F-35:The $380 billion mistake

   There are two posts after this one.

see also: The F-35 is useless
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 The F-35 is a failed program.  What is truly pathetic is that it would have been a failed program 30 years ago.

   I will now try to explain some facts about aerodynamics and aircraft structures.

   In illustration 1, (a) represents an airfoil shape with an airflow moving past it.  The airfoil shape and its inclination cause a circular to elliptical movement of air around the airfoil.  (b) shows the addition of the circular flow to the steady air flow.  This addition causes air to flow faster over the wing, where the  speeds of the two flows add, than under the wing where they subtract.  Any flow of fluid past a surface will cause a drop in pressure on that surface; the faster the flow, the greater the pressure drop.   Since the flow is faster above the wing the pressure drop is greater over the wing and the difference in pressure, higher over the wing, lower under, causes a net pressure upward producing lift and allowing flight.

   In (c) a wedge-shaped object, similar to a fighter plane fuselage, is shown in an airflow.  Under subsonic flight it cannot produce lift, as the circulating flow would be disrupted by the back of the wedge.  There is a concept in airfoil design, known as Kutta's hypothesis, which states that at the trailing edge of an airfoil the velocity must remain finite, as in (b).  The bluff rear end of the wedge prevents this and would require an infinite fluid speed to form a circulation, therefore it can only produce lift by having a separation of flow off the top of the shape which is horribly inefficient.

   However, under supersonic conditions shockwaves, light green lines, can form producing lower pressures above and higher below to produce lift.

   The other interesting case is the wedge rotating in compressible flow.  Air blowing at 180 miles-per-hour will compress about 3 percent if brought to  a stop by a wall, the number of air molecules per cubic foot would increase by 3 percent.  The compression of air increases, roughly, as the square of the velocity.  The drop in pressure for air flowing over a surface also goes as the square of the velocity(The two phenomena are related).  For lift the increase in compressibilty gives an added bonus to the total lift.  The velocity at which air is compressibile is arguable, depending on the context, but Mach .5 (one-half the speed of sound)  is a useful approximation.  That is 370 mph at sea level and 330 mph at minimum.  Owing to the compressibility, air above that velocity is, essentially, a different fluid from low speed

    When rotating in compressible flow, a wedge, as well as an airfoil,  will produce lift from non-circulating flow.  This has in common with supersonic flow that the upper and lower surfaces are independent, Kutta's hypothesis does not apply.  Lift is produced by a vortex of air that forms over the wing or body, producing  low pressure and lift.  The faster the airfoil or body rotates, the more lift is produce.                                  In 2, the plan view of a fighter is shown.  The original wings, A, are shown as well as extended wings, B.  The most important consideration in fighter wing structures is the wing stiffness, its ability to resist bending.  There are two main types of stiffness; bending stiffness, which is the equivalent of grabbing a wing tip and trying to force it up or down; and torsional stiffness, the equivalent of grabbing the leading and trailing edges of the wing and trying to force one up and the other down.

    For bending stiffness, the wing skin provides the stiffness.  The stiffness is determined by the thickness, gage, of the wing skin multiplied by the top to bottom depth of the wing (actually, measured to the center of the skin thickness) and multiplied by a material variable known as Young's Modulus.  Young's Modulus is the force per cross-sectional area of a sample divided by its fractional elongation from the force. (For steel, a force of 30,000 lbs per square inch would produce an elongation of .001, one inch in 1000 inches, for a Young's Modulus of 30,000,000 lbs per square inch.)  This means, that for a wing, if the top to bottom depth is doubled, that the skin thickness can be reduced to half for the same stiffness.  This can be done down to a skin thickness that would cause the skin to buckle, pucker up, (2,d).  This is known as thin walled buckling.

   The idea of improving aircraft performance is to enlarge the wings from their original planform, A, and increase them to planform, B.  Now things get confusing.  Wing area and planform is measured to the centerline of the aircraft, but, as previously noted, under steady, subsonic, flight , the body cannot produce circulation and, therefor, cannot produce lift.  Only the external wing area can produce steady lift.  But, under compressible rotation the body can produce lift.  A difficulty is, that away from the wings, any reduction of pressure above the body will cause air to flow from below into the low pressure (fluids flow from high to low pressure) disrupting much  of the lift.  The same effect happens at wing tips making the ends of wings inefficient at producing lift (this is why gliders have long wings, so most of the wing produces efficient lift).

