LO's F-15 vs. the F-15 Streak Eagle

[D-Scythe]

Since the other thread was about the Su-27, I'm going to start a new thread here.

 

These are the results of Swingkid's test:

 

 

As you can see, when both the Streak Eagle and LO's clean F-15C are configured at the same WEIGHTS, the Streak Eagle outclimbs the F-15C by 14 000 ft in 56 seconds - it almost gains TWICE as much altitude in the SAME timeframe.

 

Now, the counter argument is that the Streak Eagle has maxed out F100 engines that need to be overhauled right after. Now, the question is, how much thrust do these maxed out F100s produce, and is it enough to allow the F-15A Streak Eagle to climb almost twice as fast as a normal F-15C.

 

I think not - unless these maxed out F100s are secretely F119s, there is no way the F-15A Streak Eagle destroy an F-15C like that in climb rate.

[GGTharos]

These are VERY DIFFERENT AIRCRAFT. Right down to airframe alteration which changes lift and drag values, let alone weight.

 

You -cannot- configure the F-15C with the 'same weight' and claim it's a similar-performing aircraft when you're hauling pylons that cause drag, and several other things which change the drag coefficient like the flaps, paint (skin drag changes), modified engines (the 100's were more powerful than the 220's anyway, let alone the V-Max switch) and who-knows-what-else.

[hitman]

If they both weigh the same (within ballpark figure), a few antennas and a few pylons are not going to cause THAT much drag. Just how much more powerful are the 100's than the 220's? I cant see double, but I can see tops30% more performance out of the streak eagle than the C.

[D-Scythe]

These are VERY DIFFERENT AIRCRAFT. Right down to airframe alteration which changes lift and drag values, let alone weight.

 

Um, what? The airframe is basically the SAME - the only things that change are the antennaes, pylons, etc. It's STILL an F-15A, but a lighter.

 

It didn't get a new wing.

 

You -cannot- configure the F-15C with the 'same weight' and claim it's a similar-performing aircraft when you're hauling pylons that cause drag, and several other things which change the drag coefficient like the flaps, paint (skin drag changes), modified engines (the 100's were more powerful than the 220's anyway, let alone the V-Max switch) and who-knows-what-else.

 

Pylons and flaps - okay, would they cause enough drag to cut the F-15's climb rate in half?

 

Paint - what skin drag changes? Aircraft fly without paint all the time - prototype, LRIP, pre-production and evaluation aircraft no less. The reason the paint was removed was because it saved an extra 40 lbs. This is a weak argument.

 

Engines - the F100-PW-100s produced like 200 lbs more thrust than the -220s. This is a weak argument as well. Furthermore, in COMBAT, the F100-PW-220 would likely be uprated also. Finally I'm STILL looking for that number - exactly how much thrust does a Vmaxed Dash 100 produce?

 

Keep in mind, I'm not asking for Streak Eagle performance. But the fact that it climbs almost twice as fast as the F-15C in Lock On is ridiculous.

[pschelchshorn]

These are VERY DIFFERENT AIRCRAFT. Right down to airframe alteration which changes lift and drag values, let alone weight.

 

You -cannot- configure the F-15C with the 'same weight' and claim it's a similar-performing aircraft when you're hauling pylons that cause drag, and several other things which change the drag coefficient like the flaps, paint (skin drag changes), modified engines (the 100's were more powerful than the 220's anyway, let alone the V-Max switch) and who-knows-what-else.

 

FYI he is talking about the STREAK EAGLE not the STRIKE EAGLE! The latter being the E and the first being an early A model that was used for testing. Google it (:D :D :D)

 

EDIT: DAMN YOU BEEAT ME TO IT!!!

 

Flip

[pschelchshorn]

i also think Tharos was referring to the CFT Tanks and its bolted on Pylons for Mark 82s and the like, as he was misguided on the aircraft type you are talking about. These cause alot of the drag he is referring to.

 

Flip

[MiGMadness]

Why are you trying to compare a production F-15C with a Pre-production category II prototype that was redesigned especially to break the time to height record?

 

:doh: :pilotfly:

[Pilotasso]

I think we should have compared with stock F-15's not record breakers.

 

Anyway heres what i wrote about it:

http://forum.lockon.ru/showthread.php?t=22448&page=6

[D-Scythe]

Why are you trying to compare a production F-15C with a Pre-production category II prototype that was redesigned especially to break the time to height record?

