FBWHere is a description of the Typhoons FCS (boldfaced the important part):
In Eurofighter Typhoon, the aircraft responds to whatever demands and maneuver the pilot wishes, safe in the knowledge that the flight control computers will command the movement of the flight control surfaces to provide the response requested. Eurofighter Typhoon’s FCS is also aware of the flight parameters, such as speed, altitude, configuration, aircraft mass and balance, which define the prevailing structural and aerodynamic limits, so it is able to limit any response to pilot control demands and keep the aircraft within the permitted envelope. Thus, the Eurofighter Typhoon pilot cannot over-stress the aircraft structure or fly in such a way that the aircraft departs from controlled flight.
https://www.eurofighter.com/news-and-events/2005/06/carefree-handling
FBWThat applies to general 5.5g limit.. The article mentions additional limit [4g]… Is that speed related or Storm Shadow related?
No, I do not.. Because I am not entirely convinced you have not pulled this out of thin air..
Really? I’m not like you. But here are some descriptions of how the FCS work, and examples from the Rafale test on FCS control laws. Hopefully I’m not wasting my time explaining this.
This is why these new digital FCS are considered carefree handling. The system limits pitch, yaw, and roll within the load factors and departure limits. The allowable limits are based on configuration (AtA, AtG), loads (CG), or asymmetric loads. The control laws can limit pitch, roll, the allowable AoA, and keeping the g’s (sometimes because of AoA limit) within the safety margins. Changes in the aircraft’s CG (based on loadout) affect the maneuver envelope of the aircraft to prevent loss of stability or overstress.
This is an overview of the development of Digital FCS
http://www.dtic.mil/get-tr-doc/pdf?AD=ADA398738
(you may have to cut and paste this)
Now as far as control limits- the system on the Rafale (like all DFCS). The CAT III limiter on the F-16, when on it limits the pitch onset, roll, and the AoA (effectively limiting G at higher speeds) The Rafale has a similar stores settings for air to ground configurations limiting it to 5.5 G. That does not mean that the Rafale can reach that max allowable 5.5G based on the loads.
In the piece Hopsalot posted you can see several examples of how the FCS limits the envelope based on the load: https://www.flightglobal.com/news/articles/combat-ready-53125/
Read:
Slamming the throttle to maximum reheat and rolling quickly into a full stick-back hard turn to simulate a break away from a threat gave a rapid response, automatically limited initially to 18.8º alpha and 4g. As the turn progressed, the FCS allowed the incidence to increase to 19.2¼ alpha as the airspeed decayed.
Here the FCS limited the aircraft AoA to 18.8 keeping the rafale under control limit. As you read on you will see the FCS allow more AoA and G:
Once level, it was accelerated to M0.88 for a hard turn using full reheat to the FCS g limit. Although I entered the turn quickly, the voice warning (female) informed me that I had slightly exceeded the configuration limit of M0.9 (it was M0.91). The FCS limited the aircraft to 5.2g.
at 330kt, the FCS transitioned from the g to the alpha limit of 20.8º, an incidence that was maintained until I rolled out at 200kt. Finally, to give the FCS a further hard test, I made full-stick rapid rolls with the stick held fully back. At the incidence limit, the aircraft took 6s for a 360º roll and 5.5s at the g limit of 5.4g.
In the two above pieces, the FCS limited the aircraft to 5.2g. In the lower part you see, as speed decreased the limiting factor was not G but the AoA. The FCS allowed the aircraft to reach 5.4g at the lower speed.
Lastly, the FCS does not just limit “g” nor is the configuration limit of 5.5g allowable at all speeds and loads:
Four full-stick rapid rolls through 360º were made at 1g and 2g at 300kt. The roll acceleration was good and, in each case, the roll was completed in 3.5-4s. The peak roll rate was about 150º/s. Without the heavy external stores, the FCS would have allowed a higher roll rate of 250-270º/s. The aircraft was inverted briefly in level flight – something only a test pilot would attempt with two large cruise missiles and three external tanks on board – and remained easy to fly accurately. The FCS limits negative g as well as positive g, although I did not bring in the g limiter during this test point.
FBWThen the FCS is not that advanced because it doesn’t do that. It’s either 9g with light stores or empty drop tanks, or 5.5g with heavy stores.
No, a g demand system adjusts to weight, speed. The two air to ground settings limit the max g to 5.5.
Heard the same.. 9.0g/5.5g.. First time I hear about some imposed 4g hard limit..
But I gladly change my mind when some evidence is available..
Most FCS allow the pilot to slightly exceed the available for safety. It is not a hard limiter (but the system blaring warnings and will be attempting to bring aircraft under limits), not to mention the pilot will have some explaining to do.
FBWIt was limited to 4g at M0.82.. You need to have the whole envelope map in order to justify such statement..