   For an F-15 the total wing area is about 550 square feet with a wingspan of about 37 feet.  For wings, area divided by span produces a number called mean (average) cord.  The wingspan divided by mean cord is the aspect ratio of the wing.  (This is also wingspan squared divided by wing area.)  The aspect ration of the F-15 is about 2.5, so the mean cord is about 15 feet.  For the F-15 the wingtip is about 5 feet long, making the centerline wing length about 25 feet.  The fuselage of the F-15 is about 12 feet wide.  So, about 260 square feet of wing is within the fuselage and about 290 square feet is external.

   For wing, B, The maximum length along the fuselage, assuming similarity to an F-15, would be about 35 feet.  With a fuselage width of 12 feet that would allow for the wing area in the fuselage to be about 420 square feet (the forward fuselage would not readily accommodate the wing extension.)  The external wing would be (35 feet + 5 feet(wingtip) = 40 feet, divided by 2,)  =20 feet average length times 25 feet (external span) = 500square feet.  All of the numbers are about a 70% increase over the F-15 standard design.  The other limiting parameter is to not increase the total weight of the aircraft.

   Owing to the reduction in aspect ratio, the wing would not be as efficient.  The F-15 is designed to produce turning forces equal to 9 times its weight , 9g.  The larger wing could produce a higher number, I would suggest 12g would be obtainable.

   What needs to be understood is that lift is a function of atmospheric pressure and atmospheric density.  The change in pressure above and below the wing is a function of air density, but the lifting force is actually produced by air pressure.  At sea level, air pressure is about 2100 lbs per square foot.  It is half, 1050 psf, at 18 000 feet.  Air density is about one fourteenth of a lb per cubic foot at sea level an it halves at 22 000 feet.

For an F-15 wing loading, the weight of aircraft divided by wing area is around 90 psf (pounds per square foot).  For 9gs, that is 810 psf.  At 15 000 feet altitude it would be impossible to lower the pressure any more, it is impossible to create a vacuum and there is only about 1000 psf of pressure at 18 000 feet.  The only way to increase lift is to increase wing area.

   In 2b, if the wing cross section shape (wing profile) is maintained, but enlarged proportionately, for the same stiffness, the skin thickness can be decreased with the proportionate increase in cross-section length which would produce a proportionate increase in depth.  If the wing  section is twice as long, the depth at each wing position (one fourth the length, one half the length) would be twice.  The wing skin can then be one half for the same thickness to provide the same stiffness.  The wing area (twice as long but the same span ) would double, but the skin being one half as thick, would way the same.  The skin is the principal source of weight in a fighter wing to maintain stiffness.  The weight has not increased but the lift has allowing for higher turning gs.

   In 2a, the wing strip, s, owing to the reduction in efficiency from the reduced aspect ratio, would produce less lift and the center of lift would move closer to the fuselage since it is the wing tips which cause the loss of efficiency.  Both of these factors reduce the bending moment, 2c, and therefor require less stiffness.  The wing depth can remain the same and the wing can be even stiffer, or the wing skin can be reduced in thicknesss to make the wing lighter.  In addition there is something called Reynold's number which is velocity times a length divided by kinematic viscosity (the ratio of a fluid stickiness to its mass ratio).  An F-15 wing, using cord as length, has a Reynold's number of a about 100 million, twice the cord would be 200 million.  In general a thinner wing is better for higher numbers, so the wing skin thickness could be held constant and the the wing depth reduced.   Another option is to slightly extend the span while keeping the weight constant.   Additionally the cord length could be increased, which would be even more pronounced if the wing span was somewhat reduced.   Or, all of the  above could be compromised; slightly thinner, slightly more span, slightly lighter and slightly stiffer.

   The one problem is that it would fall out of the sky at low speeds and could not land, the stalling speed would be effectively raised to 300-400mph.  So, a lifting wing ,3, would have to be attached  for take-offs and landings.  A boom, similar to a refueling boom, but with 3 hinges, would attach to the fighter at its center of gravity.  The pilot would fly the two aircraft as one until they separate, at which point the lifting would fly robotically.  For connecting the boom would use laseer or radar to automatically attach when they are close enough.  If that fails, the pilot would fly his fighter with on hand while looking at a boom camera on a flat screen display and connecting the boom with his other hand.

