Israel pays for additional F-35s

[Corsair1963]

If Israel can scarf up F-15D's at a song, with decent airframe life left, and mod them to their needs, that would seem to be far more cost effective than adding F-15EX's at a price higher than new F-35I's, not to mention the Lightnings are available today, and the EX Eagle is what -- 4 or 5 years away?

Clearly....

[Corsair1963]

In the 'Real World" the F-15 Eagle would very rarely ever excess Mach 1.4 - 1.5 and even then extremely briefly. Why is this relevant to this debate. Because the F-35A has much more fuel and with a full internal load. Can easily exceed Mach 1.6 and provide superior flight performance. Even without in massive advantages in Stealth and Sensor Fusion.

[marsavian]

I suggest you read this and in particular the comments made by members like Bazdriver and TEG (that engine guy)
.....

viewtopic.php?t=13446

Very interesting thread (thanks) which in conclusion states that Mach 2.5 was just a one minute transient capability as indicated by the F-15E color speed chart above. Mach 2.3 was the sustainable maximum for both airframe and engines as well as for firing missiles. So with Amraams, Mach 2.3 for internal fuel, Mach 1.9 for CFT, these are still superior kinematically to F-35 for just getting to a point in the air faster to launch your missiles at incoming missiles/aircraft.

The tread about the F-15's Maximum Speed made it clear the F-15 doesn't even fly around at Mach 2.3 (Sustainable Top Speed) Nor. does it support that a combat loaded Eagle with CFT's could maintain Mach 1.9 let alone for any useful period.

What you believe and what actually is are two very different things...........

No. The thread backs up the official flight charts exactly just providing technical background as to how these limits came about. How sustainable Mach 2.3 is with internal or Mach 1.9 with CFT is purely a fuel availability issue and with CFT there is more fuel than a F-35 so the F-15 higher top speed is more sustainable in that case.

[steve2267]

Does anyone fly Eagles operationally without extra bags of gas? It appears that operational Eagles always have either a centerline tank, or two wing tanks.

... and with CFT there is more fuel than a F-35 so the F-15 higher top speed is more sustainable in that case.

Fuel burn rate with a pair of -229's is going to be a lot higher than the F-135 as well... so not sure that extra Eagle gas gets you much, if anything. Do you have a Dash One manual for the Lightning? Maybe you can run us the numbers and compare?

[charlielima223]

Perhaps this "test" F-35I being delivered to Israel in the 2020 or 2021 timeframe will be used by the IAF to clear F-35I for external carriage of the GBU-28 and/or addition of CFTs?

If Israel can scarf up F-15D's at a song, with decent airframe life left, and mod them to their needs, that would seem to be far more cost effective than adding F-15EX's at a price higher than new F-35I's, not to mention the Lightnings are available today, and the EX Eagle is what -- 4 or 5 years away?

F-35Is will definitely need to be certified Israeli weapons...



https://www.janes.com/article/86679/raf ... ce-missile

Imagine an F-35I tearassing around the skies with that thing on it... long range bunker busting munition

Also from my understanding the F-15EX is a more modern version of the F-15SA and QA which is the most modern variant of the F-15E. From my understanding the F-15SA and QA is being produced right now. The only reason why the EX is a few short years away is because it has to be cleared by USAF certification criterias. I would like to see potential differences an F-15IX would be from its Arab sisters.

But you are right, Israel is going to do what Israel wants despite all our clamouring and brouhaha we do here. Israel is going to do what Israel feels is in her best interest.

[Corsair1963]

Even with 1 centerline tank and 6 air to air missiles, an F-15 is still pretty fast. With CFTs and 6 air to air missiles, I'd wager an F-15I will still outrun an F-35I with full internal in the long run. Also the F-35 cannot carry 6 internal AAMs yet, nor do SACMs exist yet. An outsider trying to look in would see an F-15I being upgraded to EX specs would be better in short term and the F-35 better in the long run. Also one thing I am seeing in this discussion/debate is no mention of the improved engine F-15Is might/could get and more importantly the tactics the Israeli Airforce use...

Then you would loose that wager...As even the drag of a single Amraam has a big effect on performance. (Per Jon Beesley) Now add 7 more Sidewinders and Amraams plus external pylons and at least a centerline fuel tank. It's also worth noting that the F-15EX will likely carry external Target/Nav Pods and CFT's as standard fit.

Speaking of drag the general rule for an external fuel tank. Is it takes half of the fuel carried to just overcome the Drag and Weight of said tank. Meaning you pay a "big" performance penalty and only half of the fuel is even useable! That speaks volumes on the impact of drag on performance and fuel efficiency of a fighter with external stores.

As for the new and more powerful engines on the F-15EX. They likely would improve acceleration a little and possibly range? Yet, that would be very marginal at best....

As for the F-35 and six internal missiles and the new SACM's. The former should be available by time the F-15EX would be ready. While, the SACM's are likely some years off. Yet, the difference between 6-8 is negligible. Plus, the F-35A could carry two external Sidewinders for a very minor penalty.

