North American F-86 Sabre
Early in WWII, American
aircraft researchers were confronted with the problem of "shock waves"
building up at the frontal surfaces of aircraft particularly wing and tail
surfaces when the aircraft was flown at high speeds. These shock waves
could and did cause complete destruction of some aircraft, notably several
Lockheed P-38 "Lightnings". The North American P-86 Sabre was the first
American aircraft to take advantage of flight research data seized from
the German Luftwaffe at the end of the war.
Utilizing data gleaned from Luftwaffe experiments, the wings and the
horizontal and vertical stabilizers of the Sabre were swept back at an
angle of 35º in order to delay the onset of shock waves, thus allowing
higher speeds.
What would become a spectacular career as a combat aircraft began on May
14, 1945 when the US Army Air Corps ordered 3 copies of the North American
model NA-140 experimental aircraft. The XP-86 was first flown at Muroc Dry
Lake, California on October 1, 1947. It was equipped with a 4,000 pound
thrust J-35-C-3 jet engine built by Chevrolet. The highest speed was
attained at 14,000 feet where it clocked 618.33 miles per hour. It had a
ceiling of around 41,300 feet and its initial climb rate was 4,000 fpm.
This was fantastic performance when compared to any prop-driven plane the
US had produced up to the end of the war. Even North American’s own
prop-driven P-51 paled by comparison. Test pilots were ecstatic over the
Sabre, with comments such as "...rock-steady gun platform." and "...so
easy to fly you can almost control it with your thoughts".
The third production F-86A-1 (by this time the "P" for "Pursuit" had been
superseded by "F" for "Fighter") equipped with a new J47-GE-13 engine of
5,200 pounds thrust, set a world’s speed record of 670.98 mph on September
1, 1948. The Sabre was armed with six .50-caliber M-3 machine guns in the
nose, just aft of the jet intake. Target acquisition was aided by a new
radar assisted gun sight. It required the pilot hold the cross hairs on
his target for just one second. From then till the target was obliterated,
the pilot was free of the complicated problem of adjusting for the
target’s range during the heat of combat.
The F-86B (later
redesignated F-86A-5), with its top speed of 679 mph, and initial climb
rate of 7,470 fpm it represented a marked improvement over the A-1. A Wing
of F-86A-5 aircraft arrived in Korea on December 13, 1950 making it the
first Sabre sent to Korea. On December 17 they went into action against
the awesome and hitherto invincible MiG-15. Within two weeks, the Sabres
had established a "kill ratio" of better than 8:1 over the MIG.
Admittedly, the superior training and tactics of the US pilots brought
about a large part of this success, for the A-5 Sabre had inferior
performance when compared to the MIG-15. It was slower and unable
manoeuvre
as well as the MIG above 25,000 feet. Its service ceiling of 48,000 feet
was much lower than the MIG. Nevertheless, the appearance of the Sabre was
the beginning of the end for the MiG-15 in Korea.
The Sabre was continuously improved throughout its 10-year production run.
Each model performed better than the last. There were two major variations
of the craft. The F-86C was redesignated "YF-93" and was intended to be a
"penetration fighter". However, it eventually came to a dead end.
The second variation was
known as the F-95 until July 1950, when it was redesignated the F-86D. It
was labelled an "all weather interceptor". Some experts are of the opinion
the "D" was so different from the basic model it should have retained it’s
F-95 designation. For one thing the J47-GE-17 engine was equipped with an
afterburner which delivered a total of 7,500 pounds thrust for take-off,
giving the "D" an initial climb rate of 12,150 fpm! The nose was shaped
like a shark snout with an open mouth for an air intake. Above the mouth
and projecting forward was the shark’s nose, which housed a radar antenna
for the Hughes E-4 automatic fire control system. More than anything, the
F-86D resembled a shark right down to the fins, and should have been named
so. But the Air Force Brass was reluctant to pick a name with such a
nautical connotation.
It was the first USAF night fighter to carry only one airman and have only
one engine. The fire control system was so automatic, a second airman was
considered unnecessary. A pod containing twenty-four 2.75 "Mighty Mouse"
air-to-air rockets was located in the belly. The pod was lowered into the
air stream in order to fire the rockets, then quickly retracted so as not
to affect the speed or handling characteristics any more than necessary.
The pilot had to take great care to insure each rocket had cleared its
tube when fired. If a rocket was hanging halfway out the tube and the pod
were retracted, the rocket would explode. If the pilot wasn’t absolutely
sure of the position of the rocket, he landed the Sabre with the pod
extended. The author observed just this sort of incident in 1957 at
Wheelus Field, Libya. In this case, the instant the Sabre touched down,
the rocket fired and blasted a 15-foot hole in a rock security fence
nearly a mile and a half away!
The "E" was very similar to the "A" with the same J47-GE-13 engine. It was
designed to carry a bit heavier combat load. The "F" was furnished with
the J47-GE-27 engine with about 700 additional pounds of thrust (no
afterburner), which increased its top speed about 15 mph to 695 mph.
Combat range was increased from 660 miles to 923miles. The F was the first
Sabre to haul a 1,200 lb. nuclear bomb, which was carried under the port
wing. In order to safely deliver this weapon, the aircraft was also
furnished with a LABS (Low Altitude Bombing System) which allowed the
craft to escape the blast.
The "G" designation was temporarily given to the F-86D with J47-GE-33
engines. The plane was produced as the F-86D.
The F-86H was the final model and was specifically designed as a
fighter-bomber. It had the much more powerful J73-GE-30 Engine of 8,920
lbs thrust with afterburner. Its combat range was extended to 1,038 miles.
Later editions of the "H" had the wing slats removed and the leading edges
extended. The wing tips were also extended to provide better
manoeuvrability at high altitude. The H-5 and H-10 had the six .50 calibre
machine guns removed and replaced with four 20 mm M-39’s for greater
hitting power.
Altogether there were about 6,200 F-86 Sabres built in the US before
production ceased in December 1956. A couple thousand more were built in
25 other countries around the world. Even our old enemies the Germans flew
them, and Mitsubishi (builders of the famous World War Two "Zero")
assembled 300 for the Japanese.
SPECIFICATIONS
Span: 37 ft. 1 in.
Length: 40 ft. 4 in.
Height: 15 ft. 0 in.
Weight: 19,975 lbs. loaded
Armament: Twenty-four 2.75 in. Mighty Mouse folding fin aircraft
rockets
Engine: General Electric J47 of 7,650 lbs. thrust with afterburner
Crew: One
Cost: $344,000
PERFORMANCE
Maximum speed: 715 mph
Cruising speed: 550 mph.
Range: 800 miles
Service Ceiling: 50,000 ft.
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