By: swerve
- 21st April 2008 at 13:10Permalink- Edited 1st January 1970 at 01:00
Not necisarily directed to swerve's comment but why does evryone talk almost exclusivly about the initial unit (flyaway) costs. Isn't the real objective of the commonality unit LIFE TIME cost? It's hard if not impossibel to predict the future but does someone have the numbers for the projected F-35 unit lifetime costs? Numbers for things like yearly maintenace costs, MTBF, personel education, infrastructure investsments or anything that is required for F-35 operations. And if possibel the same numbers for another aircraft like the F-16 for comparison.
\\Dan
It's certainly interesting, but also much harder to get reliable information on than acquisition costs - and they're not easy to pin down.
By: bring_it_on
- 21st April 2008 at 13:49Permalink- Edited 1st January 1970 at 01:00
Not necisarily directed to swerve's comment but why does evryone talk almost exclusivly about the initial unit (flyaway) costs. Isn't the real objective of the commonality unit LIFE TIME cost? It's hard if not impossibel to predict the future but does someone have the numbers for the projected F-35 unit lifetime costs? Numbers for things like yearly maintenace costs, MTBF, personel education, infrastructure investsments or anything that is required for F-35 operations. And if possibel the same numbers for another aircraft like the F-16 for comparison.
\\Dan
You must remember that right now a lot of things are ANALYSIS and TALK and talk is cheap , and everyone has a different opinion :)
One can try and understand some of the requirments for AFFORDABILITY (throughout the aquisition and operational program) of the JSF , by reading some of the requirments that were set (benchmarked mainly too the F-16 ) .
A good start may be -
THE NEXT GENERATION ATTACK AIRCRAFT - AFFORDABILITY AND MISSION NEEDS
It is a RAND publication and is available for less then 14$
By: Z1pp0
- 22nd April 2008 at 22:28Permalink- Edited 1st January 1970 at 01:00
...
A good start may be -
THE NEXT GENERATION ATTACK AIRCRAFT - AFFORDABILITY AND MISSION NEEDS
It is a RAND publication and is available for less then 14$
ty bringit. I will look in to it. :)
\\Dan
New
By: Anonymous
- 22nd April 2008 at 23:19Permalink- Edited 1st January 1970 at 01:00
Pretty good english for a russian ;)
The aft nozzle clearly has influence from the Russian Yak-41. That said, I don't remember it having a lift-fan like the F-35???? Which, is really what makes the Lightning superior to previous STOVL Types..........along with internal Fuel, Weapons, and Stealth!
By: Z1pp0
- 23rd April 2008 at 00:03Permalink- Edited 1st January 1970 at 01:00
The aft nozzle clearly has influence from the Russian Yak-41. That said, I don't remember it having a lift-fan like the F-35???? Which, is really what makes the Lightning superior to previous STOVL Types..........along with internal Fuel, Weapons, and Stealth!
Actuallt the Yak-141 have 2 lift fans. Just like the the Yak-38. But they don't have a shaft connecting them to the main engine. They are independent and this has been quoted as the main reason for the claimed poor safty record for both types. Well see if and how the F-35B's shaft driven lift-fan will be better or not.
Also AFAIK LM and Yakolev did some 'reasearch' together in the 90's. Probably more of a deal for LM to get some (theoretical) experience with this configuration. The shaft-driven lift-fan configuration sertanly looks better on paper than the individual pairs. But is it? Time will tell! :diablo:
\\Dan
New
By: Anonymous
- 23rd April 2008 at 00:20Permalink- Edited 1st January 1970 at 01:00
Actuallt the Yak-141 have 2 lift fans. Just like the the Yak-38. But they don't have a shaft connecting them to the main engine. They are independent and this has been quoted as the main reason for the claimed poor safty record for both types. Well see if and how the F-35B's shaft driven lift-fan will be better or not.