   The landing gear would be on the wing which would save at least 1000 lbs from the fighter plus the additional structural weight need to accommodate the landing gear.  The vertical stabilizers, tails, could be moved under the fighter fuselage.  They can also be made smaller. The big vertical stabilizer is needed for low-speed flight and to have sufficient area above the turbulent flow when the plane is turning, inset 3, to maintain stability and prevent spin entry, when turning, the fuselage wake covers most of the stabilizer.  Since the fighter will never fly slowly, there is no need for large surfaces and underneath the fuselage will not place its wake on them.   However, for negative g, coming over the top of a curve, the fuselage might obscure them, so, it might be necessary to add strakes, ridges above the fuselage.  The F-16 has strakes under the fuselage to prevent spin when its tail is covered, so does the plane the Chinese claim is a stealth fighter.  The strakes provide an additional drag force to resist turning.
   In 4, the fighter is shown attached and being moved into the fixed position under the wing.  The  bending moments would be enormous, allowing for a section of boom 30 feet long and a fighter weight  of 50 000 lbs, the moment would be 1 500 000 lb-feet, it could not be generated by internal forces, so a cable, c, would have to lift and secure the fighter.  Once secured the fighter would have to be position by addition struts or bumpers, which are not shown.

  The pilot,  to resist g forces would have to be in a water-filled suit, similar to an astronaut suit with a scuba diver hood to prevent water from geysering around his neck under negative g.   The pilot would climb into his fighter and then the suit would be filled with water.

F-35:The $380 billion mistake II

 There is one blog if front and one after this blog.

   Hopefully, part I has been read.  In 2, it will be noted that increasing the size of the wing cross-section greatly increases the available internal wing volume for fuel storage.  This can eliminate the need for external fuel tanks.  It would be necessary to have a mechanism for dumping the excess fuel when entering combat.  One means would be to have a tank of compressed nitrogen to overpressure the fuel tank forcing the fuel out through exit lines.

   Another point that must be mentioned is the need to change direction of travel.  This requires the wings to be rotated from horizontal to vertical.  When doing this the wings act as large paddles whose turning is resisted by the air.  In addition , when plunging a wing, such as the left wing dropping to execute a left turn, the lift of the wing increases when being plunged under compressible flow. This increase in lift must be further overcome by rotating forces supplied by ailerons.

   This is where torsional stiffness becomes so important.  In order to maintain a high rate of rotation, the wing must remain rigid in sectional rotation.  When a wing is to be lifted, the aileron must be lowered to produce lift, but the aileron, located at the rear of the wing, is located in back of the torsional center of rotation.  So, the lift at the rear causes the rear of the wing to rise and forcing the front edge downwards.  Wing lift increases with increasing angle of the front edge, decreasing the leading edge angle decreases the wing lift.

This means that lowering the aileron to increase wing lift lowers the leading edge, decreasing wing lift, if the aileron manages to negate its own lift, this is known as wing reversal.  Back in World War II, the Japanese had a fighter that the U.S. called a Zero.  To save weight the wings were lightly built, at the beginning of the war the wings were also lengthened to increase range.  Near its top speed , it came close to wing reversal, owing to light construction it could turn quickly but it was slow in going into a turn or changing direction.  U.S. fighters had a maneuver called a Thach weave, it involved two U.S. fighters turning away from each other, one right, the other left, and then turning back towards each other.  Zeros had difficulty following the changes in direction, wallowing in their turns, giving the U.S. fighters a chance to shoot at the Zeros from the front as they passed.  The Japanese lost a lot of battles.

   Torsional stiffness involves wing beams, spars, that extend form the fuselage to the wing tips, combined with the wing skin, they form a beam structure.  It is similar to a diving board.  The various spars are similar to a group of diving boards side- to-side.  If, for instance, the diving board deflects by 1 inch if 100 lbs is placed upon it, that force would be multiplied by the distance to the torsional center to determine stiffness, the further from the center of torsion, the greater the stiffness it produces.  There is one problem.  In order to transmit the force through the distance to the torsional center there needs to be another beam connecting them.  If the diving board deflects 1 inch and the beam to the torsional center deflects 1 inch, the total deflection is two inches, making the wing less stiff.  It is a two dimensional matrix.  For low aspect ratio wings, the wing bends into a potato chip shape, deflecting very little along the fuselage and more in the center than at the edges of the wings.  Having a longer cord wing puts more stiffness further from the torsional center but also increases the front-to-back beam length making that beam more flexible, reducing the stiffness to the center-of-torsion.  Over all the bigger wing tends to be stiffer.

four

  One of the difficulties when an airplane begin to spin, rotating like a frisbee, is that the horizontal stabilizer, tailplane, can create an aerodynamic shadow, blocking the vertical stabilizer.  This is the principal reason for strakes to be fitted.

