F-35A versus Saab Gripen NG

[spazsinbad]

The canard 'air BRAKE' (it is not spelt BREAK) is not effective at low speed period. WING SPOILERS dump wing lift (which the A-4 had in spades at low airspeed) to put the weight on the wheels for good braking and for sure OVER HEAT the BRAKES & trouble including fire ensues. Are Gripen wheel brakes MAXARET (unlockable)? That is a big help for max. brake.

https://en.wikipedia.org/wiki/Maxaret Our Sea Venoms had these brakes which were just marvellous for braking short.

[spazsinbad]

There are a few old 'news' items of the gripping variety probably still to come but this is getting close to last I hope....

GRIPEN STRIDES AHEAD FIRST SERIES PRODUCTION JAS 39E
Feb 2020 CA

"SAAB HAS FLOWN the first series production JAS 39 Gripen E (serial 39-6002), painted in a striking splinter scheme. The flight on November 30 saw Henrik Wänseth from the Swedish Defence Materiel Administration (Försvarets materielverk, FMV) in the cockpit for the 76-minute mission. It is the first Gripen E to feature the new wide-area display (WAD) and larger head-up display and it is joining the test program for acceptance and operational development flights.

This is the fifth Gripen E, following 39-8 (first  own on June 15, 2017), 39-9, 39-10, and the first Brazilian aircraft (4100), which flew on August 26, 2019. Sweden is due to receive 60 Gripen Es and Brazil has ordered an initial batch of 28 Gripen Es and eight twin-seat Gripen Fs."

Source: Combat Aircraft Journal February 2020 Volume 21 No 2

[loke]

The canard 'air BRAKE' (it is not spelt BREAK) is not effective at low speed period. WING SPOILERS dump wing lift (which the A-4 had in spades at low airspeed) to put the weight on the wheels for good braking and for sure OVER HEAT the BRAKES & trouble including fire ensues. Are Gripen wheel brakes MAXARET (unlockable)? That is a big help for max. brake.

https://en.wikipedia.org/wiki/Maxaret Our Sea Venoms had these brakes which were just marvellous for braking short.

Gripen E brake system:

As recently as Thursday 15 June 2017, SAAB's Gripen E made its maiden flight, equipped with Meggitt wheels and braking systems, making it an unprecedented 8 maiden flights which have taken to the skies with Meggitt wheels or braking systems onboard since the beginning of 2016.

This comes hot on the heels of Irkut's MC-21-300 commercial aircraft completing its maiden flight, also with Meggitt wheels and brakes, on May 28th 2017.

Thanks to a patented heat shield design which increases the speed of natural convection cooling, removing the need for fans, the MC-21 system weighs in at 13% less than equivalent in-service aircraft. At the same time, proprietary carbon anti-oxidant paint protects the brakes, allowing operation at elevated temperatures without losing life through oxidation. Overall, tyre pressure and brake temperature monitoring systems on the MC-21 enable a turnaround time of 25 minutes between flights, almost half that of many airlines today.

Chosen by aerospace leaders

Other maiden flights with Meggitt braking systems included: Gulfstream's G600; Bombardier's Global 7000; Textron's Scorpion jet; Turboprop ATR 72; Boeing's entrant in the USAF next generation trainer competition and Piaggio's military platform, the Maritime Patrol Aircraft.

In addition to providing the complete braking system for G600 and Global 7000, these aircraft are also equipped with brake temperature and tyre pressure monitoring as well as automatic braking.

Meggitt's Aircraft Braking Systems' (MABS) President Luke Durudogan commented:

"Supporting this number of maiden flights is remarkable; in my experience it's unprecedented for one company to accomplish quite so many within eighteen months. It's a testament to the team's innovation and dedication. We're now focussed on how to build on this success in the years to come."

A braking pioneer

Meggitt's pedigree in this field dates back to the 1920s, when both Goodyear and Dunlop Aerospace, later acquired by the Group, developed the first differential aircraft braking system and continued to lead the field post-war, supplying the first carbon brakes in the 1970s for the VC10 and Concorde.

https://www.airframer.com/news_story.html?release=38415

[loke]

And brakes are cool to use until they catch on fire.

