Global Aviator December/January 2017/18 / Vol. 9 / No. 12 31
He applied maximum thrust to
all four engines thereby overriding
the other controls. Although the
airplane began to climb it was still too
low resulting in it hitting the runway
lights at the end of the runway. Only
after some 148m beyond the end of
the runway did the aircraft take-off.
Continuing to climb with difficulty,
the landing gear also hit a 1.8m high
localiser antenna and damaging it.
As if this wasn’t chaotic enough,
at around 500m beyond the runway,
the airplane barely missed the
2.24m tall airport perimeter fence.
After clearing the perimeter safely
it was also reported that the plane
miraculously missed a small brick
building by only a mere 50cm.
During this whole duration, the
tail scraped across the grass at the end
of the runway twice more before the
plane finally managed to climb and
of the runway during take-off.
This particular airplane did not
have a tail skid to protect the fuselage
from any damage in the event of a
tail strike, but it did have built-in tail
strike protection by manner of standard
operating procedures, reference
information and also the plane’s flight
control system. This protection is built
into the plane’s fly-by-wire flight-
control computer. The technology
continuously surveys the airplane’s
key performance data and sensorinput and will detect the location of the
fuselage relative to the runway, as well
as the closure rate at which the fuselage
approaches the runway during the
take off process. If an impending tail
strike is sensed by the system, it will
automatically command the airplane’s
elevators moveable – meaning that
the hydraulically powered control
surfaces located on the tail's horizontal
surface that cause an airplane's body to
rotate about its pitch axis, will generate
nose down pitching movements,
in order to avoid a tail strike.
The flight control system also
provides a certain amount of protection;
however it is not “hard” protection.
When an airplane is on the ground,
the pitch control will be in ground
mode. In order to prevent a tail strike
in ground mode, the airplane’s flight
control computer will monitor the
pitch rate and then estimate the tail
clearance margin. If the system then
determines that a tail strike is possible
the flight control computer will reduce
the amount of elevator deflection
for the given side stick position, in
order to reduce the pitch rate.
Despite this protection the rear
pressure bulkhead and the underlying
structure were still severely damaged
when the tail struck the runway.
There was extensive damage to the
hull as a result of it being scraped
along the runway, even stripping a
large surface of its external sheet. The
tail skin also has severe abrasions
and during the tail strike several
access panels were ripped off.
It was also reported that due to
the emergency landing there was
additional damage to the landing gear.Incorrect
take-off weight
Only after getting the airplane to a
safe height and while circling over the
Port Phillip Bay, did the pilots make
a startling discovery.... They had
accidentally keyed in the incorrect
weight data into the system.
Before the take-off the fuelled up
jet weighed 362 tonnes, but for some
reason they keyed in that it weighed
262 tonnes, a whole 100 tonnes less.
This resulted in too little engine power,
making it almost impossible to safely
take off. But how could such a mistake
happen? Because when on the flight
deck, both the captain and first officer
load information into the computer andreach a safe height. With their aircraft’s
fuel tanks still full, the pilots decided to
circle over Port Phillips Bay in order to
dump most of the fuel before returning
to the airport where they were given
clearance for an emergency landing
following a report of smoke in the cabin.
The plane landed safely
with no injuries.The damage
The following morning in daylight,
investigators could see gear tracks
in the soft ground past the runway
and therefore could establish that
the plane was in fact still on the
ground when it passed the endAbove: The damage to the aircraft due to
the tail strike.A6-ERG, the aircraft
involved in the accident
Pic: Steve Brimley