At about midday on the same day, the pilot found that a revised
TAF now only required the carriage of an additional 60 minutes of
holding fuel for arrival at Norfolk Island. The forecast, issued at
1133, indicated that from 1200 to 2300 there would be broken (more
than 4/8ths) cloud at 2,500 ft, scattered (4/8ths or less) cloud at
500 ft, and visibility reduced to 8,000 m in rain showers. In
addition, there would be periods of up to 60 minutes (TEMPO) of
broken cloud at 400 ft, with visibility reduced to 4,000 m in
drizzle. The minima for a straight-in landing approach to runway 11
required not more than 4/8ths cloud below 750 ft, with a visibility
of not less than 2,700 m. The alternate minima required not more
than 4/8ths cloud below 1,069 ft, and visibility not less than
4,400 m.
The aircraft subsequently departed Lord Howe Island carrying the
additional holding fuel. Before reaching his calculated point of no
return (PNR) at about 1545 the pilot received two meteorological
reports (METARs) of conditions at Norfolk Island. Both reports
described conditions below the published alternate and landing
minima. Moreover, an amended TAF for Norfolk Island issued at 1420
indicated that from 1400 to 2300 the amount of cloud at 500 ft had
increased to broken (more than 4/8ths). Based on that amendment the
pilot was required to nominate an alternate aerodrome for the
flight. However, he did not request or receive the amended weather
forecast before passing the PNR, as required by the company
operations manual.
As the flight approached Norfolk Island, the pilot was advised
of reducing visibility. He conducted an instrument approach to
runway 11 but did not become visual, and so carried out a missed
approach. In conditions of deteriorating visibility the pilot then
flew several approaches to runway 04 by descending over the sea
until he was visual, at a height of approximately 500 ft, before
tracking inbound on the instrument approach VOR (a navigation aid)
radial. On the first two approaches, the pilot was unable to see
the aerodrome and conducted a missed approach.
For the third approach, the pilot requested the aerodrome
manager to position himself on the runway threshold in order to
indicate by radio the position of the aircraft in relation to the
runway centreline. The manager did this and advised the pilot that
the aircraft had passed to the right of the centreline. On the
fourth approach, the pilot sighted the precision approach path
indicator lights and landed on the runway. Visibility at the time
of landing was recorded as 800 m in fog.
The pilot later reported that he had made the decision to
continue beyond the PNR, based on the forecast obtained at the time
he had completed his flight planning. He believed that it was still
the current forecast as he had not been advised during the flight
of any amendments to that forecast.
Several factors were considered significant to the development
of this occurrence. The meteorological conditions which developed
at Norfolk Island later in the day, were considerably worse than
those forecast by the TAFs issued at 1133 and 1420. Both forecasts
indicated that conditions would be below the landing minima for
periods of up to 60 minutes. In reality, the conditions at Norfolk
Island were below the landing minima continuously from 1130 until
after 2330. Had the pilot requested the latest TAF before passing
the PNR, he would have been obliged to return to Lord Howe Island,
the nearest alternate. In addition, the pilot did not use or did
not acknowledge the significance of the METAR information he had
received in flight to challenge the accuracy of the TAF that he
used for his decision making.
As the regulations did not require RPT aircraft conducting
flights to Norfolk Island to carry sufficient fuel for flight to an
alternate aerodrome, the pilot carried only an additional 60
minutes of fuel in accordance with the operational requirements of
the 1133 TAF. Having passed his PNR, the aircraft did not have
sufficient fuel to return to Lord Howe Island, and the pilot was
subsequently left with limited options when he encountered the
subsequent conditions at Norfolk Island.