If they are cool they don't catch fire

[spazsinbad]

The F-35 has a computer controlled braking system but the details escape me at moment.

Carbenix Military Brakes

"Honeywell’s Carbenix military brakes serves vital function in supporting domestic and international defense systems – supporting critical missions while operating in increasingly challenging environments. Military aerospace braking systems operate in extremely severe environments, support ever-increasing aircraft weight and stopping requirements, while ensuring quick turnaround time during combat situations.

Using Honeywell's Carbenix friction materials, our range of carbon brakes provide high reliability, improved weight savings and lower costs. Honeywell is continually investing in advanced friction and anti-oxidant materials, as well as new data-enabled services, to improve performance and lower the total cost of ownership.

Honeywell’s Carbenix brakes are used across a wide range of military customers on the following aircraft platforms:

• Boeing F-15
• Boeing F-18
• Boeing KC-46A
• Lockheed Martin F-22
• Lockheed Martin F-35
• Northrop Grumman B-2

Photo: https://s7d2.scene7.com/is/image/honeyw ... ly_450x450

PDF 1.4Mb Brochure: https://aerospace.honeywell.com/content ... nload=true

Source: https://aerospace.honeywell.com/en/lear ... ary-brakes

[spazsinbad]

Canada in one of the countries concerned about runways in different conditions. I'll have to find the original quote on the Canadian thread however here is the quote in the SRVL thread:

""...Q3.16 Does the F-35A Conventional Takeoff and Landing (CTOL) variant need more runway to land than other comparable fighter aircraft?
A3.16 No. Upon landing the F-35 uses an efficient braking system, which includes computer directed flight controls and an advanced anti-skid wheel brake system. The aircraft is capable of unaided stopping distances equivalent to those of Canada’s current CF-18...." viewtopic.php?f=22&t=20304&p=240231&hilit=brake#p240231

Double the links for twice the benefit: viewtopic.php?f=58&t=24027&p=306990&hilit=comparable+skid#p306990 & viewtopic.php?f=58&t=24027&p=349917&hilit=comparable+skid#p349917

ORIGINAL source: http://www.forces.gc.ca/site/pri/2/pro/ ... ng.asp#f35 [sadly URL no work no longer]

[XanderCrews]

The Norwegian contest was definitely not rigged, however, they put on quite a show, since they managed to convince the Swedes they actually had a chance... Eurofighter and Boeing both left that competition because they realized the futility of competing against F-35 in F-35 partner country Norway...

Actually I recall one thing Norway did to keep Saab in the competition. I believe they covered some of the costs Saab had on the "Gripen NG" project. I don't recall the exact amount, perhaps a few million USD, it seems it was enough to convince Saab that it was worth competing in Norway.

You are welcome.

Norway invested 15 million Euros into the Gripen NG "concept" as an alternative to the Joint Strike Fighter in April of 2007 according to an announcement by Saab

[hornetfinn]

There's a few things about landing on roads. One, the road needs to be able to handle the weight of the aircraft. There's a reason why in airfield charts there's a weight limit. Ever had one of your pilots land on an airfield not rated for the weight of the aircraft and tear it up? Try explaining that to the higher ups when the civvies want their airfield repaired.

And brakes are cool to use until they catch on fire.

True, the roads need to be built accordingly. They need to be long, wide, straight and strong enough (both underground and surface) and to allow effective air operations. Of course they also need to have provisions to accommodate fighters and necessary support and maintenance equipment and personnel. Finland has extensive network of road bases and there is actually a construction guidelines manual online in Finnish for them.

Pretty good (although not complete)resource for Cold War airfields and highway strips in various countries:
https://www.mil-airfields.de/airfields.html

European countries definitely had a lot of highway strips prepared to be used as road bases during Cold War. Of course many of those still exist and could be used if needed.

I doubt there is significant differences in abilities to use roadbases between modern fighter aircraft. Gripen has the advantage of being smallest, which makes it bit easier to maneuver in smaller roadbases. But on the other hand, you likely need more Gripens for similar effectiveness due to lower payload/range for example. Hornets and Rafale have been designed for carrier operations in mind which translates pretty well for roadbase operations (I know only Rafale M is actually carrier capable). Eurofighter has a lot of power and has short takeoff distance even with heavy loads. Rafale is not far behind and F-35 has similar power levels but also doesn't need to carry external EFTs and targeting pod. F-35A with landing chute definitely has short landing distance even in most extreme winter/icy conditions. I doubt stealth coating is any kind of issue for dispersed operations as it's obviously very durable.

