TALLRITE BLOG |
Published in the 21 Dec 2004-
5 Jan 2005 issue of![]() |
Transcripted from the original subscription-only article accessible here |
MISSILE
ATTACK : GREAT ESCAPE The
crew who survived last years Airbus A300 freighter shootdown at Baghdad By David Learmont, London |
The Airbus
A300 is on final approach to Baghdads runway 33L,
flying controls totally disabled, with the burning outer left wing ipped
apart by a missile. As he
watches Capt Eric Gennotte manipulate the only remaining control input
-the throttles -first officer Steeve Michielsen mentally rates his
survival chances at 10-20% because he knows how much can go wrong in
the remaining few seconds. At about 400 feet (120 m) on a precarious, but relatively stable long straight-in approach, crosswind and surface heat turbulence suddenly make the stricken twin-jet unsteady, lifting the left wing and turning it toward the airport buildings. Gennotte tries to lift the right wing by varying the reative thrust of the two engines while Michielsen and flight engineer Mario Rofail monitor his struggle with the turbulence. Having battled as a co-ordinated team for 25 minutes since the missile attack, they are now leaving throttle control to the captain. The crew know what happened in July 1989 to a United Airlines McDonnell Douglas DC-10, which suffered catastrophic hydraulic failure after an engine disintegrated. Despite a heroic effort from the crew, in the last 100 ft of an emergency approach to Sioux Gateway airport, Iowa, the DC-10s nose and right wing dropped, the wingtip hit the ground and the huge airliner flipped before sliding to a halt in a storm of flames. Of the 296 people on board, 111 were killed. also face attempting to land an aircraft using only throttle control. That morning European Air Transport/ DHL A300B4 arrives in
Baghdad from Bahrain earlier. Locally
the weather and visibility are good and, on the ground, work to turn the
aircraft around begins quickly. The
cargo is unloaded and reloaded with about 7t of general avargo for the
trip back to Bahrain. At
take-off the aircrafts weight is only 105t, the maximum allowable
take-off weight is 165.9t. The crew taxi the A300 out to runway 15L for take-off, with Gennotte the
pilot flying. Because of the
light weight and the need for a maximum-angle climb from lift-off to gain
as much height as possible before reaching the airfield boundary, the
selected configuration is slats only - no flap - and full power.
Climb is to be straight
ahead to waypoint LOVEK. Rocked by explosion As the aircraft powers up through 8,000 ft an explosion rocks the
aircraft, a cacophony of aural warnings erupts and lights flash for
multiple systems. Rofail
tells the pilots almost immediately that all pressure is lost from the
Green and Yellow hydraulic systems, and 20 seconds later the Blue system
pressure also begins to drop and soon hits zero.
The primary flight control surfaces and spoilers go limp as their
actuators drain, trailing in the slipstream.
The horizontal stabiliser, which controls the aircrafts pitch,
is frozen at the trim position for 215 kt (400 km/h) with climb thrust set
- the angle it is at when drained of hydraulic power.
Flaps and slats are
unavailable. The crew know something has hit their aircraft. Michielsen
believes a missile has hit the rudder because he sees the yaw damper
switches trip out, but Rofail does not rule out a collision with an unseen
aircraft. While the cause is
unknown, the effects are dramatic. Michielsen
makes an emergency call to Baghdad approach, then Rofail takes over
communication with air traffic control because the pilots are preoccupied
with fighting the aircrafts apparently out-of-control state.
From his seat behind the pilots, Rofail, like all flight engineers, can see the big picture: systems panels;
primary flight instruments;
the real horizon as it rocks and pitches
- often disappearing from
sight - and he joins the
pilots struggle to understand what - if any - control they have left. He says: The aircraft was like a piece of paper in the
air. We went through a series
of steep banks and dives -you
could not leave your
seat. The aircrafts
roller-coaster manoeuvring
throws the crew against their harnesses.
All the crew are taking part in everything, doing whatever they see needs
to be done. The rulebook
has gone out the window, explains Rofail.
