View of a Military Expert:
Why the Towers of the World Trade Center
Collapsed
The Impossibility of
Flying Heavy Aircraft Without Training
by Nila Sagadevan
Nila
Sagadevan is an aeronautical engineer and a
qualified pilot of heavy aircraft.
There are some who maintain that the mythical
9/11 hijackers, although proven to be too
incompetent to fly a little Cessna 172, had
acquired the impressive skills that enabled them
to fly airliners by training in flight
simulators.
What follows is an attempt to bury this myth once
and for all, because Ive heard this
ludicrous explanation bandied about, ad
nauseam, on the Internet and
the TV networksinvariably by people who
know nothing substantive about flight simulators,
flying, or even airplanes.
A common misconception non-pilots have about
simulators is how easy it is to
operate them. They are indeed relatively easy to
operate if the objective is to make a few lazy
turns and frolic about in the open
sky. But if the intent is to execute any
kind of a maneuver with even the least bit of
precision, the task immediately becomes quite
daunting. And if the aim is to navigate to a
specific geographic location hundreds of miles
away while flying at over 500 MPH, 30,000 feet
above the ground the challenges become virtually
impossible for an untrained pilot.
And
this, precisely, is what the four hijacker pilots
who could not fly a Cessna
around an airport are
alleged to have accomplished in multi-ton,
high-speed commercial jets on 9/11.
For a person not conversant with the practical
complexities of pilotage, a modern flight
simulator could present a terribly confusing and
disorienting experience. These complex training
devices are not even remotely similar to the
video games one sees in amusement arcades, or
even the software versions available for home
computers.
In order to operate a modern flight simulator
with any level of skill, one has to not only be a
decent pilot to begin with, but also a skilled instrument-rated
one to boot and
be thoroughly familiar with the actual aircraft
type the simulator represents, since the cockpit
layouts vary between aircraft.
The
only flight domains where an arcade/PC-type game
would even begin to approach the degree of visual
realism of a modern professional flight simulator
would be during the take-off and landing phases.
During these phases, of course, one clearly sees
the bright runway lights stretched out ahead, and
even peripherally sees images of buildings, etc.
moving past. Take-offseven landings, to a
certain degreeare relatively
easy, because the pilot has visual
reference cues that exist
outside the cockpit.
But once youve rotated, climbed out, and
reached cruising altitude in a simulator (or real
airplane), and find yourself en route to some
distant destination (using sophisticated
electronic navigation techniques), the situation
changes drastically: the
pilot loses virtually all external visual
reference cues. S/he is
left entirely at the mercy of an array of complex
flight and navigation instruments to provide
situational cues (altitude, heading, speed,
attitude, etc.)
In the case of a Boeing 757 or 767, the pilot
would be faced with an EFIS (Electronic Flight
Instrumentation System) panel comprised of six
large multi-mode LCDs interspersed with clusters
of assorted hard instruments. These
displays process the raw aircraft system and
flight data into an integrated picture of the
aircraft situation, position and progress, not
only in horizontal and vertical dimensions, but
also with regard to time and speed as well. When
flying blind, I.e., with no ground
reference cues, it takes a highly skilled pilot
to interpret, and then apply, this data
intelligently. If one cannot translate this
information quickly, precisely and accurately
(and it takes an instrument-rated pilot to do
so), one would have ZERO SITUATIONAL AWARENESS.
I.e., the pilot wouldnt have a clue where
s/he was in relation to the earth. Flight under
such conditions is referred to as
IFR, or Instrument Flight Rules.
And IFR Rule #1: Never take your eyes off your
instruments, because
thats all you have!
The
corollary to Rule #1: If you cant read the
instruments in a quick, smooth, disciplined,
scan, youre as good as
dead. Accident records from
around the world are replete with reports of any
number of good pilots I.e., professional instrument-rated
pilots who bought the farm
because they screwed up while flying in IFR
conditions.
Let me place this in the context of the 9/11
hijacker-pilots. These men were repeatedly deemed
incompetent to solo a simple Cessna-172 an
elementary exercise that involves flying this
little trainer once around the patch on a sunny
day. A students first solo flight involves
a simple circuit: take-off, followed by four
gentle left turns ending with a landing back on
the runway. This is as basic as flying can
possibly get.
Not
one of the hijackers was deemed fit to perform
this most elementary exercise by himself.
In fact, heres what
their flight instructors had to say about the
aptitude of these budding aviators:
Mohammed
Atta: "His attention span was zero."
Khalid Al-Mihdhar: "We didn't kick him out,
but he didn't live up to our standards."
Marwan Al-Shehhi: He was dropped because of
his limited English and incompetence at the
controls.
Salem Al-Hazmi: "We advised him to quit
after two lessons.
