X-35 and F-35 differences

Does someone know what are the differences between F-35 and X-35?

And does someone know the (estimated) maximum speed of F-35? I read 1400 Km/h (Mach 1.2) but that seems rather slow!

from vectorsite.net:

The F-35 has a nose 12 centimeters (5 inches) longer than the X-35 demonstrator, while the tailplane has been moved back 5 centimeters (2 inches), and the tailfins have been rearranged a bit. All the flight controls, except for the electromechanically driven leading-edge flaps. are driven by an interesting "electro-hydrostatic actuation system (EHAS)", in which the actuators are all hydraulic -- but are self-contained and driven by electrical signals, not operating off a central hydraulic system. This gives the advantage of hydraulic power with easier maintenance and greater combat survivability than traditional hydraulic systems. Although the individual weight of each of the EHAS actuators is more than that of a traditional actuator, the overall system weight is less.

The X-35 is not intended to reflect on the capabilities of the eventual F-35 aircraft. It was designed to basically demonstrate the air worthiness of the basic layout.

There are many differences between the two. For instance, the intakes are completely different. The X-35A was not build using the same materials or production method as the F-35A. From the appearances of the contruction photos, it appears to be a conventional aluminum aircraft for instance whereas the F-35 makes heavy use of composites. The X-35 had no weapon bays, different landing gear arrangements and two underbody speed brake flaps (which the F-35 lacked).

The engines are also completely different with the X-35 using practically off the shelf F-119s with a short and fat nozzle. The overall airframe has also gone through extensive aerodynamic refinements. The F-35 on the other hand will use the F135 engines which features increased thrust and higher bypass ratios.

The canopy on the X-35 is 2-piece, conventionally framed and opens to one side (ala Bf109). The F-35 has a single piece canopy that pivots on the front opening forward.

So it seems that F-35 will be pretty different from X-35. I heard that USAF/USN/USMC wanted to use X-32's motor wasn't it?

Does someone know what was usually the fate of the prototype aircraft? I bet they go to a museum. Are the prototypes accounted in the total production number? So for example: total production of F-4 was 5195... or 5195 plus the prototypes?

In the past did any prototype go into active service alongside production aircraft, maybe after an upgrade?

... and does someone know its maximum speed (afterburner on)

mt_hg wrote:So it seems that F-35 will be pretty different from X-35. I heard that USAF/USN/USMC wanted to use X-32's motor wasn't it?

Does someone know what was usually the fate of the prototype aircraft? I bet they go to a museum... Are the prototypes accounted in the total production number? So for example: total production of F-4 was 5195... or 5195 plus the prototypes?

In the past did any prototype go into active service alongside production aircraft, maybe after an upgrade?

... and does someone know its maximum speed (afterburner on)

(1) The X-32 and X35 both used the SAME engine. The X-32 has direct lift whereas the X-35 had a liftfan for the STOVL demo, hence the ductworks are different. But its the F-119 engine in both cases.

(2) No, the X-35 prototypes are not F-35s and are not counted in the 14 F-35 prototypes approved by congress the first of which is slated to fly this month. They will also not be counted in F-35 production numbers though it hardly matters with 2500+ airframes expected.

(4) Not sure about the F-4 Phantom.

(5) No, I don't think prototypes ever got patched up and sent to line units. We were never that desperate, not even during WWII.

(6) The maximum speed of the F-35 is given officially by Lockheed-Martin as Mach 1.6+ (~1930km/h). 1930 km/h is Mach 1.82 @ 40,000 ft so that is the expected meaning of the 1.6+ (greater than 1.6) figure in the statistics. The official specifications sheet dated 07/07/06 can be found here...

http://www.lockheedmartin.com/data/assets/12792.zip

Actually the prototype B-2 got an electronics swap and became a service A/C

F-35 hasn't made its maiden flight up to now (2006/12/08). So any information about F-35's maximal speed you can get now is nothing more than the guess or estimation. Not necessarily the truth it will be.

dwightlooi wrote:(6) The maximum speed of the F-35 is given officially by Lockheed-Martin as Mach 1.6+ (~1930km/h). 1930 km/h is Mach 1.82 @ 40,000 ft so that is the expected meaning of the 1.6+ (greater than 1.6) figure in the statistics.

You'll never stop !
Anyhow, I'd like to know : what's the purpose of writing "Mach 1.6+" and "Mach 1.82" in the same sentence ?
Or isn't it safer to assume the 1930 km/h figure is a rough translation of Mach 1.6 for newbies who think sound speed is some constant ?

OPIT wrote:

dwightlooi wrote:(6) The maximum speed of the F-35 is given officially by Lockheed-Martin as Mach 1.6+ (~1930km/h). 1930 km/h is Mach 1.82 @ 40,000 ft so that is the expected meaning of the 1.6+ (greater than 1.6) figure in the statistics.

You'll never stop !
Anyhow, I'd like to know : what's the purpose of writing "Mach 1.6+" and "Mach 1.82" in the same sentence ?
Or isn't it safer to assume the 1930 km/h figure is a rough translation of Mach 1.6 for newbies who think sound speed is some constant ?

It makes perfect sense because:-

(1) 1.6+ means greater than 1.6, which is absolutely true of 1930km/h or Mach 1.82 @ 40,000 ft.

(2) 1930km/h is given as the absolute speed estimate which is not relative to the speed of sound and for which no specific altitude is given. 1930km/h can be Mach 1.82 @ 40,000 ft or 1.63 @ 10,000 ft.

(3) In otherwords, the statement is most logically read to mean the aircraft will "reach faster than Mach 1.6 and approximately 1930km/h at some altitude".

YOUR interpretatioin is BOGUS and INVALID because:-

(1) If the F-35 can only reach Mach 1.6 at 40,000 ft (the defacto standard altitude for giving maximum fighter speeds) its still air speed would be 1699 km/h.

(2) There is NO WAY the F-35 will reach an airspeed of 1930km/h at ANY ALTITUDE if it can only go Mach 1.6. Why? Because in order for 1930km/h to be ~Mach 1.6 it will have to be reached at or near sea level. Which we know is IMPOSSIBLE and will make the F-35 the fastest jet ever on the deck by a huge margin.

(3)If the F-35 can only reach Mach 1.6, then it will never go 1930km/h, ground speed or airspeed (in still air), at any altitude, period. This will make the statement contradictory and bogus.

Hence, we must either assume that Lockmart's statement is bogus or that your fuzzy math interpretation is bogus. Most of us have every reason to assume that YOU are bogus and Lockmart is not. It is time French F-35 naysayers like yourself simply accept official statistics as they are given and not try to apply contrived fuzzy math to attempt to lower numbers to suit your expectations.

dwightlooi wrote:Most of us have every reason to assume that YOU are bogus and Lockmart is not. It is time French F-35 naysayers like yourself simply accept official statistics as they are given and not try to apply contrived fuzzy math to attempt to lower numbers to suit your expectations.

Thanks

X-35 and F-35 are two completely different airplanes. I doubt there is a single significant component that is the same between the two. X-35 was built in Palmdale by an entirely different team than the one that built F-35 in Fort Worth.