Article aboat F22 in South African newspaper.

[TucksonSonny]

TucksonSonny, I really suggest you read what he wrote again. Slowly. With emphasis on comprehension.

 

Ok, “barring”

Since English is only my 4th language I misunderstood the word barring.

Sorry for being kind of slow … :poster_oops:

[GGTharos]

That's ok. You should've seen some misreadings and the consequences thereof that I've done :D

[Rhen]

:huh: that's funny. This misunderstanding started to get personal before it got "smart". Seems to happen a lot around these parts. :cry:

[D-Scythe]

I don’t think so! :bye:

The Pratt & Whitney F119-PW-100 (F/A-22) engine is rated at about 35000 lb (156 kN).

The Saturn AL-41 F (prototype) engine is rated at about 176 kN (39,575 lb).

 

Sorry for just jumping into this now, but the F-22's F119 has been uprated (to an estimated 39 000lb) since the YF-22's F119. General Electric's F120 produced more engine power than the F119 when they both powered the YF-22 and YF-23, but one of the reasons why Pratt and Whitney's engine won out was because P&W argued they could uprate the F119 later on (which it seems they did).

 

The result is that the F-22A cruises faster than the YF-22 (Mach 1.7 vs. M1.5), but the extra thrust in AB doesn't contribute to a higher top speed because F-22A airframe actually overheats sooner than the YF-22's, to about Mach 1.8 from Mach 2.

[GGTharos]

I think it has to do a whole lot more with the inlets than overheating.

[D-Scythe]

I think it has to do a whole lot more with the inlets than overheating.

 

I don't think so. If I'm not too lazy, I'd post an excerpt or something, but non-variable intakes didn't stop the F-16 from reaching Mach 2. The F-22A's flight envelope is limited to Mach 1.8 though - if you observe its flight envelope chart, you'd notice that it basically hits a wall at that speed.

 

In any case, I've read it somewhere. See if I can dig it up.

[Pilotasso]

I don't think so. If I'm not too lazy, I'd post an excerpt or something, but non-variable intakes didn't stop the F-16 from reaching Mach 2. The F-22A's flight envelope is limited to Mach 1.8 though - if you observe its flight envelope chart, you'd notice that it basically hits a wall at that speed.

 

In any case, I've read it somewhere. See if I can dig it up.

 

Part of the reason why the F-18 wont reach mach 2 is beacause of the wings, they arent diamond shaped, nor delta nor even swept back, they are straight wings.

[D-Scythe]

Part of the reason why the F-18 wont reach mach 2 is beacause of the wings, they arent diamond shaped, nor delta nor even swept back, they are straight wings.

 

 

Looks pretty swept back to me.

[Pilotasso]

Your looking at the leading edges only, even then the F-18's are much less sewpt back.

I have grabbed 2 Model Kitts I have and the Hornet has at least 10º less sweep, I estimate 13º of difference.

 

When you consider going fast, first not only you need aerodynamics but structural strength for that. Look again for both aircraft and then say wich aircraft would have its wings snapped off backwards first. ;)

[169th_Crusty]

Your looking at the leading edges only, even then the F-18's are much less sewpt back.

I have grabbed 2 Model Kitts I have the the Hornet has at least 10º less sweep, I estimate 13º.

 

When you consider going fast, first not only you need aerodynamics but structural strength for that. Look again for both aircraft and then say wich aircraft would have its wings snapped off backwards first. ;)

 

You might wanna look at the cord of the wing. Notice the angle of the

wing tip rail vs. angle at the root.

[Pilotasso]

You might wanna look at the cord of the wing. Notice the angle of the

wing tip rail vs. angle at the root.

 

Not wanting to be a persistent prick but what does that contribute? To prevent from the wingtip missile snaping off at higher speeds?:blink:

 

The wing sweep and the wing lenght prevents the F-18 from going faster, and then another thing, in the falcon it blends with the airframe as oposed to the F-18.

 

Its not quite my opinion but the fact that I have read that it is a compromise for carrier aproach speeds. And since the wing is not optimized for mach 2+ why do that for the intakes?

