F-35 Joint Strike Fighter

[asianobserve]

Internal Equipment Heating:

Electronics equipment such as radars and jammers generate significant amount of heat, the more sophisticated and powerful the equipment is the more heat they will create , cooling are required not only to reduce enemy’s infrared sensor detection range but also to prevent the equipment from being overheat and shutdown

aircraft that lack significant cooling features for electronics often have higher body temperature , thus easier to detect.

For example: picture of F-16 in mid-infrared wavelength.

• Solution : As mentioned earlier , avionics can be cooled using fuels , furthermore aircraft can use open vents, thus atmosphere air can act as heat exchanger with the fuel which got heated by avionics

For example : F-35 has a scoop located on the top of the right wing-glove to provide air to the fuel/air heat exchanger. A deployable scoop is located on the left-aft fuselage to provide air to the IPP and to the avionics

The aircraft also use engines bypass air as heat exchanger

Airframe heating due to engines:

With the core temperature of several hundreds degrees of modern jet engines , without appropriate measuares, they can increase aircraft body temperature dramatically

For example : picture of Typhoon in mid-infrared wavelength

Solution :

• Airframe heating due to jet engines can be reduced by extensive use of cooling vents, the cold air at high altitude provides an isolation layer between the engine and the airframe

For example: the F-35 has two scoops located in the wing/fuselage to provide nacelle bay ventilation

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[asianobserve]

Temperature from the exhaust fumes:

The biggest contributors of signature in mid-infrared wavelength on a jet aircraft is their exhaust fumes, reduction of exhaust temperature as little as 100 degrees can reduce aircraft infrared emission by more than half

One very common misconception about jet engine and infrared signature is : an engine with higher thrust will always have a higher infrared signature, however that is an inaccurate assumption. It is entirely possible to have higher IR signature with lower thrust value.

To understand why lets have a look at the design of jet engines: below is a diagram of a normal turbofan engine commonly used in all aircraft flying nowadays:

The 2 main components that responsible for thrust are the Fan and engine core.

The compressor , turbine and combustor ( also know as the engine core ) move air at very high speed hence, they are less dependence on air density and aircraft velocity. On the other hand, the fan stage moves air at much slower rate ,which is much more fuel efficient and also mix the exhaust plume with cold air, thus reduce the temperature of the plume. Not all air suck in by the first stage fan will go through the engine’s core (compressor , turbine and combustor ) some will pass through the outer duct. The air that passed through the outer duct is called bypass air. To get to a certain thrust level, an engine can either have very big fan and small core ( good for combat radius and thermal signature ) or very big core and relatively small fan (good for speed and high altitude performance )

• Due to reasons stated above one of the solution for exhaust temperature reduction is to use engines with higher bypass ratio , the trade off of such design choice is the aircraft will not be able to fly very high or very fast. ( For example F-135 have much higher bypass ratio compared to F-119 , EJ200 , Snecma M88 , R-15 ,F404 )

• A common misconception is that engine turbine inlet temperature is also proportional to exhaust temperature, that is wrong, however, in reality, turbine inlet temperature does not reflect the engine case temperature or even the exhaust plume temperature. It simply means that the gasses entering the turbine is at a higher energy state and the engine will yield more gross energy per drop of fuel or air entering the combustor(s). That energy however, is extracted to do work first by the high-pressure turbine, then by the low-pressure turbine before going out the tail pipe at a given velocity. The final temperature depends on how much energy is extracted to drive the compressors and the fan, and how much bypass air is mixed into the exhaust. The F-35 has twice as many low pressure turbine stages which in theory will extract more energy. It also has a bigger and higher pressure ratio fan which adds energy to the exhaust as well as introduce relatively cold air into the mix. The exhaust plume temperature and engine case temperature can never be derived from the turbine inlet temperature alone.

• It is also important to remember that unlike a rocket, jet engines are air-breathing engine, which means their performance depending a lot on air density, the thinner the air the less thrust they will be able to generate, so aircraft thrust will reduce as they go higher. For example: a jet engine that can generate more than 190kN at sea level can be struggled to push out 10kN at 40-50K feet. On the other hand, a rocket engine can generate the same amount of thrust regardless of altitude.

