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Re: F-16 vs F/A-18

Unread postPosted: 11 Feb 2018, 14:51
by garrya
eloise wrote:That chart didn't come from F-15 manual either why should it be trusted more than NASA who tested on an actual F-15 with modern equipment

IMHO, NASA graphs should be even more accurate than original manual because data are recorded by more up-to-date devices. If i have to explain the differences, between them two, hummingbird's graphs probably assume a recommended safe AoA limit. But since we already take no noitice of F-14's G-limit, it is only fair that we do the same for F-15's AoA limit ( Even though, i personally prefer if both are kept)

Re: F-16 vs F/A-18

Unread postPosted: 11 Feb 2018, 18:27
by hummingbird
eloise wrote:That chart didn't come from F-15 manual either why should it be trusted more than NASA who tested on an actual F-15 with modern equipment
Image


NASA's tests & equipment were no different or more modern than those used by Grumman or Douglas, stop looking for excuses. Fact is nothing is based on more flight test data than the official EM charts by Grumman & Douglas themselves, and thus nothing is more accurate.

In short it's quite clear that the F-14 holds the ITR advantage when compared with the F-15, and anything else would also be quite odd considering how much slower the F-14 needs to go in order to reach its peak STR.

Re: F-16 vs F/A-18

Unread postPosted: 11 Feb 2018, 18:28
by hummingbird
garrya wrote:IMHO, NASA graphs should be even more accurate than original manual because data are recorded by more up-to-date devices.


and exactly where did you pull this from?

Re: F-16 vs F/A-18

Unread postPosted: 12 Feb 2018, 01:50
by gta4
hummingbird wrote:
garrya wrote:IMHO, NASA graphs should be even more accurate than original manual because data are recorded by more up-to-date devices.


and exactly where did you pull this from?


Even with the chart you provided, F15 has a Clmax of at least 1.5.

Any thought?

Re: F-16 vs F/A-18

Unread postPosted: 13 Feb 2018, 05:12
by eloise
hummingbird wrote:NASA's tests & equipment were no different or more modern than those used by Grumman or Douglas, stop looking for excuses

Though i agree with him, i actually said your graph didn't come from F-15 manual.
hummingbird wrote:in short it's quite clear that the F-14 holds the ITR advantage when compared with the F-15, and anything else would also be quite odd considering how much slower the F-14 needs to go in order to reach its peak STR

STR is a different matter because it is affected by L/D ratio and thrust rather than only CLmax and weight
And talking about sustained turn rate, i reviewed your earlier post with manual data yesterday:
hummingbird wrote:I meant max sustainable load factor, which remains at 0.82 Mach at virtually all altitudes. Hardly a coincidence

@15k ft, max sustainable load factor stay at Mach 0.85, the Ps curve trend started to change significantly at Mach 0.7
lift 15k.png


@35k ft, max sustainable load factor stay at Mach 1.4, the Ps curve trend started to change significantly at Mach 0.78
35k ft device operating.png


@35k ft but with maneuver devices not operating, the max sustainable load factor still stay at Mach 1.4, the Ps curve trend still started to change significantly around Mach 0.78
35k ft device not operating.png


you must know all of this too because you have the manual

In short, you are awfully disingenuous, as soon as we get distracted you try to deceive us.

Re: F-16 vs F/A-18

Unread postPosted: 14 Feb 2018, 01:29
by hummingbird
gta4 wrote:
hummingbird wrote:
garrya wrote:IMHO, NASA graphs should be even more accurate than original manual because data are recorded by more up-to-date devices.


and exactly where did you pull this from?


Even with the chart you provided, F15 has a Clmax of at least 1.5.

Any thought?


If the Clmax adds up to 1.5 as pr. the chart then that's what it is, nothing more to say about that.

Re: F-16 vs F/A-18

Unread postPosted: 14 Feb 2018, 01:31
by hummingbird
eloise wrote:In short, you are awfully disingenuous, as soon as we get distracted you try to deceive us.


Decieve you??! Consider yourself completely ignored henceforth.

Re: F-16 vs F/A-18

Unread postPosted: 14 Feb 2018, 15:01
by mixelflick
Is it fair to say every Viper model holds a thrust to weight advantage vs. any F-18? Both being clean of course, or with 2-4 AAM's..

I thought so, but have seen reference to 414? powered F/A-18C's having a comparable T/W ratio??

Re: F-16 vs F/A-18

Unread postPosted: 14 Feb 2018, 15:43
by zero-one
mixelflick wrote:Is it fair to say every Viper model holds a thrust to weight advantage vs. any F-18?


