F-35 First Flight Comments...

[B.Smitty]

It is not dropped at M1.4 as you suggested earlier. It glides at 150-60knts and tips over to reach it's terminal velocity... whatever that may be and it's not M1.2. It most definetly is sub-sonic as the drag coefficient is too great and the mass is not enough to break the sound barrier. It does it's little acrobatics to pick up speed but it can't break the laws of physics.

Hmm, well the F-22 is cleared for supersonic release of JDAMs. I assume it will be cleared for the same with SDB. So at least to start, the SDB/JDAM will be supersonic. No telling how long it will stay that way before drag slows it to subsonic.

Where does your information on its glide speed come from?

BTW, I added this to the above message but then realized I should've posted a new message.

Actually, there's an interesting little chart on page 3 of the above pdf, buried in the overall graphic, showing the tip-over profile. When dropped from 35kft (and presumably ~M0.85), the tip-over appears to take place at around 10-15kft. So seems reasonable that if it's dropped from 50kt @ M1.5, the tip-over could be much higher (unless this causes problems with terminal control and guidance).

 

[Big-E]

Hmm, well the F-22 is cleared for supersonic release of JDAMs. I assume it will be cleared for the same with SDB. So at least to start, the SDB/JDAM will be supersonic. No telling how long it will stay that way before drag slows it to subsonic.

The mass of the SDB will slow it down considerably... it would remain tran-sonic for only seconds before it would spread it's wings. The trajectory needed at range would require it to slow even faster. 90% of a 60nm flight would be at cruising speed.

Where does your information on its glide speed come from?

Experience with glide-bombs...

 

[B.Smitty]

The mass of the SDB will slow it down considerably... it would remain tran-sonic for only seconds before it would spread it's wings. The trajectory needed at range would require it to slow even faster. 90% of a 60nm flight would be at cruising speed.

Hmm, ok time for some mathematical voodoo.

If we accept the document's assertion that SDB can do a penetrating strike at 50nm, and that the 50nm profile is the longest one on that page 3 diagram, it would appear to take around 220 seconds flight time from ~32kft. If I do my math correctly, this would appear to give it an average ground speed of 818 kts, or a slightly higher average airspeed.

Of course that's lots of 'if's.

 

[Big-E]

Hmm, ok time for some mathematical voodoo.

If we accept the document's assertion that SDB can do a penetrating strike at 50nm, and that the 50nm profile is the longest one on that page 3 diagram, it would appear to take around 220 seconds flight time from ~32kft. If I do my math correctly, this would appear to give it an average ground speed of 818 kts, or a slightly higher average airspeed.

Of course that's lots of 'if's.

Look at the altititude of that graph and also notice ranges are not indicated. If your going to get 60nm you will not be at 32k. It you are at 32k ft and 20nm you will get to keep your airspeed on that trajectory. If you are aiming for 60nm you will fall far short. The longer the trajectory the lower the cruise speed.

 

[B.Smitty]

Look at the altititude of that graph and also notice ranges are not indicated. If your going to get 60nm you will not be at 32k. It you are at 32k ft and 20nm you will get to keep your airspeed on that trajectory. If you are aiming for 60nm you will fall far short. The longer the trajectory the lower the cruise speed.

I agree it's an incomplete picture.

I just have trouble believing it takes 20 minutes for an SDB to fly 50nm (assuming an average speed of ~150kts).

I'll try to find some fly out times.

 

[Big-E]

I agree it's an incomplete picture.

I just have trouble believing it takes 20 minutes for an SDB to fly 50nm (assuming an average speed of ~150kts).

I'll try to find some fly out times.

Just look at the possibilty of loiter... if it flew faster than that to target there is no way we could ever hope for a loiter time so it MUST take around that long to reach the target at range. If you dump it on a short trajectory of course you will have short flight times and a high KE impact.

 

[B.Smitty]

Just look at the possibilty of loiter... if it flew faster than that to target there is no way we could ever hope for a loiter time so it MUST take around that long to reach the target at range. If you dump it on a short trajectory of course you will have short flight times and a high KE impact.

Loiter? IIRC, the SDB can't loiter. It's unpowered.