[hornetfinn]

Finnish Air Force is currently training taking off from a road near Rovaniemi air field/base:
https://twitter.com/hashtag/Talvinorva2 ... htag_click



Just doing some snow plowing before taking off...
https://twitter.com/i/status/1364456271991111680

Some basic info:
https://airrecognition.com/index.php/ne ... rcise.html

You can check what kind of road it is using Google Maps:
https://goo.gl/maps/CpqwzU9C3k7o1Fo3A

That road can be used for taking off, not landing except possibly in a dire emergency.

[hornetfinn]

I think F-35A with landing chute would be very good for road bases also in winter conditions. F-35C would naturally be good (at least equal to Hornets which have worked extremely well in Finland) with arresting gear and stronger landing gear and big wing. Not to mention F-35B, but those are likely too expensive for most operators. I don't doubt that JAS Gripen works well from road bases and in winter conditions. But same is true for all the competitors as well.

Norwegian experience from couple of years ago with F-35A in winter conditions:
https://nettsteder.regjeringen.no/kampf ... interfore/

Google translated, because my Norwegian is little rusty...

Larger margins and extra flexibility

The brake screen gives us larger margins: It makes it possible to handle larger variations from the optimum. We will especially cope with the combination of high weight and slippery runway better. In addition, it gives us extra flexibility by allowing for the use of runways where brake cables are not installed.

I had the pleasure of trying myself in proper Norwegian conditions both last Friday and on Monday. On Monday, I learned for the first time that the F-35 coped well with icing conditions. It was also positive to discover how easy it was to stop the machine on the runway that was covered by "slush". Some may agree to call this "winter-ready." At least it was more wintery than in Arizona.

[spazsinbad]

Longer Earlier Dec 2017 Translation of same material posted by 'lamoey': F-35 is used on Norwegian winter conditions Article by Morten "Dolby" Hanche viewtopic.php?f=60&t=16480&p=382842&hilit=slush#p382842

[hornetfinn]

Thank you, could not find that for some reason when I searched...

[spazsinbad]

I searched on SLUSH and found I had to use a BRAKE SCREEN - the EMERGENCY HOOK was TOO FLOPPY.

[aprichelieu]

The important thing is that the Gripen functionality can be modified, extended or corrected several times per day,
The F-35 functionality can be modified, extended or corrected a few times per year.

That's true at least for the F-16, and most current USAF aircraft overall.

DWG: Briefly, what sort of improvement could you get that you wouldn’t be able to get on an F-16?

General Brown: Open mission systems. Being able - if I can actually have additional computing power and I can update code very quickly. So having flown the F-16, and you wait for an OFP.
I forget what the acronym stands for. Operational Flight Profile I believe is what it stands for. We have to wait for those and it's every couple of years.

I was just at [Kessler One]* yesterday and they said instead of waiting a year and a half, you could do this within a matter of minutes by updating the code on the airplane and particularly if you saw a new threat, versus the way we’ve done things in the past. You don’t have that in the F-16 today. You don’t have that in a number of our aircraft today. That’s where we need to go. So you’re using software to change our approaches and stay one step ahead of our adversary. Even if the airplane isn’t changed, the airplane actually changes because you’re able to push more information through it, change how it reacts to threats. That’s the aspect that we don’t have today in an F-16, for example.

*should be Kessel Run

https://cpb-us-e1.wpmucdn.com/blogs.gwu ... -JR.-1.pdf

Another article about Kessel Run and Brown.
https://kesselrun.af.mil/news/Kessel-Ru ... rview.html

F-35 Mission Systems Design is described here on pages 3-4. "Layered software design" is one short simplification.