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[asianobserve]

Using high bypass engine is not the only method of reducing exhaust temperature, however. Modern stealth aircraft also use exotic engines nozzles that either long and flat or with the serrated pattern so that exhaust fumes become unstable and mixed quicker with cool ambient air .As a result, the heat will be dissipated rapidly. In some aircraft, there are spacing between nozzle plates linked to cooling vents to help reduce the temperature of outer nozzle surface

Example :

1. F-117 and B-2 have flat exhaust nozzles

2.F-35 with serrated nozzle and cooling vents on nozzles

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[asianobserve]

3. Thermal image of exhaust fumes.First nozzle uses conventional circular design. Second nozzle use serrated design. It is estimated that fumes length is reduced by around 40%

4. Test data comparison between conventional exhaust nozzle and serrated nozzle:

• Stealth aircraft are also designed so that from front, the view of their engines nozzles will be blocked by their vertical and horizontal stabilizer

Example: conventional aircraft ( on the left ) have exposed engine nozzles while stealth aircraft ( on the right ) have masked nozzles

References :

• Barr, E. S. “Historical Survey of the Early Development of the Infrared Spectral
  Region,” American Journal of Physics, Vol. 28, No. 1 (January 1960), p. 49.
• Herschel, W. “Experiments on the Refrangibility of the Invisible Rays of the Sun,”Philosophical Transactions of the Royal Society of London, Vol. 90 (1800),
  pp. 284–292.
• Herschel, W. “Investigation of the Powers of the Prismatic Colours to Heat andIlluminate Objects; With Remarks, That Prove the Different Refrangibility ofRadiant Heat. To Which Is Added, an Inquiry Into the Method of Viewing the SunAdvantageously, With Telescopes of Large Apertures and High Magnifying
  Powers,” Philosophical Transactions of the Royal Society of London, Vol. 90 (1800),pp. 255–283.
• Hudson, R. Infrared System Engineering. Hoboken, New Jersey, John Wiley & Sons,1969.
• Huygens, C. Treatise on Light. London, Macmillan and Co., Limited, 1690.
• Naval Surface Warfare Center. Genesis of Infrared Decoy Flares. The Early Years from 1950 into the 1970s, by B. Douda. Crane, Indiana, NSWC, 26 January 2009.
  (ADA495417, UNCLASSIFIED.)
• Newton, I. Opticks: or a Treatise of the Reflections, Refractions, Inflections & Colours of Light. The Second Edition, With Additions. Printed for W. and J. Innys, printers to the Royal Society, at the Prince’s- Arms in St. Paul’s Church-Yard, London,
  1718.
• Planck, M., and Willis, A. P. Eight Lectures on Theoretical Physics. Mineola, NewYork, Dover Publications Inc., 1998. P. 92.
• Sylvania Electronic Defense Laboratories. Radiometry, by F. Nicodemus. Mountain
  View, California, Sylvania Electronic Defense Laboratories, 15 March 1965.(Report Number EDL-G324, publication UNCLASSIFIED.)
• Westrum, R. Sidewinder: Creative Missile Development at China Lake. Annapolis, Maryland, Naval Institute Press, 1999.
• Schleher, C.D. (1978) MTI Radar, Artech House.
• Schleher, C.D. (1999) Electronic Warfare in the Information Age, Artech House.
• Skolnik, M.I. (1980) Introduction to Radar Systems, McGraw-Hill.
• Stimson, G.W. (1998). Introduction to Airborne Radar, 2nd edn, SciTech Publishing Inc.
• Thornborough, A.M. and Mormillo, F.B. (2002) Iron Hand – Smashing the Enemy’s Air Defences, Patrick Stephens.Joint Advanced Strike Technology Program, Avionics architecture definition – issues/decisions/rationale document, version 1, 8 August 1994. A. Doucet, N. Gordon, and V. Krishnamurthy. Particle lters for state
• Joint Advanced Strike Technology Program, Avionics architecture definition – issues/decisions/rationale document, version 1, 8 August 1994.
  A. Doucet, N. Gordon, and V. Krishnamurthy.
• Particle lters for state estimation of jump Markov linear systems. IEEE Transactions on Signal Processing, 49(3):613–-624, 2001.N.J. Gordon, D.J. Salmond, and A.F.M. Smith.
• A novel approach to nonlinear/non-Gaussian Bayesian state estimation.In IEE Proceedings on Radar and Signal Processing, volume 140, pages 107-–113, 1993.F. Gustafsson.
• Adaptive Filtering and Change Detection. John Wiley & Sons Ltd, 2000.
• Military & War Documentaries HD (2017) Building the ultimate fighter jet – Eurofighter typhoon documentary. Available at: (Accessed: 17 January 2016).
• Katz, D. (2016) The ‘magic’ behind radar-absorbing materials for stealthy aircraft. Available at: http://aviationweek.com/aircraft-design/magic-behind-radar-absorbing-materials-stealthy-aircraft (Accessed: 28 October 2016).
• Lockheed Martin Corporation.(2010) Patent US20100271253 – Cnt-based signature control material. Available at: http://www.google.co.uk/patents/US20100271253(Accessed: 7 February 2016).
• RAO, G.A. and MAHULIKAR, S.P. Integrated review of stealth technology and its role in airpower, Aeronaut J, December 2002, 106, (1066), pp 629–641.
• ROGERS, C.B. and PAREKH, D.E. Mixing enhancement by and noise characteristics of streamwise vortices in an air jet, AIAA J, March 1994, 32, (3) pp 464–471
• SAMIMY, M., ZAMAN, K.B.M.Q. and REEDER M.F. Effect of tabs on the flow and noise field of an axisymmetric jet, AIAA J, April 1993, 31, (4), pp 609–619.
• SAMIMY, M. KIM, J.H. and CLANCY, P. Supersonic jet noise reduction and mixing enhancement through nozzle trailing edge modifications, 35th AIAA Aerospace Sciences Meeting and Exhibit, 6-9 January 1997, Reno, NV, Paper No 97-0146
• SAMIMY, M., KIM, J.H., and CLANCY, P. Mixing enhancement in supersonic jets via trailing edge modifications, 4th AIAA Shear Flow Control Conference, Snowmass, CO, 29 June-2 July 1997, Paper No 97-1877
• PANNU, S.S. and JOHANNESEN, N.H. The structure of jets from notched nozzles, J Fluid Mechanics, 1976, 74, (3), pp 515–528.
• SADDINGTON, A.J., KNOWLES, K. and WONG, R.Y.T. Numerical modelling of mixing in jets from castellated nozzles, Aeronaut J, December 2002, 106, (1066), pp 643–652.
• BANKEN, G.J. CORNETTE, W.M. and GLEASON, K.M. Investigation of infra-red characteristics of three generic nozzle concepts, 16th AIAA/SAE/ASME Joint Propulsion Conference, 30 June-2 July 1980, Hartford, CT, USA, Paper no AIAA-80-1160.
• DECHER, R. Infra-red emissions from turbofans with high aspect ratio nozzles. AIAA J, December 1981, 18, (12), pp 1025–1031.