Also AFAIK LM and Yakolev did some 'reasearch' together in the 90's. Probably more of a deal for LM to get some (theoretical) experience with this configuration. The shaft-driven lift-fan configuration sertanly looks better on paper than the individual pairs. But is it? Time will tell! :diablo:
\\Dan
Like the Yak-38 the Yak-141 had lift engines not a lift fan...........:rolleyes:
By: MisterQ
- 23rd April 2008 at 00:38Permalink- Edited 1st January 1970 at 01:00
The F-35B is a terrible way to go STOVL/VTOL, it's actually a step back from the true vectored thrust of the harrier, and adding all that weight and complexity isn't exactly bright either
New
By: Anonymous
- 23rd April 2008 at 01:24Permalink- Edited 1st January 1970 at 01:00
The F-35B is a terrible way to go STOVL/VTOL, it's actually a step back from the true vectored thrust of the harrier, and adding all that weight and complexity isn't exactly bright either
Let's see supersonic performance and cooler thrust in the vertical......Sorry, but the numbers alone would disagree with your accessment.;)
By: swerve
- 23rd April 2008 at 09:31Permalink- Edited 1st January 1970 at 01:00
Actuallt the Yak-141 have 2 lift fans. Just like the the Yak-38. But they don't have a shaft connecting them to the main engine. They are independent and this has been quoted as the main reason for the claimed poor safty record for both types. Well see if and how the F-35B's shaft driven lift-fan will be better or not.
Also AFAIK LM and Yakolev did some 'reasearch' together in the 90's. Probably more of a deal for LM to get some (theoretical) experience with this configuration. The shaft-driven lift-fan configuration sertanly looks better on paper than the individual pairs. But is it? Time will tell! :diablo:
\\Dan
IIRC the main idea LM got from Yakovlev was the swivelling main nozzle. The F-35B has a Rolls-Royce equivalent. As far as the lift-engine arrangement goes, I suspect the Yak-141 showed LM its drawbacks, & prompted them to look for a better system.
By: Distiller
- 23rd April 2008 at 15:03Permalink- Edited 1st January 1970 at 01:00
The swivel-nozzle is not a Yakovlev invention. It was first (?) used on the German-U.S. VJ-101E, aka Advanced VSTOL Tactical Fighter Weapon System (AVS) from the mid-1960's.
The big idea of the F-35 blower is cold air. It eliminates the hot-gas reingestion problem.
Only possible with advanced materials. It was done before by Focke-Wulf, on a much smaller scale, though - was a project that looked like a Ryan XV-5, but used shafts instead of bleed-air to power the fans.
Shows the blower-gearbox-clutch-shaft complex is not light (even though I have to say my SDLF weight is an estimation only), and the volumetric weight also not stellar. It's just cold, and that solves a lot of problems for VTOL ops.
The SDLF assembly of the F-35B must make for some interesting CoG problems. Any idea how they solve that?
By: swerve
- 23rd April 2008 at 15:17Permalink- Edited 1st January 1970 at 01:00
The swivel-nozzle is not a Yakovlev invention. It was first (?) used on the German-U.S. VJ-101E, aka Advanced VSTOL Tactical Fighter Weapon System (AVS) from the mid-1960's....
Ah yes - the Rolls-Royce RB.153.
New
By: Anonymous
- 23rd April 2008 at 17:25Permalink- Edited 1st January 1970 at 01:00
IIRC the main idea LM got from Yakovlev was the swivelling main nozzle. The F-35B has a Rolls-Royce equivalent. As far as the lift-engine arrangement goes, I suspect the Yak-141 showed LM its drawbacks, & prompted them to look for a better system.
Good point.......:)
New
Posts: 1,403
By: Otaku
- 23rd April 2008 at 18:00Permalink- Edited 1st January 1970 at 01:00
Back on topic, though not mentioned specifically, the weak $ may have dire long-term consequences for BAE Systems' UK production of F-35 components & maybe even the Italian assembly line:
By: Z1pp0
- 23rd April 2008 at 19:17Permalink- Edited 1st January 1970 at 01:00
...As far as the lift-engine arrangement goes, I suspect the Yak-141 showed LM its drawbacks, & prompted them to look for a better system.
Thank you swerve this was realy what I wanted to say. :)
Now I am gonna go curse on some bean conters that are closing yet another airbase here in sweden. F21 Luleå is getting axed. It has nothing to do with the F-35 price tag other than even more 2nd hand Gripens compeating for orders. sigh..