The strategy for developing the avionics system was based upon a block buildup strategy. It was founded on basic
warfighting capabilities and then built into the most advanced fighter weapons system currently in service. The most
fundamental elements were developed first, and then the design moved to higher levels of capability. In this way, the
team reduced the risk of software development produced by having a single large software release. This strategy was
adapted from previous tactical fighter programs, such as the F-16, and more recently, the F-22. Those programs
demonstrated that it is essential to break the software development into manageable blocks to reduce the complexity
and cost of testing. Incremental releases also provide more of an opportunity to manage requirements creep and
incorporate technology changes that directly benefit the warfighting capability. This was evident in the F-35 program’s
ability to implement additional weapons (e.g., GBU-39) and capabilities (e.g., operational test support changes) to
support emerging requirements. The approach is structured as three development blocks that establish the basic flight
control systems and essential mission systems before building up mission capability

System Architecture
It was recognized early in the concept development phase that the architecture of the mission systems would be
key to the program’s success. To succeed, many challenges had to be faced to develop the right architecture. One was
that the computing resources needed for the full set of capabilities could not fit within the power, weight, volume, and
thermal limitations of the air vehicle using available technology. Another was that the long development cycle and
initial low-rate production was expected to result in diminishing manufacturing source (DMS) problems. In addition,
the aircraft needed to be easily adaptable to support the unique needs of multiple countries. Further, it needed to be
unclassified on the production line and on the ramp to avoid increased production and sustainment costs. Beyond this,
it also needed to operate in future battlespaces where the movement of data at multiple levels would be key to
interoperability.
The plan for overcoming computing resource and DMS challenges was to execute multiple technology refreshes
of the computers during development. The processing update would allow Moore’s law to take effect, providing
increased processing capability over time that would fit within the limitations of the air vehicle. The updates would
also allow updates to mitigate DMS and validate that the application software was independent of the underlying
processor.
To achieve the goal of making the application software independent of the processor changes, three design
approaches were used. The first approach (Fig. 3) was to layer the software on top of commercial, off-the-shelf (COTS)
operating systems, under the assumption that the virtual platform would not change.

The second approach was to use rate-based processing for all threads when timing and latency were critical. This
approach would achieve constant system-level timing, even with faster processing. Also, it would enable analyzing
the system and proving that it was schedulable using rate-monotonic theory. Both benefits supported easier integration,
reduced regression testing, and supported airworthiness and safety certification.
The third approach was to use messages for communication among all application software components, as well
as components and subsystems [1]. This created controlled interfaces among the components and enabled moving
applications to different processors without impacting the software. The approach contributed to solving
interoperability and adapting the software for multiple countries. With the clearly defined interfaces and
communication paths in the system, it was possible to control data paths using the trusted computing base. This
enabled isolating data access for specific address spaces and ensured that the application remained at the designed
security level for a specific datalink. Further, combining the messaging and access control with a COTS operating
system with a high assurance level made it possible to design write-down applications for each datalink.
The capability was then advanced to interoperate with multiple participants in the battlespace at different
operational levels and message formats. From this, the messaging and access control was partitioned to the external
communications domain. This provided a broker for data on and off the aircraft, ensuring the correct classification
level and translating the external data into formats consistent with internal data. It also transformed internal data into
the message formats and needs of the external links.

https://sustainability.lockheedmartin.c ... cation.pdf

So yet another post which is totally irrelevant to the issue at hand.
Nothing here say that there is any mechanism to replace part of S/W functionality between missions without a full requalification.
And no, the F-16 is incapable of doing that, and so is the F-22 and the F-35.
That and the expense, is why the USAF is considering dropping the F-35 Numbers by 40% and replace them with a new 4,5 generation fighter.

[ricnunes]

So yet another post which is totally irrelevant to the issue at hand.
Nothing here say that there is any mechanism to replace part of S/W functionality between missions without a full requalification.
And no, the F-16 is incapable of doing that, and so is the F-22 and the F-35.
That and the expense, is why the USAF is considering dropping the F-35 Numbers by 40% and replace them with a new 4,5 generation fighter.

So yet another completely false post by yourself, not to mention a complete lack of knowledge on the subject!

No, the USAF is not considering dropping any F-35 numbers, let alone by 40% and is definitely NOT considering to replace the F-35 by a new 4.5th gen fighter aircraft - the later of which is the biggest bullshit that I've read in this forum, congratulations!