Situations like this are unique every time. You cannot train for them.
You cannot write a checklist for them. The crew have since
listened to the cockpit voice recorder tape and say they are quite surprised at how calm they all sound. Rofail says: All you can do is apply common sense and stay
calm. We were the right
combination of crew. What most concerns the crew is lack of control over
airspeed. Initially,
Michielsen and Gennotte try to use the control yokes and rudder pedals,
but quickly accept they are ineffective.
Although the crew know theoretically they could control the
aircraft with the throttles alone, it takes them about 10 minutes to learn
how to keep the air-craft at an acceptable attitude.
During the learning process airspeed lurches wildly between 180 and
300 kt. Because, like most big jets, the A300s engines are slung below the
wings, an increase in thrust causes the nose to pitch up, conversely a
thrust decrease causes a pitch-down moment.
The problem for Gennotte and his crew is that, on applying power,
the increase in nose-up attitude tends to dampen an increase in speed.
Then because they cannot apply any direct pitch control or change
the pitch trim, when any power-induced increase in speed exceeds the
trimmed indicated airspeed (IAS) of 215 kt there is a gradual further
pitch-up followed by a loss of speed as the nose-up attitude steepens.
Thrust reduction may provide an instant nose-down pitching moment,
but then the descending flightpath tends to make the speed increase, and
as airspeed rises above the 215 kt trim speed, the nose gradually pitches
further up. The result is a
counter-intuitive secondary effect to every power change.
Selection of asymmetric thrust provides roll control, but altering
heading or picking up a wing by this method is
painfully slow compared with the almost instant primary effect a power
change has in pitch. Violent pitchinq By the time they have carried out the first gradual, violently pitching
and rolling left turn toward the airfield (see diagram) they are at about
4,000 ft and they have the airfield in sight.
The captain calls for the gear to be lowered using the emergency
gravity system, even though air-speed is slightly higher than the 270 kt
limit for deployment. While Rofail leaves his seat to do this, Michielsen has to
push his own seat as far forward as it can go, making him temporarily
almost useless in assisting Gennotte.
To the crews relief, the gear locks down at the first
attempt. Its deployment makes
the aircraft noticeably more stable, potentially providing enough control
over air-speed and attitude to make a viable attempt at landing.
It provides the pilots with an increase in overall drag and a
slight pitch-down moment against which to use the pitch-up effect of an
increase in power. (Airbus
has since told the crew that if they had attempted a gear-up approach,
they almost certainly would not have succeeded.)
At present - although the crew does not know it - the
leading edge of the wing is complete along almost its entire length, but
the fire is gradually destroying the outer wing, creeping forward from the
trailing edge. At some stage
before they land the rear wing spar separates and the remaining structure
is held together only by the forward spar.
It is only a matter of time before that also fails.
Meanwhile, the asymmetry in thrust needed to compensate for the
difference in lift and drag between the damaged and undamaged wings is
increasing. Michielson suggested to the captain that they position for
a long, straight final approach to runway 33R starting about 37 km (20
nm) out and assists the captain with navigation by monitoring the VOR/DME
readouts. They lose
visual contact with the airport as they turn away to position the aircraft
on long final approach, but ATC has no radar to provide the crew with
vectors. Rofail is meanwhile wrestling with another task vital to keeping the
aircraft airborne. Although
the missile has not damaged
the engines, if a fuel flow interruption causes failure of either they
will be dead within a minute. When
it hit, the missile destroyed the outer left wing tank 1A - so
comprehensively that the fuel just fell out of it.
There was no explosive ignition of fuel because the tank was full,
so there was no fuel-air vapour inside if there had been, the wing would have been blown off the aircraft.
Wrestling with fuel But Rofails problem is more complex.
