On 5 June 2014, the pilot of a Beechcraft 200 aircraft, registered VH-NMW, conducted a private flight from Narrabri to Sydney Airport, New South Wales, with two passengers on board.
During the cruise, the pilot entered the arrival and approach into the flight management computer. The pilot was advised by air traffic control (ATC) to expect an instrument landing system (ILS) approach to runway 16 Left (16 L).
The pilot was cleared by air traffic control (ATC) to descend to 3,000 ft and while on descent, was given radar vectors to intercept the localiser for runway 16 L. The pilot selected approach (‘APP’) mode on the flight guidance panel (FGP) and confirmed that the aircraft had intercepted the localiser. About 2 minutes later, the aircraft was cleared for the instrument landing system (ILS) approach on 16 L however the pilot did not observe that at this stage, the aircraft was below the glideslope.
The pilot was then temporarily distracted by explaining the multi-function display to the passenger seated in the front right seat. The controller queried whether the aircraft was on the glideslope and the pilot realised that the aircraft was below the glideslope. The aircraft then maintained the current altitude until intercepting the glideslope. Prior to intercepting the glideslope, ATC advised the pilot that the aircraft was at 1,500 ft and below the lowest safe altitude. As the aircraft was established on the localiser and about 8 NM from the runway, the applicable minimum altitude was 1,700 ft AMSL.
This incident highlights the importance of continuously monitoring aircraft and approach parameters and the impact distractions can have on maintaining a stable approach profile.