 

:doh: :pilotfly:

 

Do people not read? What's the point of having a forum if nobody's going to FULLY read another's post before responding to it while trying to sound smart?

[GGTharos]

No, I think you're completely misguided as to what I'm talking about ;)

 

I'm talking about comparing the F-15C with the STREAK Eagle prototype modified specifically to break time-to-climb records ;)

You don't need a lot of drag to change your record altitude by 1000'.

I forget where it was mentioned, but at high speed, a small percentage in speed difference between two aircraft when they begin a climb may easily result in a significant difference in the altitude it will max out at.

Of course speed is also reduced in some proportion to the thrust and drag as you're going up. So *everything* counts.

 

i also think Tharos was referring to the CFT Tanks and its bolted on Pylons for Mark 82s and the like, as he was misguided on the aircraft type you are talking about. These cause alot of the drag he is referring to.

 

Flip

[Mobius1]

Holy S%$*. An F-15 to 103,000 ft, I never knew...

 

 

http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=621

[D-Scythe]

I'm talking about comparing the F-15C with the STREAK Eagle prototype modified specifically to break time-to-climb records ;)

 

Kay, once again, the external modifications were insignificant - there is no reason why the Streak Eagle would climb twice as fast as an F-15C at the exact same weight.

 

They basically took some equipment out and removed some pylons. You're telling me that that will almost double your climb rate?

 

You don't need a lot of drag to change your record altitude by 1000'.

I forget where it was mentioned, but at high speed, a small percentage in speed difference between two aircraft when they begin a climb may easily result in a significant difference in the altitude it will max out at.

Of course speed is also reduced in some proportion to the thrust and drag as you're going up. So *everything* counts.

 

By 14000ft in 56 seconds? Don't think so.

[D-Scythe]

You also should remember that several hundred pounds of paint and wiring were removed from the Streak Eagle. Along with another several hundred pounds of avionics and other equipment that were not needed for this flight testing. Where did the weight figures come from?

 

And if you read my post, you would've known that an equivalent amount of fuel on board Lock On's F-15C was removed in order match its weight with that of the Streak Eagle.

 

Do I have a "LOSER" sign taped on my forehead? Why do people think I don't know what the Streak Eagle is or what had been done to it?

 

Anyway, since not reading other people's post seems to be in Vogue, I will repeat my position once again - Lock On's F-15C should NOT match the Streak Eagle in climb performance even at the exact same weight (yes, it SHOULD be slower) but being outclimbed by 14 000ft in 56 seconds is RIDICULOUS.

[S77th-GOYA]

D-Scythe, I am a member of the choir to which you are preaching. I know for a fact that climb performance of the 15 as well as every other fighter in this game has been thoroughly discussed and has been overwhelmingly deemed lacking. Is there a point in rehashing this?

[D-Scythe]

Yes, it certainly does seem to be in vogue, because if you had read my post, I asked where the weight figures came from?

 

Weight figures came from the Streak Eagle - Lock On's F-15 just had its fuel load reduced to match that. As for the exact weight the Streak Eagle and where it's available, I don't have it handy but I'm sure I can dig it up if required (or Swingkid can - it's always better to skip the middle man and just ask him).

 

Sorry for being a prick, but it's been a long day and the fact that people keep trying to EXPLAIN to me what the Streak Eagle is like I'm some kind of idiot is grating on the nerves.

 

Now, I agree that LOMACs F-15 is underpowered, but this comparison isn't a good way to prove that.

 

I have to disagree.

 

Drag is a major factor, and we also don't know how the engines were set up on the Streak Eagle compared to the average, every day F-15C.

 

Enough to almost DOUBLE the climb rate? You're telling me that a couple hundred pounds of thrust and the removal of a few pylons would do that?

 

(and yes, unless someone comes up with a Vmax thrust figure for the F100-PW-100, I'm going to assume that there are going to be no INSANE increases in thrust that would DOUBLE one's climb rate)

 

I believe that was mentioned somewhere too, but I guess you didn't read that part. :D

 

Pretty sure I read and refuted those points already ;)

[D-Scythe]

D-Scythe, I am a member of the choir to which you are preaching. I know for a fact that climb performance of the 15 as well as every other fighter in this game has been thoroughly discussed and has been overwhelmingly deemed lacking. Is there a point in rehashing this?

 

No.

[S77th-GOYA]

No.

 

OK. Preach on, brother!