https://basicsaboutaerodynamicsandavionics.wordpress.com/2016/03/04/stealth-techniques-and-benefits/

 

[asianobserve]

First Italian Navy F-35B Has Arrived At NAS Patuxent River After Completing Transatlantic Crossing

On Jan. 31, the first Italian Navy F-35B completed its transatlantic crossing landing at Naval Air Station Patuxent River in Maryland.

At Pax River, the aircraft, serialled MM7451/4-01 and taken on charge by the Marina Militare at the Cameri FACO on Jan. 25, 2018 will obtain the Electromagnetic Environmental Effects certification, before moving to MCAS Beaufort, South Carolina home of U.S. Marine Corps F-35B pilot training.

The ferry flight from Cameri to the U.S. was a joint effort that saw the Italian Air Force supporting the crossing (that included a stopover in Lajes): two test pilots, one belonging to the ItAF, the other one belonging to the Navy, both serving with the Reparto Sperimentale Volo (Italian Air Force Test Wing) flew the aircraft. During the navigation, the F-35B was also supported by a C-130J from the 46^ Aerobrigata (Air Brigade) from Pisa, in Oceanic SAR configuration, by a KC-767A tanker from the 14° Stormo (Wing) from Pratica di Mare, that refueled the aircraft, as well as by a two seater TF-2000A Eurofighter Typhoon belonging to the 4° Stormo from Grosseto, that chased the JSF along the way.

