Forum: F-16 Spotting & Photography

Interesting Youtube vid, IMO. Maybe I wasn't seeing everything or simply making poor analysis of this aspect and what it implies, etc.. but if you watch the entire 14min vid you'll notice every Viper and Hornet taking off in AB power, while the final 4-ship Block 60 (starting @ 13:45 into vid) appear to launch under Mil-power?? Any confirmation or feedback?

Furthermore, the take-off climb rates seem pretty impressive under Mil power as well, observed in the very final second of vid, albeit with only CL tank, CFT and minimal A-A loadout by the looks of it..

So is the 32k lb class power providing this much superior thrust enabling standard MIL-rated takeoffs... and perhaps more efficient cruise envelopes, despite the block 60s increased overall weight? Thanks in advance.

http://www.youtube.com/watch?v=703qUto2 ... annel_page

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geogen wrote:

Interesting Youtube vid... ... the final 4-ship Block 60 (starting @ 13:45 into vid) appear to launch under Mil-power?? Any confirmation or feedback?

I'd confirm that, yes only MIL power.

geogen wrote:

So is the 32k lb class power providing this much superior thrust enabling standard MIL-rated takeoffs... and perhaps more efficient cruise envelopes, despite the block 60s increased overall weight?

The GE-132 has a higher flow fan and lower BPR. Both would help increase MIL thrust. While it did gain a new augmentor fuel system we're not talking that right now..

Quote:

Mass flow (-100 and variants) 269.8 lb/s, (-129) 270 lb/s, (-132) normally limited by F-16 inlet to 275.6 lb/s. Bypass ratio (most) 0.76, (-132) 0.68.

Power quoted as follows:

Quote:

Maximum dry (MIL):
F110-GE-100 17,530 lb st
F110-GF-129 17,000 lb st
F110-GE-132 19,100 lb st
Maximum afterburner:
F110-GE-100 28,000 lb st
F110-GE-129 29,000 lb st
F110-GE-132 32,130 lb st

Important thing to note is that the MAX SFC is higher in the GE-132 than the GE-100 and with the additional thrust, that means lots more fuel burnt on a MAX take-off.

Quote:

Maximum dry (typical) 0.64 lb/h/lb st
Maximum afterburner:
F110-GE-100 2.06 lb/h/lb st
F110-GE-129 1.90 lb/h/lb st
F110-GE-132 2.09 lb/h/lb st

Now on cool days, or with lighter loads I've seen PW-229 Vipers doing the same thing on a routine basis. (Even PW-220s would use MIL take-offs in winter conditions) PW-229s make about a 1.3K less thrust in MIL than the GE-132 and when you figure engine weight into the equation the gap would be even lower, account for Block 60 (w/conformals) airframe weight and I'd bet they're almost even, drag and/or MIL thrust/weight ratio.

MIL take-offs save fuel ($$$) and extends flight times if they versus MAX. Everything depends on the density-altitude of the field at the time and the take-off weight of the Viper in question. There are restrictions for field length too (I believe) that will or won't allow for MIL take-offs.

For comparison the PW-229's fan decreased BPR to 0.36 while retaining a flow of 254lbs/s and the fan/core overall pressure ratio was raised to 32.4 (From the -220's OPR of 24.5) to give the improved performance. MIL thrust is rated at 17,800 lb st, MAX at 29,100 lb st, and the MAX power SFC is 1.94 lb/h/lb st.

I'm sure the extra MIL thrust allows them to play much harder without tapping that thirsty 'burner. Cool

Keep 'em flyin' Thumb

TEG

Sure is impressive, I can't believe our government is to dumb to use this plane as a gap filler.

Pretty sure the max thrust on the -132 was limited by Lockheed and not GE?

20,000lb's at mil is pretty much a 220 at full wick. Well 4000 short at way less fuel flow. What is the weight difference of a B60 with CFT's full of fuel versus a 16 with wing tanks full? No weapons.

03fomoco wrote:

I can't believe our government is to dumb to use this plane as a gap filler.

Using Block 50+/52+ would be better. The systems/engines would match what the USAF already has infrastructure/logisitcs to cover. Wouldn't be a 'new' aircraft or engines.

F-16E/F Block 60 with F110-GE-132 isn't in service and would require lots of other 'new' things to match the 'new' aircraft. The purchase of the aircraft only accounts for a fraction of the overall cost when training, logistics, support, spares etc are considered.

03fomoco wrote:

Pretty sure the max thrust on the -132 was limited by Lockheed and not GE?

Not intentionally by either; the performance of the GE-132 (Or PW-229 in a 'Small-mouth) is dependent on the airflow handling limitations of the inlet. The Blk60s 'Big-mouth' inlet is only capable of passing 270lbs of air per second.

So unless Lockheed developed a 'Huge-mouth' inlet or added additional inlets somewhere else on the Viper ahead of the engine, 270lbs/sec is the limit. From there the engine would need a higher OPR or TIT (faster/hotter) to gain thrust. Remember thrust is mass X velocity. If one can't increase mass you must increase velocity. (GE is mainly mass, where PW is mainly velocity; why PW engines can use the smaller inlets)

On the other hand the GE-129EFE (pre GE-132) was tested up to 36K thrust MAX on a test-stand, but there it has almost unlimited airflow. Armed with this one could install GE-132 with MORE thrust in the F-15 with it's 'huge' inlets, but then the engine's TBO would suffer. Inversly if you 'tuned-down' a GE-132 to only 29K of thrust, it would gain almost 50% more TBO. This is what PW is doing with the PW-229EEP. By infusing new F119 and F135 technology they've made the engine more efficient and robust. Knowing they're at the upper limit of the inlet, PW has gone with a longer lived and safer motor to save the customer $$.