When the missile hit, the engines were both feeding directly from
their respective inboard wing tanks (tanks 1 and 2) and he is keeping it
that way. But as well as
destroying tank 1A, the missile also pierced tank 1, so it is losing fuel. Rofail does not want to open the crossfeed valve to transfer
fuel from right wing to left for fear of bleeding away all the fuel; and
neither does he want - unless there is no alternative - to break the
golden rule that separate engines should be fed from separate sources. So he does not open the crossfeed, but monitors the fuel
quantity and feed to both engines and selects ignition on both permanently
on. Gennotte, with Michielsens guidance, flies the aircraft
outbound and crosses the extended centreline for 33R from right to left,
setting up for a teardrop turn to the right onto final approach. When the aircraft begins to turn toward the airport, it is
about 37 km out and at about 3,000 ft.
Gennotte stabilises the aircraft at that height, heading inbound in
approximately level flight,. Michielsen
monitors the DME to determine when they are approaching a standard 3°
descent point toward the runway. The
visibility is excellent, but Gennotte realises the aircraft is drifting to
the right. He calls
Michielsen for a wind vector reading and is told it is 290° at about 20
kt. The crew find they are
lined up for 33L and, despite it being shorter than 33R, they decide to
use it. Runway 33L is further
from obstacles and they cannot guarantee their touchdown point or heading.
Early in the long final approach, Michielsen points out
that, counter-intuitively, Gennotte must not retard the throttles before
touchdown. It was that move
which, after brilliant handling beforehand, led the Sioux City crew to a
crash-landing, as the nose and one wing dropped just before the aircraft
landed. The crews co-operation is impeccable, Gennotte is not
merely an able pilot, he is also no autocrat and makes good use of all
information fed to him by his crew. Rofail, the senior crew member by far in terms of age and experience,
carries out the final approach checks in his head without disturbing the
pilots. He depressurises the
aircraft so the doors can be opened on landing.
The gear is down and there are no high lift devices to deploy.
Gennotte does not call for the landing checklist: he and Michielsen
are busy trying to direct the aircraft and manage its stable descent
toward 33L. Rofail knows the
spoilers will not deploy on touch-down and, since their airspeed will
still be about 210-215 kt, he knows the aircraft will want to keep flying
when it hits the surface, so he readies himself to slam on full reverse
thrust. Final approach Gennotte handles the approach, with call-outs from
Michielsen to guide the descent profile, and the aircraft is almost
stabilised when it passes 1,000 ft. At
this point, Michielsen still gives himself only a 20% chance of survival,
but that percentage is climbing as they close with the runway.
Then, at 400 ft, surface-generated turbulence starts to upset the
aircraft and the left wing tips upward, turning them toward the buildings
between the two runways. Gennotte
manipulates the throttles relative to each other to control the
aircrafts roll, but its response is agonisingly slow.
As landing becomes imminent the aircraft is going to make it to a
runway touchdown, but with its heading 8° to the left of centreline.
In an attempt to line up, the right throttle is retarded slightly,
but there is no attempt to close them both, as would be instinctive.
The right wing drops and they touch down, right wheel first.
Both pilots revert to instinct and are pumping the rudder pedals, stick
and control wheel -
uselessly. Rofail
grabs the throttles and slams them fully into reverse.
The aircraft has departed the runway into the sand to its lefthand
side, the wheels and thrust kicking up a plume of thick dust, but the sand
is helping to slow them down. The
aircraft is suffering jolts registering 7.5g vertical acceleration on the
uneven ground and several tyres have failed.
They career through the razorwire fence to the left of 33L and
carry it with them before the aircraft comes to a halt.
Into a minefield Rofail already has both front doors open and the crew exit down the slide
on the right. They run from
the aircraft, believing the fuel tanks could explode at any moment, but
are stopped by soldiers s Records
show the aircraft touched down with a nose-up attitude and a descent rate of about 10 ft/s (3 m/s) - a normal touch-down rate, with a 10° right
bank. That evening the crew were back in their hotel bar in
Bahrain when the news item about what they had just been through came onto
CNN. Michielsen says: In
the morning we were just freighter pilots.
That evening a Lockheed C-S test pilot from Andrews Air Force Base
wanted to shake our hands. .
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