FBWI apologize if I offended you, sincerely. I would admit to a prickly demeanor and being combative especially when having to respond to inaccuracies that are oft-repeated on this forum, it isn’t always easy to differentiate those who have read previous discussions on said topic and choose to continue to repeat what has already been addressed and those who have not. Do not mistake this for a lack of respect for the value of a spirited discussion. It is wrong conceptions and opinions I am hostile to, not the poster (mostly).
As far as the bay issues, these are not unique to the F-35 (and I believe the bay heating is mostly an issue at low level IIRC). A few years ago I posted a presentation from a symposium discussing the thermal challenges faced by this and the next generation of aircraft. The current methods of thermal management have reached their limits, especially on LO aircraft. It isn’t just aerodynamic heating. It is the power requirements for AESA, IRST, EW suites, processors that have pushed current cooling methods, such as using fuel as a heat sink, to their limit. In previous generations, ram air heat exchangers could cope with thermal load. Even if IR/RF signature wasn’t a concern, sustained high speed flight makes these less efficient for cooling.
FBW??????? For what I know the Gripen speed is set at mach 2 and the same Rafale is 1.8 like the F/A-18 (hardly a runner) that’s in every case more than 200km or +100 knots more in my book…
In percentage it means that even the previously slower fighter planes around has almost 10% more speed than our truly, all other have almost a 25%.
To put it simply, I just think it is not possible to reach such a result short of such radical changes in the plane own aerodynamics to result absolutely not worth the effort.
While in the case of the other slow movers you can blame the bad T/W ratio or the presence of fixed intakes, both those just doesn’t apply to the F-35 as its excellent subsonic performance seem to suggest.
It has an excellent engine, a more than decent t/w ratio DSI intakes (i.e. still better than a fixed one) still is anyway limited to mach 1.6.
So what can be except a general aereodynamic shape that it’s not more efficient above a certain limit i.e. that would not allow if not a very slight increase of speed even in the case of a consistent increase of thrust or a more efficientit
What you describe as “trademark chauvinism” would be fact that I have little tolerance for people who repeat falsehoods and have no idea what they are talking about yet repeat it over and over.
One- the Rafale is limited to 750knots/ Mach 1.8. Meaning below ~30,000 feet it’s fcs restricts it to 750 knots, above it’s Mach limited.
Two-Gripen is operationally limited to the same. The E/F says Mach 2, we will see.
Three- the F-35 is limited by it’s fcs to 700knots/Mach 1.6.
Not to mention, the F-18 is stated as Mach 1.8. One look at the flight manual shows this to be a largely theoretical speed (as is true of many aircraft with stated Mach 2 performance).
Fifty knot KCAS. Period. Now why are they all similarly limited by control laws?
Because the idea is relatively carefree handling and flying, the pilot does not have to be as concerned with overspeed on the deck, thermal loading at high Mach, canopy damage, damage to RAM on leading edges.
Not to mention, sixty years experience of operating supersonic aircraft. Does it matter that the F-16 and Typhoon are rated as 800 knot aircraft and can achieve Mach 2 (clean x2 AAM in the case of the F-16), does that 50-100 knots make an operational impact 99% of the time? The designers and operators of the latter think not. Mainly because experience tells them that aircraft rarely, if ever require Mach 2 speeds for the types of missions they perform.
As far as the F-35, it is not “aerodynamics” in the case of the F-35A. It has flow to near Mach 1.7. The designers have stated it can overspeed easily in spite of CLAWS. It is a 700 knot/ Mach 1.6 aircraft because that was the requirement. It is limited by said flight control system. The bay has thermal issues at those speeds. All three variants can reach Mach 1.6 (though the B is limited to 630 knots), that alone should tell you that the “A” is not limited by aerodynamics.
FBWWith regard to current DSI testing, your pretty much correct XB-70.
NASA studied the DSI as early as the 1950’s. There were more than RCS considerations that led to both the US and China adopting DSI on their aircraft; weight, complexity, maintenance, and that testing showed that the DSI had greater pressure recovery at supersonic speeds (up to Mach 1.8 in the case of the F-16 test platform, I believe). It isn’t just the bump, the entire fore body shaping is part of the inlet efficiency in the case of the F-35.
Irregardless, it has little to do with pervious posters comments about the F-35. As far as DSI belong limited to Mach 2. DSI have been tested to Mach 2, and that testing on the F-16 showed increased flow separation above Mach 1.8. Decreased efficiency and spillage, but that was on the modified F-16. Considering the evolution of DSI shapes and inlet design, I wouldn’t say that’s an absolute limit.
FBWSay what?
I do recall one reported test run by a F-35A where it actually had to “unload” in order to reach Mach 1.6
Unload means it had to point its nose downward compared from a sustained altitude flight.
Say what?