[mikoriad]

I don't think so. If I'm not too lazy, I'd post an excerpt or something, but non-variable intakes didn't stop the F-16 from reaching Mach 2. The F-22A's flight envelope is limited to Mach 1.8 though - if you observe its flight envelope chart, you'd notice that it basically hits a wall at that speed.

 

In any case, I've read it somewhere. See if I can dig it up.

 

 

Taking all the other top speed/ cruise speed comments into account also... I think it comes down to, we do not know how fast the F-22 is capable of going. I believe it would be naive to think it cannot go faster than mach 2.

 

Here's how a member of f-16.net explains it:

 

 

Just because the inlet on the F-22 doesn't use 40 year old technology of hydraulically powered ramps like an F-15 doesn't mean it isn't as good or better.

 

Modern inlet systems do not have to physically change geometry to provide optimum pressure recovery for the engine. Traditional supersonic inlets have moving ramps, cones or other devices to capture the normal shock in the inlet throat and alter capture area. The F-22 inlet system does the same thing without traditional moving parts. No moving parts makes RAM treatments inside the inlets more durable and reduces RCS.

 

Like old technology inlets, each F-22 inlet is spaced away from the forward fuselage to form a boundary layer diverter. This prevents low energy turbulent air from entering. The F-35 uses the fuselage "hump" in front of the inlet to accomplish the same purpose.

 

The upper inboard corner of the F-22 inlet lip creates a series of oblique shocks. Air is slowed by passing through those shocks and is compressed in an external 3D compression ramp before entering the inlet throat.

 

In the inlet throat, a sophisticated porous plate bleed system traps a normal shock and airflow becomes subsonic. The bleed system dumps overboard through the parallelogram-shaped door on top of the fuselage about 3 feet behind the upper inlet lip.

 

Pressure increases as subsonic airflow passes through a gradually diverging duct with a 6:1 length-to-engine face diameter ratio. The 6:1 ratio assures uniform airflow quality at the engine face.

 

Any excess airflow is dumped overboard through a hexagonal grid on top of the fuselage near the wing root. The bleed and dump functions are controlled by the integrated flight and propulsion control software in a CIP.

 

This technology was demonstrated in the YF-22s and is repeated in the F-22A.

[Ross-impress]

I heard Lakenheath (UK) will replace all his F15's for F22 and this in the past "5" years.. Also the 15's won't be sold to another country, they will go to the dessert :( I was there last week. Wow great to see this birds taking off!!

 

Grtz....Ross....

[TucksonSonny]

Taking all the other top speed/ cruise speed comments into account also... I think it comes down to, we do not know how fast the F-22 is capable of going. I believe it would be naive to think it cannot go faster than mach 2.

 

Here's how a member of f-16.net explains it:

 

 

Just because the inlet on the F-22 doesn't use 40 year old technology of hydraulically powered ramps like an F-15 doesn't mean it isn't as good or better.

 

Modern inlet systems do not have to physically change geometry to provide optimum pressure recovery for the engine. Traditional supersonic inlets have moving ramps, cones or other devices to capture the normal shock in the inlet throat and alter capture area. The F-22 inlet system does the same thing without traditional moving parts. No moving parts makes RAM treatments inside the inlets more durable and reduces RCS.

 

Like old technology inlets, each F-22 inlet is spaced away from the forward fuselage to form a boundary layer diverter. This prevents low energy turbulent air from entering. The F-35 uses the fuselage "hump" in front of the inlet to accomplish the same purpose.

 

The upper inboard corner of the F-22 inlet lip creates a series of oblique shocks. Air is slowed by passing through those shocks and is compressed in an external 3D compression ramp before entering the inlet throat.

 

In the inlet throat, a sophisticated porous plate bleed system traps a normal shock and airflow becomes subsonic. The bleed system dumps overboard through the parallelogram-shaped door on top of the fuselage about 3 feet behind the upper inlet lip.

 

Pressure increases as subsonic airflow passes through a gradually diverging duct with a 6:1 length-to-engine face diameter ratio. The 6:1 ratio assures uniform airflow quality at the engine face.

