Aviation Week & Space Technology January 8, 2007 - 5
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size, the F-22 ranks below the F-15 and other earlier fighters. Aerial
engagements like the encounter between Anger and Jacob are supposed to
help prove the Raptor’s case. Still, one argument offered by F-22
opponents is that the jet’s reported victories over F-15s are often
scripted and unreliable gauges of Raptor superiority. T he Raptor’s
silhouette stood out against the thick wool of clouds building nearly
18,000 ft. up. The two airplanes lined up their noses on an imaginar y
starting line and accelerated from 250 kt. at an altitude of 13,000 ft.
Inside the F-15, Jacob’s body slammed backward and the two fighters
stayed even for about 10 sec. The F-15 hit 450 kt. in full afterburner in
level f light after 20 sec. The F-22 hit 500 kt. in maximum afterburner
and pulled away, ending the race. Jacob laughed. “That’s it,” he
said. “My F-15 can’t accelerate any more.” The F-15 was designed and
built to be a quick, maneuverable dogfighter. It has Pratt & Whitney
F100-P-W100 turbofan engines powering a lightly loaded and advanced
airframe. Weighing in at about 42,160 lb., the F-15 has a thrust-to-weight
ratio approaching 1.2 when stripped and not in a combat configuration and a
wing loading of about 69 lb. per sq. ft. By comparison, the F-22 has a
thrust-to-weight ratio closer to 1 and wing loading of about 80 lb. per
sq. ft. But the Raptor has two Pratt & Whitney’s F119 low-bypass,
augmented 35,000-lb. class engines with twodimensional vectored thrust
nozzles. Jacob circled above the Raptor as A nger put the fighter through
several maneuvers. He illustrated three key tac- tical moves—the J-Turn,
high-alpha turn and the classic, Russian Cobra. There are times during an
air-to-air engagement when any of them could be employed, but the J-Turn
is used more than the Cobra, says Lt. Col. Wade Tolliver, commander of the
27th Fighter Sqdn. Roughly, the J-Turn begins with the nose of the F-22
pointed up. Then, at high alpha angle of attack , the rudder is kicked and
the nose swings until pointed downhill. F-22 pilots describe a flight path
mimicking the shape of a candy cane. The J-Turn is a vertical maneuver
used to quickly reverse the aircraft’s direction using a very small turn
radius. After a planned stall, Anger’s Raptor pivoted through a
rapid-minimum, 180deg. J-Turn at 250 kt. in maximum afterburner with full
aft stick. It’s also known as the “Herbst Maneuver,” after Wolfgang
Herbst, a German proponent of using post-stall flight in air-to-air
combat. The aircraft pulled into a 60-70-deg. bank, nose high, with
roughly a 60-deg. angle of attack. Anger applied full stick and
pro-rudder, turning into the aircraft’s roll. The Raptor’s nose yawed
down into the vertical. For the second maneuver, Anger pulled the Raptor
into a high-alpha loop, powering again to 250 kt. He pulled 3-4g to about
180 kt. in the pure vertical, reaching 20-30 deg. past the vertical with
full aft stick. The AOA increased beyond 60-70-deg. alpha as the upward
motion slowed. Normally a rapid pitch rate would stop the aircraft’s
nose, but thrust vectoring carried the F-22’s nose back over the top,
completing the loop. In contrast, the legendary Cobra maneuver is done
from the horizontal plane, and the nose pitches up past vertical and
returns to the horizontal after a pronounced deceleration. To force an
opponent to overshoot, Anger yanked the Raptor into a dynamic, nose-high
attitude made possible by brute engine power—a maneuver that Russian
Su-27 pilots introduced to air show crowds. First, Anger slowed to 250
kt., pushed both throttles to the military power detent, then pulled the
control stick to its full-aft position. The Raptor’s nose pitched up to
a 60-70-deg. attitude, so the fighter’s belly remained aligned with the
flight path, creating enough drag to immediately slow the aircraft
substantially. He then pushed the stick full forward to snap the
Raptor’s nose back to level flight. T he Cobra is used to “gain high
ground and stop your forward travel,” Tolliver says. “The Cobra is a
great air show maneuver, but most of us don’t typically use it during
aerial combat.” Fighting—or even keeping up with the Raptor—requires
extremely fast assessment and reactions. “Faster than required for any
other aircraft I’ve flown against,” Jacob says. A nger and Jacob had
planned to engage in mock combat. However, a flashing indicator light
warned that something could be wrong with the F-22. But the flight was
enough to make a believer of Jacob. “Maybe, with some tricks or tactics,
I can beat it,” he said. “But that would be a one-time set of
circumstances. As for a Raptor-beating tactic—there’s no such
thing.” C For F-22 video, see www.aviationweek. com/f22 ERIC
HEHS/LOCKHEED MARTIN www.aviationweek.com/awst AVIATION WEEK & SPACE
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Aviation Week & Space Technology January 8, 2007
Table of Contents for the Digital Edition of Aviation Week & Space Technology January 8, 2007
Aviation Week & Space Technology January 8, 2007 - 1
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Aviation Week & Space Technology January 8, 2007 - 3
Aviation Week & Space Technology January 8, 2007 - 4
Aviation Week & Space Technology January 8, 2007 - 5
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Aviation Week & Space Technology January 8, 2007 - 8
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