   The landing gear would be carried by the lifting wing on booms, 5. 

The landing gear would be in front of an behind the fighter wing, giving four sets of wheels and struts.   For landing, The forward landing gear would be extended to allow all  wheels to land at eh same time.  This is necessary because the center of mass would be between the forward and rear gear and, if only the rear gear struck the ground, the aircraft would rotate downward onto the front gear causing a hard landing.

   For take-offs, a forward wing could be built onto the wing, 7.  The forward wing would produce lift to raise the angle-of-attack to increase lift for take-off.  Whatever weight cannot be lifted by the forward wing must be lifted by the forward landing gear.  The one problem is that flow from wings flows backwards and downwards and flow form the forward wing would be ingested into the fighter plane's engines.  This is really bad.  Turbulent flow would induce additional stresses into the compressor of the engines.  Worse, maintaining combustion in a turbine engine is not simple.  In fact, the people who know how to build combustors  for turbine engines wear long black capes with hoods  and Runic lettering written on the back.  Designing them requires a lot of science, engineering and a magic touch.  Having pulsating flows can cause the engines to flame out.

    Most maintenance would be done with the fighter and wing connected.  For additional work, a cart can be slid beneath the fighter and the fighter's weight lifted.  The wing and fighter can then be slightly separated for access.  If ti is necessary to completely separate them, a heavy vehicle would be driven to the front of the wing and attached to provide a counter-balance, the rear landing gear would then be raised and the fighter withdrawn backwards, 6.

   In 7, the wing end can be folded down to reduce space for parking and to allow it to be placed into an aircraft shelter.

   The reason for the fighter to be built in two pieces is because high- speed, compressible flow, is essentially a different fluid from low-speed incompressible flow.  An attempt to deal with this phenomenom was variable geometry, also known as the swing wing, 8. It was an incredibly stupid idea, it adds mass to the aircraft and makes a flexible wing, both of which are unwanted in military aircraft.  Any competent engineer should have dismissed the idea within an hour.  Instead it took twenty years for it to be realized that it did not work.

   8b, shows the difference in turning radius between 9gs and 12gs.  At 600mph, 9g is a 2800 ft radius and 12g is 2100 ft.

   This is important for the F-35.  The idea of the F-35 is that it can fire missiles before it is seen.  The missiles are called high-probability-of- intercept, meaning they are likely to hit their target.  But that is for 9gs, at 12gs they would be high-probability-of-miss.  In order to hit a 12g target, the winglets of the missile would have to be enlarged adding wight, additionally, the body of the missile would have to be made heavier because of higher stresses.  The only way that weight can be compensated is by reducing the weight of fuel.  The drag of the missile would increase with the larger winglets and, combined with the reduction in fuel would result in a shorter range.  The idea with the F-35 is that missiles can be fired beyond-visual-range (BVR), meaning the missile are fired before the plane is seen.  The reduced range would at least reduce the margin of safety and in a turning fight a 9g fighter could not fight a 12g fighter, it would be suicide. 

   The one limitation to a 12 g fighter is power-of -maneuver.  The aircraft engines must replace the energy from drag in maneuvers or the fighter will slow down, eventually losing maneuvering ability.  