My contention is you could load a F-35A with full fuel and internal weapons. With an F-15EX similarly equipped but external. The Lightning is in fact going to eat the Eagle for lunch.....(based on performance)

The same can be said with a heavy load....

Now take in the lower price of the F-35 and it's advantages is Stealth and Sensor Fusion. You have no "case" that the F-15 (in any version) is an alternative...


"IMHO"

[marsavian]

In the 'Real World" the F-15 Eagle would very rarely ever excess Mach 1.4 - 1.5 and even then extremely briefly. Why is this relevant to this debate. Because the F-35A has much more fuel and with a full internal load. Can easily exceed Mach 1.6 and provide superior flight performance. Even without in massive advantages in Stealth and Sensor Fusion.

F-35 design limit is a hard Mach 1.6. F-15s loaded with bombs are limited to Mach 1.4 and under but if you are on a bombing mission you are going to do that subsonically anyway for range/endurance reasons so the F-35 is faster for a mission that doesn't need it (bombing) and slower for a mission that does (intercepting). The F-35 is pretty great for its primary role of stealth strike and secondary role of air superiority but for long range strike or very fast intercepting there are superior specialist aircraft of which F-15E is but one example.

[charlielima223]

In the 'Real World" the F-15 Eagle would very rarely ever excess Mach 1.4 - 1.5 and even then extremely briefly. Why is this relevant to this debate. Because the F-35A has much more fuel and with a full internal load. Can easily exceed Mach 1.6 and provide superior flight performance. Even without in massive advantages in Stealth and Sensor Fusion.

You always mention, in the real world.

Okay, in the real world an F-35 wont be spending much time near mach 1.4 or 1.5 let alone 1.6. In the real world its flight speeds will be closer to that of operational F-16 and F-18. Even though the F-35 is capable of reaching mach 1.6 in its standard all internal configuration (impressive in its own right), it too would struggle to get to that top speed and it too would be guzzling gas like a fat kid drinking soda just to get there. The F-35 is more comfortable for mid altitude (high) subsonic stuff. It wasnt designed for the high altitude highspeed kinda stuff. Let the aircraft designed for high altitude high speed stuff do the high altitude high speed stuff.

An F-35 isnt an F-15 and vice versa. Its obvious Israel has a use for both aircraft. If it didnt then it wouldnt want second hand F-15s.

[Corsair1963]

Does anyone fly Eagles operationally without extra bags of gas? It appears that operational Eagles always have either a centerline tank, or two wing tanks.

... and with CFT there is more fuel than a F-35 so the F-15 higher top speed is more sustainable in that case.

Fuel burn rate with a pair of -229's is going to be a lot higher than the F-135 as well... so not sure that extra Eagle gas gets you much, if anything. Do you have a Dash One manual for the Lightning? Maybe you can run us the numbers and compare?

Everything is a trade off....Sure you can load up the F-15EX with CFT's and External Fuel Tanks. Yet, they would have a "massive" impact on performance. Yet, only offer a slight gain in range. When combat loaded...

The F-35's aerodynamic performance is very good. Yet, it's designed for exceptional "transonic acceleration" not high top speed. Yet, as we've discussed the latter has little impact in the real world of aircombat. As nobody "dogfights" at Mach 2+

Honestly, this is nothing new as this has been discussed over and over again.........

[steve2267]

The point I was trying to make, and apparently not very well, is that ALL operational Eagles are limited to a maximum speed of 1.5 Mach.

Any F-35A (or F-35I) in combat configuration with four (by the time the F-15EX is available, probably six) internal AIM-120s, and 18,500lb of gas can go 1.6Mach.

IMO, the practical kinematic differences between a combat ready F-15EX, in an operational configuration, and an F-35 is nil, but I strongly suspect the F-35 has the edge.

Until someone coughs up a -1 for the Lightning, though, this debate is so much pissing in the wind (or sloshing beer at the bar).

[Corsair1963]

In the 'Real World" the F-15 Eagle would very rarely ever excess Mach 1.4 - 1.5 and even then extremely briefly. Why is this relevant to this debate. Because the F-35A has much more fuel and with a full internal load. Can easily exceed Mach 1.6 and provide superior flight performance. Even without in massive advantages in Stealth and Sensor Fusion.

You always mention, in the real world.

Okay, in the real world an F-35 wont be spending much time near mach 1.4 or 1.5 let alone 1.6. In the real world its flight speeds will be closer to that of operational F-16 and F-18. Even though the F-35 is capable of reaching mach 1.6 in its standard all internal configuration (impressive in its own right), it too would struggle to get to that top speed and it too would be guzzling gas like a fat kid drinking soda just to get there. The F-35 is more comfortable for mid altitude (high) subsonic stuff. It wasnt designed for the high altitude highspeed kinda stuff. Let the aircraft designed for high altitude high speed stuff do the high altitude high speed stuff.

An F-35 isnt an F-15 and vice versa. Its obvious Israel has a use for both aircraft. If it didnt then it wouldnt want second hand F-15s.

