F-14 low speed prowess vs Other Aircraft

[BlackLion213]

It wasn't just because of the inlet scheduling?

 

 

 

It does, just not by that much :)

 

 

The lowered top speed was an operational recommendation that came out in the 1990s and actually applied to all Tomcats. It was due to inadequate rudder authority at very high speed...and maybe to help the Hornet pilots with that "insecurity problem" :D.

 

The F-14D flew to Mach 2.51 with 4 sparrows loaded during it's OpEval. Inlet scheduling wasn't a problem, though maybe that changed later.

 

-Nick

[GGTharos]

Hornet pilots can barely cross the mach if they have any payload other than 4 missiles onboard, so I don't think an M1.8 limitation on the cat would make them feel too much better :D

[lunaticfringe]

The genius at Boeing who thought it wise to order the forms for the Super Hornet adjusted with the 4 degrees of pylon angling based on wind tunnel data, rather than prior to the Navy's desired separation testing, should be shot.

 

Seriously.

[turkeydriver]

The genius at Boeing who thought it wise to order the forms for the Super Hornet adjusted with the 4 degrees of pylon angling based on wind tunnel data, rather than prior to the Navy's desired separation testing, should be shot.

 

Seriously.

 

It's hilarious, the Growler has a better wing because they decreased the outward can't on the pylons. I've read it's a better jet clean but who knows.

[captain_dalan]

The alarming thins is, the USN will have to stick with these birds for their AS role in the next 20-30 years at least.

[Hummingbird]

Pretty interesting:

 

[captain_dalan]

It is an interesting assessment, however i think we should take it with a bit of healthy skepticism. Terms such as maneuverability are often thrown around freely and although in this case it is a bit more specific by addressing the lower speed advantage, to say that it will always win that fight is a bit of a long shot.

 

That and we always must consider the specific doctrine and intended use the plane is meant to fill and perform with...

[Hummingbird]

It is an interesting assessment, however i think we should take it with a bit of healthy skepticism. Terms such as maneuverability are often thrown around freely and although in this case it is a bit more specific by addressing the lower speed advantage, to say that it will always win that fight is a bit of a long shot.

 

That and we always must consider the specific doctrine and intended use the plane is meant to fill and perform with...

 

 

Jives pretty well with what we've assessed so far though, that the F-14A holds a significant advantage at low altitudes and esp. at low speeds, the TF-30 engines suffering at high altitudes.

 

The GE powered B & D models cured the problem and extended the F-14 envelope of superiority in maneuvers to higher altitudes.

[Hummingbird]

Actually it takes the maneuvering devices into account, and those don't operate once past 55 degrees wing sweep anyway, so the benefit is only in the low-mid subsonic region :smilewink:

 

Actually looking in the manual the maneuver slats seem to be operational at nearly all wing sweep angles, whilst the CADS manages between the two split flaps (main & auxilliary) at various sweep angles :)

[Hummingbird]

Some more excerpts from the book Iranian Tomcat Units In Combat by Tom Cooper & Farzad Bishop:

 

[captain_dalan]

Actually looking in the manual the maneuver slats seem to be operational at nearly all wing sweep angles, whilst the CADS manages between the two split flaps (main & auxilliary) at various sweep angles :)

Look again, it actually states 50 degrees :thumbup:

 

EDIT:

For clarification:

-page 132

"Maneuver flaps

 

With the wing sweep angle less then 50 degrees, the main flap segments can be extended from 0 to 10 degrees as maneuver flaps, with proportional slats extending from 0 to 8.5 degrees. This maneuvering flap/slat feature is provided to augment the aircraft maneuver capability in the subsonic, mid-wing at higher load factors, over a wider range of altitudes"

Edited March 23, 2015 by captain_dalan

[Hummingbird]

Look again, it actually states 50 degrees :thumbup:

 

EDIT:

For clarification:

-page 132

"Maneuver flaps

 

With the wing sweep angle less then 50 degrees, the main flap segments can be extended from 0 to 10 degrees as maneuver flaps, with proportional slats extending from 0 to 8.5 degrees. This maneuvering flap/slat feature is provided to augment the aircraft maneuver capability in the subsonic, mid-wing at higher load factors, over a wider range of altitudes"

 

Ah yes, I was actually reading the wing sweep angle backwards :P Makes sense now, and 50 degrees is also over half way back (20-68*), and the maneuver slats/flaps operate all the way up to Mach 0.85 (which is rather fast).

 

Like so:

[mjmorrow]

 

Man I can't wait for the F-14 :bounce:

 

Yeah, the F-14 will be a childhood dream come true. Given the quality of the LNS Mig21bis and my childhood fascination with the Tomcat, the LNS F-14 Tomcat will be my go to DCS 4th generation fighter, without a doubt. :thumbup: MJ

[captain_dalan]

Ah yes, I was actually reading the wing sweep angle backwards :P Makes sense now, and 50 degrees is also over half way back (20-68*), and the maneuver slats/flaps operate all the way up to Mach 0.85 (which is rather fast).