From the many positive reports about each aircraft we can conclude and extract their strengths. If you take a dozen pilots of the F-22, at least ten of them will have mentioned its flying abilities, in one for or another. Similarly, lion share of Rafale pilots will have mentioned agility, ergonomics and loadout possibilities.
Most F-35 pilots will have mentioned how comfortable the seat is.. :very_drunk: ROTFL..
No Msphere, your absolutely wrong. You don’t need to have the Rafale’s “envelope map”. The Rafale is limited to 5.5 g with heavy stores are fitted to the AtG stations. The aircraft, like all modern fighters with an advanced FCS, constantly adjusts available g and AoA to the weight of the aircraft. So once the 2000L tanks are fitted, the aircraft is limited to 5.5g max, and goes down from there based on weight. The idea of carefree handling allows the pilot to use full control imput without worrying about “breaking: the aircraft. Ex. full lateral stick input will give max roll rate at a particular weight. These FCS are more advanced that the F-16 CAT I/III limiters.
Most anyone with a conception of aircraft design and flight control grasps that, you and Picard seemingly do not. BTW, he was on here before, and could not defend his blog posts to the forum as they were, as people have said, fiction. You can go ahead support the postings on that particular blog, no one has to provide you with evidence. Most of us know better, because we have a basis of understanding on which to discard his conclusions.
FBWPerhaps you are right, perhaps not:
http://www.thehindu.com/todays-paper/article733276.ece
So if 4 of 5 had failed before Gripen was tested and 4 of 6 had failed after Gripen was tested what does that tell you?
Nothing, there were several conflicting reports about the MMRCA trials. Some blogs posted the information that the US fighters had difficulty with the engine restart. Several reports stated that only the Mig-35 and Typhoon passed. Others, that 5 out of 6 failed some portion, others stated 4-6 failed. The Broadsword blog post was used by several sites to claim that the Gripen passed. In reality, there is nothing but conflicting evidence from a variety of sources.
The news from the time of the MMRCA competition was rife with inaccuracies. One news article related to the portion of testing does not prove much. The Gripen could have passed the restart and failed other sections, there is a huge amount of misinformation out there about the MMRCA test eval scores. Nothing official was released about how each fighter did on different test points.
In the end, we are sure that the Typhoon and Rafale had the two highest scores on the test and evaluation portion. Had they failed a significant part of the Leh trials, most likely that would have impacted scores, no?
FBWDuring the MMRCA trials there were a lot of discussions around which a/c successfully completed the “Leh” trials: well it seems Gripen was one of them:
I would caution you from that assumption. Four of the six aircraft failed parts of the Leh trials. Just because the Gripen took off does not mean that it met all criteria. Considering only the Typhoon and Rafale were shortlisted from the testing and eval stage, I doubt one of those two failed.
FBWThe purpose of me quoting it was to represent how Msphere, and others, are happy to use one source when denigrating another without even a cursory investigation of their validity.
It is simple, on one side you have blog posters, APA, Sprey, et al., the “informed critics” of the F-35 whom the press turn to for a negative soundbite. On the other, you have pilots, officials from a myriad of air forces, defense analysts (in short, professionals), that know what the F-35 is capable of. Their views are generally positive (with qualifications), all agree that the F-35 is massively capable.
When you look into the credentials and statements made by those who claim to be the “informed critics”, it becomes very clear:
1) they are neither experts nor professionals in the pertinent areas
2) they throw in a few retired military to lend credibility (see Chris Mills)
3) confirmation bias- the most obvious issue with those listed above and displayed in spades by Msphere. (Best example- “The F-35 can’t dogfight” article. There are STILL posters who think that it was some sort of maneuverability test.)
FBWWhat do I care who is quoted.. All perfectly credible people to me.. It’s the message which is important for me, not the messenger..
Please, you know better. Picard was a poster here for a time. The message is wrong, you’ve got to have more common sense than you are displaying. When a poster starts using Picard’s blog defenseissues…… that is where credibility goes out the window.
Yes, Msphere everyone has been strong armed into purchasing the F-35, that is why Norway, UK, Israel, S. Korea, Japan , others, are looking to accommodate F-35 purchases with limited defense budgets. Or maybe it is because they realize that purchasing a fighter with the capabilities of the F-35 is imperative.
FBWSo rather than derail the Canadian thread, I thought I would continue on this one….
If Typhoon and Rafale end production by 2025 (for arguments sake), what happens between then and 2040 when they are slated to bow out?
Are we not looking at a new manned project for Europe that must be underway long before 2025 in order to replace European with European?
I am assuming that FCAS is a parallel effort for these purposes that allows technology and skills to be applied to a future manned fighter just as much as a UCAV.
Point being, those in the know, must already be muttering about what comes next right?