Read more at https://theaviationist.com/2018/02/...g-transatlantic-crossing/#xuZIhAzvbGwmoOVw.99

 

[Singh]

Fairly interesting video; from a left wing source though

 

[asianobserve]

Fairly interesting video; from a left wing source though

These people will rant at anything. But anybody wishing to criticise the F-35 program must consider this: the $1 trillion price tag is the projected whole program for 50 years. That includes all the expenses needed to operate the aircraft in that time including weapons, spares, maintenance, basing, staffing and future upgrades.

And 1/3 of the 1 trillion USD amount also includes the projected inflation rate for the entire 50 years.

I don't know if there's any other weapons system in history that has a more detailed calculation for its entire service life cost as the F-35.

Just look at the flyaway cost alone, the last Lot 10 acquisition cost for the F-35A is $94.6M per unit while the Rafale flyaway cost to India per some sources is already $100M plus. And F-35A's price is set to go down further into as low as $85M. For the jet you are getting that's a bargain!

 

[Shashwat]

Why are we fighting over an aircraft which hasn't even got FOC? India can not and will not buy it. Everyother news is basically vaporware.

 

[asianobserve]

Oh no, we're not fighting, we're arguing.

Sorry, debating...

 

[asianobserve]

LRIP 11 negotiations for F-35s resume after one-year hiatus

US government officials have delivered the first formal response to Lockheed Martin’s 14-month-old pricing proposal for more than 100 F-35s ordered under the 11thannual lot of low-rate initial production (LRIP 11), says Lockheed chief financial officer Bruce Tanner.

“We’re about 50% of the way spent through LRIP 11 at this point of time,” Tanner says. “We’re actually fairly late in the day for getting an offer back. Hopefully, we’ll get to closure pretty soon.”

https://www.flightglobal.com/news/a...tions-for-f-35s-resume-after-one-year-445737/

 

[asianobserve]

Carrier based fighter Lockheed Martin Lightning II F-35C began a third phase of testing

 

[BON PLAN]

A good synopsis by Mediapart of the f-35 program and some good questions by Henri de Waubert of Genlis.

"The real question that must be asked: Is the stealth of a fighter aircraft enough to accept a device with performance significantly lower than those of others? And how long does this stealth go? it last? "

"But if there was only that ... It was not counting on the faults highlighted during the assessments made by different countries: the low autonomy due to the reduced internal fuel capacity, the worrying and handicapping "buffeting" when cornering under a high load factor or the low acceleration from Mach 0.8 to Mach 1.2 ... These problems will not be resolved anytime soon because these are design problems. "

"On the other hand, the many criticisms to know: software bugs, the bad fusion of the data of the different sensors, the reliability of the motor victim of overheating, the system of oxygen, the ejection seat, the helmet visual of the pilot, the fire hazards ... are development issues that will be solved after months and months of additional delays and a few billion extra dollars, but they will settle. " => I find it optimistic about the software part for the rest on the other hand I think that indeed it can be adjusted.

"The British parliament, on 19 December, tired of having only imprecise answers from the Ministry of Defense, demanded in a document released to put an end to the lack of transparency both technical and financial that surrounds this program The former British defense minister described it as a "white elephant." Great Britain, which had committed 48 F35Bs for its two aircraft carriers to come and ordered a total of 138 F35s, reviewed the decline in quantities around 70. The same goes for Italy which should go from 131 (including 30 F35B) to 90, the Netherlands from 85 to 35, Australia from 100 to 70 ... Even the US air force, which was to receive 80 aircraft a year, will eventually be limited to 60 copies. " => Orders went from 450 to 250 (not counting Canada).

"The first is that five European countries have invested significant funds for the development and purchase of the F35.These funds will no doubt be missed when Europe decides, hopefully, to launch the future development of its own fighter. "=> not counting the will, but it will be especially wanting to the other components of the armies of these countries.