 

[Big-E]

Loiter? IIRC, the SDB can't loiter. It's unpowered.

I apologize... I thought you had read global security.

"The Small Diameter Bomb range is extended to 60 nautical miles by pop-out wings and the speed and altitude of the aircraft using it. A Phase 3 version may have the ability to loiter or autonomously seek out targets."

 

[B.Smitty]

I apologize... I thought you had read global security.

"The Small Diameter Bomb range is extended to 60 nautical miles by pop-out wings and the speed and altitude of the aircraft using it. A Phase 3 version may have the ability to loiter or autonomously seek out targets. The Small Diameter Bomb is considered one of the most significant programs on the books because it will dramatically increase the strike capability of every combat aircraft in the inventory."

That's Phase 3. We aren't even to Phase 2 yet.

The Phase 3 weapon may look completely different.

 

[Big-E]

That's Phase 3. We aren't even to Phase 2 yet.

The Phase 3 weapon may look completely different.

I said "Just look at the possibilty of loiter" refering to future version. It doesn't have to be powered to get a loiter if you spiral the trajectory from maximum altitude. With a 20 minute time to target you could get 10 minute loiter with a 25nm kill zone.

 

[B.Smitty]

I said "Just look at the possibilty of loiter" refering to future version. It doesn't have to be powered to get a loiter if you spiral the trajectory from maximum altitude. With a 20 minute time to target you could get 10 minute loiter with a 25nm kill zone.

I still think they were referring to a powered variant here.

 

[Big-E]

I still think they were referring to a powered variant here.

Semantics... The point is SDB is not a cure-all for stand-off weaponry. The more KE you need on a target the less range it has. It can't carry the spectrum of munitions that JASSM can and will not replace it... it will complement it. If your looking to use SDB as an example of F-22s economy over JSF your picking the wrong battle... that is all.

 

[B.Smitty]

Semantics... The point is SDB is not a cure-all for stand-off weaponry. The more KE you need on a target the less range it has. It can't carry the spectrum of munitions that JASSM can and will not replace it... it will complement it. If your looking to use SDB as an example of F-22s economy over JSF your picking the wrong battle... that is all.

No, actually i'm not. I don't think you make a valid case for the F-22 to replace the F-35 by itself, unless the threat just doesn't warrant an all stealth fleet. If that's the case, you can just stick with F-teens plus a larger buy of F-22s.

IMHO, it has to be the combination of the F-22 plus UCAV, with existing F-teens acting as gap-fillers until UCAVs arrive.

Both the X-45C and X-47 could carry 2000lb-class munitions, and have EO/IR/SAR sensor suites, and each promised to be a third the price of an F-35. (not to mention having a significantly smaller deck spot than the F-35C, 50% greater range, and cost of ownership advantages)

The major challenges remaining for J-UCAS was demonstrating and perfecting automated AAR, and carrier landing. But nothing seems insurmountable.

 

[Big-E]

No, actually i'm not. I don't think you make a valid case for the F-22 to replace the F-35 by itself.

I certainly never advocated that... I thought I was defending JSF and JASSMs. It doesn't make much sense for me to point out the limitations of SDB if I'm going to support 1000 F-22s which I am CLEARLY against!!! I support the USAF demands of ca. 400 F-22s and ca. 1,600 JSFs with the Dept. of the Navy getting ca. 700.

 

[B.Smitty]

I certainly never advocated that... I thought I was defending JSF and JASSMs. It doesn't make much sense for me to point out the limitations of SDB if I'm going to support 1000 F-22s which I am CLEARLY against!!! I support the USAF demands of ca. 400 F-22s and ca. 1,600 JSFs with the Dept. of the Navy getting ca. 700.

I'm sorry, I mistyped my earlier post. I meant to say, "I don't think one can make a valid case for the F-22 to replace the F-35 by itself, unless the threat just doesn't warrant an all stealth fleet."

Meaning I don't think the case can be made to replace the F-35 with the F-22 unless a) the threat doesn't warrant an all stealth fleet, or b) you consider the combination of F-22 and UCAV as the replacement.