Hani Hanjour: "His English was horrible, and
his mechanical skills were even worse. It was
like he had hardly even ever driven a car.
Im still to this day amazed that he could
have flown into the Pentagon. He could not fly at
all.
Now
lets take a look at American Airlines
Flight 77. Passenger/hijacker Hani Hanjour rises
from his seat midway through the flight,
viciously fights his way into the cockpit with
his cohorts, overpowers Captain Charles F.
Burlingame and First Officer David Charlebois,
and somehow manages to toss them out of the
cockpit (for starters, very difficult to achieve
in a cramped environment without inadvertently
impacting the yoke and thereby disengaging the
autopilot). One would correctly presume that this
would present considerable difficulties to a
little guy with a box cutterBurlingame was
a tough, burly, ex-Vietnam F4 fighter jock who
had flown over 100 combat missions. Every pilot
who knows him says that rather than politely hand
over the controls, Burlingame would have
instantly rolled the plane on its back so that
Hanjour would have broken his neck when he hit
the floor. But lets ignore this almost
natural reaction expected of a fighter pilot and
proceed with this charade.
Nonetheless, imagine that Hanjour overpowers the
flight deck crew, removes them from the cockpit
and takes his position in the captains
seat. Although weather reports state this was not
the case, lets say Hanjour was lucky enough
to experience a perfect CAVU day (Ceiling And
Visibility Unlimited). If Hanjour looked straight
ahead through the windshield, or off to his left
at the ground, at best he would see, 35,000 feet
-- 7 miles -- below him, a murky
brownish-grey-green landscape, virtually devoid
of surface detail, while the aircraft he was now
piloting was moving along, almost imperceptibly
and in eerie silence, at around 500 MPH (about
750 feet every second).
In a real-world scenario (and given the reported
weather conditions that day), he would likely
have seen clouds below him completely obscuring
the ground he was traversing. With this kind of
situational non-awareness, Hanjour
might as well have been flying over Argentina,
Russia, or Japanhe wouldnt have had a
clue as to where, precisely, he was.
After a few seconds (at 750 ft/sec), Hanjour
would figure out theres little point in
looking outsidetheres nothing there
to give him any real visual cues. For a man who
had previously wrestled with little Cessnas,
following freeways and railroad tracks (and
always in the comforting presence of an
instructor), this would have been a strange,
eerily unsettling environment indeed.
Seeing nothing outside, Mr. Hanjour would be
forced to divert his attention to his instrument
panel, where hed be faced with a
bewildering array of instruments. He would then
have to very quickly interpret his heading,
ground track, altitude, and airspeed information
on the displays before he could even figure out
where in the world he was, much less where the
Pentagon was located in relation to his position!
After
all, before he can crash
into a target, he has to first find
the target.
It is very difficult to explain this scenario, of
an utter lack of ground reference, to non-pilots;
but let it suffice to say that for these
incompetent hijacker non-pilots to even consider
grappling with such a daunting task would have
been utterly overwhelming. They wouldnt
have known where to begin.
But, for the sake of discussion lets
stretch things beyond all plausibility and say
that Hanjourwhose flight instructor claimed
couldnt fly at allsomehow
managed to figure out their exact position on the
American landscape in relation to their intended
target as they traversed the earth at a speed
five times faster than they had ever flown by
themselves before.
Once
he had determined exactly where he was, he would
need to figure out where the Pentagon was located
in relation to his rapidly-changing position. He
would then need to plot a course to his target
(one he cannot see with his eyesremember,
our ace is flying solely on instruments).
In
order to perform this bit of electronic
navigation, he would have to be very familiar
with IFR procedures. None of these chaps even
knew what a navigational chart looked like, much
less how to how to plug information into flight
management computers (FMC) and engage LNAV
(lateral navigation automated mode). If one is to
believe the official story, all of this was
supposedly accomplished by raw student pilots
while flying blind at 500 MPH over unfamiliar
(and practically invisible) terrain, using
complex methodologies and employing sophisticated
instruments.
To get around this little problem, the official
storyline suggests these men manually flew their
aircraft to their respective targets (NB: This
still wouldnt relieve them of the burden of
navigation). But lets assume Hanjour
disengaged the autopilot and auto-throttle and
hand-flew the aircraft to its intendedand
invisibletarget on instruments alone until
such time as he could get a visual fix. This
would have necessitated him to fly back across
West Virginia and Virginia to Washington DC.
(This portion of Flight 77s flight path
cannot be corroborated by any radar evidence that
exists, because the aircraft is said to have
suddenly disappeared from radar screens over
Ohio, but lets not mull over that little
point.)