    In 8 c,d,e show the connection between boom and fighter.  Two trunnions would be inserted into the end of the boom to connect the airframes and still allow for angular movement of the boom end

  In 9a, a bucket is swung on a rope.  If a water balloon is placed in the bottom of the bucket it will splay out, if the bucket is spun it will splay out even further.  But, if the bucket is filled with water. the balloon will stay round no matter how hard the bucket is spun, as the pressure inside and outside the balloon will be equal, b.  The human body is basically a water balloon.  In the 1960s, engineers at the Naval Air Warfare Center in Warminster, Pa.  had a centrifuge for spinning people in g experiments.  One day they got bored and put a fish tank with fish on the centrifuge.  They spun the fish to 40gs and it did not care.  If the fish is under 1 foot of water, 40 gs would be like 40 feet of water, no problem for a fish.  They then built what they called "the iron maiden", an aluminum tank in which they could place a person before filling it with water and spinning the people to 32 gs.  Normally,people would have trouble at 9 gs when oriented top to bottom, as the blood drains from the head to the legs.  With the water the subjects had no difficulties.  In World War II water filled pants were tried for anti-g.  They worked but they weighed 50 lbs.  A suit similar to an astronaut suit with a scuba hood could be filled with water after a pilot climbs into a cockpit to withstand gs. No one ever tried building a suit like this.

  If the pilot ejects, the suit can work as a survival capsule in water.  To further protect the pilot an additional neoprene hood with clear flexible plastic mask could be worn. It would have a snorkle with an opening maybe 4 inches by 1/4 inch.  It would have slits in the hard plastic and an interior flexible membrane, the membrane would collapse under water pressure to prevent aspiration of water, it would spring open when the water drops.  Seawater weighs 64 lbs per cubic foot, water 2 inches deep would produce 10 lbs per square foot pressure.  Breathing at 30 feet per second would produce 1 lb per square foot.  A similar snorkle could be added to commercial survival suits, p.

   The ability to make automatic connection between fighter and wing was available in 1975, every fighter built since then has been obsolete.  The entire air force needs to be scrapped and replaced and the F-35 is idiocy.

F-35:The $380 billion mistake III

   Further explanation of why the F-35 is militarily useless.
   There are two previous posts.
   The Reynold's number measures the separation of flow.  A method to reduce the separation of flow form the wing is to reduce the thickness to cord ratio, the greatest thickness, top to bottom measurement of a wing divided by the cord, front to back edge measurement.  For structural considerations, the wing depth is measured from the center of the top wing skin to the center of the bottom wing skin.  If this depth is A and one half the top thickness plus one half the bottom thickness is B the outer, aerodynamic, thickness is A+B.  If the depth is doubled but the thickness is halved the outer depth is 2A+1/2B.  If that is divided by twice the cord the wing is aerodynamically thinner, lower thickness to cord.  That would improve high-speed flight.  As explained previously, a further thinning might be achieved to improve aerodynamics.

   Incompressible flow likes straight wings, compressible flow prefers highly swept wings.  Normally, the wing has to be compromised to allow for both flows.  By separating the aircraft into two parts an optimal wing can be chosen for both flows.  This means that the combination aircraft can be designed for short take-offs, 1200=1500 foot runways instead of 3500 foot runways.  In addition the wing profile, cross sectional shape, of the fighter can be chosen entirely for high speed flow, ignoring low speed flows, and possibly providing some additional aerodynamic improvement.
   Stability and control are the other serious considerations.  One definition of designing aircraft is choosing which instabilities on can live with and then designing the aircraft around them.  Under subsonic flow the aerodynamic center(a-c), the average point of lift is located at eh 1/4 cord point, 1/4 of the distance from the front to the trailing edge of the wing.  Under supersonic flight the a-c is at 1/2 cord, the longer the cord the greater the shift and the more compensation required.
   Attempts to build separable aircraft tended to fail because they placed the separating aircraft on top of the carrier aircraft, this raised the center of mass making the two aircraft set less stable and required extreme care at separation to avoid collisions.  Hanging the aircraft underneath and extending it on a boom before separation solves both problems.
   Operationally, a two part aircraft requires a higher workload.  Once  the fighter has separated the lifting wing must either land, and then take-off again to recover the fighter, or fly around in circles taking up air space and burning fuel until the fighter returns.  Landing means twice as many aircraft movements form the airfield and circling leaves the wing vulnerable to being shot down.  If the fighter is going to land at a different field, the wings could be sent by a different route as long as the flight times are comparable, if the fighter has a one hour mission , the wing can fly one hour, 500 miles to another field for recovery.  For long range transfers, the fighter could fly on the extended boom as a two aircraft formation.  There would be a need to have extra wings for contingencies.  It should be possible to transfer fuel down the boom, allowing the wing to be used as a robotic tanker.  The other potential use for the wing would be as a cruise missile bus, loaded with cruise missiles and fuel it could fly forward and release them.
   For carrier operations, ideally, the wing would be vertical landing.  This would obviate the need for arresting wires and a landing strip, allowing the carrier to be divided into three zones; a rear landing zone, a middle aircraft handling zone and a forward catapult launching zone.  There should be two landing zones, one left and one right across the deck.  This would allow for simultaneous landings and, combined with the ability to launch and recover at the same time allow for a higher tempo of aircraft operations. To have two landing zones the deck would probably have to be at least 300 feet wide.  That would require a hull 200 feet wide.  Aircraft carriers are built as 6:1 ships, 6 times as long as wide, that means the the hulls of carriers should be 1200 feet long.  They are currently about 1080 feet.  There is a carrier named Reagan, since Reagan bought the wrong and obsolete aircraft as well as miss-designed under-sized carriers, it is a fitting, although ironic, fact that he should have one of those miss-designed carriers named after him as a monument to his own incompetence.  There is no need to worry about replacing the carriers, they only cost $8 billion.
   For catapult launches, there may have to be two catapult tracks for each launch, owing to the duel forward landing gear, attaching only one to a catapult would drag the aircraft down the deck crabwise.  A second track, attached to the other gear, which would be a non-active catapult, would allow for a cleaner take-off.
   AWACS aircraft would have to also be vertical landing to remove the use of arrestor wires.  The radome would be placed under the aircraft to lower height and allow for placing onto the hanger deck.
   The main advantage for a two part aircraft for carrier operations is that the fighter would be identical to an air force fighter.  Currently, air force fighter use an aspect ratio of 2.5 and naval fighters use an aspect ratio of 4 to allow for lower landing speeds.  The higher aspect ratio means a heavier wing wich is less efficient in high speed flight.