Do you actually know what you are talking about? I know the answer to that…. NO
It was the F-35C that they referred to using a Rutowski profile. And to get to maximum speed quickly, or climb rate, that is common, and efficient. As we all know defense reporting is always accurate and not sensational at all.
Personally, I’ve always found the F-35C to be compromised, 2 1/2 tons heavier, different wings, wing design, camber. It’s transonic acceleration shows the wave drag impact of increased wing area. Yet it still reaches Mach 1.6. Time to start thinking of the substantial differences between F-35 variants.
The F-35A has exceeded Mach 1.6. It has been tested with full weapons and fuel to Mach 1.6. It exceeds Mach 1 at sea level. It can easily overspeed even with control laws. Questions?
FBWI think this would be absolutely not possible, F-35 is not slow because of a bad T/P ratio a.t.c. it is better on that regard than the same MiG-31:
it’s about aerodynamics a.k.a. being a flying brick.:dev2:
.
Sure marc, so are the Rafale and Gripen which are a whopping 50 KCAS faster.
The ignorance never ceases to amaze me. Sure, the F-35 is CLAWS limited to 700 knots because of aerodynamics. Any other gems you want to share?
FBWWell after the G7 summit this weekend, I think it’s safe to say that Trudeau is on the phone with the DND urging them to purchase F-35’s and Super Hornets from the US.
Ooph, that went well.
FBWHallow,
This is one of the curious side effects of transparency in defense programs, and government oversight. Literally every weapon system has deficiencies, ones documented since the advent of DOT&E reports (as I mentioned before, it would have been interesting to read a 1970’s DOT&E report on the F-15, had those reports existed because there were serious issues unresolved as F-15 production ramped up). Even with hundreds of deficiencies, the F-35 is safer, more reliable (in some ways), and operationally suitable for FRP than the previous generation of US combat aircraft.
The transparency of us defense testing and evaluation is a double edged sword. It applies rigor to evaluating operational suitability of weapons, but exposes large, high profile defense projects to some uninformed, bias, criticism from “reformers” at tender stages of development. The F-35 has never, and perhaps,won’t escape negative public opinion promulgated by former AvWeek writers and those with an “Axe” to grind (double entendre). Much of the criticism was deserved prior to 2012. Ironically, it was roughly around that time the program got back on track (ok more accurately set the groundwork to get the program back on track).
It is difficult to make an analogous comparison to France’s combat aircraft development and testing (lacks documentation). But the lack of oversight in French naval projects is astounding. Perhaps France needs their own DOT&E
The Rubis class was borderline obsolete upon commissioning, insufficient speed, flow noise, machinery noise. Significant redesign and rebuilding was required to make them operationally suitable for ASW operations.
The Cassard class- again borderline obsolete upon commissioning. Unsuitable for area defense of a carrier battle group, protection against SSM swarming attack.
The CdG- design issues impacted operational suitability, unable to reach design speed first due to loss of propeller then reactor power levels, loss of propeller specifications (and vibration issues that resulted in reusing old prop).
Not pointing this out to disparage the French Navy, more to illustrate that the problems with the F-35 are neither unique nor more severe than other extremely large and ambitious defense projects, just more public.
FBWResolved, not fixed !!!!! Huge diference and again mismanagement.
By resolved they mean some will be “fixed” , workarounds will be developed for others, and services will sign off on degraded specifications on certain issues.
Again this is not unique and says absolutely zero about current program management.
FBWSo basicaly what is happenning, once again, unfinished with known (or unknown) deficiencies will be delivererd. And the retrofit costs will be sunk into maintenance costs… Not good when you want to reduce them by 38%…
And as has been noted in the past, that is the true of most programs. JPO stated that most category one deficiencies will be resolved before FRP, and unsurprisingly some likely won’t. If you follow or read other GAO reports, you would realize how common this is. The Super Hornet was in production for years with the radar failing to meet requirements, the Growler went into production with known deficiencies in EW & radar interaction. If you look back to the 70’s when the USAF was accepting F-15’s and F-16’s into production, there were known issues with engine reliability, radar, structural concerns.
It is up to the services and Congress to decide on suitability. GAO is going to make recommendations, JPO in this case, seems to agree that most major cat 1 issues will be resolved (or fixed) by the time of FRP. If you wait for a weapon system to be 100% free of issues, you’ll add billion of dollars and years to SDD.
Not making bad jokes about arrival in UK delayed by storm…
– stop reading De Briganti, that would help. I don’t see any need to take risks flying across the Atlantic with storms off the east coast, I’m sure if you were the one who had to make multiple air refuelings, you’d agree. If you recall, the Rafales and E-2C flying in for Chesapeake took two days and landed in Azores and Iceland.
FBWTruth is Eagle, IDAS in modern aircraft are about the most classified components in regards to capabilities, algorithms, and modes.
