Operational Performace Comparison: Viper, Beagle, and Stubby

The F-35 compared with other modern jets.
  • Author
  • Message
Offline

eloise

Elite 1K

Elite 1K

  • Posts: 1725
  • Joined: 27 Mar 2015, 16:05

Unread post08 Feb 2019, 17:16

sprstdlyscottsmn wrote:By my model (and I have a fairly high confidence in this model) an F-15SA with 14 AMRAAMS and two AIM-9Xs with CFT only has a top aerodynamic speed of ~1.59M. With 60% fuel, it would take 54s to reach Mach 1.2 from 0.8 at 30,000ft and using 1,280lb of fuel to do it. It would have 3 minutes of AB time remaining under these conditions before nominal BINGO (3* reserve remaining).

Weighing in at 60,580lb, it has a Wing Loading of 99.6, and Lift Loading of 60.8, a remaining Fuel Fraction of 0.22, and an excess thrust to weight at 0.85M@36,000ft of 0.18. That T/W correlates to a 10 deg climb or an acceleration of 3.4kt/sec or 0.006M/sec. There is a lot of power in two F100-GE-129s.

Very impressive, so top speed of a fully loaded F-15X is only slightly slower than F-35 and transonic acceleration is 15% faster than F-35A. In short, F-15 can shorten the distance between 2 aircraft when they are both accelerating, but once they reach top speedthe distance getting bigger and bigger because F-35 is faster. How long can F-35 fly with AB in that case? Will it goes bingo before or after F-15X?
If the F-35 open fire first from 60 km away with 12 CUDA, then turn back and run away, assuming F-15X can intercept all missiles with its MSDN, can it close in 60 km separation distance between the two while both fighters are accelerating?
Offline

sprstdlyscottsmn

Elite 4K

Elite 4K

  • Posts: 4484
  • Joined: 10 Mar 2006, 01:24
  • Location: Phoenix, Az, USA

Unread post08 Feb 2019, 17:29

quicksilver wrote:spr, :salute: the work that has gone into your model. fwiw, it seems to be very generous wrt transonic accel in that configuration. Maybe the delta to my understanding is about the engines...

It's the engines. The -229s and -129 are monsters. The F-15E-1 says a -229 powered bird with CFT, Lantirn, 8AAM load at 60,700lb takes 300s to reach just under 1.65M from 0.83M at 40,000ft. My -129 model shows 1.715M in that same time.

dropping to 30,000ft I show -129 hitting a 1.661M top speed in less than 300s with 1.2M taking less than 45s. I can get accurate transonic AB thrust models (based on the -229) at 10k, 40k, 50k, and 60k, with the -1s acceleration and envelope charts. I look at the 10k and 40k number to derive 20k, 30k, and 36k numbers. making sure the trends make sense.
"Spurts"

-Pilot
-Aerospace Engineer
-Army Medic
-FMS Systems Engineer
Offline

SpudmanWP

Elite 5K

Elite 5K

  • Posts: 8391
  • Joined: 12 Oct 2006, 19:18
  • Location: California

Unread post08 Feb 2019, 17:36

hornetfinn wrote:
sprstdlyscottsmn wrote:
eloise wrote: then when F-35 is empty, it can be run down

Still have to find it first


While not being killed by other F-35s in the area watching you closely...

That are also jamming the MSDM/SACM interceptors to give their AAMs a better chance of hitting you.
"The early bird gets the worm but the second mouse gets the cheese."
Offline

sprstdlyscottsmn

Elite 4K

Elite 4K

  • Posts: 4484
  • Joined: 10 Mar 2006, 01:24
  • Location: Phoenix, Az, USA

Unread post08 Feb 2019, 17:42

eloise wrote:Very impressive, so top speed of a fully loaded F-15X is only slightly slower than F-35 and transonic acceleration is 15% faster than F-35A. In short, F-15 can shorten the distance between 2 aircraft when they are both accelerating, but once they reach top speedthe distance getting bigger and bigger because F-35 is faster. How long can F-35 fly with AB in that case? Will it goes bingo before or after F-15X?
If the F-35 open fire first from 60 km away with 12 CUDA, then turn back and run away, assuming F-15X can intercept all missiles with its MSDN, can it close in 60 km separation distance between the two while both fighters are accelerating?

