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U-2
DRAGONLADY
Thanks and credit goes to John Stone for publishing Lt. Col. Charles Wilson's detailed account of what is involved in conducting a U-2 mission.
The U-2 was originally designed
as a high altitude reconnaissance platform to penetrate the airspace of
the
Soviet Union in the mid-1950s. Most of the U-2 fleet today was made in
the
mid-late 1980s. The U-2 was built to operate at altitudes above 70,000
feet.
This caused the aircraft to be made with long wings (today’s U2 has
about
a 104’ wing span) and configured with a bicycle (tandem) type landing
gear.
Aerodynamically it is a fairly “clean” aircraft-it likes to fly. It
does
fly very well, as long as it is in the “envelope” it was designed for.
That is, flown within the speed parameters and G limits.
Compared to other aircraft, the U-2 is perhaps the most difficult for a
pilot to fly. With its long wing and bicycle landing gear, it is
especially difficult to land (as I said before it likes to fly). The
pilot needs to
stall the aircraft from about two feet, to get it on the ground. But
more
on that later.
A typical high altitude flight is pretty involved. The day prior to one
of these flights, two pilots are identified, a primary and a backup.
The backup pilot is also called a mobile officer. The mobile officer
has two primary functions. He is a safety observer/mission monitor and
becomes the mission pilot in the event the primary pilot has become
sick. The mission is thoroughly planned.
Both pilots go into crew rest 12 hours prior to the launch. They also
watch their diets. On the day of the flight, the pilot and mobile
officer show
two hours and fifteen minutes prior to launch. They receive a weather
brief
and an intelligence brief. They take the time to eat a high protein
meal.
This is particularly important. A high protein meal (steak & eggs)
provides the pilot with the necessary energy to sustain him through a
nine hour flight without gastrointestinal discomfort. Following the
meal, the primary pilot receives a physical exam. During this exam, the
pilot’s pulse rate, blood pressure, body temperature, ears, nose and
throat are scrutinized to ensure that he is ready to endure the high
altitude flight environment that can exceed nine hours in duration. The
previous night’s sleep and any meals are also reviewed. Then our
primary pilot is integrated into a full pressure suitmuch like an
astronaut wears.
Why a pressure suit? A pressure suit is needed as a redundant system.
The hazardous physiological regime of high altitude flight dictates
this.
Also, with a cabin altitude of U-2 about 30,000 feet, the pilot must
prebreathe 100% oxygen for 60 minutes prior to takeoff to avoid getting
the bends. The pressure suit would be needed if the pilot were exposed
to the atmosphere from a rapid decompression or having to eject from
the aircraft. Two reasons for this are Boyle’s law and Armstrong’s
line.
Boyle’s law is that a given quantify of gas varies proportionately with
the amount of pressure exerted upon it. We humans are used to 14.7
pounds of pressure per square inch (psi) at sea level. We are at the
bottom of an ocean of air. This air has weight. The pounds psi at
altitude is less than a half-pound. Armstrong’s line says that at
63,000 feet pressure altitude, conventional liquids boil at 98 degrees
Fahrenheit. If the pilot were exposed to the environment at70,000 feet,
the gases in his body would rapidly expand causing a disastrous burst.
Not to mention what a “boiling” body temp of
98.6 would cause. Yes, it would ruin his whole day. Obviously this is
not
conducive to a successful mission. In the meantime, the mobile officer
is performing a preflight inspection of the aircraft. He sets up the
cockpit and checks all the systems i.e. electrics, hydraulics,
navigation, avionics. Also, he will walk around the entire aircraft
inspecting the aircraft’s structure. It is crucial for another
qualified pilot to perform these tasks for the mission pilot because
the bulkiness of the pressure suit limits the pilot’s
mobility, reduces his manual dexterity and can cause rapid heat buildup
if
he were to move around too much. When this is done, the pilot is
integrated
into the cockpit.
Just as it took a team of specialists to integrate the pilot into the
suit, the same team integrates him into the aircraft. They connect the
many belts, straps, hoses, cables and communication lines to the pilot.
Once he is strapped in he will run appropriate checklists and start the
aircraft. It is now ready to taxi.
Taxing the U-2 is challenging. Turning into the wind, the turn radius
is about 189 feet. Turning away from the wind, the turn radius can
exceed
300 feet. The pilot must judge turns carefully or get stuck and need
the
aircraft to be repositioned by the ground crews. No easy task either.
Typical
fighter aircraft have turn radii as small as 20-50 feet.
During this activity, our mobile officer follows along in a
high-performance chase car. The mobile, who is in radio contact with
the pilot, is in the
role of safety observer, monitoring the aircraft as it moves. Out on
the
runway, the ground crews remove the safety pins from the pogos. The
pogos
are outrigger gear that allow the aircraft to taxi without dragging a
wing. The mobile officer gives the aircraft a “last chance” check,
making sure
everything looks normal.