AN/ASQ-239 supports jamming functions, that we know. It uses the APG-81 to perform EW functions (as all sensors on the aircraft are fused in the ICP modules), the brochure does suggest jamming functions independent of the radar. It does make sense, the entire aircraft has embedded apertures to support ID and location of emitters. Compare the size of the arrays to praetorian system, or spectra.
In the end, your asking for definitive proof for capabilities that are classified, the best your going to get is the statements from BaE, and they seem pretty cut and dry “jamming without interfering with radar”.
FBWWas posted over in news. De Briganti’s editors notes have become highly amusing as of late. He really has to dig to find negatives. Apparently he doesn’t have access to satellite weather maps off the US coast right now.
Flying across the Atlantic with multiple refuelings is obviously just like hopping on the interstate.
FBWThe point which you are missing is that to some extent, latter predicts the former.
The point is that they don’t. Variable intake ramps, strengthened canopies, materials and structure needed for mach 2+ flight actually increase weight and impact acceleration.
The F-22 has superior transonic and supersonic acceleration to the F-15. The F-22 is limited to roughly mach 2 (though actual speed is classified). The Typhoon and Rafale are limited to 800 and 750 knots respectively. Both have superior supersonic acceleration and persistence to predecessors like the F-4 or Mirage 2000, yet lower maximum speeds.
Take to the Mig-25, it has the highest maximum speed of any fighter fielded, do you think it’s acceleration is comparable to any of the aforementioned aircraft that are limited to 700-800 knots at ~30,000? No, the F-35, Gripen, Rafale, Typhoon will all have superior acceleration.
FBWTurkish Government issues formal tender for AIRCRAFT ARRESTING SYSTEMS (AAS) technology.
It intends to begin development efforts for the 300+ metre Aircraft Carrier arresting system for STOL aircraft. This will most likely be for land based testing and development phase.
See formal tender document in English: https://www.ssm.gov.tr/Images/Uploads/MyContents/V_20180516180632000492.pdf
You realize that some air bases have arresting systems too, right? Did you also note that the system is requested by the Turkish Air Force?
But of course, Turkey, which is still a few years from launching it’s LHD (built with plans and technical assistance from Navantia) is ordering these arresting systems for a table model 300+ meter carrier. Got it.
FBWLots of oversimplification in this thread. Top speed figure is not ‘useless’ but rather an indication of fighters supersonic performance. Just because both are limited to relatively modest maximum mach number while carrying stores does not mean that faster aircraft doesn’t have any advantage. Variable inlet ramps give a fighter better supersonic performance through the envelope, whereas plane with fixed inlets can give best performance over much narrower part of its envelope.
Actually it is worthless. Start with your first point. It is not an indication of supersonic performance across the envelope. The Rafale is limited to 750 knots/ Mach 1.8. Does that mean it’s inferior to the F-4 in transonic or supersonic acceleration? Is the F-22 inferior to the F-15 in supersonic acceleration or persistence? No.
Variable ramps do give better performance, mostly due to less spillage at higher Mach. Across most of the transonic and low Mach speeds a fixed inlet is comparable, and lighter. In DSI testing on the f-16, the DSI inlet outperformed a fixed and variable ramp inlet at certain speeds, was comparable at transonic, and became less efficient above Mach 1.7-8. So, again how many fighters can fly above Mach 1.8 when armed and carrying pylons? The aforementioned F-15 can reach speeds of 800+ knots (35,000 feet) carrying four missiles (and little fuel which makes it impractical). Once you add even a centerline pylon, speed decreases.
In practical terms it means that faster aircraft can reach its practical top speed faster, and in wider altitude regime, even if practical maximum speeds are in same ballpark. In interceptions this means better acceleration and less fuel burned to achieve the interception -> more practical endurance.
We’ve seen the opposite is true, most recent fighters are limited to 700-800 knots (Mach 1.6- 2.0 ~30,000 feet). They can actually reach those speeds while armed. The same is not true of 3rd gen- early 4th gen fighters with Mach 2+ theoretical top speeds.
Also, top speed might help a pilot to save his bacon from unfavourable situation once weapons and stores are expended. 20% higher dash speed means that enemy missiles have 20% smaller window to shoot you down.
Finally, there might be operational requirement sometimes to identify high-speed bandits in non-shooting war scenarios. In those cases, external stores are not necessarily required and all that matters is the ability to acquire target visually.These are not necessarily huge deal-breakers when evaluating overall fighter performance, but it is incorrect to say that F-35 or say F/A-18 have equivalent speed to F-15 in practical terms.
Acceleration is far more important than a theoretical dash speed that is operationally unreachable. The F-35 and F/A-18 don’t have the speed of an F-15C, but by speed I mean transonic acceleration. Theoretical top speed aside, as operationally the F-35 when armed has better supersonic persistence and is at best 50-80 knots slower than an eagle carrying usual missile load and pylons.
FBWAnswer over in f-35 thread.
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