Eh, the DRAG LIMITED top speed of the F-15X is slightly lower than the PLACARD limited F-35A. Once supersonic wave drag quickly catches up to the F-15X. I used 30,000ft because that is the F-35 spec. At 30,000ft the F-35A can reach a speed of 1.6M, the F-15X can only reach 1.486M and use ALL of it's available fuel to get there. 54 seconds to 1.2M, 72 to 1.3, 107s to 1.4, and never getting to 1.5.
"Spurts"

-Pilot
-Aerospace Engineer
-Army Medic
-FMS Systems Engineer
Offline

quicksilver

Elite 2K

Elite 2K

  • Posts: 2670
  • Joined: 16 Feb 2011, 01:30

Unread post08 Feb 2019, 17:44

“...dropping to 30,000ft I show -129 hitting a 1.661M top speed in less than 300s with 1.2M taking less than 45s.”

And so, 14 amraams and CFTs only add 9 seconds to the 1.2 number?
Offline

sprstdlyscottsmn

Elite 4K

Elite 4K

  • Posts: 4484
  • Joined: 10 Mar 2006, 01:24
  • Location: Phoenix, Az, USA

Unread post08 Feb 2019, 17:54

quicksilver wrote:“...dropping to 30,000ft I show -129 hitting a 1.661M top speed in less than 300s with 1.2M taking less than 45s.”

And so, 14 amraams and CFTs only add 9 seconds to the 1.2 number?

No, adding 6 amraams and taking away a few thousand pounds of fuel adds 9 seconds. It already had 8, CFTs, Lantirns, and more than 60% fuel.
"Spurts"

-Pilot
-Aerospace Engineer
-Army Medic
-FMS Systems Engineer
Offline

quicksilver

Elite 2K

Elite 2K

  • Posts: 2670
  • Joined: 16 Feb 2011, 01:30

Unread post08 Feb 2019, 18:03

sprstdlyscottsmn wrote:
quicksilver wrote:“...dropping to 30,000ft I show -129 hitting a 1.661M top speed in less than 300s with 1.2M taking less than 45s.”

And so, 14 amraams and CFTs only add 9 seconds to the 1.2 number?

No, adding 6 amraams and taking away a few thousand pounds of fuel adds 9 seconds. It already had 8, CFTs, Lantirns, and more than 60% fuel.


Your model is very generous.
Offline

sprstdlyscottsmn

Elite 4K

Elite 4K

  • Posts: 4484
  • Joined: 10 Mar 2006, 01:24
  • Location: Phoenix, Az, USA

Unread post08 Feb 2019, 18:09

If you think so. I had to make sure the envelope, acceleration, and STR specs lines up for both a clean aircraft and one with CFTs, LANTIRN, 4 AAMs, 12 MK82s, and a centerline pylon. I quite literally spent over 100 hours calibrating this model against the -1.
"Spurts"

-Pilot
-Aerospace Engineer
-Army Medic
-FMS Systems Engineer
Offline

quicksilver

Elite 2K

Elite 2K

  • Posts: 2670
  • Joined: 16 Feb 2011, 01:30

Unread post08 Feb 2019, 19:58

Understood. We’ve discussed before albeit in different context.

45 seconds...or even 54 seconds...in those configurations is far better than what my expectation might be.
Offline

eloise

Elite 1K

Elite 1K

  • Posts: 1725
  • Joined: 27 Mar 2015, 16:05

Unread post09 Feb 2019, 02:14

sprstdlyscottsmn wrote:Eh, the DRAG LIMITED top speed of the F-15X is slightly lower than the PLACARD limited F-35A. Once supersonic wave drag quickly catches up to the F-15X. I used 30,000ft because that is the F-35 spec. At 30,000ft the F-35A can reach a speed of 1.6M, the F-15X can only reach 1.486M and use ALL of it's available fuel to get there. 54 seconds to 1.2M, 72 to 1.3, 107s to 1.4, and never getting to 1.5.

