The pilot of a Navajo Chieftain was intending to take off on
runway 34L from the intersection of taxiway B 10 at Sydney, at
night. A Saab 340 had been cleared to depart prior to the
Chieftain. Another Saab 340 was on final approach to land on the
same runway.
Once the departing Saab had been cleared to take off, the
arriving Saab was cleared to land. The pilot of the Chieftain was
then given a conditional clearance to line up on the runway, behind
the landing aircraft. In the same transmission, the pilot was also
given instructions regarding the direction of turn and heading to
adopt after becoming airborne.
The pilot of the Chieftain heard the line-up clearance and the
after take-off instructions, but did not hear the condition that he
should line up behind the landing aircraft. The pilot read back the
instructions he had heard to the controller, however, the
controller did not notice that the condition on the line-up
clearance was not read back to him. The Chieftain then commenced to
line up on the runway. The pilot saw an aircraft on final approach
to runway 34L as he lined up, and was expecting an immediate
take-off clearance from the controller. The crew of the Saab
noticed an aircraft on the runway and, after contacting the tower,
commenced a go-around from a height of approximately 35 ft,
overflying the stationary Chieftain at a height of about 150
ft.
The Civil Aviation Safety Authority recommends in Aeronautical
Circular H12/95, that if an aeroplane is fitted with strobe
lighting it should be turned on before entering an active runway.
The pilot of the Chieftain believed that he had done so. However,
neither the controller nor other flight crew recalled seeing the
strobe lights of the Chieftain.
Although the conditional take-off instruction was correctly
issued by the controller, the read-back of the clearance by the
pilot was incomplete, which was not detected by the controller.
When the Chieftain then entered the active runway it is possible
that the pilot did not switch on the strobe lights, reducing the
likelihood of the crew of the approaching Saab, and the controller,
seeing the aircraft on the runway. The subsequent go-around of the
Saab was initiated when the crew saw the aircraft on the runway.
For undetermined reasons the controller did not notice by normal
visual scan, or by reference to the surface movement radar, that
the Chieftain had already entered the runway, contrary to its
assigned clearance.