The pilot of a Saab Aircraft AB SF-340B (Saab), on final to
runway 16R at Sydney airport, was instructed by the aerodrome
controller (ADC) to turn right heading 240 degrees M due to an
unidentified aircraft in the control zone. The unidentified
aircraft was observed to turn north and pass the Saab with 2 NM
lateral and 400 ft vertical displacement. The required separation
standard was either 3 NM laterally or 1,000 ft vertically. The
unknown aircraft was subsequently identified as a Piper Aircraft
Corporation PA-23-250 (Aztec). The Aztec pilot had entered the
Sydney control zone without a clearance, resulting in an
infringement of separation standards.
The Aztec pilot had intended to conduct a visual flight rules
(VFR) flight from Bankstown, located 9.5 NM west of Sydney, to
Grafton. He had recently purchased the Aztec and this was the first
significant trip in that aircraft. The pilot had previously flown a
Beech Baron and had completed a flight check on the Aztec.
Flights under the VFR conducted below 10,000 ft required a pilot
to operate in the following meteorological conditions:
- flight visibility greater than 5,000 m;
- clear of cloud when in a general aviation control zone;
and
- 1,500 m horizontally and 1,000 ft vertically from cloud while
en route.
The Bankstown terminal area forecast, issued at 0433, covering
the period from 0600 to 1900 Eastern Summer Time forecast a flight
visibility of 5,000 m in smoke and a few (1 to 2 OKTAS) clouds at
3,000 ft. The forecast indicated that visibility was expected to
increase to greater than 10 km by mid afternoon. The actual
meteorological conditions reported at Bankstown during the morning
of the occurrence were:
- 0900: westerly wind at 9 kts with visibility of 8,000 m, no
cloud below 12,500 ft and temperature of 18 degrees C;
- 0900 report was amended at 0919: westerly wind at 9 kts with
visibility of 3,000 m in smoke, no cloud below 12,500 ft with the
sky obscured and temperature of 18 degrees C;
- 0930: south-westerly wind at 6 kts with visibility of 6,000 m,
no cloud below 12,500 ft and temperature of 18 degrees C;
- 1000: wind was calm with visibility of 7,000 m no cloud below
12,500 ft and temperature of 19 degrees C; and
- 1030: north-westerly wind of 4 kts with visibility of 7,000 m,
no cloud below 12,500 ft and temperature of 20 degrees C.
The actual reported weather conditions at Sydney during the
morning were:
- 0900: southerly wind at 7 kts with visibility of 4,000 m in
smoke and scattered (3 to 4 OKTAS) clouds at 1,600 ft and
temperature of 18 degrees C;
- 0920: southerly wind at 7 kts with visibility of 6,000 m in
smoke with a few (1 to 2 OKTAS) clouds at 4,500 ft and temperature
of 18 degrees C;
- 0930: southerly wind at 7 kts with visibility of 6,000 m in
smoke with a few (1 to 2 OKTAS) clouds at 4,500 ft and temperature
of 18 degrees C; and
- 0955: south-easterly wind at 7 kts with visibility of 7,000 m
in smoke with a few (1 to 2 OKTAS) clouds at 4,500 ft and
temperature of 19 degrees C.
Weather conditions at the time were visual meteorological
conditions that had been affected by bushfires in the Sydney
basin.
The pilot had delayed departing from Bankstown in anticipation
of the weather conditions improving and subsequently departed at
about 0945. Immediately after takeoff, while the pilot was still
monitoring the Bankstown ADC frequency, the right engine commenced
to `run rough'. The pilot reduced power on that engine and
attempted to identify the cause of the problem. The pilot decided
to return to Bankstown as the situation could not be rectified and
the aircraft was vibrating. As he manoeuvred to return, the flight
visibility was such that the pilot could not see Bankstown airport.
He was aware of the aircraft's proximity to the Sydney control zone
and reported that he was about to call Sydney air traffic control
for a clearance when he was advised by the departure south
controller that the Aztec had infringed the control zone.
The Aztec pilot had selected code 1200, the nominated code for a
VFR flight operating in non-controlled airspace (and not
participating in a radar information service) and was operating the
aircraft's transponder.
The Sydney Aerodrome and Director West controllers saw, on the
air traffic control radar, that the Aztec was in the control zone,
northwest of Canterbury racecourse, and likely to conflict with
aircraft on final to runway 16R. The ADC instructed the pilot of
the Saab to turn right to avoid the Aztec. The pilot of another
aircraft was similarly instructed.
Before the pilot could return to Bankstown, the right engine on
the Aztec started to operate normally. The pilot decided to
continue the flight and tracked to the north to vacate the control
zone and to join the VFR lane. The flight continued uneventfully to
Coffs Harbour where the pilot refuelled the aircraft. Subsequently,
after take-off from Coffs Harbour, at approximately 300 ft, the
right engine surged and the pilot landed the aircraft on the
remaining runway. The pilot taxied the aircraft to a hangar for
maintenance action and on reaching the hangar the left engine
stopped. Inspection by a licensed aircraft maintenance engineer
(LAME) found that the cooling flaps on both engines were
inoperative and had caused the engines to overheat. The LAME
re-rigged the cowl flaps for maximum cooling and a subsequent
engine ground run confirmed normal operation.