 

Any excess airflow is dumped overboard through a hexagonal grid on top of the fuselage near the wing root. The bleed and dump functions are controlled by the integrated flight and propulsion control software in a CIP.

 

This technology was demonstrated in the YF-22s and is repeated in the F-22A.

 

Hehe, this old thread is bumped up again…

Anyway I think that it is the supercruise compromise.

The supercruise jet-engine is optimized for NOT using the afterburners (the same goes for the typhoons)

Classical jet-engine are optimized for using the afterburners (multiple stages of AB)

Mach 2+ requires full AB and burns your fuel like crazy.

My further speculation on this new engines is also the kind of material used for the jet-engine (engines in carbon materials don’t like AB too much)

[Pilotasso]

Just one quote from that, ''it flies higher, faster and further than any other fighter in the world.'' Further yes, Flanker is a close second. Faster, now that depends on weather he is talking of top speed but we know or believe to know that it cannot brake M2 because of it's intakes. Height, well the Eagle's combat ceiling is 65k. The StreakEagle reached 92k for a few seconds. The Raptor's listed combat ceiling is 50k+, that + could be quite a lot higher.

 

At 80K altitude there is no weather

[Alfa_Kilo]

I will not dare to enter a competition on the mig knowelege base :D however I happen to have several issues of the AFM magazine showcasing several russian proposals for indian Mig purchases among them the Mig-29M2 wich has been shown is festivals bearing the Bars-29 AESA radar, basicaly of the same technology as the ones mounted onboard of the Su-30MKI.

 

The N-011M Bars on the -30MKI is a PESA (not AESA :cry_2:). Though, unlike most phased arrays, this one features mechanical scanning, complementing electronic scanning for a wider scan cone.

[D-Scythe]

I heard Lakenheath (UK) will replace all his F15's for F22 and this in the past "5" years.. Also the 15's won't be sold to another country, they will go to the dessert :( I was there last week. Wow great to see this birds taking off!!

 

Grtz....Ross....

 

Really? Hmm, I always thought the Lakenheath F-15Cs were pretty new - would have thought that most of them would be slated for upgrade as part of the 178 "golden" F-15s slated to supplement the F-22 force.

[ViperEagle]

Almost all of the 178 "Golden Eagles" have been moved or are slated to move to Langley and Eglin AFB. They've all been selected and that is due to the matienence history, hours put on the airframe and such.

 

BTW, Lakenheaths F-15C's, while being "young", FY 85-86, which means they were delivered between 87 and 89, arent the most capapble.

 

The 18 APG-63 V2 AESA radar equipped F-15's at Elmendorf AFB in Alaska hold that honor. And the fate of the F-15's? They're going to transfer to guard units as the F-22 replaces them. The Massachusets ANG, the 101st FW, is transitioning to the F-15C from the F-15A. My guess is that eventually all the F-15A units will tansition to the F-15C from the active duty.

 

Essentially, the 178 Golden Eagles will be enhanced BVR killers, while still retaining their dogfight capability. And yes, the APG-63 V3 IS that lethal.

[D-Scythe]

Almost all of the 178 "Golden Eagles" have been moved or are slated to move to Langley and Eglin AFB. They've all been selected and that is due to the matienence history, hours put on the airframe and such.

 

BTW, Lakenheaths F-15C's, while being "young", FY 85-86, which means they were delivered between 87 and 89, arent the most capapble.

 

The 18 APG-63 V2 AESA radar equipped F-15's at Elmendorf AFB in Alaska hold that honor. And the fate of the F-15's? They're going to transfer to guard units as the F-22 replaces them. The Massachusets ANG, the 101st FW, is transitioning to the F-15C from the F-15A. My guess is that eventually all the F-15A units will tansition to the F-15C from the active duty.

 

Essentially, the 178 Golden Eagles will be enhanced BVR killers, while still retaining their dogfight capability. And yes, the APG-63 V3 IS that lethal.

 

Just out of curiosity...will these new F-15s get the F100-PW-220 or -229 engines? I heard somewhere they were getting re-engined, or something.