Once cleared for takeoff, the pilot moves up the throttle to maximum
thrust. As soon as the wings start generating lift, the pogos drop onto
the runway. With an initial climb rate that exceeds 15,000 ft/min, a
U-2 takeoff is an impressive sight. The climb rate varies depending on
a few things like gross weight, temperature and pressure altitude. That
climb rate tapers off, around 25,000 feet. Shortly afterwards, the
ground crews recover the pogos and stow them in a truck until the
aircraft lands. The pogos will be put back in place after the aircraft
lands. The pilot then flies his U-2 to above 70,000 feet and
accomplishes his assigned reconnaissance mission.
At 70,000 feet you are twice as high as the airliners fly. You begin to
see the curvature of the earth and the sky begins to blacken as the
outerlimits of the atmosphere are reached. If our pilot wasn’t so busy
on an operational mission, it would be easy for him to get a lonely
feeling up there at 70,000 feet hundreds or even thousands of miles
away from home base. After the reconnaissance portion of the mission is
accomplished, our pilot heads for home and prepares to descend. He runs
the appropriate checklists. Even with the landing gear down and speed
brakes out, the descent takes about 45 minutes. As I said before, the
aircraft likes to fly. During the descent, our mobile officer has
reviewed the weather and positioned himself in the chase car at the
threshold (or beginning) of the runway. Monitoring the mission
frequency the whole time. He is there to help the pilot with any
unusual difficulty that may be encountered. Our pilot now finds the
runway with his navigation instruments, visually acquires it, and
crosses the runway threshold at about 10 feet.
Despite being exposed to serious threats and a hazardous physiological
environment, our pilot is about to engage in the most challenging part
of the mission-landing the U-2. The U-2 is without a doubt, the most
difficult aircraft in the inventory to land. With its bicycle landing
gear, long wingspan and its “desire” to keep flying (even with idle
power), the pilot has his hands full putting it on the ground. The
mobile officer also has a big role to play here.
Keep in mind our pilot has been in a hazardous physiological
environment for over nine hours. Not much to eat, no chance for a
break, unable to get up and walk around. He is dehydrated, fatigued,
and has a skewed depth perception from the high altitude.
Still, our pilot brings the aircraft to cross the runway threshold at
10 feet precisely on centerline. The mobile chases the aircraft down
the
runway, making altitude calls at about every two feet. Deviations are
also
called out. To successfully land this aircraft, the pilot must achieve
a
full stall at two feet above the runway. I don’t mean killing the
engine. By stalling I mean to cause the aircraft’s wings to stop
generating lift. Our pilot does this through exact airspeed control. No
easy task considering the condition he is in along with the bulkiness
of the pressure suit. As it slows, the tail wheel lowers to the runway
and when the U-2 reaches a stall, the main wheel touches down. The
maneuver looks graceful to onlookers, but tends to feel violent inside
the cockpit as the pilot feels the stall, touches
down and struggles to keep the wings level.
But, it is not over yet. The pilot still has to “fly” the wings until
the aircraft can stop. Remember, the pogos fell out upon takeoff so as
long
as the airplane is rolling and the wings are producing some lift, the
pilot
must fly the wings to keep them off the runway. Finally, as the
aircraft
begins to stop, the pilot will gently put one wing on the ground. Each
wing has a titanium skidplate so that they are not damaged during this
phase. The ground crews now reinstall the pogos so that the pilot can
taxi back. The mobile is monitoring the whole event. After parking, our
team of specialists assist the pilot in getting out of the cockpit. The
pilot is tired and stiff from this long day, but still, it is not over.
After getting out of the pressure suit, the pilot attends the
maintenance debrief where equipment problems are discussed.
Intelligence debrief when required. Finally, the pilot attends an
operations debrief. Following a flight like this, a U-2 pilot cannot
fly for 48 hours with the first 24 hours being mandatory off. This is
to
allow his body to recuperate from a most physically demanding mission.
Who are these pilots? Well, they are a very tough breed. We recruit
only the best pilots. They must have 1500 hours of flying time. 900
first pilot/instructor time. They generally have experience in one-two
and sometimes three aircraft. They need outstanding records and a wing
commander recommendation. With all this, they might get an interview.
The interview lasts two weeks. We bring prospective pilots out to Beale
AFB, CA for a physical and three inflight evaluations in the U-2. Bear
in mind, they haven’t flown this type aircraft before. They must be
able to land
it three ways. No-flap, no-voice and normally. If they can do that,
they
might make it. Additionally, these prospective pilots are interviewed
by
the wing commander, his squadron commanders, and ops officers. Colonel
Wilson
reports that the last summer he was at Beale (1994), 17 pilots
interviewed with eight of them making it.
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