Leap in Performance - F-4 J79-19?

Unread postPosted: 17 Aug 2019, 18:01
by kdub104
We are very well aware of the giant leap in performance with the installation of the J79-19 in the F-104: 18,900 lbs of thrust. High altitude and the high Mach numbers gave a huge performance gain. The impossible became possible and no other Western fighter could come close to matching the new "numbers". Perhaps the F-22 comes close. "Dozer" stated in an interview when talking about the F-22 of accelerating at Mach 2 with 10-15 degree nose up at 60,000 ft. This is clearly F-104 -19 territory.

Was there a noticeable performance gain when the F-4 received the J79-19 (17)? If my numbers are correct the -19 (17) provided an additional 3000 lbs thrust increase. This means 6,000 additional pounds of thrust for the Phantom.

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 17 Aug 2019, 18:56
by f-16adf
I have spoken (in person --many, many, many years ago, and by email) with a handful of Marine Corps/Navy F-4 Phantom pilots. And the general impression was that the original F-4B (J79-8) was a better performer than the F-4J (J79-10). The J79-10 had 17,900lbs of thrust, like the -17 in the AF F-4E. The reason is because the upgraded F-4J gained a substantial amount of weight (and slightly more drag due to the bulged wing for the thicker main wheels and slotted stab) vs the much lighter F-4B. I know one said the B was faster, and I think also that it climbed quicker than the J. But the J was a better all around (go to war) jet than the B. It had a much better radar in the APG-59/AWG-10. And in the F-4S model (digital AWG-10B/ maneuver slats) it became the ultimate Navy Phantom variant.

The USAF F-4E also gained much weight (and drag with slats) vs the F-4C/D. So I doubt that it was faster or a better climber than the earlier AF Phantoms. But with the nose cannon, slats, and the solid state APQ-120 radar, -it was a better jet. There are a couple of Phantom pilots on this forum who could probably explain this FAR acutely than me.



One quick question, I thought the -19 put out 17,900lbs vs 18,900lbs? I think it was mainly used on the Italian F-104S and one USAF Starfighter unit.


edit: The GAF F -4F was lighter than the standard F-4E, but I still think its slats made it slower than a hard wing Phantom (-8, -15 powered). Yet, I don't have any numbers for its climb rate or acceleration.

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 18 Aug 2019, 00:42
by sprstdlyscottsmn
In Project Skyburner an F-4 (pre E USAF model) was taken to 2.62M with modified -8s. -19s would probably have done as well or better based on what they did in the F-104s.

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 18 Aug 2019, 01:13
by kdub104
f-16adf wrote:One quick question, I thought the -19 put out 17,900lbs vs 18,900lbs? I think it was mainly used on the Italian F-104S and one USAF Starfighter unit.


My mistake. You are correct. Walt BJ said they detuned the thrust for longevity:

http://www.916-starfighter.de/Ruminatio ... 0F-104.htm

"The -3B engine gave us 9600 lbs in military and 14000 in AB - when it was new, that is. The -19 gave us 12850 in military and 18900 in AB, later reduced for peacetime longevity to 11870/17500."

I too think it is 17,900 not 17,500 lbs.

Lighter airframe with less drag equals more performance even with less powerful engines. Any idea just how much weight was gained going from B model to E or J or S?

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 18 Aug 2019, 01:29
by kdub104
Walt BJ in his article focuses on high Mach and high altitude performance increase and, I imagine this is a clean F-104. Been thinking if this translates to the F-4 in any way. True, a speed and energy increase is natural with a hotter engine but, just how much of a gain would the F-4 see?

1 x 600gal
2 x 370 gal
Winders with racks and Sparrows

Tactically would the -10/-17 F-4 be more capable? I am not sure. Seems the turned up J79 versions really shine on the extreme performance end of the envelope, of which is negated with a full A2A load out.

Apples to Apples; would the -19 F-104 be as potent loaded up with its Mach 2 capable tip tanks, fuselage mounted AIM-9s and wing pyloned Sparrows as the loaded -10/-17 F-4?

Really wish we had an Italian F-104S pilot on the board.

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 18 Aug 2019, 01:31
by kdub104
sprstdlyscottsmn wrote:In Project Skyburner an F-4 (pre E USAF model) was taken to 2.62M with modified -8s. -19s would probably have done as well or better based on what they did in the F-104s.



For the Canadian altitude record I think the CF-104G reached M2.68 @32,000ft (dive?). Not sure which variant... -11?

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 18 Aug 2019, 01:47
by jetblast16

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 18 Aug 2019, 02:00
by f-16adf
I think the F-4J was around 30,000 lbs empty. The early F-4B was a little less than 28,000lbs. The F-4S was 31- 32,000lbs empty.

I almost forgot to mention that a few RF-4B's received the higher thrust -10 motors. So that variant was probably the fastest of all regular "in service" Phantoms.

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 18 Aug 2019, 03:38
by kdub104
The -19/-17/-10 engine was going into the 104 in 1969. Untouchable Foxbat overflights of Israel were in 1970. IAF asked for a super F-4 to reach high Mach and high altitude to "intercept" the MIG-25. Saw an article and photo of an F-4 with CFT filled with methanol for water injection to stop the overflights.

https://tacairnet.com/2015/06/18/redeve ... spy-plane/

Surely a "-19" engined and clean F-4 could at least get close to lock the MIG-25? I suspect scramble times would be the weak point due to Pressure Suit preparations? Carry only Sparrows to decrease drag?

Or instead of all the time and effort going into this water injected Phantom, why not talk to the boys out at Luke who were making 70,000+ foot, Mach 2+ flights with their re-engined -19 104s? Walt said he was no where near max altitude or speed in the -19 104 at these speeds and altitudes. Carry two AIM-9s under the fuselage or put the AIM-9 seeker head on a Sparrow?