By: MisterQ
- 24th April 2008 at 00:43Permalink- Edited 1st January 1970 at 01:00
Let's see supersonic performance and cooler thrust in the vertical......Sorry, but the numbers alone would disagree with your accessment.;)
Supersonic performance has nothing to do with the engine and everything to do with the airframe, the F135 engine + lift fan is what I'm talking about, adding weight to create thrust which can only be used for lift, whersas a F135 changed from a 0.2 bypass to a 1.2 bypass using a pegasus style main fan would generate roughly 51000lbs of dry thrust (given the current estimates and released info on the F135 of roughly 28000lbs) with some simple lightweight ducting it could also be used to provide thrust in level flight while maintaining low RCS (actually easier with a low RCS airframe due to the layout) and you can still use the same 3 bearing pivoting tail and afterburners (afterburning 3 nozzle pegasus varients have existed for more than 20 years) giving 56000lbs or so (again using released data from PW on the F135), and the weight penalty for the ststem would probably be much lower than the lift fan, gearbox, ductwork and doors of the current F-35B system.
Posts: 13,432
By: swerve - 21st April 2008 at 13:10 Permalink - Edited 1st January 1970 at 01:00
It's certainly interesting, but also much harder to get reliable information on than acquisition costs - and they're not easy to pin down.
Posts: 12,109
By: bring_it_on - 21st April 2008 at 13:49 Permalink - Edited 1st January 1970 at 01:00
You must remember that right now a lot of things are ANALYSIS and TALK and talk is cheap , and everyone has a different opinion :)
One can try and understand some of the requirments for AFFORDABILITY (throughout the aquisition and operational program) of the JSF , by reading some of the requirments that were set (benchmarked mainly too the F-16 ) .
A good start may be -
THE NEXT GENERATION ATTACK AIRCRAFT - AFFORDABILITY AND MISSION NEEDS
It is a RAND publication and is available for less then 14$
Posts: 12,109
By: bring_it_on - 21st April 2008 at 17:04 Permalink - Edited 1st January 1970 at 01:00
Pentagon gives conditional OK for F-35 production
http://www.star-telegram.com/business/story/587673.html
Posts: 1,403
By: Otaku - 22nd April 2008 at 10:15 Permalink - Edited 1st January 1970 at 01:00
"Get the pigeon, get the pigeon..."
F-35B inventor talks on YouTube:
http://www.flightglobal.com/blogs/the-dewline/2008/04/f35b-inventor-talks-on-youtube.html
Posts: 12,109
By: bring_it_on - 22nd April 2008 at 13:33 Permalink - Edited 1st January 1970 at 01:00
Pretty good english for a russian ;)
Posts: 1,403
By: Otaku - 22nd April 2008 at 18:43 Permalink - Edited 1st January 1970 at 01:00
I think his toupee's russian :)
Posts: 204
By: Z1pp0 - 22nd April 2008 at 22:28 Permalink - Edited 1st January 1970 at 01:00
ty bringit. I will look in to it. :)
\\Dan
By: Anonymous - 22nd April 2008 at 23:19 Permalink - Edited 1st January 1970 at 01:00
The aft nozzle clearly has influence from the Russian Yak-41. That said, I don't remember it having a lift-fan like the F-35???? Which, is really what makes the Lightning superior to previous STOVL Types..........along with internal Fuel, Weapons, and Stealth!
Posts: 204
By: Z1pp0 - 23rd April 2008 at 00:03 Permalink - Edited 1st January 1970 at 01:00
Actuallt the Yak-141 have 2 lift fans. Just like the the Yak-38. But they don't have a shaft connecting them to the main engine. They are independent and this has been quoted as the main reason for the claimed poor safty record for both types. Well see if and how the F-35B's shaft driven lift-fan will be better or not.
Also AFAIK LM and Yakolev did some 'reasearch' together in the 90's. Probably more of a deal for LM to get some (theoretical) experience with this configuration. The shaft-driven lift-fan configuration sertanly looks better on paper than the individual pairs. But is it? Time will tell! :diablo:
\\Dan
By: Anonymous - 23rd April 2008 at 00:20 Permalink - Edited 1st January 1970 at 01:00
Like the Yak-38 the Yak-141 had lift engines not a lift fan...........:rolleyes:
Posts: 475
By: MisterQ - 23rd April 2008 at 00:38 Permalink - Edited 1st January 1970 at 01:00
The F-35B is a terrible way to go STOVL/VTOL, it's actually a step back from the true vectored thrust of the harrier, and adding all that weight and complexity isn't exactly bright either
By: Anonymous - 23rd April 2008 at 01:24 Permalink - Edited 1st January 1970 at 01:00
Let's see supersonic performance and cooler thrust in the vertical......Sorry, but the numbers alone would disagree with your accessment.;)
Posts: 13,432
By: swerve - 23rd April 2008 at 09:31 Permalink - Edited 1st January 1970 at 01:00
IIRC the main idea LM got from Yakovlev was the swivelling main nozzle. The F-35B has a Rolls-Royce equivalent. As far as the lift-engine arrangement goes, I suspect the Yak-141 showed LM its drawbacks, & prompted them to look for a better system.