Keep 'em flyin' Thumb

TEG

I wasn't aware the U.S. were flying Block 60s with CFTs.

Forum Veteran Joined: Jul 01, 2007 - 07:22 PM Posts: 620

In an air to air config like what the 60s had its standard to take off in mil. Any single bag Viper can take off in mil. The CFTs don't add as much weight and drag as the externals on stations 4 and 6 do. When the Aggressor Eagles were taking off, they were in mil as well.

Side note: The climb performance wasn't that great or even any better than any other single bag Viper taking off in mil. Remember, that jet is a lot heavier than the Block 50 so the extra thrust is compensating for that.

I was there for night launches and while I didn't watch every takeoff, they were always taking off in augmentor. Why they took off in MIL power in that video , who knows? I'm sure it must have been a mission requirement that particular day.

Regards, El Guapo

Enthusiast Joined: Aug 12, 2007 - 05:33 PM Posts: 20

That_Engine_Guy wrote:

Now on cool days, or with lighter loads I've seen PW-229 Vipers doing the same thing on a routine basis. (Even PW-220s would use MIL take-offs in winter conditions)

MIL take-offs save fuel ($$$) and extends flight times if they versus MAX. Everything depends on the density-altitude of the field at the time and the take-off weight of the Viper in question. There are restrictions for field length too (I believe) that will or won't allow for MIL take-offs.

RNoAF with PW220E use Mil power only, at all time, all weight, unless something special demands AB (Short runway, tailwind, Hot & High, Bird avoidance takoff and etc).

At Excercise Bold Avenger 09 at Karup AB in Denmark, the Tower called the Ops to tell that RNoAF was the only participant to always use Mil only, when the other used AB.

Mil takoff also reduces the noiseprint in the community around the airbase. (Happy neighbours isn't a bad thing.. Smile

)

Enthusiast Joined: Aug 12, 2007 - 05:33 PM Posts: 20

Quote:

Power quoted as follows:

Quote:

Maximum dry (MIL):
F110-GE-100 17,530 lb st
F110-GF-129 17,000 lb st
F110-GE-132 19,100 lb st
Maximum afterburner:
F110-GE-100 28,000 lb st
F110-GE-129 29,000 lb st
F110-GE-132 32,130 lb st

Is the dry thrust on F110-GE-129 actually lower than the F110-GE-100??

Dudes, no need for such detailed analysis here, the answer is simple. The fact that they were doing MIL takeoffs, as Snakehandler said, had to do with their takeoff performance in that particular configuration. If the TOLD (takeoff and landing data) permits, it is usually standard to do a MIL-powered takeoff in a clean or single-bag (centerline fuel tank equipped) jet... as we see with the Block 60's here. If the takeoff distance exceeds 50% of the available runway, then an AB (afterburner) takeoff will be made. If you look at most of the other Vipers taking off in that video, they are configured with two bags (external wing tanks), likely making an AB takeoff necessary based on the TOLD. 99% of the time, when you see a two-bag jet taking off, it will be in afterburner. At around 4:40 in the video, you see a clean Aggressor Viper taking off in AB--the pilot chose to take off in AB versus MIL. No big deal... you burn a little more fuel but you accelerate much faster. Speed is LIFE in case you need to zoom the jet to eject or to a key position for a flameout landing.

Ahhhhyiiiiiii don't know... I think I'm detecting some potentially underrated respect for the Block 60's performance here Smile

While I have to agree in the final analysis with TEG, that USAF would be better off overall with PW-229 powered, modernized block 50+/52+ rather than block 60s as 'gap-fillers', the comparative 'mass-launch' take-offs of A-A mission configured viper C/D and 60s were almost equal with exception of wing-tip AMRAAM for most C/D launches and apparent Aim-9 for AZ/UAE 60s.

That is: 2 wing bags for C/D vs CL tank + CFT for 60s. (roughly same external fuel load)? Thus, all things being equal, i.e., same weather conditions, same loads, same runway conditions (plus an extra 100m length for MIL Takeoff, noted), I'm just saying it was impressive to see the 60s being able to do the Takeoffs in MIL, while I truly would have liked to have seen twin bagger C/D, w/ CL ECM, plus AMRAAM do this MIL launch in the same flight..

Furthermore, wouldn't the cleaner profile - with all comparative load-outs virtually equal - also enable higher cruising efficiency w/less drag, or higher cruising speed at same fuel burn rate? So is the block 60 a heavier jet, requiring the extra power? Sure. But perhaps we could wager that when combined with CFT and in said equal A-A config, the thing in fact does over-compensates and performs one step up. (with superior avionics a bonus). Respects due Applause

p.s., yeah TEG, I'd love to see a "Huge mouth" delta-winged (Vip)er mod with that 36k lb max power.. but would settle for it in F-15SE and SLEP'd F-15C/D/E Thumb

so if I understand your point TEG,a PW-229 B52+ with CFT could possibly TO in Mil power?

yakuza wrote:

so if I understand your point TEG,a PW-229 B52+ with CFT could possibly TO in Mil power?

Any Viper can TO in MIL given the proper conditions. Weight, Density/Altitude, runway length, etc.

thanks Master

Forum: F-16 Spotting & Photography

Block 60s launching in MIL power... Red Flag vid.