I certainly didn't think you were advocating cutting the F-35.

 

[Musashi_kenshin]

Hey, guys.

Could someone please address my previous question about how the project is likely to progress now with probable time-scales for the various steps that will have to be taken before mass production can start?

 

[Aussie Digger]

Does this help Musashi?

First Flight – Short but Sweet
By Graham Warwick

Lockheed Martin’s F-35 Lightning II Joint Strike Fighter exceeded expectations on its 15 December first flight, despite a sensor anomaly that curtailed testing. “The aircraft handled well, better than the simulator,” says F-35 chief pilot Jon Beesley, at the controls for the 35min maiden flight from Fort Worth, Texas.

Beesley was surprised by the aircraft’s performance on take-off, saying: “The climb-out was steeper than I anticipated.” He praises the responsiveness and controllability of the aircraft and its engine, the 40,000lb thrust-class Pratt & Whitney F135: “I could fly to a test point and put the aircraft where I wanted to.”

The test plan then called for the gear to be retracted, but there was a small sensor anomaly and mission rules required the aircraft to come back, he says, describing the problem as a calibration issue with one of the air-data probes. “There was an angle-of-attack miscomparison. It was a little off,” he says.

Redundancy in the air-data system ensured the aircraft flew safely, says Dan Crowley, F-35 programme general manager. The sensor design has already been changed for future JSFs, he says: “We will go away from this type of probe to a new type.”

The original plan to cycle the gear during a 60min first flight was “aggressive”, according to Beesley. “We didn’t want to be bored, so we planned to raise the gear. That would have exceeded other programmes.”

“We completed the majority of flight-test points,” says Crowley. “The few related to raising the gear were not accomplished, but we are really pleased with the quality of flight test data we got.”

Lockheed plans to fly the first JSF, aircraft AA-1, five to six times a month over the next 18 months as it completes construction the 14 “optimised airframe” F-35s that will be used for the bulk of the 6,000-plus test flights. The first of these – BF-1, the first short take-off and vertical landing F-35B – is scheduled to fly in 2008.

Although structurally different, AA-1 is representative of the production aircraft, says Crowley: “Fit, finish and quality is the same as you will see in production. We have proved you can make a distributed international team work collaboratively.”

“I have never been involved with a first aircraft that was so solid, yet so sophisticated,” says Beesley. “We flew around 90% of what will be in the other aircraft.” This includes the navigation system and “finger-on-glass” touchscreen cockpit displays.

The F-35’s electrically signaled and actuated flight controls worked flawlessy, Beesley says, adding: “This is the first electric jet.” Handling qualities are similar to, but better than, those of Lockheed’s F-22, he says, adding: “It flies like a smaller and quicker Raptor.”

Tom Burbage, general manager, F-35 programme integration, says that, as soon as the F-35 lifted off from the Fort Worth runway, his cellphone began ringing with calls from the international JSF partners. “This was a flight that was heard around the world,” he says.

courtesy of: www.lockheedmartin.com

"It flies like a smaller and quicker Raptor." Won't THAT comment put some noses out of joint around here??? :nutkick

 

[Musashi_kenshin]

Thanks, Aussie. That was interesting and informative.

 

[chrisrobsoar]

F-35 Flight Program, what next?

This was taken from LM site.

JSF Program

The System Development and Demonstration (SDD) phase of the F-35 JSF program started with the signing of the SDD contract in October 2001. First flight is scheduled for 2006. Delivery of the aircraft is scheduled to begin in 2009.

During the SDD phase, 23 aircraft (5 flying test aircraft and 8 ground-test aircraft) will be produced and tested for safety and effectiveness, and to verify the product the Lockheed Martin F-35 team proposed.

The JSF program is slated to produce a total of 2,593 aircraft for the United States' and United Kingdom's armed forces.

http://www.lockheedmartin.com/wms/findPage.do?dsp=fec&ci=15140&rsbci=11173&fti=0&ti=0&sc=400


The pdf file at the end of this post is taken from the JSF.mil site.

It is the latest presentation. I cannot cut and paste data to here because of the construction of the document. However, I have attached a copy of page 12 of the presentation showing an overview of the program. I will try to de-code it for you.