This actually interesting, the highest thrust to weight hornet is the F/A-18C with GE F404-402 EPE upgrade, can this compete with the lowest T/W ratio Vipers, what is it block 42 or block 25. some export versions maybe?

Now I know it takes more than T/W ratio to beat a Viper in its own game, that whole airframe is fine tuned to retain E, the Hornet on the other hand is fine tuned to go slow, so it'll take more than big motors to out viper a viper

Re: F-16 vs F/A-18

Unread postPosted: 14 Feb 2018, 16:02
by gta4
zero-one wrote:
mixelflick wrote:Is it fair to say every Viper model holds a thrust to weight advantage vs. any F-18?


This actually interesting, the highest thrust to weight hornet is the F/A-18C with GE F404-402 EPE upgrade, can this compete with the lowest T/W ratio Vipers, what is it block 42 or block 25. some export versions maybe?


http://www.nationalguard.mil/Leadership ... xtlink%5D/

Block 42 have engine upgraded to pw229 a decade ago. Now block 42 is one of the most powerful block in viper family...

Re: F-16 vs F/A-18

Unread postPosted: 14 Feb 2018, 18:41
by garrya
eloise wrote:And talking about sustained turn rate, i reviewed your earlier post with manual data yesterday:
hummingbird wrote:I meant max sustainable load factor, which remains at 0.82 Mach at virtually all altitudes. Hardly a coincidence

@15k ft, max sustainable load factor stay at Mach 0.85, the Ps curve trend started to change significantly at Mach 0.7
lift 15k.png

@35k ft, max sustainable load factor stay at Mach 1.4, the Ps curve trend started to change significantly at Mach 0.78
35k ft device operating.png


@35k ft but with maneuver devices not operating, the max sustainable load factor still stay at Mach 1.4, the Ps curve trend still started to change significantly around Mach 0.78
35k ft device not operating.png

you must know all of this too because you have the manual
In short, you are awfully disingenuous, as soon as we get distracted you try to deceive us.


TBH, I was mislead as well. Cheers for clear things up.

mixelflick wrote:Is it fair to say every Viper model holds a thrust to weight advantage vs. any F-18? Both being clean of course, or with 2-4 AAM's..

I thought so, but have seen reference to 414? powered F/A-18C's having a comparable T/W ratio??

You can DM Sprstdlyscottsmn, he have all the flight manuals and very knowledgeable.

Re: F-16 vs F/A-18

Unread postPosted: 14 Feb 2018, 20:33
by sprstdlyscottsmn
garrya wrote:
mixelflick wrote:Is it fair to say every Viper model holds a thrust to weight advantage vs. any F-18? Both being clean of course, or with 2-4 AAM's..

I thought so, but have seen reference to 414? powered F/A-18C's having a comparable T/W ratio??

You can DM Sprstdlyscottsmn, he should have all the flight manuals and very knowledgeable.

Good thing I am following this thread.

The worst F-16 T/W would be a HAF Block 52+ with CFTs. Rated thrust is 29,160. Empty weight is 22,000lb and fuel load is 10,000lb IIRC (dont have that one on me). This gives T/W of 1.33 empty and 0.91 with fuel and no weapons.

The best F/A-18C T/W will be the -402 powered planes with 35,400 lb rated thrust, 24,500lb empty weight, and 10,810 fuel. This gives T/W of 1.44 empty and 1.00 with fuel and no weapons.

With (2) AIM-9 and (2) AIM-120 and 60% fuel the -402 Hornet has a best sustained turn rate or 19.2 at sea level and 12.3 at 15,000ft. The HAF with no CFT under same conditions is 18.5 and 12.63.

Re: F-16 vs F/A-18

Unread postPosted: 14 Feb 2018, 23:00
by marsavian
Do you happen to have the E-M graphs for that 402 Hornet ? Pretty good sustained numbers for a fighter more famed for its instantaneous and AOA ability.

Re: F-16 vs F/A-18

Unread postPosted: 14 Feb 2018, 23:26
by sprstdlyscottsmn
As far as I know there are no declassified E-M plots for Hornets. Original doc is found here.

https://books.google.com/books?id=XCcLA ... rn&f=false

Re: F-16 vs F/A-18

Unread postPosted: 15 Feb 2018, 09:51
by gta4
sprstdlyscottsmn wrote:With (2) AIM-9 and (2) AIM-120 and 60% fuel the -402 Hornet has a best sustained turn rate or 19.2 at sea level and 12.3 at 15,000ft. The HAF with no CFT under same conditions is 18.5 and 12.63.


It's not the same condition. HAF F-16's loadout drag index = 50 which equals 6+ AMRAAMs + pylongs. Hornet's loadout has a drag index of only 17-20.