[TucksonSonny]

I heard Lakenheath (UK) will replace all his F15's for F22 and this in the past "5" years.. Also the 15's won't be sold to another country, they will go to the dessert :( I was there last week. Wow great to see this birds taking off!!

 

Grtz....Ross....

 

Why wouldn’t they sell it to Israel or Japan or the Saoudi-Arabs having already the F-15 in their inventory?

Or give them away for free (also better than the dessert) :D

[ViperEagle]

Just out of curiosity...will these new F-15s get the F100-PW-220 or -229 engines? I heard somewhere they were getting re-engined, or something.

 

 

Good question, one I dont entirely have an answer for. There were tests undertaken during the 1980's and 1990's with fitting P229 engines to the albinos.

One F-15A, 77-0139, could fit both the F100-P220 and P229 engines, and the pilots loved it. Because it's lighter than the F-15E, the P229 made the F-15A (and C) an absolute hot-rod. They unoffically attempted to shatter the Time to Climb records set by the F-15 Streak Eagle and SU-27. One story is this:

 

I worked on this jet when I was stationed at Edwards. This jet was unique in that, so far as I know, it was the only F-15A in the world that could take PW -220 and -229 engines. The pilots loved it because it was such a hot rod. I once watched it get off the ground in about 1000 feet and climb to over 10000 feet in about two minutes or less. Doing maintenance runs was always fun, because we always had to use the A-model and C-model TO's On the Fini flight of our British foreign exchange pilot, he came blasting across the lakebed at about 50 feet and pulled in to the vertical right over ops desk. We were essentially looking up in to the burners as he blasted off in to the blue about 75 feet over our heads. Needless to say, he got a "stern talking to" but nothing else. Guess I really am getting old, when my jets end up in the boneyard.

IF the Golden Eagles get reengined, it'll take structural modifications for cooling and strengthening the airframes. Regretibly the F-15's arent getting any younger. The average F-15 age is older than me (I'm 22). Granted they live less stressful lives than their navy counterparts (the youngest F-14 was only 12 years old when it was retired). The P229 would turn the F-15C into a speed demon, more so than it already is, and with AB, it'd make it's T/W ratio much better than it already is. The F-15A is lighter than the F-15C, but it would still make it an entirely different aircraft. Alot of things could make the F-15C far better than it already is, TVC, LO technology and material, upgraded avionics.

 

BUT..it's still an older airframe, to reduce the airframe hours would require new tails, new wings, new sections of framing. Basically, it would require ALOT of money, which the AF doesnt really want to spend because they rightfully want more F-22's (500 would do the trick nicely :music_whistling: ). And the ANG may not have the funds for even one of those items. The ANG F-15's already have goodies the active duty dont have, such as BOL rails which provide extra chaff and such. So far, I've seen strengthening plates and straps on the wings of the Hawaii ANG F-15A's and a few of the Florida ANG F-15As.

 

Aging sucks, especially for aircraft.

[ViperEagle]

Not really. The sentimental side of me agrees with you, that anything would be better than the desert, but AMARC is a pretty valuable resource for parts. Heh...maybe Wings Over the Rockies will get one of these babies and I'll get to participate in the restoration process. That would be a dream come true. :pilotfly:

 

 

There is already a F-105 F/G that is being restored to flying status. And the truth is, the F-15A and F-15C have such a high level of parts commonality, I'd rather see them be used to keep OUR F-15's flying. The F-15 family in general has a pretty high level of part commonality, so much so I've seen some Tyndal F-15's with dark gray radomes from F-15E Mudhen and F-15E's with light gray radomes from the albinos.

[p_o_d_2_2]

About the Golden Eagles, why are they not considering the F-22's engines? IIRC, they put out 35,000lbs of thrust which is more than the F-15E's engines right?

[D-Scythe]

Good question, one I dont entirely have an answer for. There were tests undertaken during the 1980's and 1990's with fitting P229 engines to the albinos.

