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 I?ve heard this ludicrous explanation bandied about, ad
nauseam, on the Internet and the TV networks?invariably 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-offs?even landings, to a certain
degree?are relatively ?easy?, because the pilot has visual
reference cues that exist ?outside? the cockpit.
But once you?ve 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 wouldn?t 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 that?s all you have!
The
corollary to Rule #1: If you can?t read the instruments in a quick,
smooth, disciplined, scan, you?re 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 student?s 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, here?s 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.
I?m still to this day amazed that he could have flown into the
Pentagon. He could not fly at all.?
Now
let?s 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
cutter?Burlingame 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 let?s 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
captain?s seat. Although weather reports state this was not the
case, let?s 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 Japan?he wouldn?t have had a clue as to
where, precisely, he was.
After a few seconds (at 750 ft/sec), Hanjour would figure out
there?s little point in looking outside?there?s 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 he?d 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 wouldn?t have known where to begin.
But, for the sake of discussion let?s stretch things beyond all
plausibility and say that Hanjour?whose flight instructor claimed
?couldn?t fly at all??somehow 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 eyes?remember, 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 wouldn?t relieve them of the burden of navigation).
But let?s assume Hanjour disengaged the autopilot and auto-throttle
and hand-flew the aircraft to its intended?and invisible?target 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 77?s 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 let?s 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 couldn?t 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 O?Brian, 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 wasn?t 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 Pentagon?and one
occupied by top military brass, including the Secretary of Defense,
Rumsfeld. Presumably in order to save these men?s 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 shan?t 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 Pentagon?s 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 wingspan?until 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 missiles?and 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, they?d 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.