[D-Scythe]

OK...so, does LOMAC allow you to remove hardpoints? How about countermeasures dispensers? Can those be removed in LOMAC and their bays sealed? How about the flaps? Can we remove those along with the speedbrake and get rid of the required joints for those moving parts that cause enormous amounts of drag? Can we seal the gun hole? If we can do all of those things in LOMAC, then I'm sold...until then, I'm skeptical. ;)

 

If you're telling me...that things like counter measure dispensors (which have an outer covering on the F-15 AFAIK), flaps (which don't have to be used), the speedbrake (also, which don't have to be used) and the "joints" for these moving parts (which are aerodynamically "hidden" from causing too much drag)...cause enough drag to cut your climb rate in HALF, then I don't know what to say. It's obvious I cannot convince you otherwise - all I have is my words against yours.

 

About your only good point was the gun - in this case, though the mass can be accounted for by reducing the fuel load, the extra drag cannot be compensated for - and I'll give you that. But there is still NO way a gun causes a difference of 14 000 ft in 56 seconds between the two climb-rates.

[hitman]

Just thought of something: what if the weight of the aircraft in LOMAC is porked? That M61 isnt exactly lightweight...we're talking several hundred pounds here, and thats just for the barrels. 800 rds of ammunition at 3/4 lbs each, not to mention the magazine, the hydraulics that run it, and everything else included with the gun would make it close to 2000lbs total. THAT would be a better fact based judgement...if the rated 100 type engine plants on the streak were classified. No it wouldnt give you your estimate, D-, but that in a nutshell, I doubt even the model has a specific center of gravity set.

[rogue_blade]

OMG THE WEIGHT OF THE PILOTTTTTTTTTTTTT OMGOMGOMGOGMOMG THAT SAYS IT ALLL

[SwingKid]

For the record -

 

Comparing against the Streak Eagle records was not my idea, but rather the suggestion of an Eagle crew member. The same crew member was of the opinion that with the CFTs removed, the F-15E would easily out-perform the Streak Eagle, by virtue of its higher-rated engines. However for "political" reasons, USAF F-15E pilots are forbidden to do so, since this would reduce the apparent relative superiority of the F-22, when it breaks those records in the near future as planned.

 

The question should not be whether the F-15C behaves like the Streak Eagle, but rather whether it behaves more like the Streak Eagle than it does like the Lock On F-15. And it does - the unclassified Dash-1 manual of the F-15 specifies how much the performance is degraded by weapons pylons, various stores, even the presence/absence of engine exhaust "turkey feathers" (IIRC). As D-Scythe correctly estimates, the degradation is very small, nowhere near the ~30% we see here.

 

Taken together, there is plenty of unclassified material available for verifying F-15C performance in Lock On - for anyone who wants to. To suggest that flawed research is inferior to no research is indicative that we don't.

 

-SK

[GGTharos]

Well, I'm satisfied, carry on the fight. :D

 

(And I don't mean just SK's post)

[SwingKid]

Just how much more powerful are the 100's than the 220's? I cant see double, but I can see tops30% more performance out of the streak eagle than the C.

 

F100-PW-100 is rated at 23,830 lbs each with afterburner, but the Streak Eagle added about 2500 lbs per engine with the use of the Vmax switch that GG mentioned.

 

F100-PW-220 delivers 23,450 lbs each with afterburner.

 

http://www.ecf.utoronto.ca/~pavacic/lomac/dragind1.jpg

http://www.ecf.utoronto.ca/~pavacic/lomac/dragind2.jpg

http://www.ecf.utoronto.ca/~pavacic/lomac/scan0183.JPG

 

-SK

[GGTharos]

Holy ... that's some performance description SK!

[upyr1]

Why are you trying to compare a production F-15C with a Pre-production category II prototype that was redesigned especially to break the time to height record?

 

:doh: :pilotfly:

Theonlhy reason the streak eagle should be considered in this thread is it is an F-15 before discounting the thread list the following.

1. thrust to weight ratio of the Streak Eagle

2. the strak eagle's climb to hight

3. Thrust to weight ratio of a standard F-15C

4. an avrage climb to hight table published by the military.

We know the Streak Eagle was stripped down and the engines were supped up so to expect identical performance between the Streak Eagle and a stock F-15 would be out of the question but be can use it as a yard stick if we can not pick up the facts to fill in number 4. I would asume that if the Stock F-15C has 10% less thrust to weight than the Streak Eagle then it should reach 9000 feet in the same time the Streak Eagle reaches 1000 feet with the throttle wide open and on full after burner.