   When the fighter is under the wing, it would be best to have the cockpit in front of the engine intakes for the wing, allowing the pilot to eject.  The danger comes when the pilot is attached by the boom when extended, as the pilot would have to separate and disentangle from the connection before ejecting.
   One question, would be when and how to eject water form the pilot's suit during the ejection sequence.  Compressed air could be blown in and a relief valve would allow purging.  The pilot would probably wear something like an olympic swim suit next to his skin.This would men the pilot would have to eject with a clothing bundle to dress for evasion and escape.
   The flight controls could actually be contained in pressure sensitive gloves.  The pilot's arm could be on an arm rest while his hand would be around a neutral object, a post.  For control, the pilot would press his hand against the post , the squeezing of the glove between hand and post would register as  a control signal.  The pilot would be able to use finger-tip pressure pads to "type" in instructions as well as possible voice activation.
   For the survival snorkle,  it would be 3 inches tall but the water pressure would collapse the diaphram under 2 inches of water preventing water ingestion and aspiration.  At the narrow ends of the snorkle, a teardrop shaped post would be insine the diaphragm with the diaphram trapped between the post and structural tube.
The pointed inner edge of the post might have ogive curves to provide a better seal when the diaphram closes.      The diaphram itself would have ridges or waves in vertical cross-section to provide a  better seal when closed.  The snorkle would be attached to the hood with effectively, a large rubber band.