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 18 Aug 2019, 04:05
by madrat
What eyepiece on such Sparrow would have survived Mach 3 flight without degradation? None. A Falcon-derivative on the other hand, maybe with some help. There's a reason Falcon was carried internally and relied on canisters. High speeds heat up the seekers too much.

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 18 Aug 2019, 05:34
by sprstdlyscottsmn
madrat wrote:What eyepiece on such Sparrow would have survived Mach 3 flight without degradation? None. A Falcon-derivative on the other hand, maybe with some help. There's a reason Falcon was carried internally and relied on canisters. High speeds heat up the seekers too much.

Sparrow is a Radar missile that flies at M4+, I think you are thinking about Sidewinders?

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 18 Aug 2019, 07:03
by sferrin
sprstdlyscottsmn wrote:In Project Skyburner an F-4 (pre E USAF model) was taken to 2.62M with modified -8s. -19s would probably have done as well or better based on what they did in the F-104s.


Assuming they did the same engine modifications. Skyburner had pre-compressor water/alcohol injection. The Soviets did the same to the MiG-25 that did the climb to 123,000 feet.

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 18 Aug 2019, 15:50
by f-16adf
Maybe a "stripped down" F-104S could attempt to intercept a Foxbat with only 2 Aspide or Aim-7 medium range AAMs loaded on it. But would probably be a very short flight due to fuel. Putting wingtip (or under wing) tanks in addition to the 2 large medium range AAMs I'm guessing would be way too draggy.

F-104S  Starfighter.jpg


Guessing for greater endurance the reason for just one Aspide and one Sidewinder?

F-104S 3.jpg

F-104S.JPG





The bare metal Starfighters certainly win the beauty contest:


CF-104 Starfighter.jpg

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 18 Aug 2019, 18:56
by kdub104
madrat wrote:What eyepiece on such Sparrow would have survived Mach 3 flight without degradation? None. A Falcon-derivative on the other hand, maybe with some help. There's a reason Falcon was carried internally and relied on canisters. High speeds heat up the seekers too much.



Roger.

Sidewinders might reach Mach 2 at lower altitudes? But I wonder what speed it would achieve in the thin air above 60k being launched at Mach 2?

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 18 Aug 2019, 18:59
by kdub104
f-16adf wrote:Maybe a "stripped down" F-104S could attempt to intercept a Foxbat with only 2 Aspide or Aim-7 medium range AAMs loaded on it. But would probably be a very short flight due to fuel. Putting wingtip (or under wing) tanks in addition to the 2 large medium range AAMs I'm guessing would be way too draggy.


The tip tanks and underwing tanks would be jettisoned leaving 6,000 lbs of fuel for the intercept - a further 500 lbs if the gun and ammo can is removed.

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 18 Aug 2019, 19:05
by kdub104
f-16adf wrote: Guessing for greater endurance the reason for just one Aspide and one Sidewinder?

The bare metal Starfighters certainly win the beauty contest:


CF-104 Starfighter.jpg


I also wondered why one Aspide and Sidewinder. The Norwegians discovered 2 Sidewinders under the fuselage offered less drag at supersonic speeds than under the wings or on the wing tips.

Bare metal Starfighters... agreed and Amen!

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 19 Aug 2019, 06:24
by madrat
sprstdlyscottsmn wrote:
madrat wrote:What eyepiece on such Sparrow would have survived Mach 3 flight without degradation? None. A Falcon-derivative on the other hand, maybe with some help. There's a reason Falcon was carried internally and relied on canisters. High speeds heat up the seekers too much.

Sparrow is a Radar missile that flies at M4+, I think you are thinking about Sidewinders?


kdub104 said, "Carry two AIM-9s under the fuselage or put the AIM-9 seeker head on a Sparrow?"

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 19 Aug 2019, 13:58
by sprstdlyscottsmn
Missed that, apologies.

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 19 Aug 2019, 15:31
by mixelflick
kdub104 wrote:
f-16adf wrote: Guessing for greater endurance the reason for just one Aspide and one Sidewinder?

The bare metal Starfighters certainly win the beauty contest:


CF-104 Starfighter.jpg


I also wondered why one Aspide and Sidewinder. The Norwegians discovered 2 Sidewinders under the fuselage offered less drag at supersonic speeds than under the wings or on the wing tips.

Bare metal Starfighters... agreed and Amen!


That's really interesting, thanks for passing it along. I assume the same would be true for Sparrows? Less drag under fuselage vs. when carried under wing?

We have a beautiful F-104C here at the New England Air Museum. Surprised just have thin/razor sharp the wings were! Unbelievable performance, especially for the time. I think the one on display here got over 90,000 ft and mach 2.4 on at least one run.

Beautiful piece of aviation history..

Re: Leap in Performance - F-4 J79-19?

Unread postPosted: 20 Aug 2019, 01:13
by kdub104
Unable to find the Norwegian article but they had numerous intercepts due to their geographical location and this is what they discovered. Makes you wonder why the Italians didn't mount a winder and sparrow under the fuselage. Could have carried wing tanks in place of the missiles - increased endurance and range. I guess air forces/countries didn't share information like we'd think they should.

The sparrow is a mere 2 feet longer than the sidewinder so it will fit under the fuselage.

I've been fascinated by the 104 since I was a boy. My father flew them late 60s and early 70s. Canadian Air Force CF-104G. He was a 104 demo pilot for the airshow circuit in 70 and 71 and gave it up for 72 as I was born June of 72.

The 104 was never maximized. Its potential never fully realized. Italy came closest. Money/politics overruled potential. Can endlessly visit and re-visit a modernization program, but I have a thread up on this already.