 

Depending on the altitude, yes. It still doesn't help the one portion of the envelope, the F-14 is most deficient at.

[Hummingbird]

Depending on the altitude, yes. It still doesn't help the one portion of the envelope, the F-14 is most deficient at.

 

You mean between approx Mach 0.8-1.05 ? :)

[captain_dalan]

You mean between approx Mach 0.8-1.05 ? :)

Yep :)

 

I have never see charts with wing sweep on manual, but maybe extending the wings at transonic would make a difference. I know it helps on high altitudes, but has more to do with maintaining stable flight during hard maneuvering then sustaining the turn per se. Well that, and it helps with the very "short" range of subsonic knots you have available above 25000ft.

[lunaticfringe]

They used to be more unswept until the CADC was reprogrammed after the first dozen or so (based on Navy not liking the amount of flex).

[Hummingbird]

They used to be more unswept until the CADC was reprogrammed after the first dozen or so (based on Navy not liking the amount of flex).

 

Yeah it does look kinda of wild when those wings take a sudden high G load fully extended - although if I am not mistaking they could easily take it.

 

But as you said they instead went with Ps instead of CLmax.

[lunaticfringe]

They could. It was simply the economic dynamics and such at the time.

 

Had the Navy's original plans to run off a few blocks of TF30 'cats, then replaced the motor with a F100/F110/etc analogue, and essentially get double the total number of airframes than what they eventually purchased, the limitations would not have held, and the CL Max programming would have likely stayed put.

 

Instead, the energy crisis happened, stressing Grumman's bottom line based on the prior negotiations with the DoD and Congress, and hampered the eventual plan.

[Hummingbird]

They could. It was simply the economic dynamics and such at the time.

 

Had the Navy's original plans to run off a few blocks of TF30 'cats, then replaced the motor with a F100/F110/etc analogue, and essentially get double the total number of airframes than what they eventually purchased, the limitations would not have held, and the CL Max programming would have likely stayed put.

 

Instead, the energy crisis happened, stressing Grumman's bottom line based on the prior negotiations with the DoD and Congress, and hampered the eventual plan.

 

Why do I feel an urge to ask the devs to give us the ability to hack the CADS all of a sudden? :D

[captain_dalan]

I just ran 3 hours of simulations at low altitude in the Aerosoft's F-14 with manual sweep override, both at military and full afterburner power. If their sim FM is at least nearly as authentic (and i have no reason to think it isn't), for best Ps=0 you do want your wings swept all the way back when transonic. I ran 3 separate settings, at 22, 45 and 68 degrees (2X2X2X2 externals).

 

Under military power, the jet would not even reach mach 0.9 with the wings forward. At mach 0.85 in mil power and nearly full internal fuel i could sustain from 3.8 (at 22) to 4.2 (at 68 ) g's.

 

At half internal fuel and full AB, i could sustain from 6 (at 22) to 8.5+ (at 68 ) around mach 1.

 

So, if you want pitching authority and high ITR's, go for manual sweep, if you want best STR, go for auto sweep. Those guys at Grumman, didn't make things up when they said they optimized the wing sweep computer program for best Ps=0. :book:

[Hummingbird]

I just ran 3 hours of simulations at low altitude in the Aerosoft's F-14 with manual sweep override, both at military and full afterburner power. If their sim FM is at least nearly as authentic (and i have no reason to think it isn't), for best Ps=0 you do want your wings swept all the way back when transonic. I ran 3 separate settings, at 22, 45 and 68 degrees (2X2X2X2 externals).

 

Under military power, the jet would not even reach mach 0.9 with the wings forward. At mach 0.85 in mil power and nearly full internal fuel i could sustain from 3.8 (at 22) to 4.2 (at 68 ) g's.

 

At half internal fuel and full AB, i could sustain from 6 (at 22) to 8.5+ (at 68 ) around mach 1.

 

So, if you want pitching authority and high ITR's, go for manual sweep, if you want best STR, go for auto sweep. Those guys at Grumman, didn't make things up when they said they optimized the wing sweep computer program for best Ps=0. :book:

 

8.5+ G's at Mach 1? Wow.. that's pretty damn impressive, and more than the F-15C which can just manage 8 G's at that speed.

 

Kind of confirms my guess that the extra thrust of the GE engines would increase the F-14's envelope of superiority in STR.

[captain_dalan]

8.5+ G's at Mach 1? Wow.. that's pretty damn impressive, and more than the F-15C which can just manage 8 G's at that speed.

 

Kind of confirms my guess that the extra thrust of the GE engines would increase the F-14's envelope of superiority in STR.

Nah, the F-15 would probably do around 9 in similar conditions.

[GGTharos]

More than 9g at M1 with MORE than half fuel at SL (actually, about as much fuel as the half-fuel Cat :) ).

[captain_dalan]

Yep.

We don't have a comparable load for this case though. Still, the F-15 definitely has it.