Home' Australian Aviation Magazine : January February 2010 Contents 59
JANUARY/FEBRUARY 2010 AUSTRALIAN AVIATION
less than 300m northeast of the end of the
strip. e pilot, the only occupant, suf-
fered serious injuries and the aircraft was
destroyed. e turn, progressively steepened
to avoid the intervening spur, had begun
at too low an airspeed, with a stall the
result. Experienced PNG pilots agreed that
a missed approach should not have been
attempted. A crash landing on the airstrip
was the only alternative.
A rare exception to this general rule was
achieved by a Cessna 206 pilot who per-
formed an 'instant' stall turn into the ravine
beside the mountain strip at Aseki, inland
from the Huon Gulf. e pilot got away
with this extremely risky manoeuvre, avert-
ing a collision with a Piper Aztec on the
ground, only because the C206, flying into
the strip to pick up bags of coffee beans,
had no load on board. Other aircraft that
attempted similar "go arounds" at Aseki on
two later occasions both crashed.
e precipitous jungle clad ranges form-
ing the "spine" of the interior of Papua New
Guinea, include mountain peaks rising to
almost 15,000ft, while many of the passes
and gaps in the ranges have an elevation of
8000ft or higher. Density altitude consid-
erations thus become a serious problem.
And often to reach remote airstrips it is
necessary to fly up narrow valleys below
the cloud base. e problem then becomes
one of recognising the right entrance to
the valley amongst the mountains. Some of
the valleys are "blind", becoming progres-
sively too narrow for an aircraft to turn and
fly out again if the pilot has mistaken the
entrance. A catastrophic accident is often
inevitable if the pilot has misidentified the
Because of the elevation and nature of
the terrain, instrument flight rules are out
of the question for all but high flying air-
craft. In any case, PNG's NDBs are often
affected by atmospheric interference. Accu-
rate visual navigation is thus highly critical.
A thorough knowledge of the country and
its weather is essential, as well as high ma-
nipulative skills, and a detailed knowledge
of the aircraft's handling characteristics.
A former RAAF flying instructor tells of
an incident during a training exercise in the
PNG Highlands in a HS.748.
"We took off from Madang after lunch,
planning to visit Mount Hagen, Minj and
Banz along the Waghi Valley, surrounded
by mountain ranges of up to 14,000ft. e
airstrip lengths were just adequate for our
planned weights at the high density alti-
tude takeoffs and landings involved.
"Climbing to 15,000ft, we headed for
Minj, some 100 miles southwest over rugged
country. As we passed over the Ramu Valley,
heavy cloud was covering the mountain gaps
adjacent to the 14,800ft Mount Wilhelm.
PNG weather is characterised by massive
cloud build-ups over the ranges by early
afternoon, but the HS.748 has good altitude
capability and I knew that, providing we
stayed VMC, we could climb out of trouble.
"With only five minutes to our ETA
for Minj, reports told us heavy rain was
reducing visibility around Mount Hagen to
the northwest and Goroka to the southeast.
One report was of lowering visibility in the
Waghi Valley. We dropped the landing gear,
and lost height in a series of turns to keep
clear of stratus and towering cumulus, but
the sight of rain clouds drifting across the
base of the mountains leading down to the
valley made me uneasy. Cloud around Minj
was low and black, and we had to circle at
1000ft above the valley to get a pinpoint.
Neither Minj, or nearby Banz, were visible
in the rain.
"Once under the main cloud base, we
could see dark veils of rain cloud blocking
both ends of the Wahgi Valley, so I felt the
time had come to get back to Madang --
and fast! e cloud break we had descended
through had already filled over, and so
close to the mountains, it would have been
suicidal to climb in IMC. We were relieved
to spot a TAA Twin Otter emerging from
the rain and heading down the valley for
Goroka, and I turned to follow him.
"As we flew past the tiny airstrip of
Chimbu on a ridge overlooking the
Chimbu River, I made a mental note that
as a last resort I would plant the HS.748
squarely on the threshold, and work out
how to get out of the place once safely
ensconced. Meanwhile the Twin Otter had
SHORT FIELDS About to land at Pindiu's 610m/2000ft strip. (Brad Weir)
TAPINI The infamous variable slope of the Tapini strip is evident in this picture. The maximum gradient is
11.6 per cent and full power has to be applied immediately on landing to reach the parking area at the top of
the slope. (Peter Lovell)
A highly experienced PNG pilot's general advice
for operations there is "only fly where you can see."
Links Archive December 09 March 2010 Navigation Previous Page Next Page