Wrong....the Mach 1.4 - 1.5 would be the top edge of the flight envelope in regards to top speed for the F-15 in combat conditions. Even then that speed is in a clean or a light configuration. (think Red Flag) Both would spend most of their time in the transonic region. Which, is between high subsonic and low supersonic! That would just as easily apply to both the F-15 and F-35. Yet, the F-35 is clean with little drag and excellent aerodynamic performance and a lot of internal fuel....Sorry, in a dogfight the F-35 is going to kick the F-15's A$$.....Again that doesn't include it's advantages in Stealth or Sensor Fusion. Which, is another ballgame altogether...

BTW Israel acquire secondhand F-15's because they were cheap and because the F-35's would arrive both slowly and in small numbers...

[charlielima223]

Even with 1 centerline tank and 6 air to air missiles, an F-15 is still pretty fast. With CFTs and 6 air to air missiles, I'd wager an F-15I will still outrun an F-35I with full internal in the long run. Also the F-35 cannot carry 6 internal AAMs yet, nor do SACMs exist yet. An outsider trying to look in would see an F-15I being upgraded to EX specs would be better in short term and the F-35 better in the long run. Also one thing I am seeing in this discussion/debate is no mention of the improved engine F-15Is might/could get and more importantly the tactics the Israeli Airforce use...

My contention is you could load a F-35A with full fuel and internal weapons. With an F-15EX similarly equipped but external. The Lightning is in fact going to eat the Eagle for lunch.....(based on performance)

The same can be said with a heavy load....

Now take in the lower price of the F-35 and it's advantages is Stealth and Sensor Fusion. You have no "case" that the F-15 (in any version) is an alternative...

"IMHO"

I remember attending the airshow at Nellis AFB. I talked to one F-35 test pilot who used to be on the Strike Eagle. I remember asking about flight performance. He said if all were equal in terms of standard payload the F-35 could keep up with the F-15. Once the F-15 goes AB the F-35 starts to struggle to keep up. He didnt get into much detail but Im not going to call that guy a liar.

In performance the F-35 is impressive for what it is and what it can do, but it isnt the greatest thing since sliced bread and butter baked into it.

Your contention is you feel you have to be right...

[Corsair1963]

I remember attending the airshow at Nellis AFB. I talked to one F-35 test pilot who used to be on the Strike Eagle. I remember asking about flight performance. He said if all were equal in terms of standard payload the F-35 could keep up with the F-15. Once the F-15 goes AB the F-35 starts to struggle to keep up. He didnt get into much detail but Im not going to call that guy a liar.

In performance the F-35 is impressive for what it is and what it can do, but it isnt the greatest thing since sliced bread and butter baked into it.

Your contention is you feel you have to be right...

Funny, that is contradictory to remarks my other former F-15E Pilots that now fly the F-35A. Never heard anyone stating the "F-35" ever had a problem keeping up with any 4th Generation Fighter. As a matter of fact the direct opposite. As the F-35 is known for it's excessive power.........(ie P&W F135)

Honestly, I wouldn't hesitate to call that out...........

[charlielima223]

[
Wrong....the Mach 1.4 - 1.5 would be the top edge of the flight envelope in regards to top speed for the F-15 in combat conditions. Even then that speed is in a clean or a light configuration. (think Red Flag) Both would spend most of their time in the transonic region. Which, is between high subsonic and low supersonic! That would just as easily apply to both the F-15 and F-35. Yet, the F-35 is clean with little drag and excellent aerodynamic performance and a lot of internal fuel....Sorry, in a dogfight the F-35 is going to kick the F-15's A$$.....Again that doesn't include it's advantages in Stealth or Sensor Fusion.

BTW Israel acquire secondhand F-15's because they were cheap and because the F-35's would arrive both slowly and in small numbers...

Really? I remember reading somewhere hear that the Typhoon and Rafale in wvr can still give the F-22 a run for its money from time to time. I always saw the Typhoon as Europe's answer to the F-15. Even the F-16 can put up a good fight for the F-22. Go ahead and argue that the F-22 is a kinematically inferior to the F-35... I dare you. I also read somewhere here (somewhat recently) that the Typhoon can give the F-35 some stiff competition. Last I checked Typhoon is capable of sustained supercruise in specific operational configurations. Go ahead and claim that the Typhoon is a kinematic slug compared to the F-35. The F-15E is a little bit heavier and bigger than the F-15C but I'd wager the Strike Eagle (especially her crew) is not going to be a push over... especially to an F-35.

It seems that all the benefit of stealth and sensor fusion becomes less important in a swirling circle jerk hairball in the sky.

Also as you stated second hand F-15s are cheap and the F-35Is are coming slowly and in small batches. Wouldnt it be in Israeli's best interest as of now to get the more readily available and less costly?

[marsavian]

Wrong....the Mach 1.4 - 1.5 would be the top edge of the flight envelope in regards to top speed for the F-15 in combat conditions. Even then that speed is in a clean or a light configuration. (think Red Flag)

Where are your actual facts and charts to back this ridiculous assertion up and not heresay. In a clean to light configuration the top edge of the flight envelope is Mach 1.9 (with CFT) to Mach 2.3-2.5 (without), many flight charts of actual testing flights state and prove this. Mach 1.4 is the lower end of the flight envelope with heavy combat load, again the manual charts prove this.