One F-15A, 77-0139, could fit both the F100-P220 and P229 engines, and the pilots loved it. Because it's lighter than the F-15E, the P229 made the F-15A (and C) an absolute hot-rod. They unoffically attempted to shatter the Time to Climb records set by the F-15 Streak Eagle and SU-27. One story is this:

 

I worked on this jet when I was stationed at Edwards. This jet was unique in that, so far as I know, it was the only F-15A in the world that could take PW -220 and -229 engines. The pilots loved it because it was such a hot rod. I once watched it get off the ground in about 1000 feet and climb to over 10000 feet in about two minutes or less. Doing maintenance runs was always fun, because we always had to use the A-model and C-model TO's On the Fini flight of our British foreign exchange pilot, he came blasting across the lakebed at about 50 feet and pulled in to the vertical right over ops desk. We were essentially looking up in to the burners as he blasted off in to the blue about 75 feet over our heads. Needless to say, he got a "stern talking to" but nothing else. Guess I really am getting old, when my jets end up in the boneyard.

IF the Golden Eagles get reengined, it'll take structural modifications for cooling and strengthening the airframes. Regretibly the F-15's arent getting any younger. The average F-15 age is older than me (I'm 22). Granted they live less stressful lives than their navy counterparts (the youngest F-14 was only 12 years old when it was retired). The P229 would turn the F-15C into a speed demon, more so than it already is, and with AB, it'd make it's T/W ratio much better than it already is. The F-15A is lighter than the F-15C, but it would still make it an entirely different aircraft. Alot of things could make the F-15C far better than it already is, TVC, LO technology and material, upgraded avionics.

 

Well, the F-15E can already supercruise (without CFTs) when fitted with the F100-PW-229 engines. The F-15A/C would be a completely different aircraft if re-engined - it's thrust-to-weight ratio would be comparable if not superior to any current or projected next-generation fighter aircraft.

 

BUT..it's still an older airframe, to reduce the airframe hours would require new tails, new wings, new sections of framing. Basically, it would require ALOT of money, which the AF doesnt really want to spend because they rightfully want more F-22's (500 would do the trick nicely :music_whistling: ). And the ANG may not have the funds for even one of those items. The ANG F-15's already have goodies the active duty dont have, such as BOL rails which provide extra chaff and such. So far, I've seen strengthening plates and straps on the wings of the Hawaii ANG F-15A's and a few of the Florida ANG F-15As.

 

Aging sucks, especially for aircraft.

 

Well, the good thing about reducing the fleet to 183 aircraft is that the remaining 400 can be used as spare parts whenever a wing is needed. However, there are no spares for a new TEWS suite - it would be awesome if some contemporary EW equipment (either from the later F-16s or the F/A-18E/F) could be fitted into the Eagles.

 

About the Golden Eagles, why are they not considering the F-22's engines? IIRC, they put out 35,000lbs of thrust which is more than the F-15E's engines right?

 

Parts and cost has a lot to do with it - there are plenty of spare F100 engines left over as the legacy fighter fleet gets slowly replaced.

[ViperEagle]

Yes, the F-15C with P229 engines would have a better T/W ratio than anything except perhaps a light, clean Raptor.

 

The wonderful thing about the F-15 is that it's got ALOT of "undeveloped space" in its' airframe. If the money was available and slated for that, it could easily accomidate a new TEWS suite.

 

As one poster said "why not F119s?", the problem is it would be like putting a big block 454 engine into a car that just cannot handle the stress. It would require structural changes, enhanced cooling ducts and systems (the F-15A with the P229's already had those modifications). Plus the airframes havent been stress tested for them. What I would say would be a better bet would be P229's with 3D TVC. So far only the ACTIVE F-15's have had any sort of thrust vectoring, and that was only 2D.

 

For spares, all the retired F-15's will be a gold mine for sure, plus as I said, the parts commonality between a F-15E and a F-15C arent that off, so they can still get some spares from the Boeing production lines (because MDD doesnt exist anymore).

 

My guess is that FY's 84,85, and 86 will be making up the majority of the Golden Eagle fleet, with FY's 80-83 filling the ANG ranks. But that is just an educated guess on my part.