So F-15 with 16 A2A missiles or more can't catch F-35
How about this F-15 assuming it had used 4 missiles.
F56F74EC-432A-4A3F-9D58-4CEE2EE8D8AD.png

A3C7DE80-EE3C-4163-8A7B-BA79E8E1B7EE.jpeg
Offline

sprstdlyscottsmn

Elite 4K

Elite 4K

  • Posts: 4484
  • Joined: 10 Mar 2006, 01:24
  • Location: Phoenix, Az, USA

Unread post09 Feb 2019, 17:57

Which one, those are different
"Spurts"

-Pilot
-Aerospace Engineer
-Army Medic
-FMS Systems Engineer
Offline

eloise

Elite 1K

Elite 1K

  • Posts: 1725
  • Joined: 27 Mar 2015, 16:05

Unread post10 Feb 2019, 03:11

sprstdlyscottsmn wrote:Which one, those are different

The first one, btw how fast can that one fly and accelerate after all missiles are launched?
Offline
User avatar

jetblast16

Forum Veteran

Forum Veteran

  • Posts: 651
  • Joined: 23 Aug 2004, 00:12
  • Location: USA

Unread post10 Feb 2019, 03:16

How about with F110-GE-132 engines, the F-15(C)X lol?
Have F110, Block 70, will travel
Offline

sprstdlyscottsmn

Elite 4K

Elite 4K

  • Posts: 4484
  • Joined: 10 Mar 2006, 01:24
  • Location: Phoenix, Az, USA

Unread post10 Feb 2019, 06:43

eloise wrote:The first one, btw how fast can that one fly and accelerate after all missiles are launched?

Just pylons? Mach 1.81. Residual pylon drag plus CFT drag is DI 75. It'll get there pretty darn quick too. From 0.8M at 30,000ft to 1.81M at 41,390ft in a mere 510 seconds. Only takes all the usable fuel. Covers 125nm. Won't do much though. What is it chasing again in theory? A specter of a retreating F-35?

jetblast16 wrote:How about with F110-GE-132 engines, the F-15(C)X lol?


Now it only has 480 seconds of AB time. It gets to 1.885M at 42,060ft. It gets there in 250-270 seconds before sustaining the dash. Covers 126nm.

"What about the uprated ones that put out 36,000lbs of thrust?"
Now it only has 450 seconds of AB time. It gets to 1.970M at 43,360ft. It gets there in about 200-220 seconds and is steady state dashing the rest of the time. Covers 126nm.

These are neat drag race ideas and all, but completely absurd. An F-15X is not going to be engaging the missiles fired by an F-35. If it intercepted one, the next one would come from dead six at 5nm.
"Spurts"

-Pilot
-Aerospace Engineer
-Army Medic
-FMS Systems Engineer
Offline

eloise

Elite 1K

Elite 1K

  • Posts: 1725
  • Joined: 27 Mar 2015, 16:05

Unread post10 Feb 2019, 09:51

sprstdlyscottsmn wrote:The first one, btw how fast can that one fly and accelerate after all missiles are launched?
Just pylons? Mach 1.81. Residual pylon drag plus CFT drag is DI 75. It'll get there pretty darn quick too. From 0.8M at 30,000ft to 1.81M at 41,390ft in a mere 510 seconds. Only takes all the usable fuel. Covers 125nm. Won't do much though. What is it chasing again in theory? A specter of a retreating F-35.

I was talking with a friend about the new F-15X with 22 AIM-120.
His argument: F-15X can carry enough MSDN/SACM to intercept anything F-35 thrown at him then after that an empty F-35 is a good as a jumbo jet against F-15X with dozens AIM-120 or AIM-9x
My argument: F-35 can launch all its missiles then run.
The break even point is wherether F-15X with all its rails and amber rack can catch a fleeing F-35
PreviousNext

Return to F-35 versus XYZ

Who is online

Users browsing this forum: No registered users and 2 guests