"Beyond the purely financial aspect, the sovereignty of the countries using this system - outside the USA - is likely to be restrained and this poses many questions: To maintain their sovereignty, the purchasing countries that still have the necessary resources, should not remain bound with this product, so they should immediately limit their engagements with the F35 to NATO-type missions and establish their own sovereignty missions on another type of aircraft. "

We urge countries that have not yet switched to this program to re-read the communiqué of Ellen Lord, Assistant Secretary of State for Defense and responsible for the new department "acquisition and maintenance in operational condition", when she said on January 31st: "Pentagon can not afford the Sustainment cost on F-35s". => IF only the Belgians could hear but there is not a deaf person who does not want to hear ...

https://blogs.mediapart.fr/emilie-d...fiasco-pour-les-usa-et-un-danger-pour-leurope

 

[BON PLAN]

A proof that F35 is not mature and under spec : more SH18 for the navy...

https://www.heraldnet.com/business/trump-to-seek-24-boeing-super-hornets-in-budget/

add the F16 extended life initiative :

http://www.janes.com/article/71414/...p-to-include-more-aircraft-and-airframe-hours
https://www.flightglobal.com/news/a...-16-service-life-extension-solicitati-443521/

poor F35.... an industrial disaster.

 

[BON PLAN]

After the cut in the GB order, the italian order, the netherlands order, the israel order... now the turkish order ?

https://ahvalnews.com/us-turkey/turkeys-opponents-congress-seeking-block-f-35-deal-newspaper

 

[Immanuel]

Why are we fighting over an aircraft which hasn't even got FOC? India can not and will not buy it. Everyother news is basically vaporware.

And what makes you such an expert on what IAF will and won't do. Half the time even IAF doesn't know what it's doing.

 

[Immanuel]

After the cut in the GB order, the italian order, the netherlands order, the israel order... now the turkish order ?

https://ahvalnews.com/us-turkey/turkeys-opponents-congress-seeking-block-f-35-deal-newspaper

And what about the French AF Rafale order cut, what about the original plan of buying 286 but only 180 so far and roughly 169 delivered. Actually there are more F-35's flying today than the Rafale and will continue to increase by the month and eventually at peak production per day.

Regardless of order cuts, a 3000+ F-35 order book is inevitable

 

[BON PLAN]

And what about the French AF Rafale order cut, what about the original plan of buying 286 but only 180 so far and roughly 169 delivered. Actually there are more F-35's flying today than the Rafale and will continue to increase by the month and eventually at peak production per day.

Regardless of order cuts, a 3000+ F-35 order book is inevitable

You're wrong.
At the arly beginning it was 320 Rafale that was needed !

1) After the USSR collapse, france and some others reduced the defense budget. Leclerc MBT was cut from 1400 to 380. Rafale was cut. Charles de Gaulle carrier was postponed and a sister ship scratched.

2) The 180 on french ferm orders are made of four batch. A last fifth is on the agenda. The actual final target is 225, but maybe 240 or 245 in the wave of the last increase in defense expenses (last week it was publicly said that France air force will have 15 new tankers instead of 12. Navy 4 fuel tank ships and not 3, army will have more ligh & medium tanks, new riffle HK416 will be hurry up...)

3) The plane is so effective and highly available that less are needed.

And it's not the fast track production mode that made something to be better.
A shit in mass product remain a shit.

 

[BON PLAN]

Regardless of order cuts, a 3000+ F-35 order book is inevitable

Ah AH AH.....

Never ! (and USAF + USN + USMC will never take 2000).

mark my words.

 

[Immanuel]

You're wrong.
At the arly beginning it was 320 Rafale that was needed !

1) After the USSR collapse, france and some others reduced the defense budget. Leclerc MBT was cot from 1400 to 380. Rafale was cut. Charles de Gaulle carrier was postponed and a sister ship scratched.

2) The 180 on french ferm orders are made of four batch. A last a fifth is on the agenda. The actual final target is 225, but maybe 240 or 245 in the wave of the last increase in defense expenses (last week it was publicly said that France air force will have 15 new tankers instead of 12. Navy 4 fuel tank ships and not 3, army will have more ligh & medium tanks, new riffle HK416 will be hurry up...)

3) The plane is so effective and highly available that less are needed.

And it's not the fast track production mode that made something to be better.
A shit in mass product remain a shit.

Seems like whole bunch of excuses

 

[BON PLAN]

Seems like whole bunch of excuses

as USA with F22, Comanche Helo, A12....
GB, Italy, Germany with EF,
Canada with SSN,
etc...