   For pilots in the ocean, a rescue submersible, 10, could be deployed from a C-130 or a C-17.  A three man crew would be seated facing backwards on crash resistant seats, 10a.   The entire craft would be slowed by parachutes and, additionally, rockeet motors to slow the descent.  After entry into the water, one crew member would  enter the forward driver area while the remaining two would remain in the rear shelter area.  For the rescue, a side door would be opened and a resue swimmer would pull the pilot alongside and then both crew would pull hi inside assisted by a winch if necessary.  They would stabilize the pilot and await rescue.
   The vehicle would be 16-20 feet long, 8-10 feet wide and 8 feet tall overall.  It would weigh 10 000- 20 000 lbs.  It would be made out of aluminum armor plate and have a heavy windshield.  A flotation ring could be inflated for additional buoyancy after water entry.  Its engine would use a liquid mono-propellant  for long term storage and to prevent the engine being drowned.  It would have a hatch in its roof to allow helicopter evacuation of personnel.  It could also be lifted by a crane onto a ship's deck.
   For the rescue,  The pilot would have a strobe  light and the vehicle would have a strobe, the airccraft after deploying would circle directing one strobe onto the other.
   Unfortunately, back in the 1960s, there was a TV show called The Thunderbirds, it used marionettes for characters, a pOf all teh goofy nonsense produced for militarrocess the creator called "super-marionettization", a scientist had his secret location and used  rockets and submersibles for daring missions.  One of those craft, labelled Thunderbird 1, Thunderbird 2, etc., I think, looked something like this.  Sorry.
   The separation of a fighter into two parts would have given a significant improvement in performance as soon as fighters hit 600 mph, that was 1950.  For all the goofy nonsense produced for military aviation during the 1950s, such as prototypes of a super-sonic seaplane fighter, a two piece aircraft was never tested, even though it would have greatly improved performance.
  There were some test flights with a plane called the McDonnell XF-85 Goblin which was intended to be carried in the bomb bay of the B-36 bomber and flew off of a trapeze and had no landing gear.  It was intended to allow fighters to be available for bombers and was not done to improve overall fighter performance.
   The problem at that time was that there was no way to automatically join the aircraft, two additional crew members would have been needed to fly the wing, one to pilot, the other to work the boom. It still would have been worth testing.  By 1968, in Vietnam, laser guided bombs became available.  They required two planes, F-4s,  one dropped the bomb, in dive-bombing, the other flew a baked turn with a pilot in the back seat shining a laser pointer through the side canopy.  Lasers are the most obvious way for the connection to be accomplished.
   I will be generous and say 1975 was when a test aircraft could have been built.   That was Donald Rumsfeld's first time as Secretary of Defense.  It was the Ford administration, telephones had wires and music was produced from twelve inch plastic discs, it was a long time ago.  Every fighter produced since then, F-15, F-16, F-18, F-22, F-35, Typhoon, Tornado, Rafale, Grippen, Su-27, Su37,  Mig-29, were all obsolete, it is the biggest procurement failure in military history.  The entire Reagan defense build-up was a complete waste of money, they only bought obsolete garbage.  All of the secretaries of defense, air force and navy have been negligent along with the president and both houses of congress, especially the armed services committees and their members and staffs.  And no one will ever be held accountable.
   I wrote to DARPA in 2010, they said they do not take suggestions.  These re the idiots who actually publicly announced that they gave money to study  helicopter Humvee.  That will not work, the rotor dynamics say that for 10 lbs disc loading, weight divided by the circular area swept by rotors, 90 fps thrust would be produced, that must be multiplied by 4/3 to account for inefficiencies for a flow of 120 fps.  One horse-power is 550 ft-lbs/sec.  They said 500 hp.  550X500/120= 2500lb total weight.  A Humvee carries 1500 lbs.  At 5 lb disc loading; 63 fps X4/3= 84fps.  550X500/84 = 3300 lbs.  In a few minutes, Icould tell them it would not work, but they do not ask me.  The requirements for working at DARPA are having too much degree and not enough ability.  If you have a Ph.D. but are not actually very good at engineering, a DARPA career could be in your future.
    This entire design is a third year engineering problem, not even graduate level, separating a problem into two parts and solving each individually is a standard technique in mathematics and engineering.
   I also wrote to the air force and they ignored me.  I guess i should have tried the Russian and Chinese embassies, since the U.S. does not want to modernize, maybe they would.  There is no point in contacting congress, all the members, and all their staffs are useless.  There is a wall of psychosis around the government and it cannot be breached.  They have lost at least a year of development and any other nation that wishes can enter the race for the 12g fighter, if anyone ever reads this blog.
 
 Another method of launching form catapults is similar to what the navy did when they had single engine propeller aircraft; they attached a cable into the wheel wells and then attached the cable to the catapult.  After take-off, the cable was dropped into the ocean.
    A cable could be re-used by having it retract into one of the landing gear struts:  The cable would be partially retracted; the end attached to the opposite strut would detach; since they are extended well below the position of the fighter, there would be no danger of the cable striking the fighter; the remainder of the cable would then be retracted.  A sheave block with a pulley could be used to attach to the catapult,  When retracted, it would be held against the strut.
   In order to prevent the aircraft from being flipped, the lower strut would be longer than the upper strut in order to lower the attachment points at the knees, the center of mass of the aircraft would also be further back from the forward wheels providing a greater stabilizing moment.