F-14 low speed prowess vs Other Aircraft

[captain_dalan]

On that i think we pretty much agree :thumbup:

[lunaticfringe]

Furthermore, page 670, under chapter Factors Affecting Deployment of CAP/DLI clearly states:

"The cycle time of a CAP or DLI, should provide enough fuel to conduct the flight, complete one or more intercepts and have sufficient fuel remaining to delay recovery until the raid has departed the vital area. In order to accomplish this, the cycle time should be based on a maximum landing weight, plus an expendable fuel package of several thousand pounds."

 

This is where you're dealing with an aircraft that can internally stow 16,000lbs of gas, hang another 3600, and top off on the outbound to the CAP, you're operating with a good 14K worth of gas just in CAP time, with a gross total weight of 64K carrying six Phoenix, two Sidewinder. When you run that through the drag and cruise indexes...

 

...you can get to four hours on less than 12K in a 25K altitude CAP without a top off. Seven thousand pounds with 150 miles both ways and a fight? Totally doable with a reasonable margin. Sure, they might have to send up a tanker if you bolter (although SOP is going to have one available anyways), but if you're on the bleeding edge of a full-on shooting war, its what you do.

[captain_dalan]

You could probably do even better if you set your CAP at 35000ft. IIRC 350KIAS and 35000ft was the usual F-14 cruise speed/altitude? The loiter air speed might be even lower than that to maximize endurance.

 

BTW, the CAPS were usually set at 50-100-150nm from the boat? I'm not sure if the memory serves well, but i think i've heard of ones set all the way at 200nm? :huh:

[lunaticfringe]

Further. Procedures existed to mitigate the decreased loiters.

[captain_dalan]

That makes sense. Just doing some basic calculations, i can easily get 100nm per 1000lbs of fuel when flying at angels 35, at lower fuel states.... :book:

[Hummingbird]

Capt. Dalan,

 

Having looked through the F-14B/D performance charts I have corrected your earlier estimated F-14B/D vs F-15C STR chart with the actual performance values of the F-14B/D:

 

 

As you can see the GE engines do indeed increase the F-14's envelope of superiority in STR over the F-15C quite noticably, spanning from Mach ~0.33 to ~0.74.

Edited March 27, 2015 by Hummingbird

[captain_dalan]

Are you sure you are looking at the right Ps curve and not the -100ft/s one? :book:

[Hummingbird]

Are you sure you are looking at the right Ps curve and not the -100ft/s one? :book:

 

Yes, at -100 ft/sec almost 15 deg/sec is reached.

 

I have another chart comparing the F-14D & F-15E as well, which is rather interesting as the figures for the F-15 below Mach 0.3 seem a lot more fitting considering its' stall speed & lift curve. Here the F-14's superiority spans all the way from the bottom (Mach 0.2) to Mach 0.82.

Edited March 27, 2015 by Hummingbird

[captain_dalan]

Well then, shouldn't it be 14 at 0.6 , slightly above 12.5 at 0.8 and definitely 4 at 0.2? :thumbup:

[Hummingbird]

Well then, shouldn't it be 14 at 0.6 , slightly above 12.5 at 0.8 and definitely 4 at 0.2? :thumbup:

 

Max STR at 10 kft is 14.2 dps @ Mach 0.62, otherwise it's:

 

14 dps @ Mach 0.6

12.7 dps @ Mach 0.8

5.2 dps @ Mach 0.2

 

:)

[captain_dalan]

14 dps @ Mach 0.6,

12.7 dps @ Mach 0.8

5.2 dps @ Mach 0.2

 

:)

We can nitpick about that 5.2 :P but i'll let it drop :thumbup:

Now look at your graph:

almost 14.5 at 0.6 and bit more then 13 at 0.8 :)

[Hummingbird]

We can nitpick about that 5.2 :P but i'll let it drop :thumbup:

 

I'm looking at the chart right now, it's most definitely 5+ dps @ 0.2. Drawing a line gives me 5.2 dps.

 

Now look at your graph:

almost 14.5 at 0.6 and bit more then 13 at 0.8 :)

 

Shouldn't go higher than 14.2 dps at 0.62, and ~13 dps at Mach 0.8, just as on the original chart.

 

My graph might be a tad too high at 0.6 & 0.8 though, that we could probably nitpick over :P (roof of doghouse needs a slight steepening :P)

Edited March 27, 2015 by Hummingbird

[captain_dalan]

I'm looking at the chart right now, it's most definitely 5+ dps @ 0.2. Drawing a line gives me 5.2 dps.

 

 

 

Shouldn't go higher than 14.2 dps at 0.62, and ~13 dps at Mach 0.8, just as on the original chart.

 

My graph might be a tad too high at 0.6 & 0.8 though, that we could probably nitpick over :P (roof of doghouse needs a slight steepening :P)

We are looking at the same one mate :smilewink:

If you want to make the F-14 look better by raising the STR by 1/4 of 1/2 a degree, be my guest :smilewink:

[Hummingbird]

We are looking at the same one mate :smilewink:

If you want to make the F-14 look better by raising the STR by 1/4 of 1/2 a degree, be my guest :smilewink:

 

Then I have no clue how you arrived at 4 dps at 0.2 :)

[GGTharos]

Is there not an actual STR chart that can be used instead of attempting to compute from Ps curves?

[captain_dalan]

Is there not an actual STR chart that can be used instead of attempting to compute from Ps curves?

There is (at least for this particular instance) and we are both looking at it, we just "see" differently :megalol:

EDIT: honestly, would you fly the thing any different based on that much STR change?

Edited March 27, 2015 by captain_dalan

[Hummingbird]

There is and we are both looking at it, we just "see" differently :megalol:

 

To be fair I've drawn 90 deg lines to verify the accuracy of my readings :)

 

My first graph is not perfect at all, neither is yours :)

[captain_dalan]

I never said "my" chart was perfect, neither am i :)

[Hummingbird]

I never said "my" chart was perfect, neither am i :)

 

Or i :)

[GGTharos]

I wouldn't. I can do things with the extra half a degree, but the flying would be the same :)

 

Anyway I asked for STR to STR comparison because computing from PS may not necessarily be accurately applicable (to within a quarter or half a degree) depending on how the data is collected.

 

As you pointed out, it's nit-picking ;)

 

EDIT: honestly, would you fly the thing any different based on that much STR change?

[captain_dalan]

My thinking exactly :P

[Hummingbird]

Isn't it beautiful? :D

[Hummingbird]

Interrstingly when looking at the F-15Es performance charts I get a 10 kft STR of 4 dps @ mach 0.2, and this is with just 4x AIM 7s onboard and weight at 42,000 lbs. Thats quite a ways from the 7.5 dps of the F-15C chart.

[GGTharos]

Because you're comparing apples to oranges. The F-15E is a deep strike fighter replacing the F-111. It's not an air superiority fighter, as a result the F-15C performs quite a bit better in that role.

[Hummingbird]

Because you're comparing apples to oranges. The F-15E is a deep strike fighter replacing the F-111. It's not an air superiority fighter, as a result the F-15C performs quite a bit better in that role.

 

So you're saying that its so aerodynamically different because of the larger canopy that looses almost from 25-50% of its STR performance at low subsonic speeds?