Think this chicken little concern was blown way out of proportion by certain AvWeek reporter. It is clear that the defense base for building a future European consortium aircraft will exist should the requirement arise: BAE has work on the F-35, a share in any future Typhoon upgrades, FCAS. Dassault has the Rafale and future FCAS (or proprietary UCAV) for the next two decades, Saab has invested in the Gripen for the next three decades. The UK MoD recently had an article about 60 billion in aerospace projects on the horizon. The days of a single nation developing and fielding a fighter may be over (but then so too will it most likely be in the US, the sixth gen fighter project will reach out to an international consortium as the F-35 has) but European firms have plenty of pooled resources, experience, and future work to keep them in the game.
What comes next? Most likely, a shared platform with customized sensors and software suited to each nation. I doubt that anyone, even the US manufacturers, will allow one firm to control the codes. Simply put, it will look more like shipbuilding with multiple firms as subcontractors building parts as part of a consortium, with the lead contractor (Dassault, L-M, BAE, EADS, NG, etc) doing assembly in respective countries.
FBWthey can certainly make decision before 2022 but money will be only available by 2022 and seeing the rest of the budget and demographic change in next 5 or 6 years Canada will end up some where between Brazil and Argentina. there is no prospect that Canada can again become a military power.
Which will put it comfortably above Russia in GDP, and slightly older than Russia in Median age. Meanwhile, back to reality.
FBWThis isn’t for FBW in particular.
There are two things I want to address in relation with the F414 engine in Gripen NG.
One is the idea that the USG will block the sale of F414 engines to Brazil for some reason. This is not going to happen barring some major political event in either Brazil or the U.S. that makes Brazil somehow a pariah state to the U.S. No, the reduction of U.S.-made components in the Gripen NG is not sufficient reason. Cutting off your nose to spite your face is not a profitable action.
.
All very true, there is a difference between blocking a sale and not transferring sensitive technology. Saab made the decision to use the F414 for obvious reasons: size, power, familiarity with the F404, bypass ratio, economies of scale. It is absolute bunk to think that Saab could/would just “drop” in a replacement engine such as the EJ2000. Simply does not work that way: you might have to redesign the intakes and ducting, redesign the rear fuselage, center of gravity issues, on and on. For what? Would the UK allow Rolls Royce, or Germany allow MTU, to export restricted technology?
I cant think of very many nations that the US would raise a howl over Saab selling the Gripen to (that Sweden and others owning intellectual property in the Gripen would be willing to), and the objection would likely be on the sale any fighter to said nation.
For ITAR restrictions on the F414, the issue is the transfer of hot section components (high and low pressure blades, vanes, disks- esp. actively cooled), information on the composition (composites, alloys, thermal coatings) of restricted engine sections,etc. The restrictions have actually eased in the last few years over what can be exported. Note: the new ITAR rules are not specifically about exporting the engine, it restricts the classified technology needed to design/build high performance turbofans. As the PLAAF has found, you can have the engine, reverse engineer it to a degree, but the methods for manufacturing, metallurgy, tolerances, are not easily replicated.
FBWSome of you posting here about ToT of the F414 would do well by reading the new ITAR laws. There are certain parts of domestic fighter turbofans that are absolutely restricted from ToT agreements as S. Korea is finding out the hard way on the T-50. GE cannot transfer; Saab cannot transfer this technology as it is restricted.
It is this simple:
FBWLooking out to 2022, as mentioned by someone else, Gripen and F35 are both certain to be available. SH probably not. Rafale likely. Typhoon would require an order from at least one significant buyer to still be viable in that time-frame pending purchases from the existing partners.
Moot point for this thread though because procurement of Canadian jets won’t be put off until 2022, or at least we don’t have any information yet that would indicate that would be the case. All indications are that there will be a decision made by around this time next year. Denmark and Finland will also likely be in around the same time horizon. All countries are aware of the production cliff for SH and Typhoon.
No the report does not come out till the end of this year. The actual decision could be years away. The competition tender would not even open until 2017 at the earliest. This is a flat out stall, there will be no fighter bought under Trudeau, unless he can keep a government together for 4-5 years. I doubt that. Most likely , the liberal party will not hold the majority for long, any coalition government (not that one would be likely in Canada) would be in a poor position to make a decision on the F-18 replacement. Maybe there will be a new PM making a replacement decision circa 2020
FBWWhy are you posting an article from 2014? For the record, because apparently people still don’t get it, Pierre Sprey had nothing to do with the design of the F-16.
Nor the A-10, he was with the OSD and all he did was write requirements. If I write up the need for an “interstellar warp drive space exploration vehicle” can I be the dubbed the “designer of the starship” whenever it debuts? Harry Hillaker must be rolling in his grave every time they refer to Sprey as “designer of the F-16”.
FBWOld news, he is just going on trial now. This is not a new problem. The B-2 IR reduction methods incorporated in the exhaust were also compromised by a US national working for the PRC as a contractor.
Sign In