Posts: 4,674
By: Distiller - 23rd April 2008 at 15:03 Permalink - Edited 1st January 1970 at 01:00
The swivel-nozzle is not a Yakovlev invention. It was first (?) used on the German-U.S. VJ-101E, aka Advanced VSTOL Tactical Fighter Weapon System (AVS) from the mid-1960's.
The big idea of the F-35 blower is cold air. It eliminates the hot-gas reingestion problem.
Only possible with advanced materials. It was done before by Focke-Wulf, on a much smaller scale, though - was a project that looked like a Ryan XV-5, but used shafts instead of bleed-air to power the fans.
Evolution of actually built auxiliary lift engines:
Type -- Thrust -- Weight -- Length -- Diameter
RB.162 -- 4400lbs -- 275lb -- 52in -- 26in
XJ99 -- 8800lbs -- 500lb -- 60in -- 25in
RD-41 -- 9000lbs -- 650lb -- 63in -- 25in
F-35 SDLF -- ~20000lbs -- ~1900lb -- ~60in -- 50in
Shows the blower-gearbox-clutch-shaft complex is not light (even though I have to say my SDLF weight is an estimation only), and the volumetric weight also not stellar. It's just cold, and that solves a lot of problems for VTOL ops.
The SDLF assembly of the F-35B must make for some interesting CoG problems. Any idea how they solve that?
Posts: 13,432
By: swerve - 23rd April 2008 at 15:17 Permalink - Edited 1st January 1970 at 01:00
Ah yes - the Rolls-Royce RB.153.
By: Anonymous - 23rd April 2008 at 17:25 Permalink - Edited 1st January 1970 at 01:00
Good point.......:)
Posts: 1,403
By: Otaku - 23rd April 2008 at 18:00 Permalink - Edited 1st January 1970 at 01:00
Back on topic, though not mentioned specifically, the weak $ may have dire long-term consequences for BAE Systems' UK production of F-35 components & maybe even the Italian assembly line:
http://www.janes.com/news/defence/business/jdi/jdi080422_1_n.shtml
Posts: 204
By: Z1pp0 - 23rd April 2008 at 19:07 Permalink - Edited 1st January 1970 at 01:00
So true! :D soz
\\Dan
Posts: 204
By: Z1pp0 - 23rd April 2008 at 19:17 Permalink - Edited 1st January 1970 at 01:00
Thank you swerve this was realy what I wanted to say. :)
Now I am gonna go curse on some bean conters that are closing yet another airbase here in sweden. F21 Luleå is getting axed. It has nothing to do with the F-35 price tag other than even more 2nd hand Gripens compeating for orders. sigh..
\\Dan
Posts: 475
By: MisterQ - 24th April 2008 at 00:43 Permalink - Edited 1st January 1970 at 01:00
Supersonic performance has nothing to do with the engine and everything to do with the airframe, the F135 engine + lift fan is what I'm talking about, adding weight to create thrust which can only be used for lift, whersas a F135 changed from a 0.2 bypass to a 1.2 bypass using a pegasus style main fan would generate roughly 51000lbs of dry thrust (given the current estimates and released info on the F135 of roughly 28000lbs) with some simple lightweight ducting it could also be used to provide thrust in level flight while maintaining low RCS (actually easier with a low RCS airframe due to the layout) and you can still use the same 3 bearing pivoting tail and afterburners (afterburning 3 nozzle pegasus varients have existed for more than 20 years) giving 56000lbs or so (again using released data from PW on the F135), and the weight penalty for the ststem would probably be much lower than the lift fan, gearbox, ductwork and doors of the current F-35B system.
Get it now?