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F-100 Super Sabre Jet
This is the Fastest Fighter in the World
More jet power, more sweep of wing, and a low-drag fuselage
make the F-100 the swiftest fighter plane in our air arsenal.
With the F-100 Super Sabre jet now in production, the Air Force gets a truly
supersonic weapon.
By Herbert O. Johansen
The "Y" has been taken off the North American YF-100 jet fighter.
That means it is no longer experimental, that the U. S. Air Force now has in
production the world's fastest fighter - one that can sustain supersonic speed in
level flight.
We - and the British, and probably the Russians - have for some time had jets
that were capable of faster-than-sound flight in dives accompanied by the sensational
sonic bangs or, perhaps, in brief supersonic bursts boosted by jet afterburner.
But the F-100 is a new breed of plane-it is supersonic in level flight. It is built
and powered for super-sonic flight as routine operation - not just as a stunt or
an all-out record-setting, headline-making effort.
A Whole Supersonic Air Force
The F-100 is a milestone, marking the coming-of-age of the jet age - the first
in a series of new faster-than-sound fighting airplanes. Among these are the Air
Force's McDonnell YF-101 twin-jet Voodoo long-range bomber escort; the Convair YF-102
delta-wing fighter; Republic's XF-103 research fighter and YF-105 fighter-bomber;
Lockheed's YF-104; and for the Navy, the Douglas XF4D-1 Sky-ray delta-wing fighter
(which in recent tests flew faster than 760 m.p.h.), the Grumman XF10F-1 Jaguar
variable-sweep-wing fighter, and the McDonnell XF3H-1 Demon.
Some of these newcomers have been flown, some are being built and others are
still on paper. Some may not get into production as better and faster models develop
from lessons learned. But as the Ys - for-experimental drop off, our military air
forces become truly supersonic. A daytime fighter, the F-100 is a gun platform.
Its main mission is to destroy enemy fighters over enemy territory to give us not
only air superiority but the control of the air we would need during those last
critical miles as an A-bomber neared its target. For that job it must be able not
only to fly high and fast, but for long distances, which means great loads of fuel.
So it is big; and, since it is big, it can carry under-wing loads of bombs or rockets
for a secondary mission as a low-level air-ground attack weapon. Such external loads
would necessarily slow the plane down, but once the load was dropped, the F-100
could fight its way back to base at supersonic speeds.
Big Intake at nose lets F-100 gulp vast amount of air needed
for supersonic speed.
Thick, straight wing, stubby nose, protruding guns, bulging
canopy of World War II Republic Thunderbolt would have acted as drag brakes at speeds
that jet makes possible.
Jet Power made its U.S. debut in this Bell P-59 Airacomet that
first flew in October 1943. Absence of propeller enabled designers to clean up the
fuselage.
More Wing Sweep Increases Speed
Although it is an evolution of the F-86 Sabrejet that has broken many speed records
and made aerial-combat history over MIG Alley in Korea, the F-100 Super Sabre is
a new plane. That it is supersonic would mean that it can fly faster than sound
at all altitudes, which varies from 660 miles an hour at a combat altitude of 40,000
feet to 762 miles at sea level. Bigger than the F-86 fighter, the F-100 is 45 feet
long and weighs more than 20,000 pounds.
Most notable change is in the wing. Where the latest F-86 has 35-degree sweep,
the F-100 has a thinner wing that is swept back 45 degrees. The tail also has more
sweep back.
Power behind the F-100 is a new design in jet engines, the split-compressor J-57,
claimed by the manufacturer, Pratt & Whitney, to be the most powerful production
engine in the world. With it, the Super Sabre is reported to have more than 10,000
pounds of thrust and about 15,000 pounds with afterburner (the F-86D has 7,600 pounds
of thrust with afterburner).
First Operational Jet Fighter, the Lockheed F-80 Shooting Star,
met Red MIGs in combat in Korea. Although the wing is still straight, it is much
thinner for less drag.
As More Powerful Jet Engines enabled planes to nudge the speed
of sound, designers were forced to sweep back the wings, as in this North American
F-86 Sabrejet.
Split-compressor. or twin-spool, means that an engine has two compressors in
series, each driven by a separate turbine. There are two shafts with no mechanical
connection between the two turbines. The first (low-pressure) compressor feeds the
second (high-pressure) compressor. The result is a higher range of compression ratios
than can be obtained on a single-shaft compressor.
Jet Speeds Bring New Designs
Among the advantages of the split-compressor are lower fuel consumption for range
or higher power output for speed and maneuverability; the elimination of "surging,"
or back-flow, problems in the thin air at high altitudes; easier starting, and fast
acceleration.
As jet engines became more powerful, new fuselages and wings were designed around
the engine, and the early Lockheed F-80 Shooting Star and the Republic F-84 Thunderjet
were born. Wings were still straight, but streamlining sent speeds up 100 and more
miles an hour. Then jet-engine power went up and greater speeds forced the designers
to go to thinner and swept-back wings to delay drag and the turbulence that wings
run into at transonic speeds.
Ever-increasing jet speeds have posed other problems. When our first jet plane,
the experimental Bell P-59 Airacomet, was announced in 1944, the Air Force thought
it had the makings of a simple, lightweight fighter that would burn almost anything
as fuel. Kerosene was it - at first. Disillusionment came fast-as fast as speeds
increased. Jet engines had to abandon kerosene for gasoline, and today that has
had to be replaced by special, high-grade JP fuels.
Principle of split-compressor jet engine that powers the F-100
is shown in drawing above.
Then there was the matter of weight. After all, a jet plane is only a shell built
around a blowtorch. Nothing complex about that. But again, greater speeds and more
powerful engines changed the picture - there was the pilot to consider.
Pressure suits enabled him to take the terrific Gs at jet speeds, but he must
also fly and fight at high altitudes to take advantage of lower fuel consumption.
That meant a pressurized cockpit and an improved oxygen system to keep him alive
should the pressurization fail.
Speed of Sound varies with altitude. Critical speed area is
the transonic where the air-frame runs into violent turbulences. At supersonic speeds
air becomes smooth again.
Heat created by friction necessitated refrigeration of the cockpit, and because
it is bitter-cold up there, heaters had to be provided to prevent guns from freezing.
Add to this an ejection seat for the pilot in case of bail-out, computing radar
gunsights and power controls, and you have what is mildly called "complexity."
Now that the Air Force has hit the supersonic, the question arises, "How much
faster will we fly?"
Top fighter men in both the Navy and the Air Force say, "At least 100 miles an
hour faster than the enemy."
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