a plug in the engine to increase their length to sit properly in the nacelles. This plug is not on installations in other aircraft.

My related point is that AFAIK, for the Super Tomcat 21, you don't need to make any changes to the nacelles from the F-14D.

And if this is way too late, is Emily Litella used to say, "Never mind" ( boy, does that date me!)!

 

[apparition13]

I know this is very late, I just stumbled across this. If you're still working on this, you don't need to change the housings. The F-14 was always designed to take multiple engine choices. The F110s all have the same diameter and length.For their installation in the Tomcat, there is a plug in the engine to increase their length to sit properly in the nacelles. This plug is not on installations in other aircraft.

My related point is that AFAIK, for the Super Tomcat 21, you don't need to make any changes to the nacelles from the F-14D.

And if this is way too late, is Emily Litella used to say, "Never mind" ( boy, does that date me!)!

ST21 was to use ATF tech - would that have included the engines, either F119 or F120? How much wider are those than the F110 (or F401 the F-14 was originally supposed to have).

 

[Scott Kenny]

Pardon me, this popped up in the "Related Threads" sidebar.

ST21 was to use ATF tech - would that have included the engines, either F119 or F120?

I don't remember. Possibly. My understanding is that it was all the avionics, not engines.

How much wider are those than the F110 (or F401 the F-14 was originally supposed to have).

F110 has a 35.66" inlet diameter and 46.5" overall diameter.

F119 has a ~40" inlet diameter, ~48" overall diameter, and 50" max width.

YF120 I only have a 42" diameter. I suspect that is inlet diameter.

F401 I only have a 50.5" max width.

So it looks like you could stuff an F119 into the existing Tomcat Nacelles! Not sure about F120s. That said, IMO you'd need to enlarge the inlets a bit.

 

[apparition13]

Pardon me, this popped up in the "Related Threads" sidebar.

I don't remember. Possibly. My understanding is that it was all the avionics, not engines.

I've seen the ASF-21 design quoted as having a supercruise speed of as much as 1.8, which implies ATF engines;

F110 has a 35.66" inlet diameter and 46.5" overall diameter.

F119 has a ~40" inlet diameter, ~48" overall diameter, and 50" max width.

YF120 I only have a 42" diameter. I suspect that is inlet diameter.

F401 I only have a 50.5" max width.

So it looks like you could stuff an F119 into the existing Tomcat Nacelles! Not sure about F120s. That said, IMO you'd need to enlarge the inlets a bit.

and this makes it plausible. The engines that is, I have doubts about the quoted speed.

Since it was supposed to be a new build anyway, though less so than a Superhornet compared to a Hornet I believe, I suspect tweaks to make everything fit and improve performance and maintenance would have been in the cards.

 

[Scott Kenny]

I've seen the ASF-21 design quoted as having a supercruise speed of as much as 1.8, which implies ATF engines;

and this makes it plausible. The engines that is, I have doubts about the quoted speed.

Even without much tweaking besides any inlet size changing, I think that the M1.8 speed isn't unreasonable. Doesn't the F-22 supercruise at M1.6 with those 40something degree swept wings? ASF-21 still has swing wings, and a 68deg sweep.

Since it was supposed to be a new build anyway, though less so than a Superhornet compared to a Hornet I believe, I suspect tweaks to make everything fit and improve performance and maintenance would have been in the cards.

A quick check of inlet areas is kinda surprising, the F119 is actually 25% more cross section area than an F110. And given the massively higher dry thrust of an F119, you probably would have to widen the inlets of the F-14 by about 4". IMO that would be a rather trivial modification, though you'd need to add larger inlet ramp actuators to go with it.

 

[apparition13]

Even without much tweaking besides any inlet size changing, I think that the M1.8 speed isn't unreasonable. Doesn't the F-22 supercruise at M1.6 with those 40something degree swept wings? ASF-21 still has swing wings, and a 68deg sweep.

I think that's closer to the YF-22's supercruise, I believe the F-22 is faster, higher than 1.8, at least if I've read between the lines of interviews with F-22 pilots correctly. My doubts are down to the aerodynamics of the airframe, which isn't optimized for supercruise, but I'll admit it's not an area I have expertise in, or how easy it would be to tweak it for supercruise.

A quick check of inlet areas is kinda surprising, the F119 is actually 25% more cross section area than an F110. And given the massively higher dry thrust of an F119, you probably would have to widen the inlets of the F-14 by about 4". IMO that would be a rather trivial modification, though you'd need to add larger inlet ramp actuators to go with it.

Having the engines in "pods" makes modifications easier, but I wouldn't want to lose any space between the nacelles for carrying missiles and bombs. That might make it tricky to widen the inlets, rather than just increase their height, with whatever aerodynamics effects those changes could have.

 

[Scott Kenny]

I think that's closer to the YF-22's supercruise, I believe the F-22 is faster, higher than 1.8, at least if I've read between the lines of interviews with F-22 pilots correctly. My doubts are down to the aerodynamics of the airframe, which isn't optimized for supercruise, but I'll admit it's not an area I have expertise in, or how easy it would be to tweak it for supercruise.

As I understand it, there's no difference in terms of aerodynamics. Just a function of sufficient thrust and sufficient exhaust velocity.

The only redesign that might be required is in terms of thermal management. 100nmi at M1.8 (~1200kts) is ~5 minutes.

Having the engines in "pods" makes modifications easier, but I wouldn't want to lose any space between the nacelles for carrying missiles and bombs. That might make it tricky to widen the inlets, rather than just increase their height, with whatever aerodynamics effects those changes could have.

I was meaning to move the outer edge of the inlet outboard, the inner edge stays as stock on an F-14D, to keep the inlet well clear of the boundary layer of the forward fuselage. If you look at a Tomcat head-on, the inlets are smaller/narrower than the overall nacelle.

 

[apparition13]

As I understand it, there's no difference in terms of aerodynamics. Just a function of sufficient thrust and sufficient exhaust velocity.

The only redesign that might be required is in terms of thermal management. 100nmi at M1.8 (~1200kts) is ~5 minutes.

So if you stuck EJ200s in a Phantom it could supercruise?

I was meaning to move the outer edge of the inlet outboard, the inner edge stays as stock on an F-14D, to keep the inlet well clear of the boundary layer of the forward fuselage. If you look at a Tomcat head-on, the inlets are smaller/narrower than the overall nacelle.

The main gear folds into the wing box. There isn't room to widen the inlets outboard. You'd have to widen the wing box and that's likely a major redesign.

 

[Scott Kenny]

So if you stuck EJ200s in a Phantom it could supercruise?

If EJ200s have a high enough exhaust velocity, yes.

The main gear folds into the wing box. There isn't room to widen the inlets outboard. You'd have to widen the wing box and that's likely a major redesign.

View attachment 792042

Probably easier to redesign the landing gear.

Though I'd give the inlet duct a small S duct. Starting outboard, moving inboard to clear the gear, and then to center on the engine.

 

[Manuducati]

There is no need for that brainstorming. F-14 inlets and ducting were designed for an engine with a 42" diameter. The Cat has been underpowered all its live (except the few ones with GE engines of course).

As far as upgrades are discussed, the ST-21 was the best realistic option. Grumman saw the ASF-14 proposal as a "look how far we could push the thing". But it would require new airframes exclusively (the ST-21 could have been upgraded from existing airframe), a complete redesign, and cost as much as a brand new program.

 

[apparition13]

I suspect if the SF-21 had gone forward the ASF-21 would have as well. AST-14 is a stretch, as much as I would like to see what capability it would have had. I suspect we'd be looking at something F-15EX-like two decades earlier.