Top left AS PDR – That Air System (the whole aircraft) PDR – Preliminary Design Review. This is a key milestone that he design is sufficiently well defined to precede.

Near the dashed vertical line, that represents time now. There are three CDRs – Critical Design Reviews – one for each aircraft type (they are colour coded), CDR 1 for USAF= CTOL = F-35A, CDR2 for USMC = STOVL = F-35B, CDR3 for USN = CV = F-35C. These review confirm that everything is in place before commencing the next stage.

CTOL FF is the first flight (at the end of last week), however this development aircraft AA-1 that will be used for initial testing of the fundamentals of the aircraft operation.

CTOL is a production representative aircraft of the F-35A. The design of the F-35 has evolved so that this aircraft although included as an option is being constructed and be flown shortly after the STOVL production representative aircraft. Both scheduled for around the end of 2007 and the start of 2008. The CV (Carrier Version) first flight will be early in 2009.

The bars in the middle show that the test program will be divided into three bocks.

In each case the first phase will be DT & E - Development (or demonstration) Test & Evaluation – by industry. The second phase will be OT & E Operational Test & Evaluation – by the military. The work will be conducted on several aircraft (more of that later), of each variant and in each block of flying. Each aircraft will be used for a different aspect of the test program (i.e. engines, flight control systems, weapons etc).

The starts on the right marked IOC – Initial Operational Capability, is when the military units are stood up with a basis capability.

The green bars are the production phase, as usual commencing with Low Rate Initial Production (LRIP) contracts. At the beginning of each bar the LL means funding is released for the procurement of Long Lead items. Later in the bar the FF means Full Funding of the order. Obviously at the right hand end of each bar shows the variant produced by each LRIP contract (usually annual contracts).

The last bar is MYP1 Multi Year Production Contact 1 – EOQ - Economic Order Quantity – means procuring the components in quantities to get the best price break rather than just buying all you need for a one years production.

The contractor does not get all the money in one lump, for each contract, usually there is a payment plan based on the achievement on particular events, such 20% of contract value for placing orders for long lead items. 30% for delivery of each aircraft, a small percentage may be held back until acceptance by the customer. The components suppliers down the logistic chain are managed in the same way.

Having annual programme reviews enables everyone to know what is going and also to discuss and decided if changes are required and how they will be implemented.

Page 17 of the review provides more detail of the forth-coming milestones. It mentions that 5 STOVL & 3 CTOL centre fuselages are in assembly, reasonable because these will be the first variants to fly in just a little over a year’s time.

Further on different aspects of the aircrafts anticipated performance is reviewed. They are using “traffic lights” Red for OK Yellow for we have a slight problem and Red for major areas of concern. Using bars in this fashion “normalises” performance against required performance and avoids having to quote actual figures that may be classified.

At this stage there is only a lot of fat in the presentation explaining what the aircraft is all about, roles, tasks etc, because not much has actuary been demonstrated at this stage. When the test results start to come in this section gets thinned down. Later these aspects are reintroduced when the military evaluation phase is underway. Particularly when they state what went well and what needs to be improved. It is also the stage where we have to be careful about requirement creep, where the kit performs as on the box, but the operators have change their minds about what they want. This is where the manufactures Program Director has to hold to the company line, “if it works in accordance with the original requirement, tick the box and we will help you define what you would like changed, so that we can agree a change to the specification and negotiate a price”.

Being too helpful at this stage can delay programs for years.

A good tactic is to throw in a few phases like spiral development, ask a nearby team member to get him another drink and spot someone at the other end of the hall that you just have speak to immediately.

This review is worth reading. The 2006 review with out published in the new year and will be mush better, because the fun work has started.

F-35 Lightning II Program Briefing 26 Sept 2006-12-17

http://www.jsf.mil/downloads/documents/AFA Conf - JSF Program Brief - 26 Sept 06.pdf




Chris

 

[Big-E]

"It flies like a smaller and quicker Raptor." Won't THAT comment put some noses out of joint around here??? :nutkick

It might just be the better dog-fighter after all. Vectored thrust isn't everything...