74 AUSTRALIAN AVIATION
Art meets science
Textron demonstrator pilot Karen
DeMauro is already at the base of the
air stair entrance when I arrive at the
aircraft. However, before we climb
aboard there is a great deal to see on
the outside that speaks volumes about
the aeroplane.
As we commence our walkaround
Karen points out the nacelle lockers,
which give way to fuel tanks on the ER
version. With a 136kg capacity each
side, the lockers are long and suitable
for skis or golf clubs and one would
suspect that the lockers generally
bulk out before they reach their
weight limit.
Along the trailing edge are the
Fowler flaps with an initial extension
speed of 202kt and a full extension
speed of 158kt and the system has
automatic flap asymmetry protection.
Accordingly, if there is a difference
in the degree of flap extension
detected between the two wings, the
system stops extension to prevent
any unwanted roll moment that may
occur. The combination of flap speeds
and a landing gear extension speed
of 182kt make it easy to appreciate
that drag is very manageable and the
aircraft is relatively straightforward
to slow down when entering the
terminal area.
The more demanding Part 23
certification requirements soon
become apparent through the level
of redundancy on the aircraft. Each
landing gear has a pair of tyres, yet
it can clear the runway and taxi if
one tyre should deflate. Each flight
control surface has dual pushrods,
even though a single pushrod to the
elevator, aileron or rudder can still
actuate the control surface if needed.
Each engine has a 300-amp electrical
generator capable of supporting the
entire system without shedding its
load should a generator fail, and a dual
bleed air system offers the same degree
of redundancy for pressurisation and
anti-icing.
The upturned, composite winglets
are marked with the 350i name tag
and tipped with static-wicks. In
offering an effective increase in the
wingspan of one metre, the winglets
increase fuel efficiency while Karen
emphasises that their major benefit
lies in reducing the time taken to
reach cruising altitude.
Within the wings are held a total of
1,635kg (3,600lb), distributed through
pairs of main and auxiliary tanks,
although the pilot’s interface with the
system is that it is simply left wing
and right wing, with no management
required between the various tanks.
As the aircraft is approved for flight
into known icing, the leading edges
of the wing, like the tailplane, host
pneumatic de-icing boots. There is
also icing protection on the four-
bladed, 2.67m Hartzell propellers and
while not a major issue in Australia,
there is ice protection on the brakes.
What can be significant in Australia
is the use of the ice vanes located in
the engine intakes, but not as you
maythink.
Designed to protect the engine
from ice ingestion, the vanes deflect
the ice down and out of the engine
before it can enter the engine.
Interestingly, the vanes can also
be used to guard against foreign
object damage from ingestion on
runways and taxiways in exactly the
same way.Dominating the wings of the King
Air are the equally revered Pratt &
Whitney PT6 engines, which have
a heritage parallel to the King Air’s.
The 350i is fitted with the PT6A-60A
which is flat-rated to 1,050shp and
features a time between overhauls
(TBO) of 3,600 hours. The engine is
even certified to operate for 150 hours
between overhauls using AVGAS
as a measure to avoid an aircraft
being stranded in the absence of
turbine fuel. That being said, AVGAS
is becoming the rarer commodity
these days.
The engine is also very well thought
out with its accessories and hot section
(1,800 hours HSI) located at the
rear of the engine. Easily accessible,
this reduces maintenance downtime
and costs.
Each engine is also equipped with‘The PT6
engines have
a heritage
parallel to the
King Air’s.’
The 350i is powered by a pair of
PT6A-60As.TEXTRON AVIATIONAIR TEST Beechcraft King Air 350i