According to FAA radar controllers, Flight
77 then suddenly pops up over Washington DC
and executes an incredibly precise diving
turn at a rate of 360 degrees/minute while
descending at 3,500 ft/min,
at the end of which Hanjour allegedly
levels out at ground level. Oh, I almost forgot:
He also had the presence of mind to turn off the
transponder in the middle of this incredibly
difficult maneuver (one of his instructors later
commented the hapless fellow couldnt have
spelt the word if his life depended on it).
The
maneuver was in fact so precisely executed that
the air traffic controllers at Dulles refused to
believe the blip on their screen was a commercial
airliner. Danielle OBrian, one of the air
traffic controllers at Dulles who reported seeing
the aircraft at 9:25 said, The speed, the
maneuverability, the way that he turned, we all
thought in the radar room, all of us experienced
air traffic controllers, that that was a military
plane.
And
then, all of a sudden we have magic. Voila!
Hanjour finds the Pentagon sitting squarely in
his sights right before him.
But even that wasnt good enough for this
fanatic Muslim kamikaze pilot. You see, he found
that his missile was heading towards
one of the most densely populated wings of the
Pentagonand one occupied by top military
brass, including the Secretary of Defense,
Rumsfeld. Presumably in order to save these
mens lives, he then executes a sweeping
270-degree turn and approaches the building from
the opposite direction and aligns himself with
the only wing of the Pentagon that was virtually
uninhabited due to extensive renovations that
were underway (there were some 120 civilians
construction workers in that wing who were
killed; their work included blast-proofing the
outside wall of that wing).
I
shant get into the aerodynamic
impossibility of flying a
large commercial jetliner 20 feet above the
ground at over 400 MPH. A discussion on ground
effect energy, tip vortex compression, downwash
sheet reaction, wake turbulence, and jetblast
effects are beyond the scope of this article (the
100,000-lb jetblast alone would have blown whole
semi-trucks off the roads.)
Let
it suffice to say that it is physically
impossible to fly a
200,000-lb airliner 20 feet above the ground
at 400 MPH.
The
author, a pilot and aeronautical engineer,
challenges any
pilot in the world to do so in any
large high-speed aircraft
that has a relatively low wing-loading (such as a
commercial jet). I.e., to fly the craft at 400
MPH, 20 feet above ground in a flat trajectory
over a distance of one mile.
Why
the stipulation of 20 feet and a mile? There were
several street light poles located up to a mile
away from the Pentagon that were snapped-off by
the incoming aircraft; this suggests a low, flat
trajectory during the final pre-impact approach
phase. Further, it is known that the craft
impacted the Pentagons ground floor. For
purposes of reference: If a 757 were placed on
the ground on its engine nacelles
(I.e., gear retracted as in flight profile), its
nose would be almost 20 above the ground! Ergo,
for the aircraft to impact the ground
floor of the Pentagon, Hanjour would have needed
to have flown in with the engines buried 10-feet
deep in the Pentagon lawn. Some pilot.
At
any rate, why is such ultra-low-level flight
aerodynamically impossible? Because the reactive
force of the hugely powerful downwash sheet,
coupled with the compressibility effects of the
tip vortices, simply will not allow the aircraft
to get any lower to the ground than approximately
one half the distance of its wingspanuntil
speed is drastically reduced,
which, of course, is what happens during normal
landings.
In
other words, if this were a Boeing 757 as
reported, the plane could not have been flown
below about 60 feet above ground at 400 MPH.
(Such a maneuver is entirely within the
performance envelope of aircraft with high
wing-loadings, such as ground-attack fighters,
the B1-B bomber, and Cruise missilesand the
Global Hawk.)
The very same navigational challenges mentioned
above would have faced the pilots who flew the
two 767s into the Twin Towers, in that they, too,
would have had to have first
found their targets. Again,
these chaps, too, miraculously found themselves
spot on course. And again, their final
approach maneuvers at over 500 MPH are
simply far too incredible to have been executed
by pilots who could not solo basic training
aircraft.
Conclusion
The writers of the official storyline expect us
to believe, that once the flight deck crews had
been overpowered, and the hijackers took
control of the various aircraft, their
intended targets suddenly popped up in their
windshields as they would have in some arcade
game, and all that these fellows would have had
to do was simply aim their airplanes at the
buildings and fly into them. Most people who have
been exposed only to the official storyline have
never been on the flight deck of an airliner at
altitude and looked at the outside world; if they
had, theyd realize the absurdity of this
kind of reasoning.
In reality, a clueless non-pilot would encounter
almost insurmountable difficulties in attempting
to navigate and fly a 200,000-lb airliner into a
building located on the ground, 7 miles below and
hundreds of miles away and out of sight, and in
an unknown direction, while flying at over 500
MPH and all this under extremely stressful
circumstances.